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PETROGENESIS OF CHROMITE AND ASSOCIATED MINERALS IN THE UPPER MANTLE PERIDOTITE OF THE NORTHERN SEMAIL OPmOLITE (UAE) “Volume I”
DISSERTATION
l*resented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University
by Solaiman Al-Aabed, MS.
*********
The Ohio State University 2000
Dissertation Committee: Approved by Professer Michael Barton, adviser Professer Hallen Noltimeir Professer Douglas Pride Adviser Professer Terry Wilson Department of Geological Sciences UMI Number 9982513
Copyright 2000 by Al-Aabed, Solaiman Ali
All rights reserved.
UMI*
UMI Microform9982513 Copyright 2000 by Bell & Howell Information and Leaming Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code.
Bell & Howell Information and Leaming Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 ABSTRACT
The northern part of the Semai I (Oman) ophiolite extends along the northeastern border of the UAE. The upper mantle peridotites of this ophiolitic section contain chromite deposits in three main localities: Al’Hel, Siji and Zikt. The study is focussed in the Al’Hel and Zikt areas. Siji is not considered in detail because it is chemically similar to Al’Hel. Field, pétrographie, and geochemical evidence is used to divide the chromite fields into three major zones: Al’Hel, E. Zikt, and S. Zikt. The Al’Hel zone is very close to the mantle-crust transition, and is characterized by less depleted peridotites than those in Zikt. Al’Hel chromitites contain minor modal pyroxene, along with low-grade, Al-rich chromites. In contrast, the Zikt zone is located deeper in the mantle sequence, with E.
Zikt closest to the mantle-crust transition, and S. Zikt furthest from the transition. The S.
Zikt fields contain the highest-grade, Cr-rich chromites, whereas, the chromite composition at E. Zikt is between that of Al’Hel and S. Zikt.
Chromite is always associated with olivine (sometimes with trace amounts of pyroxene) in chromitite and dunite lensoid bodies. The chromite/olivine ratio varies from
1 to zero, from massive chromitite to dunite. Olivine and chromite show a variety of textures such as net and circular texture. Some textures are characteristic for a specific zone (e.g. nodular texture at Zikt). Pré-, syn-, and post-emplacement deformation obliterated most of the original textures and formed new deformation fabrics. However, some original magmatic textures such as rhythmic layering are preserved.
A magmatic origin for the formation of chromite and associated minerals is indicated by whoie-rocks and mineral geochemistry. The geochemical characteristics of the Al’Hel bodies are different from those of Zikt. Disequilibrium interaction between rising melts and the wall rocks was the main driving mechanism for chromite precipitation, particularly the massive chromitites. This process leads to Mg and Si enrichment in the melts by dissolution of some peridotite materials (e.g pyroxene).
Increasing silica content increases polymerization and decreases Cr (and probably other heavy metals) solubility in the melts, and thus triggers chromite precipitation.
It is concluded that there were three genetic stages of formation of chromite bodies in the UAE Semai 1 ophiolite. First, partial melting at a MOR spreading occurred center during drifting of Afro-Arabia from Eurasia (~ 200Ma ago). No significant chromite accumulation is expected during this phase. Second, island arc magmatism occurred above an intra-oceanic subduction zone that formed due to northeastward movement of Arabia toward Asia (begining at ca. 110 Ma). At this stage, the Zikt chromite orefields originated by interaction of calc-alkaline melts with upper mantle harzburgites. Third, back-arc (marginal basin) spreading began, and the Al’Hel orefields formed through interaction of MORB-like melts with the relatively less depleted peridotites. In other words, Al’Hel chromite bodies formed from MORB-like tholeiite melts in a marginal basin environment, whereas, the Zikt chromite bodies originated fiom calc-alkaline to boninite melts in an island arc to fore arc environment.
Ill DEDICATION
To my motherfor her love and patience To my wife fo r ahvays being with me To my sisters and my brothers for their encouragement and support
IV ACNOWLEDGMENTS
I thank my advisor Michael Barton for his assistance and patience, and for beneficial discussion. I would like to recognize Hallen Noltimeir, Douglas Pride, and Terry Wilson for serving in my committee, and for valuable guidance. I am grateful to Dr. Henery Clemmey from Derwent Company for his assistance and discussion in the field work. I would like to thank my family for their continuous support and encouragement, while 1 am at home and abroad. I greatly thank the UAE University and all people in the Department of Geological Sciences at the Ohio State University for the comprehensive support to make this study possible. VITA
December, 21, 1965 ...... Bom -Dibba, Ai Fujairah,UAE
1984 ...... Graduate, Uqba Bin Nafi High School, Diba A1 Fjairah
1988 ...... B.S., Geology Department, UAE University, AI Ain
1988-1990 ...... General Science and Geology Teacher, A1 Khalidiah School, Dibba AlFfujairah
1995 ...... M.S. in Geological Science. The Ohio State University
FIELD OF STUDY
Major Field: Geological Sciences
VI TABLE OF CONTENTS
Page
Dedication ...... iv
Acknowledgments ...... v
Vita...... tdi
List of Tables ...... vii
List of Figures ...... ix
List of Plates ...... xxi
Chapters;
1. Introduction ...... 1
1.1 Preface...... I 1.2 Historical synopsis ...... 2 1.3 Oman Chromites ...... 12 1.4 The present study ...... 14 1.5 Research organization ...... 15
2. Oman mountains, ophiolites & the Semail ophiolite ...... 17
2.1 Regional geology ...... 17 2 .1.1 The Arabian (Persian) Gulf and Zagros Fold Belt ...... 20 2.1.2 The Gulf of Oman and the Makran platform ...... 23 2.1.3 The Arabian platform ...... 24 2.2 Tectonostratigraphy of The Oman mountains ...... 36 2.3 Ophiolites ...... 42 2.4 Oman (Semail) ophiolite: ...... 44 2.4.1 Tectonic setting of the Semail ophiolite ...... 49
\T l 3. Chromite fields in the UAE ...... 59
3.1 Introduction ...... 59 3.2 Al’Hel zone ...... 60 3.2.1 Iceberg (Wadi-fi) ...... 63 3.2.2 Wadi-1...... 68 3.2.3 Viking ...... 68 3.3 Zikt zone ...... 71 3.3.1 East Zikt: Palace...... 71 3.3.2 South Zikt ...... 80 3.3.2.1 The entrance...... 80 3.3.2.2 Black Sharq ...... 84 3.3.2.3 Black Scorpion ...... 87 3.2.3 North Zikt: Vera ...... 92 3.4 Siji...... 95 3.5 Deformation & magmatic textures ...... 95
4. Pétrographie investigations ...... 98
4.1 Introduction ...... 98 4.2 Harzburgite ...... 98 4.2.1 Olivine...... 99 4.2.2 Pyroxene ...... 106 4.2.3 Chromite ...... 112 4.3 Dunite...... 113 4.3.1 Olivine...... 116 4.3.2 Pyroxene ...... 118 4.3.3 Chromite ...... 118 4.4 Chromitite ...... 120 4.5 Pyroxenite, amphibolite, and talc ...... 123 4.6 Granitic intrusions ...... 127
5. Chromite textural relations ...... 130
5.1 Introduction ...... 130 5.2 Original textures ...... 130 5.2.1 Massive vs. disseminated texture...... 130 5.2.2 Branching-networking texture ...... 134 5.2.3 Chromite net-occluded silicate texture ...... 134 5.2.4 Layering-banding texture ...... 135 5.2.5 Circular texture...... 137 5.2.6 Gangue-schlieren texture ...... 137 5.2.7 Pseudo-porphyritic texture ...... 141 5.2.8 Nodular texture ...... 141 viii 5.2.9 Lobate & cuspate ...... 145 5.2.10 Inclusions ...... 145 5.3 Deformation fabrics ...... 146 5.3.1 Pillow band texture ...... 147 5.3.2 Mini-cave texture...... 147 5.3.3 Mini-faulting & folding ...... 147 5.3.4 Sheath folds...... 150 5.3.5 Pull-apart texture ...... 150
6. Geochemical analyses ...... 152
6.1 Introduction ...... 152 6.2 Whole rock analysis ...... 153 6.2.1 Major elements ...... 153 6.2.2 Trace elements...... 162 6.2.3 Rare earth elements (REE)...... 167 6.2.4 Platinum group elements (FOE) ...... 172 6.3 The mineral chemistry ...... 176 6.3.1 Chromite ...... 176 6.3.1.1 Al’Hel Chromite ...... 179 6.3.1.2 E. Zikt (Palace) chromite ...... 185 6.3.1.3 S. Zikt chromite ...... 192 6.3.2 Silicates...... 202 6.3.2.1 Olivine...... 202 6.3.2.2 Pyroxene ...... 208 6.3.2.3 Amphibole ...... 213
7. Petrogenesis of chromite and associated minerals ...... 218
7.1 Geothermometry & geobarometry ...... 218 7.2 Oxygen fugacity ...... 221 7.3 Chromite genesis ...... 223 7.3.1 Disequilibrium interaction or mantle metasomatism ...... 223 7.3.2 The genetic stages of formation ...... 228 7.3.3 Lines of evidence that support for the postulated genetic process ...... 232 7.3.3.1 Field observations ...... 232 1 3 3 .2 Pétrographie evidence ...... 235 7.3.3.3 Whole rock chemistry ...... 238 7.3.3.4 Mineral chemistry ...... 242 7.4 Support from other research work ...... 253 7.5 Chromite precipitation ...... 253
IX 7. Conclusion ...... 256
Appendices:
A. Petrography A I Introduction ...... 259 A.2 Al'Hel...... 259 A.3 E. Zikt (Palace)...... 267 A 4 S. Zikt (Palace)...... 276 A.5 List of main samples and their location ...... 282
B. Whole-rock analysis ...... 285
G. Minerai chemistry ...... 308 C.l Chromite analysis ...... 313 C.2 Olivine analysis ...... 502 C,3 Pyroxene analysis ...... 567 C.4 Amphibole analysis ...... 602
Bibliography ...... 615 LIST OF TABLES
Table Page
3.1 Positions of the present UAE chromitite fields represented by geographic coordinates (see also Figure 3.1) ...... 62
6.1 The range of selected elements from the whole-rock analysis of harzburgite and dunite. Number in a bracket represents a sample outside the range ...... 157
6.2 The range of selected elements from the whole-rock analysis of massive and disseminated chromitites. Number in the bracket represents a sample outside the range ...... 157
6.3 The range of oxide values of chromite analyses in all rock types of Al’Hel fields (& LMl 17 of Siji). Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix ...... 180
6.4 The range of oxide values of chromite analyses in all rock types of Palace field (E. Zikt) and pyroxenite dikes (NE of Palace). Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix ...... 188
6.5 The range of oxide values of chromite analyses in all rock types of S. Zikt fields. Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix...... 193
7.1 Equilibration temperatures of Mg-Fe exchange between olivine and spinel, calculated from the olivine-spinei geothermometer of Sack & Qhiorso (1991a) ...... 220
7.2 Log oxygen fugacity (log/ 0 2 ) averages obtained by calculated Fe^^ ratio (100*Fe / Fe^‘^+ Al^*+ Cr^^ and using Murck & Canpbell (1986) diagram at a recommended temperature of 1250°C and QFM buffer system ...... 220
B.l Analysis of major and trace elements ...... 286
B.2 Taylor and McClennan’s (1985) chondrite values ...... 292
B.3 Analysis of incompatible trace element ...... 293
XI B.4 Analysis of Rare Earth Elements (REE) ...... 299
B.5 Analysis of Patinum Group Elemetns (FOE) ...... 305
C. I List of standards used in analyzing the oxide minerals ...... 309
C.2 List of standards used in analyzing the silicate minerals ...... 310
XU LIST OF FIGURES
Figure Page
2.1 Simplilled tectonic index map showing the geologic boundaries of Arabia, location of the Oman mountains, Arabian Gulf (A), Gulf of Oman (B), and the eighteen Alpine - Himalayan fold ranges: 1. Betic Cordillera; 2. Pyrenees; 3. Atlas; 4. Alps; 5. Apennines; 6. Dinarides; 7. Carpathians; 8. Hellenides; 9. Pontides; 10. Taurides; 11. Caucasus; 12. Zagros; 13. Alborz; 14, Hindukush; 15. Karakorum; 16. Himalaya; 17. Kunlun; 1 8. Indo-Burma ranges (From Lippardet al., 1986) ...... 19
2.2 Geotectonic map of the Oman mountains and surrounding areas, showing the general lithology and structural relationship of the Makran, Zagros fold belt and Oman mountain chain. Note the Quaternary volcanic arcs north of Jaz Murian depression, and the Arabia-Makran subduction zone traced by the meter depth contours of Gulf of Oman A-B cross-section is drawn in figure 2.15 (from Coleman, 1981 ...... 21
2.3 Tectonostraligrapgic chart of Oman (from Droste, 1997), reproduced to briefly represent the major tectonic and deposition events of the Arabian plate geologic history. Labels of the deposition units may vary throughout the region ...... 25
2.4 Arabian Platform as part of Gondwanaland at about 640 Ma, before the rifting of the Red sea separating Arabia from Africa. Asir, Hijaz and Midyan terranes as well as Afif and Ar Rayn are in the western half of the Arabia. Note the old Tethyes ocean in the northern Arabian plate (Husseini, 1989) ...... 27
2.5 Simplified map showing the desripution of the all ages ophiolites of the Arabian plate: Pan-African in the Arabian Sheild, Mesozoic (Semail) in the eastern edge. Tertiary (TA) in the south of the Arabian shield. JW, Jabel Wask; JE, Jabel Ess; BU, Bir Umq; AH, Al-Amar-Idsas & Halaban Itithal; TA, Tihama-Asir complex; AD, Ad Darb transform fault; DSR, Dead Sea Rift; ED, Eastern Desert, Egypt; Z, Zabergad Island; M, Makran; KM, Kuria Muria Islands; S, Salalah; NL\, Masirah island; JJ, Jabel Ja’alan (After Coleman, 1984) ...... 28
xiii 2.6 Schematic reconstruction of the extensional regime elements of the Arabian plate in the InfraPrecambrian- Cambrian (600 to 540 Ma). Triple junction at Sinai, Najd left-lateral fault, and Zgros right lateral-fault (Husseini, 1989) ...... 29
2.7 Late Permian reconstruction showing the closing accretion process of the PaleoTethys toward Eurasia, and initial growing of Neo-Tethys with progressing faster spreading rate (From Stampfli, 1996) ...... 32
2.8 Tectonic map showing the position of Rub Al Khali sandy region in the eastern half of Arabia, Masirah line parallel to the Gulf of Aden transform faults. Tertiary folds in the Oman mountains, Zagros, and Makran, and Strait of Hormus (From Lippard et al., 1986) ...... 37
2.9 Complete tectonostratigraphic scheme of the Oman mountains, showing all units of the Autochthonous and Allochthonous sequences (From Lippard et al., 1986). Musandam carbonate basement represents the northern Oman mountains shelf carbonates. Thamama group of (Alsharhan & Naim, 1986) is equal to Kahmah group and unit 4 of Musandam group (Alsharhan, 1989) ...... 39
2.10 Sample scheme of the typical ophiolite complex (After Nicolas, 1989) revealing the mantle and crustal sequences. Transition zone with the seismic and petrological Mohos, ultramafic small intrusions, gabbroic dikes, and some leucocratic intrusions. Chromitite lenses also shown to be enclosed in dunite envelopes ...... 43
2.11 Elevation map showing the international boundary between UAE and Oman, and Jabel Akhdar as the highest regions in the Oman mountains.The mountains are here divided into northern, central and eastern, but the northem/southem division may be more used. Main routs to the mountains are shown, which mostly represent major wadis (valleys) (From Lippard et al., 1986) ...... 46
2.12 Intra-oceanic detachment at the spreading center of MORE setting, followed by thrusting, as suggested by Boudieret al., (1985). It is similar to that of Coleman (1981) and others, but with an oceanic crust duplication made by oceanic thrusting ...... 50
2.13 The Semail ophiolite formation, thrusting and emplacement as proposed by EL-Shazly & Coleman (1990): (A) Toctonic map that Masiiirh ophiolite as part the Semail ophiolite thrust. (B) Movement vectors of the Arabian plate. (C) Intra-oceanic detachment, thrusting and duplication, similar to that
x iv of Boudier et al., (1985). However, a continental crustal thickening (A-type subduction) preceding the detachment is suggested here (a-b). It was resulted from a Lower Cretaceous change in the plate motion between Africa and Eurasia, and causing the HP/LT metamorphism found in the basement and shelf deposits. The last stage, the ophiolite gravity sliding and emplacement as a result of isostatic uplift, is close enough to that of Lippard et al. (1986) ...... 52
2.14 Figure 2.14: Sequential evolution of the Semail ophiolite from the initiation until emplacement, in form the oceanic Supra-subduction regime as presented by Lippard et al. (1986) ...... 55
2.15 Stylized cross section from Oman to Iran (A-B in Figure 2.2). It reveals Makran ridges and accretion wedge above the present day subduction. The Gulf of Oman sediments sealed the Neo-Tethyan oceanic crust from which the Oman ophiolite was originated (Coleman, 1981) ...... 57
2.16 A close look reconstruction of the processes of the Semail ophiolite formation and its associates, taken place at a supra-subduction zone (Searle&Cox, 1999) ...... 57
3.1 Reconstructed geologic map of the UAE Semail ophiolite section, based largely on Glennie et al. (1974)’s map, and on Boudier & Nicolas (1988), Searle et al. (1983), Hunting reference map, and the present field work. The map shows the locations of the present UAE chromite fields with designated symbols representing the relative sizes of the fields ...... 61
3.2 A simplified section of the ophiolite stratigraphie column, showing the relative positions of the three studied chromite zones in the mantle sequence, and their relation with the dominant foliations. Note that the high temperature spreading foliations at and close to the transition zone are rotated parallel to Moho and to the magmatic foliations in the layered gabbros above ...... 64
3.3 Sketch map shows a traverse from SSW to NNE of the Iceberg chromite pit, revealing the main structural features of the site. A detailed lithology is reduced for clarity ...... 67
3.4 A simplified interpretation of the structural position of the upper mantle peridotite surrounded by gabbros in the Al Hel area, and the position of theViking chromite site. It is proposed that the transition zone in Al’Hel area is in a relatively thin ...... 72
3.5 Sketch map shows a traverse of the northern half of the Palace chromite pit, starting at the west entrance and ending close to the east entrance. Note that
XV a curved comer of about 1.5m at station #4 Is neglected, and for clarity, a detailed lithology is removed here ...... 75
3.6 The recumbent fold and the large granitic and serpentinized dunite-chromitite dikes illustrated in the east wall of the Palace field. Note that the continuation of the fold axial plane can be projected close to the lower termination of the dikes where they are largely thinned ...... 77
3.7 A folded and twisted granitic dike in the recumbent fold forms boudinage and sigmoid structures. Note also the aureole of serpentine and carbonate materials surrounding the dike due to metasomatism of the peridotite during dike intrusion ...... 79
3.8 A drawing illustrating the fault zone that ruptures and splits the major chromititic granitic dike of Scorpion into two parts. One is at the west wall of the entrance, and the other is in the first canyon of the pit. This is why neither parts are present in the other side of the entrance nor in the second canyon ...... 94
3.9 A sketch of one chromitite body in Vera, showing the spheroid nodules at the center of the body, while the ovoid nodules at the body margins and their long axes are parallel to the margins ...... 94
4.1 Schematic drawings of the apparent olivine fabrics that can be found in harzburgites and/or dunites of the studied fields. Fractures and alteration space-fillings are present in most types. Dashed arrows are elongation direction (foliation) ...... 101
4.2 Twiss & Moores (1992)’s proposal to yield preferred crystallographic orientations by minimizing the geometric misfit in a polycrystalline aggregate composed of crystals with only one slip system ...... 103
4.3 A schematic sketch showing the variable response between olivine, pyroxene, and chromite to the plastic shear flow. The resistance to the shearing process increases from olivine to pyroxene to chromite (Modified from Lippard et al., 1986 and Bartholomew, 1993) ...... 107
4.4 Simple drawings of the visible pyroxene fabrics that can be found in the harzburgites of the studied fields, and some may also be detected in the dunites. Alteration products could occur in or around any of these types. Dashed arrows are the elongation direction (foliation) ...... 109
4.5 Illustrations of the common forms of the chromite accessories that occur in the harzburgites, dunites, and pyroxenite dikes of the studied fields ...... 114
XVI 4.6 Simplified schemes of some examples of dikes and space-filling bodies observed in the studied areas. The right side is the field view (except the last one), and the left side is the thin-section view without magnifîcation 124
5.1 A gradual change from massive chromitite to disseminated chromitite to dunite and to harzburgite. The body is assumed to be semi-concordant with foliation plane and minerals are elongated parallel to lineation. The scale of the sketch is arbitrary, because the ore body can be as small as a few centimeters and as large as tens of meters ...... 132
5.2 A sketch showing a networking and branching fabric of some chromitite bodies inside dunite pockets ...... 132
6.1 Plotting of the whole rock analysis of the Al’Hel and Zikt mantle harzburgites. The upper plot, SiOz wt % against MgO wt %, shows negative correlation. The lower plot, NiO wt % against Mg #, shows positive correlation ...... 154
6.2 Plotting of the whole rock analysis of the AI’Hel and Zikt mantle harzburgites. The upper plot is Mg # against CriOz/AliO], and the lower plot is CrzOz wt % against NiO wt %. Both plots show positive correlation ...... 155
6.3 Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against Zn ppm, shows negative correlation. The lower plot, MgO wt % against SiOz wt %, shows positive correlation ...... 158
6.4 Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against NiO wt %, shows positive correlation. The lower plot, MgO wt % against V ppm, shows negative correlation ...... 159
6.5 Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against CrzOz wt %, shows negative correlation. The lower plot, MgO wt % against AlzOz wt %, also shows negative correlation that is more clear in Al’Hel than Zikt ...... 160
6.6 Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against MnO wt %, shows negative correlation. The lower plot, MgO wt % against TiOz wt %, also shows negative correlation ...... 161
6.7 Chondrite normalized incompatible trace element patterns of the mantle harzburgites in the studied fields ...... 164
x v ii 6.8 Chondrite normalized incompatible trace element patterns of the Al’Hel chromitites (upper) and dunites (lower) ...... 165
6.9 Chondrite normalized incompatible trace element patterns of the Zikt chromitites (upper) and dunites (lower) ...... 166
6.10 Chondrite normalized REE patterns of the mantle harzburgites from the studied fields, showing concave shape. The first two samples from Al’Hel and the rest from Zikt ...... 169
6.11 Chondrite normalized REE patterns of the Al’Hel chromitites (upper) and dunites (lower) ...... 170
6.12 Chondrite normalized REE patterns of the Zikt chromitites (upper) and dunites (lower). Note the enrichment of LREE relative to HREE ...... 171
6.13 Chondrite normalized PGE patterns of some mantle harzburgites from Al’Hel and Zikt, show high depleted PGE concentrations relative to chondrites ...... 173
6.14 Chondrite normalized PGE patterns of some analyzed dunites from Al’Hel and Zikt, show high depleted PGE concentrations relative to chondrites ...... 173
6.15 Chondrite normalized PGE patterns of chromitites from Al’Hel and Zikt. Note the high enrichment in Os, Ir and Ru relative to Pt, Pd and Au ...... 175
6.16 Plotting of AI 2O3 wt % against CrzOs wt % of chromite in the rocks of Al’Hel, E. Zikt and S. Zikt. More than 1330 analyzed points. Wadi-I (Al’Hel) is the highest in Al, while B. Scorpion (S. Zikt) is the highest in Cr. The prefixes in the legend: WI, Wadi-I; Ice, Iceberg; Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite; CrH94Perid, Al’Hel harzburgites 178
6.17 Plotting of Mg # against Cr # of chromite from Al’Hel rocks. Most analyses plot in the ophiolite field of Leblanc (1987) and Leblanc & Nicolas (1992), but outside the abyssal peridotite field of Dick & Bullen (1984). Legend prefixes are the same as in figure 6.16 ...... 181
6.18 Plotting of AI 2O3 wt % against Cr 2Û3 wt % of chromite from Al’Hel rocks. The plotting forms negative correlation. Legend prefixes are the same as in figure 6.16 ...... 182
XVIII 6.19 Plotting of FeO wt % against MgO wt % of chromite from Ai’Hel rocks. The plotting forms linear negative correlation. Legend prefixes are the same as in figure 6.16 ...... 182
6.20 Plotting ofTiOz wt % against Cr # of chromite from Al’Hel rocks. Harzburgites are mostly plotted in the depleted field of Jan & Windley (1990). Legend is the same as in figure 6.18 ...... 186
6.21 Plotting of AI 2O3 wt % against MgO wt % of chromite from Al’Hel rocks. Legend is the same as in figure 6.18 ...... 186
6.22 Plotting of CriOs wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. The harzburgites form a diagonal array with decreasing CrzOs/MgO ratio. Al’Hel peridotites (CrH94Perid) is added to more distinguish the mantle array. Dunites and chromitites project a trend normal to this array ...... 190
6 .23 Plotting of AI 2O3 wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. The harzburgites form a diagonal array with positive Al2 0 3 /Mg 0 correlation. Al’Hel peridotites (CrH94Perid) is added to more distinguish the mantle array. Dunites and chromitites project a trend normal to this array ...... 190
6.24 Plotting of FeO wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. With increasing MgO/FeO ratio, the harzburgites form a diagonal array, separating from the one formed by chromitites and dunites ...... 191
6.25 Plotting of TiOz wt % against CrzOz wt % of chromite from Palace (E. Zikt) rocks. The plot clearly shows chromites from dunites and chromitites have much higher TiOz contents than those of harzburgites ...... 191
6.26 Plotting Mg # against Cr # of chromite from S. Zikt field rocks and pyroxenite dikes (Pxtdike) of E. Zikt. All chromitites and dunites are plotting in boninite field, and Zikt harzburgites form a wide range in the ophiolitic chromite field. Ophiolitic chromite field from Leblanc (1987) and Leblanc & Nicolas (1992), and Boninite field from Bloomer & Hawkins (1987). The legend prefixes; Sh, B Sharq; Sc, B Scorpion; Pxt, pyroxenite ...... 195
6.27 Plotting AlzOz wt % against MgO wt % (upper) and CrzOz wt % against MgO wt % (lower), of chromite from S. Zikt chromitites and dunites. Note the progressive increase in CrzOz and MgO and decrease in AI 2O3 from Sharq to Vera to Scorpion. The legend prefixes: Sh, B. Sharq; Sc, B. Scorpion ...... 196
XIX 6.28 Plotting CrzOs wt % against FezOs wt % (upper) and CrzOa wt % against NiO wt % (lower), of chromite from S. Zikt chromitites and dunites. Note the progressive decrease in FezOs and slight increase in NiO from Sharq to Vera to Scorpion. The legend prefixes; Sh, B. Sharq; Sc, B. Scorpion ...... 197
6.29 Plotting FeO wt % against MgO wt % of chromite from S. Zikt rocks. With increasing MgO/FeO ratio, the harzburgites form a diagonal array, separating from the one formed by chromitites and dunites. The prefixes in the legend: Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite, CrH94Perid, Al’Hel peridotites ...... 199
6.30 Plotting of TiOz wt % against Cr # of chromite from S. Zikt rocks. Harzburgites are mostly plotted in the depleted field of Jan & Windley (1990) and Zhou et al. (1996). Legend is the same as in figure 6. 29 ...... 199
6.31 Plotting of AlzOa wt % against MgO wt % (upper) and CrzOs wt % against MgO wt % (lower), of chromite from S. Zikt rocks.The harzburgites form a diagonal array with increasing AlzOz and MgO, and decreasing CrzOs/MgO ratio. Al’Hel peridotites (CrH94Perid) is added to more distinguish the mantle array. Dunites and chromitites project a trend normal to this array. The prefixes in the legend: Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; [*xt, pyroxenite; CrH94Perid, Al’Hel peridotites ...... 200
6.32 Plotting Fo (Mg* 100/(Mg+Fetot.) against NiO wt % of olivines from mantle harzburgites of all fields. Note that NiO content of harzburgites in all fields is constant at about 0.4 wt % ...... 203
6.33 Plotting Fo (Mg* 100/(Mg+Fetot.) against SiOz wt % of olivines from dunites and chromitites of all fields. HIOl: Al’Hel, PlOl: Palace (E. Zikt), ShOl: Sharq & Sc: Scorpion (S. Zikt) ...... 205
6.34 Plotting Fo (Mg* 100/(Mg+Fetot.) against NiO wt % of olivines from dunites and chromitites of all fields. Note that the smooth positive correlation between Fo and NiO changes to steep correlation at Fo94.4 where is no more Al’Hel samples. HIOl: Al’Hel, PlOl: Palace (E. Zikt), ShOl: Sharq & Sc: Scorpion (S. Zikt) ...... 205
6.35 Plotting NiO wt % contents of the core and rim of chromites (upper) and coexisting olivines (lower) in some dunite and chromitite samples from Palace (E. Zikt). The first five samples from the left are chromitites and the others are dunites ...... 206
XX 6.36 Plotting NiO wt % content of the chromite rims with that of the rims of coexisting olivines from a few dunite and chromitite samples of Palace (E. Zikt). Note the negative correlation between the two types of rims ...... 207
6.37 Plotting pyroxene compositions from mantle harzburgites of Al’Hel (upper) and E. Zikt (lower) in the pyroxene quadrant shows the dominant of enstatite. The few diopsides are from dunites and chromitites. En, enstatite; Fs, ferrosilite; Di, diopside; Hd, hedenbergite ...... 209
6.38 Plotting pyroxene compositions from mantle harzburgites of B. Sharq (upper) and B. Scorpion (lower) in the pyroxene quadrant shows the dominant of enstatite. En, enstatite; Fs, ferrosilite; Di, diopside; Hd, hedenbergite ...... 210
6.39 Plotting Mg # against MnO wt % (upper), FeO wt % (middle), and AI2O3 wt % (lower) of orthopyroxene from mantle harzburgites of all fields. All show negative correlation. Sample Z9-Scl0 reveals exceptional high AI 2O...... 2 1 2
6.40 Plotting Si atoms pfu against Na+K atoms pfu of amphiboles from mantle harzburgites of all fields reveals dominant tremolite composition of these amphiboles ...... 214
6.41 Plotting Al atoms pfu against Na+K atoms pfu of amphiboles from mantle harzburgites of all fields also reveals dominant tremolite composition of these amphiboles ...... 214
6.42 Plotting Si atoms pfu against Na+K atoms pfu of amphiboles from dunites and chromitites of all fields shows compositional range from tremolite to hornblende to pargasite ...... 216
6.43 Plotting Al atoms pfu against Na+K atoms pfu of amphiboles from dunites and chromitites of all fields also shows compositional range from tremolite to hornblende to pargasite ...... 216
.XXI 7.1 Schematic sketch of the MORB divergent regime that was forming the Neo-Tythan oceanic spreading during drifting of Afro-Arabia away fi-om Eurasia, started about 200 Ma ago. At this period, melt extractions by partial melting depleted the upper mantle lithosphere and might modify its mineralogy. This then caused a wide range of chromite variations in the upper mantle harzburgite, but probably without significant chromite accumulations ...... 229
7 .2 Schematic sketch of the intra-oceanic subduction regime that thought to initiate as a result of the northeastward movement of Afro-Arabia, started about 110 Ma ago. Island arc magmatism commenced 95 Ma ago. Due to the disequilibrium conditions, the subduction zone calc-alkaline magmas interacted with the harzburgitic lithosphere and precipitated Cr-rich chromite bodies as those found in Zikt field ...... 231
7 .3 Schematic sketch of the intra-oceanic subduction regime interfered by marginal basin formation (back arc spreading). Diapirs of MORB source, rising from deep in the asthenosphere and slightly contaminated by subduction fluids, interceded and suspended island arc magmatism and formed a back are spreading floor Interactions of these tholeiitic melts with the host lithosphere were less and close to the mantle-crust transition zone. These melts crystallize Al-rich chromites as those observed in Al’Hel fields...... 233
7.4 Microprobe scanned image shows a small chromite inclusion (pale gray) at the center of an olivine grain (gray) that is in turn enclosed in chromite grain. Composition o f the chromite in the center is about the same as that of the outer chromite grain. The bar in the photo equals 20 micro. Sample Z9-P3 ...... 237
7.5 Plot of the whole rock Ta/Yb against Th/Yb ratios of dunites and chromitites of all fields, in Pearce et al. ’s (1983) discrimination diagram. All rocks (except two of Al’Hel) plot within the field of subduction related magmas and outside MORB zone. They also reveal a relative enrichment of Th over Ta and Yb ...... 241
7.6 Plot of FeO wt % against MgO wt % of chromite in all rock types of all fields. With increasing MgO/FeO ratio, Zikt chromitites and dunites form a different trend form that of the mantle harzburgites, whereas the trend of Ai’Hel chromitites and dunites is located in the harzburgite trend to slightly below it ...... 243
7.7 Plot of AlzOs wt % against MgO wt % of chromite in all rock types of all fields. The mantle harzburgite forms a distinct diagonal array from low MgO and AI 2O3 (high depletion end) to high MgO and AI 2O3 (less
XXM depletion end). Al’Hel dunites and chromitites plot within and close to the border of this array at its less depleted side. By contrast, Zikt dunites and chromitites project trends perpendicular to the harzburgite array and at its high-depleted side, with dunites forming the mutual connection with the array ...... 244
7.8 Plot of CrzOs wt % against MgO wt % of chromite in all rock types of all fields. The mantle harzburgite forms a distinct diagonal array from low MgO/CriO] ratio (high depletion end) to high MgO/CrzO] ratio (less depletion end). Al’Hel dunites and chromitites plot within and close to the border of this array at its less depleted side. By contrast, Zikt dunites and chromitites project trends perpendicular to the harzburgite array and at its high-depleted side, with dunites forming the mutual connection with the array ...... 245
7.9 Plot of Mg # (100*Mg/(Mg+Fe)) against Cr# (100*Cr/(Crt-Al)) of chromite in all rock types of all fields. Most chromitites and dunites of S. Zikt plot in boninite zone while those of Al’Hel plot in and outside MORB zone E Zikt chromitite and dunites are in between and within Troodos zone. MORB field from Dick & Bullen (1984), Troodos from Cameron (1985), and boninite zone from Bloomer & Hawkins (1987) ...... 247
7 .10 Plot ofTiOz wt % against CrzOs wt % of chromite in all rock types of all fields, showing the mantle harzburgites contain very low TiOz values, < 0.1 wt %, while dunites and chromitites include higher values reaching up to 0.285 wt %. This higher values is an indication of magmatic and different source region than the host harzburgite for the precipitating melt ...... 248
7.11 Plot of TiOz wt % against Cr# (100*Cr/(Cr+Al)) of chromite in all rock types of all fields, showing the mantle harzburgites plot in the depleted mantle field. Zikt chromitites and dunites mostly plot in the boninite field, while those of Al’Hel plot close to and in the MORB field (Fields from Zhou et al., 1996) ...... 249
7.12 Chromite precipitation model suggested in this study is presented in the olivine-chromite-quartz ternary diagram of Irvine (1977). Interaction of the primary melt (A) cotectically precipitating olivine and chromite will lead the crystallization to inter the chromite primary volume, forming massive chromitites along the trend A-B (in a similar way presented by Zhou et al., 1994, 1996). Fractionation of chromite will form two different trends based on the primary melt and the host rock interacted with. Trend B-C2 is expected to produce in Al’Hel as interaction mechanism would lead to pyroxene saturated melt in Al’Hel relatively more than in Zikt that form the fractionated trend B-C1. Mixing of the fractionating melts with a new
xxm primary pulse (A) also produces two different hybrid melts (dotted lines), but both are located in the chromite volume ...... 255
C. I Sample form of chromite formula calculation ...... 312
C 2 Sample form of olivine formula calculation ...... 501
C 3 Sample form of pyroxene formula calculation ...... 566
XXIV LIST OF PLATES
Plate page
3.1 Three semi-massive chromitite dikes intruded an antinodular chromitite body and are terminated by gabbro in a thrust contact. Note the chromite rich dunite responded to the thrusting compression by folding between the more competent, massive chromitite. Iceberg ...... 65
3.2 Olivine phenocrysts in a massive chromite matrix forming porphyry texture. Iceberg ...... 65
3.3 Antinodular texture with Chr/01 ratio almost equal to 1. Alteration effect on olivine is clear between the less altered I*‘ sample (yellow) and highly altered 2"** sample (brown). Iceberg ...... 69
3.4 Chromitite small layers with sheath fold terminations, Wadi-1 ...... 69
3.5 Disseminated chromitite (chromite-rich dunite) bands in a massive chromitite host, Wadil ...... 70
3.6 Tongue like end of massive chromitite bands in disseminated chromitite host, Wadi-1 ...... 70
3.7 Several phases of chromite precipitation. Large to medium chromite grains gradually change to small grains at the center of the sample; tongue like terminations of massive chromitites and exotic fragments of chromitite and dunite are present. All may represent layering, and possibly related to magma turbulence or episodic deposition. Viking ...... 73
3.8 The recumbent fold as seen in the east wall. The fold plunges a few degrees toward the east, and the upper right side, small parts of the granitic and dunitic chromititic dikes are shown ...... 76
3.9 The highly altered dunitic chromitite dike (center) set between serpentinized peridotite, and a part of the granitic dike appears at the upper left comer. Palace...... 76
3.10 The granitic intrusion (center) shows a diatreme-like shape. Palace ...... 78
XXV 3.11 Sigmoid (center) and boudinage (upper center) in the lower fold flank. Palace...... 78
3.12 Crosscutting relation between chromitite and granitic dikes and sills in serpentinized peridotites, Palace ...... 81
3.13 Massive to disseminated chromitite network in a chromite bearing dunite. Palace...... 81
3.14 Pyroxenite dikes cut through harzburgite structures at about 500m NE of the Palace field...... 82
3.15 A fragile structure of a fault plane above the ore hole, NW Sharq. Note peridotite & chromitite fragments hosted in carbonated serpentines and talc...... 85
3.16 A thick layer of carbonated serpentines (white) filling a fault plane in peridotite, Sharq ...... 85
3.17 Continuous massive chromitite layers (black) in a dunite host. Two layering sequences can be recognized, starting from >5cm layer to 3.18 Hand specimen showing an example of a centimeter-scale rhythmic layering that includes massive chromitite, disseminated chromitite and dunite, Sharq .....86 3.19 Small massive chromitite pods or lenses (black) enclosed in a fresh dunite, Sharq ...... 88 3.20 The main entrance of the first two canyons of the Scorpion pit. Note the chromititic granitic dike (white, the upper half of center) occupying the center of the first hole. Scorpion ...... 89 3.21 The other part of the major chromi-granitic dike lies at the west wall of the Scorpion entrance. Note the large chromitite fragments and lenses (e.g. below the hammer) and the small ones (e.g. above the hammer). Scorpion ...... 90 3.22 A more focused photo inside the entrance granitic dike, revealing large chromitite lenses (e.g. below the hammer) and small ones (e.g. above the hammer). Scorpion...... 91 3.23 Massive chromitite dike (at the hammer) is parallel to the east part of the granodiorite dike (blue), center of the Scorpion 2"*^ canyon. The pale brown cover of the right half is work dust ...... 93 XXVI 3.24 Large nodules (grapeshots) in a matrix of chromite bearing dunite, Vera ...... 93 3.25 Pop-up structure revealed in the LMl 17 field, Siji ...... 96 3.26 Olivine occluded texture in massive chromitite (left), and lineated and pillow bands texture (right), Sij ...... 96 4.1 Photomicrograph of a fractured olivine grain that reveals undulose extinction and at least one dominant fracture set filled with serpentine. The blue fragments at the lower left comer are another olivine grain. View Length; 1.12mm, XPL, Z9-Sc8 ...... 100 4.2 Photomicrograph of a fragmented olivine grain that show a parallel metamorphic lamella. Spaces between fragments are occupied by serpentine. View Length: 1.12mm, XPL, Z9-Sh3 ...... 100 4.3 Photomicrograph of less moved and deformed olivine grains (survivals) that still keep the original 120°edge angle. The white elongated grains at the right side is orthopyroxene with small subhedral chromite grains at it top end. View Length: 4.43mm, XPL, H4-16/26A ...... 104 4.4 Photomicrograph of new recrystallized olivine grains (neoblasts), with good 120" edge and intersection angles and without internal fractures or deformation strains. View Length: 1.12mm, PPL, Z8-Shl8 ...... 104 4.5 The same photo showing the mosaic texture as the upper but under the crossed polars (XPL) ...... 105 4.6 Photomicrograph revealing pyroxene grains (whit) surrounded by a zone of shimmer patchy aggregates of amphibole and tele, with a few biotite (brown) in places. The blue fractured subhedral grain in the upper left comer is olivine with small subhedral chromite (black) at the top. View Length: 2.8mm, XPL, Z7-P20 ...... 105 4.7 Photomicrograph of a complete zoned alteration of a pyroxene grain. Relict serpentinized pyroxene fragments (high relief) in the core are surrounded by chlorite middle zone (at extinction state, pale yellow color) which in turn mantled by amphibole/telc outer zone (higher relief and anomalous interference color). The fragments around the altered pyroxene are olivines, and at the lower left comer, a part of a lobate chromite grain exist. View Length: 2.8mm, XPL, Z9-Sh3...... 108 4.8 Photomicrograph showing kink-bands structure of a large pyroxene grain that is also sli^tly retorted. View Length: 2.8mm, XPL, Z7-P20 ...... 108 XX VÜ 4.9 Photomicrograph showing herringbone structure: a simple twining combined with polysynthetic twining, of a large pyroxene grain, with clinopyroxene streaky lamellae and exolution. Clinopyroxene also present as a small blue grain between orthopyroxenes at the top left side. Euhedral small chromite crystals and medium chromite grain with cuspate form are distinct at the upper left comer. View Length: 4.43mm, XPL, Z9-PI ...... 111 4.10 Photomicrograph of highly deformed Iherzolite close to the metamorphic sole, showing 2 types of opaque: small black aggregates, and medium corroded nodules with yellowish brown color, all in an olivine and pyroxene matrix with grain size reduction. View Length: 2.8mm, PPL, Mas9-5 ...... I ll 4.11 Photomicrograph of highly deformed Iherzolite close t the metamorphic sole, showing irregular corroded spinel grains (black) surrounded by aureole of serpentine in olivine and pyroxene matrix with grain size reduction. View Length: 2.8mm, PPL, Mas9-3 ...... 115 4.12 Photomicrograph clearly showing biotite aggregates (brown) surrounding some olivine fragments, with a few iron oxides (black dots). The dominant alteration product Riling all spaces is serpentine. One small euhedral chromite occurs at the right edge. View Length: 2.8mm, PPL, Z8-Shl4 ...... 115 4.13 Photomicrograph of dunitic olivines exhibiting distinct undulose extinction and chrysotile serrate-like veins cut through olivine grain. View Length: 2.8mm, XPL, Z8-Shl4 ...... 117 4.14 Photomicrograph showing intercumulus relation between olivine and pyroxene with one medium elongated chromite grain at the upper right comer. View Length: 4.43mm, XPL, Z7-P28 ...... 117 4.15 Photomicrograph displaying a mesh texture (the right half) where olivine fragments occupy the mesh centers and serpentines form the mesh rims. The other half is largely occupied by one survival olivine grain revealing normal extinction, 120° edge angle, and less fracturing. View Length: 1.12mm, XPL, Z9-Sh3 ...... 119 4.16 Photomicrograph showing ribbons structure prograded ftom mesh texture in a fragmented serpentinized olivine during elevation of deformation and serpentinization. Note also the tension gashes that formed perpendicular to fragments elongation. View Length: 1.12mm, XPL, H9-WI2.2 ...... 119 4.17 Photomicrograph of a section in a chromite grain that is reddish brown in the fresh parts and black at the oxidized parts (around cracks and fracture). x x v iii The grain also includes olivine/serpentine inclusions and a pull-apart fracture filled with a chrysotile serrate vain. View Length: 1.12mm, PPL, H9-WI2.1 ...... 122 4.18 Photomicrograph in a section of a semi-massive chromitite, showing a mesh texture with ribbons (the right half) in the serpentines, and hourglass texture at the left upper comer. The present chromite grains evidently reveal parallel pull-apart fractures that are perpendicular to chromite elongation. View Length: 2.8mm, XPL, H8-I13 ...... 122 4.19 Photomicrograph taken at the sharp contact between a massive chromitite and amphibolitized pyroxenite, showing amphibole/pyroxene grains occupy the interstices and inclusions of chromites, and inclusions appear to be more at the chromite margins. View Length: 2.8mm, XPL, Z 8 -BScl...... 125 4.20 Photomicrograph taken in one Iceberg fault plane filling, showing a part of the faulted contact between the second domain (disseminated chromitite in a chain silicate matrix) and the third domain (disseminated chromitite in an olivine matrix). Note that chromites in the second domain are more coalescent than those in the other. View Length: 4.43mm, XPL, H8-I5 ...... 125 4.21 Photomicrograph in a section of talc filling fault plane space in Sharq field, viewing euhedral to subhedral small chromite grains hosted in a fine talc. View Length: 4.43mm, XPL, Z8-Shl5 ...... 128 4.22 Photomicrograph taken in a section of a granitic dike. Plagioclages with oscillatory zoning and albite twining dominate the view and show alteration to sericite & Kaolinite (pale gray dots) and to clinozoisite (strong blue). Mafic part is represented by biotite (yellowish brown) and hornblende (with simple twining) grains. View Length: 2.8mm, XPL, Z7-P10 ...... 128 5.1 Field view of irregular impregnated bodies of massive chromitites that have a sharp contact with dunite. Palace ...... 133 5.2 Massive chromitite rock with few fractures and interstices filled with mostly serpentine, and mark chromite crystals outlines (more obvious at the lower left comer). Palace dunite-chromitite dike ...... 133 5.3 (upper): Chromite net texture occupied the entire sample that are cut by caitonatized amphibolite vein (white) that replaced some of the olivine matrix in the rock. Iceberg ...... 136 5.3 (lower): The first sample (right) shows chromite net slightly stretched toward the foliation direction. The second one (left) shows a classic antinodular texture where chromite/olivine ratio is close to one. Iceberg ...... 136 x x ix 5.4 A vertically cut face of a hand specimen reveals several of layered phases: massive chromitite, disseminated chromitite, dunite, stooping (upper left and right). These may represent irregular and discontinuous rhythmic layering, Sharq ...... 138 5.5 Another example of the multiple generations of layers with stooping (gangue) at the upper massive layer. The layers may include a certain texture that can be only seen in the horizontal view such as the chromite net that occur on the to top of the sample, Sharq ...... 138 5.6 Photomicrograph showing the circular texture where chromite grains (black) form circles that joint at mutual junctions, in fragmented olivine matrix. Note that some grains reveal lobate and cuspate forms. View Length: 4.43mm, XPL, H8 -I8 ...... 139 5.7 Nodular chromitite (small nodules) graded into disseminated chromitite with a small dunite band, and large dunite exotic inclusion (gangue texture), Vera...... 140 5.8 Massive chromitite (upper) at sharp contact with chromite rich dunite (lower), and each rock reveals a distinct texture. Pseudo-porphyry texture in the chromitite and gangue texture in the dunite, Siji ...... 140 5.9 Massive chromitite graded into small nodular chromitite with chromite rich dunite layer cut in between them. The nodular part reveals several initial orbicules (dashed circles), Vera ...... 143 5.10 Large nodules “grapeshot” with some pull-apart fractures and interstices that outlines the chromite crystal boundaries. Note that some nodules are ill sorted (lower right) and collectively forming a massive section that grades into disseminated chromitite (right side), Vera ...... 143 5.11 Large nodules "grapeshot" with some pull-apart fractures and interstices that clearly outlines the chromite crystal boundaries. The host dunite is highly altered and serpentinized. Palace dunite-chromitite dike ...... 144 5.12 A massive layer (middle) grades into small nodular chromitite that includes several immature orbicules (squares at the right half) and some cuspate and lobate forms. Palace ...... 144 5.13 sheared and foliated layers of massive and chromite rich dunite that originally include chromite net and circular textures. Shearing of the rock led to form chromite pillow bands (middle and upper right), and olivine pillow bands (left half), Sharq ...... 148 XXX s. 14 \ zone of olivine pillow bands marks the lower part of this massive rock and reveals the h i^ elevation of shearing that the rock suffer from and probably led to recrystallize chromites to smaller aggregates, Siji ...... 148 5.15 Photomicrograph showing the mini-cave texture in foliated massive chromitite. Chromite grains (black) were extended and coalesced at the long ends with formless shapes, keeping irregular elongated interstices (caves). View Length; 4.43mm, PPL, Z7-P41 ...... 149 5.16 Dunite rock consists of small chromitite layers distorted by mini-faults that led to move and transfer parts of layer materials, Sharq ...... 149 5.17 The sample showing three distinct features: 1) three rock types with sharp contact: nodular chromitite, disseminated chromitite, and dunite, 2 ) folding of the rock types, and then 3) faulting (left side) that cut and slightly moved the fold parts. This order is also chronologically correct ...... 151 XXXI CHAPTER I INTRODUCTION 1.1 Preface Despite intensive studies, the occurrence and origin of many minerals, economic mineral in particular, is not yet fully understood. Chromite and associated minerals (e.g. olivine & pyroxene) have been studied, for more than a century but there is no generally accepted model for the origin of chromite in rocks, especially in ophiolitic hosts. Several workers have come up with a reasonable explanation for chromite formation in particular location but the mechanisms that they propose can not usually be applied to other localities. This might reflect the large variety of textures and appearances of the chromites in the rocks, as well as variations in the chemical composition. Consequently, a mechanism of formation that works in a certain locality may not be valid for a different one. Ophiolite complexes are major hosts of chromite rocks after igneous layered complexes (ILC). Harzburgite-type peridotites are the main carrier of chromite in ophiolitic rocks, in contrast with Iherzolite-type peridotites that have almost no chromite. The mantle sequence of the Semail ophiolite is largely harzburgitic-type peridotites. According to Nicolas (1989), the Semail ophiolite contains chromite less than similar ophiolites such as those Greece & the Philippines. Lack of abundant chromites also characterizes the Bay of Island ophiolite, and is attributed to a fast spreading rates at least for the Semail ophiolite (Nicolas 1989; Nicolas & AL-Azri 1991). However, Nicolas conclusions are preliminary because research on chromite in the Semail ophiolite is still in progress. The Semail ophiolite provides an excellent opportunity for studying chromite, associated minerals, and host rocks. In most previous works, the chromite studies were apart of a larger regional study of the Semail ophiolite and focused on the territory of Oman. This present study focuses on chromites and chromitites and associated minerals of the northern part of the Semail ophiolite in the UAE. 1.2 Historical Synopsis Studies on chromite deposits began several centuries ago. In the eighteenth century, crocoite (or crocoisite), a saffron chromate of lead (PbCr 0 4 ), was mined in the Ural Mountains and shipped to Europe before about 1760 (Carr 1994). From this mineral, chromium was discovered independently by Nicholas L.Vauquelin and by Martin H. IClaproth in 1797. It was separated using a high temperature reduction of CrOs by carbon by Vauquelin in 1798 (Bums & Bums 1975; Stowe 1987). In the same year, chromium was discovered in chromite from Ural Mountains deposits by the German chemist J. T. Louwitz. The beautiful variant colors of this metal lead A. F. Founcouy & J. Hauy to name this element chromium (Bums & Bums 1975), which is derived from the Greek term for color, (chroma). Early in the nineteenth century, the work of Isaac Tyson Jr. in 1827 lead to the discovery of probably the first economically important chromite deposit in the United States, that became the Reed mine ( Harford County Md). He also discovered the Wood mine in Lancaster County Pa., which was worked out from 1827 to 1882 (Pratt & Lewis 1905; Knopf 1922). This site and others in Pennsylvania and Maryland were the only chromite sources in the world between 1828-1860 (Knopf 1922). Tyson also noticed an association between chromite and serpentine. In 1873, Rosenbusch published his book "‘Microscopical Physiography of Rock- Making Minerals" which was translated in to English by J. P. Iddings in 1893. Rosenbusch noted the assosiation of chromite with the early formed magnesium minerals in rocks, namely olivine and serpentine. He also described the dissemination of chromites in the magnesium rocks of the Archean Formation (Iddings 1905). In the second half of the Nineteenth century, many geologists debated the origin of peridotites and associated rocks, seeking to distinguish between a sedimentary or igneous origin. Their debate led to discovery of new chromite occurrences in peridotites and serpentinites. Some of those workers involved in this research between 1875 and 1904 are C. D. Smith, Sterry Hunt, A. A. Julien, M. E. Wadsworth, A. P. Low, J, S. Diller, T. M. Chatard, H. B. C. Hitze, Theodore D. Rand, William Glenn, J.H. L. Vort, J. V. Lewis, J. H. Pratt, Waldemar Lindgren, and Arthur Keith. Their findings are summarized by Pratt & Lewis (1905), and indicate that chromite occurs in all peridotites in variable amounts and it is the only mineral in these rocks that shows complete crystal faces consistent with slow crystallization from magma. Hence they concluded that the occurrence of chromites is one of the major lines of evidence that testifies the intrusive igneous nature of peridotites. Most studies of chromite during the 19‘*' century concentrated on potential ore production and petrography of chromites and their host rocks. 3 In the first quarter of the 20'** century, many workers continued the work that began in the former century, with most emphasis on the mode of occurrences of chromite, based mostly on field observations and petrography with a few chemical analyses (J. H. Pratt (1900); J. H. Pratt & J. V. Lewis (1905); E. C. Harder (1910); L. G. Westgate (1922) and E. B. Knopf (1922). Nevertheless, it is only in this century that explorations for chromite deposits triggered interests in the origin of this mineral. In an important study, the Australian mineralogist & chemist, Edward Simpson (1920) graphically represented chromites in terms of CriOs. AI 2O3, FeO and MgO and divided the spinel- chromite group into four end members: spinel (MgAlz 0 4 ), hercynite (FeAl 2Û4 ), chromite (FeCr2 0 4 ) & picrochromite (MgCr 2 0 4 ). Although this representation is acceptable, it does not take into account ferric oxide (Fe 2 0 ]) which apparently always occurs in chromites. In 1929, Lloyd Fisher (Ph.D. dissertation at Johns Hopkins University) did include Fe2 0 3 in his study of the “spinellid” group. He divided the later into four isomorphous series: aluminates, chromâtes, manganates & ferrates. Chromite forms the main part of chromâtes, is related to the mafic end of the aluminates, is not related to any of the manganates, and is related to ferrates only by magnetite and magnesioferrite. Therefore Fisher (1929) added magnetite (Pe 3 0 4 ) and magnesioferrite (MgPe 2 0 4 ) to the spinelling group. He also concludes that pure chromite (FeCr 2 0 4 ) is only found in meteorites, and FeCr 2 0 4 is not a definite formula for chromite that he considered being a physical mixture between a pure chromite molecule and other isomorphous chromium spinels. Nevertheless, Rollin Steven (1944) expressed the general chromite formula as: (Mg, Fe)0.(Cr, Al, Fe) 2 0 3 . Using 52 complete analyses of samples collected from the two Americas, he represented the spinel group in a triangular prism where the six end 4 members occupy the apices of the prism. He then classified the composition of chromium-bearing spinels into three main series (chromite “Cr^^”, spinel “Al^^”, magnetite “Fe^) based on the general formula given above, which can be represented in a ternary diagram with each main series at one apex of the triangle. The chromite analyses that he reported are concentrated between the chromite and spinel apices and mostly near the chromite series. This means that the samples contain more magnesium than iron. Steven then named PeCr2 0 4 “ferrochromite”, and noticed from the ratio RO: R 2O3 that the FeiO] content in chromite is negligible and can be calculated. In the middle of 20“’ century, layered intrusion complexes (LIC) had become a focus of study of many geologists, but the origins of these complexes were controversial. Fischer (1950), and Keith (1954), postulated liquid immiscibility as a mechanism for chromite formation based on phase equilibrium studies. However, other workers (e.g. Schairer & Yagi (1952), Hess (1955) and Cameron & Emerson (1959)) showed that this mechanism is not completely satisfactory and proposed magmatic differentiation and crystal setting as the major mechanism of chromite formation. This view became widely accepted. By comparing compositions of chromites from several localities, Thayer (1943, 1946) showed that high Cr-chromites occur in feldspar-free peridotites (Pacific Coast province-E. Oregon), high Al-chromites occur in feldspathic peridotites (Caribbean province-Cuba), and high Fe-chromites occur in pyroxene-rich stratiform complexes (Bushveld & Stillwater). However, there is compositional overlap between chromites in these different rocks, especially between those in different types of peridotite. Clark & Ally (1932), Steven (1944), DeWet &Van Niekerk (1952) and MacGregor & Smith (1963) discussed the relation between the unit cell and chemical composition of chromite. 5 They concluded that there is an approximate correlation between the chemical composition and physical properties such as color, unit cell dimension and re&active index. MacGregor & Smith (1963) also pointed out that chrome spinels are sensitive indicators of compositional variations in the crystallizing magma. Experimental studies on synthetic spinel end members, made by (Rait 1946; Warshaw & Keith 1954; Fischer & HofBnan 1956; Tumock 1959; Muan & Somiya 1960; Phillips & Muan 1962; Ulmer 1964, Ulmer 1969) revealed the existence of solid solution between spinel end-member compositions at various temperatures. Phase relations and the effect of oxygen fugacity on the crystallization and differentiation of igieous rocks were studied by many workers including Osborn (1959), Osborn & Roeder (1960), Yoder & Tilley (1962), and Hamilton et al. (1964). Irvine (1965) used thermodynamic data to derive a theoretical expression for calculating the oxygen fugacity (foi) using chromium spinels and emphasized that these minerals are potential indicators ofyÔ 2 of magmas. Irvine (1967) applied his model to several major ultramafic and mafic ore-rocks (Bushveld, Great Dyke, Stillwater & Muskox intrusions, and some Alpine-type orebodies), and found that: a) the ratio FeiOs/RiO; of chromite is positively correlated with foi for the intrusion, and b) most chromites of Alpine-type peridotites generally crystallize at low foi. He also noted that the ratios Mg/Fe’^ & Cr/Al of chromite decrease with stratigraphie elevation during fractional crystallization, which is consistent with earlier observations by VanDer Walt (1941) for the Bushveld complex, and by Worst’s (I960) for the Great Dyke. Following Irvine’s work, Ulmer (1969) concluded that variations foi in the parent magma could control cyclic crystallization as well as compositional variations of the spinel and silicate layers o f chromite deposits. 6 During the 1950s and 1960s, two significant events in the history of the geological sciences occurred. The first was the development of the electron probe micro analyzer (EPMA) in the 1950s by Castaing (although the basic idea was first proposed by Moseley 1913), and the second was development of plate tectonic theory in the late 1960s, which replaced Alfred Wegener’s (1915) theory of continental drift. Using the characteristic .x-ray radiation, EPMA have advanced the precision of the chemical analyses by permitting non-destructive analysis of an area as small as -1pm" of the sample. Plate tectonic theory answered many of the unsolved questions left firom the continental drift hypothesis, and explains distributions of continents and oceans as well as geological phenomena such as regional-scale deformation and mountain buildings. Development of EMPA techniques and of plate tectonic theory has greatly impacted studies of chromite. The chromite investigations have then been conceived in the light of the plate tectonic view, and probe analyses have become a strong piece of evidence, as they provide valuable information about chemical and mineralogical compositions of minerals. Many symposia and conferences have focussed on the occurrence and origin of chromites and their associated minerals and rocks. Of these is the Chromite Conference of Carnegie Institution of Washington in 1974, (organized by T.N. Irvine, J.S. Dicky & G.C. Ulmer) at which the physicochemical behavior and petrologic significance of chromium was discussed. Twenty-four papers describing the results of the conference were published in Geochimica et Cosmochimica Acta, special volume 39 in 1975. One of the major topics of interest at this conference was the stability of chromium. Crz^^O] is relatively a “neutral” oxide in terms of acid-base characteristics (Lux 1939 in Muan 7 1975); thus is compatible with both acid (e.g.SiOz) and basic (e.g. MgO) oxides (Muan 1975). Although this is the most stable oxide o f chromium under near surface conditions at high temperature, all oxidation states, from Cr (I) to Cr (VI), might occur under different conditions (Rollinson 1973; Bums 1975; Bums & Bums 1975 and references therein). Cr^* occurs at the lowest fo2 and is found in lunar rocks that also contains blue diopsides (Bums 1975; Muan 1975), and may occur in the metallic phases of carbonaceous meteorites (Bums & Bums 1975). Cr"*^ occurs only at high pressure, and CrOz is the only stable oxide at pressure greater that 70 kbar (White & Roy 1975). Cr^^ is stable at high pressure in special compounds such as apatites and spodiosites. Cr^^ & Cr^* are the only stable states at atmospheric pressure. However, Cr®* exists only at the highest foi under strongly oxidizing conditions, in the presence of high concentrations of low field strength cations (Muan 1975; White & Roy 1975) such as very basic oxides (e.g. CaO & BaO). Consequently, the relationship between oxidation state of chromite and fo2 is dependent on the spinel compositions (Mao & Bell, 1975). Since the mid 1970’s most studies have concentrated on the mechanism of chromite formation, on the nature of the host rock in which chromite occurs, on the magmas involved in chromite precipitation, and on tectonic environment. These studies have advanced understanding of chromite formation in specific localities. Nevertheless, many aspects of the problem remain to be solved. Recognition o f relict magmatic textures in the ophiolitic podiform chromitites plays an Important role in modem thinking about the origin of chromite. J. Dickey (1975) suggested that chromites formed along accreting plate boundaries in elongated magma pockets at the base o f the cumulate sequence, and that the podiform autoliths sink into the 8 underlying residual harzburgite. Greenbaum (1977) proposed a similar model for the Troodos chromites. This model involves early fractionation from mafic melts in the magma chamber. The deposits are then folded into the underlying mantle peridotites. These hypotheses, however, is difficult to apply to many ophiolite complexes such as the Oman ophiolite (Brown, 1980; Christiansen, 1982) and the New Caledonia ophiolite (Leblanc 1987). Menzies & Allen (1974) suggested that chromites represent early fractionates from rising picritic melts. The idea is that olivine then chromite are the earliest fractionates from picritic melts ascending through the upper mantle, close to the spreading axis. It was suggested that these minerals precipitate in small pockets before the magma reaches the main chamber. This model was applied by Allen (1975) for the Troodos complex (Cyprus), by Malpas (1978) and Talkington & Malpas (1980) for the Bay of Island complex (Newfoundland), and by Neary & Brown (1979) and Brown (1980, 1982) for the Al’Ays (Saudia Arabia) and Semail (Oman) complexes. Lago et al. (1982) postulated a similar model in which chromites accumulate from rising diapiric magma in connective pockets in response to the thermal contrast between the colder conduit wall and the hot magma. As the rising mantle diapir crosses the adiabatic/conductive heat transfer limit below the Moho (Nicolas, 1989), there is a sharp temperature decrease and the upward convection velocity decreases. This causes large chromite grains to precipitate and settle out, and this settling further impedes upward flow in the conduit and causes precipitation of all chromite (Leblanc & Ceuleneer, 1992). Zhou & Robinson (1994,1996) proposed a melt-rock interaction model for the precipitation of chromite, which is enhanced by disequilibrium between the magma and the host peridotites. Chromite occurrences show a variety of textures and structures, many of which are common between stratiform and podiform bodies. Nonetheless, some (e.g. nodular and orbicular structures) are found only in the ophiolitic podiform chromitites (Thayer, 1969), and the origin of these is still not clear. Greenbaum (1977) listed the following possible origins for nodular structure (from Malpas & Robinson, 1987): 1. Aggregation of chromite grains before settling, 2. Pelletization resulting from chromite rolling down banks of crystallized silicates in the magma chamber, 3. Snowballing within turbulent zone of magma segregation, 4. Abrasion of already concentrated chromite ore during rock flowage, and S. Solidification of globules of chromite rich immiscible liquid. The observation of dendritic of chromites in nodules let him to suggest formation by supercooling of Cr-rich magma. For Orbicular structures, Ceuleneer & Nicolas (1985) suggested disaggregation and erosion of dunite wall rocks into pellets by the invading magma and during magmatic transport. The pellets are then coated by chromite during suspension in the magma. Malpas & Robinson (1987) preferred mechanical accretion of already formed chromite and olivine about nucleus of dunite as the result of rolling across the magma chamber floor. Ballhaus (1998), however, rejected both models and proposed a model involving mingling of two distinct magmas of different silica activity and viscosity with chromite nucléation occurring in the deeper (high pressure) and low-SiOz melts. The origin of massive chromitites is of a major importance in chromite studies. This arises from the fact that the Cr content of mafic melt is relatively small (<500-1200 ppm), and it is difficult to see how large amounts of chromites could form from such melts. Ulmer (1969) found that theyOi of the parent magma can regulate the cyclic 10 crystallization of spinel and silicate minerals, and hence changes in jOz might enhance chromite precipitation. Cameron & Desborough (1969) reached the same conclusion. Irvine (1977) interpreted the massive chromite layers of the Muskox intrusion to result from mixing between mafic magmas, one relatively evolved and the other relatively primitive. Mixing moves the hybrid magma into primary chromite phase volume. This model was applied to chromites in the Bushveld intrusion by Sharpe & Irvine (1983). Murck & Campbell (1986) pointed out the importance of both oxygen fugacity and magma mixing. They noted that lowering temperature at constant will reduce Cr^^ solubility in the melt leading chromite supersaturation. Other factors such as changes in total pressure (Cameron, 1977) and volatile content (Johan et al., 1983) have been also evaluated. However the very high distribution coefficient for Cr between chromite and mafic mama (100-1000) lead Roberts & Neary (1993) to conclude that magma mixing is probably important for the formation of massive chromites. On the other hand Zhou et al. (1994, 1996) and Zhou & Robinson (1997) concluded that interaction between crystallizing melt and wall rocks will modify the melt to the extent that chromite is the only phase to crystallize. Tectonic environment and the type of magma from which chromite has crystallized are also controversial and related to the question of the origin of ophiolites. The view that podiform chromite is a refractory residue of partial melting (Leblanc et al., 1980) has been gradually replaced by magmatic models involving crystallization (Talkington & Malpas, 1980; Brown, 1982; Lago et al, 1982; Roberts, 1986). This change in view resulted from observations of remnant magmatic textures in podiform chromites. Magmas are generated in three main plate tectonic environments: divergent 11 margins (MOR, back arc), convergent margins (Island arc), and within plates (oceanic island, continental flood, continental rift). Therefore, three magma types are important for chromite formation: MOR tholeiilte, oceanic island and platform olivine-alkali basalts, and island arcs calc-alkaline basalts (Yoder, 1979 in Stowe 1987). Komatiites have been also found to contain Cr-rich spinel, but these rock types are only abundant in Archaean tcrranes. MORBs, back-arc basalts and island-arc basalts arc all suggested parents magmas of chromite deposits, but increasingly workers are rejecting a MOR setting in favor of island arc setting with or without back-arc basin. Hence supra-subduction zone setting are now more widely accepted for the formation of ophiolitic chromitite rocks (Roberts, 1986 & 1992; Zhou & Robinson, 1997; Malpas et al., 1997). Some have even suggested formation of chromite from boninitic magmas (Zhou et al., 1996; Zhou & Robinson, 1997; Leblanc, 1997), whereas Leblanc (1995 & 1997) and Malpas et al., (1997) proposed that Al-rich chromite formed from tholeiites in back-arcs, and Cr-rich chromite formed from boninite magmas in island-arcs. 1.3 Oman Chromites The study of chromites in the Semail ophiolite began with the work of Glennie’s group in the Oman Mountains during the 1960s (Glennie et al., 1973 & 1974). Their chromite partial study located orebodies about 100-200 m below the cumulate sequence, and related to the mantle-crust transition zone. They described four types of chromite occurrence: 12 1) Stringers of tabular bodies parallel to layering in the ultramafic bodies: massive chromitites grade into “schlieren- platte”, and if not strongly tectonized, they grade into disseminated chromitites and chromite free-dunites. 2) Lens-shaped podiform and sack-like bodies bordered by shear or fault planes; both 1 & 2 types are parallel to ultramafic layering. 3) Single crystals or small clusters of chromite throughout serpentinized dunites. 4) Dike-like deposits that have sharp contacts with the wall rocks, indicating tension crack filling and mobilization of preexisting deposits (Peters & Kramers, 1974; Glennie et al., 1974). Carrey & Welland (1974) grouped Oman chromitites into podiform, stratiform and banded layers. The later may show graded bedding, suggesting an origin by crystal accumulation. However, original textures are overprinted by plastic flow and/or metamorphic fabrics. This work was followed by that of Coleman’s American and French group in the southern part and by a group from Britain’s Open University in the central and northern part of the Oman mountains. These groups made new discoveries and reached important new conclusions about the Oman ophiolite and about the chromite formation. The most important of their achievements are: • Magmatic origin of chromite (Brown 1980, 1982; Roberts 1986) indicated by some relics of cumulate textures (in contrast to Peters & Kramers (1974) who found no magmatic textures). • Division of chromites into three groups according to structural position in the Oman ophiolite (Auge 1987): 1) at the base of the cumulate sequence (stratiform), 2) within 13 1 km of the mantle sequence (more frequent), 3) and deeper in the mantle sequence (small). • Detailed descriptions of chromite textures & structures (Nicolas, 1989). • Studies of silicate and sulfide inclusions in chromite (Lorand & Ceuleneer 1989). • Appraisal of the importance of ridge activity in chromite formation (Nicolas & AL Azri 1991). • The abundances of platinum group elements (PGE) in Oman chromite (Page et al., 1982; Leblanc, 1991). 1.4 The Present Study The Semail ophiolite is about 500 km in length and 75-85 km in width, and chromite deposits occur mainly in the northern part of the Semail ophiolite. Chromites or chromitites in the part of the Semail ophiolite located in the UAE have never been studied. All previous work has been done in the Oman section of the Semail ophiolite. The major goal of this work to address the following questions, keeping in mind the genetic association between chromites and the Semail ophiolite: 1. Why are major chromite regions such as Al’Hel (Hayl) and Zikt chemically distinct? 2. From what type(s) of magma (s) did the UAE chromites and associated minerals form? 3. What was the tectonic setting in which the Semail ophiolite formed? 4. What is the mechanism of formation of the UAE chromitites? 14 5. What is the nature of the host rocks in chromitite deposits? And, do they have any influence in the precipitation and/or general characterization of the chromite and its associated minerals? 6. What is the origin of different in chromitite textures (e.g. massive and others)? 1.5 Research Organization: The Semail ophiolite forms the largest body in the Oman Mountains. Therefore, the regional geology of Oman Mountain and surrounding areas are described in chapter 2. A brief description of the ophiolites and Semail ophiolite in particular along with a summary of previous work on the tectonic setting and emplacement of the Semail ophiolite are also given in this chapter. Chromitites in the UAE are found in three zones: Siji, Al’Hel and Zikt, and the present study is concentrated in the last two regions. Field descriptions of the chromitite bodies in Zikt and Al'Hel ore fields are given chapter 3. This chapter includes a description of the various rock types, structures, and chromitite textures, based on the field observations. Pétrographie descriptions of the minerals and their distinctive textures and deformation characteristics, of the rock types in each field zone are given in chapter 4. Chromite and its associated minerals (mainly olivines) exhibit a variety of magmatic and deformation textures in the rocks during precipitation and subsequent deformations during high and low temperature plastic flows. The original and deformational textures of UAE chromites are described in chapter 5. 15 Three types of geochemical analyses had been made. Microprobe analysis for mineral chemistry, XRF and ICP-MS for whole rock analysis, and NiS fire assay for PGEs analysis. The results of these chemical analyses are presented and discussed in chapter 6. Chapter 7 is a discussion of the origin of the chromites in the UAE segment of the Semail ophiolite, based on the outcomes from the previous chapters. Chapter S is a summary of conclusions the research. Details of the petrography, analytical methods, calculation procedures, chemical analyses, and others are given in the appendixes. The bibliography is at the end. 16 CHAPTER 2 OMAN MOUNTAINS, OPHIOLITES & THE SEMAIL OPHIOLITE The UAE chromite fields are located in the mantle sequence of the Semail ophiolite. The later forms the greatest part of the Oman Mountains. Regional geology and petrology of the Oman Mountains and surrounding areas are summarized in this chapter that also includes an introduction to the Semail ophiolite and its tectonic setting. 2.1 REGIONAL GEOLOGY The Oman Mountains form an elongated chain along the northeastern margin of the Arabian Peninsula that extends from the southern side of the Strait of Hormuz (North) to Rass AL-Hadd (South-East), between latitude 55°-59° E and longitude 22®-26®5' N (Figure 2.1). They form an arcuate belt around 700-800 km long and o f30 -140 km wide parallel to and bordering the coastline of the Gulf of Oman (Figures 2.2; Glennie et al., 1974; Manchnani and Coleman, 198; Lippard et al., 1986). Their summit, Jebel Akhder, reaches an elevation of ca. 3000m (Mann and Hanna, 1990; Figures 2.11). Workers from the Indian geological survey (e.g. Carter, 1850; Blanford, 1872) appear to have been the first geologists to study the Oman mountains (Lippard et al., 1986). However, Lees (1928) was the first to give a logical and relevant description of the Semail ophiolite and its related rocks. Although this work is still relevent, 17 Lees (1928) proposal that the Semail ophiolite and Hawasina nappes were allochthonous was rejected by subsequent workers such as Morton (1959), Tschopp (1967), and Wilson (1969), who favored an autochthonous origin for the nappes as well as for the underlying basement. Until the 1960s, the geologic history of the Oman mountains remained obscure The pioneering work of Glennie et al (1974) throughout the 1960s paved the way for all later field, petrologic, tectonic, and geochemical studies. Glennie et al. (1974) studied the entire region and made a simplified but accurate and complete reference base map. Their work was followed by that of Coleman’s American group (Journal of Geophysical Research, v.lO, B, 1981), and French group (Tectonophysics, v. 151, 1/4, 1988) in the Southern Oman Mountains, and by a British Open University group from the (Lippard et al., 1986) in the northern part of Oman. Because hot and humid weather predominates for most of the year, the mountains are free of vegetation except for a few trees and palm oases. Therefore, the rock exposures are excellent. However, the rugged relief together with a lack of roads makes it difficult to study this region except in the more accessible parts. The Oman mountains and surrounding areas can be divided into three distinct sectors. These are the Persian Gulf and Zagros fold belt in the north and northwest, the Makran continental margin and Gulf of Oman in the east and northeast, and the Arabian platform, the northeastern edge of which is occupied by the mountains, in the south and west. The Oman mountains form the northeastern edge of the Arabian Platform. 18 ar «• ^ B lack S e a EURASIA > * Jledlterranean Sea IRAN INDIA AFRICA VO ol Figure 2.1 ; Simplified tectonic index map showing the geologic boundaries of Arabia, location of the Oman mountains, Arabian Gulf (A), Gulf of Oman (B), and the eighteen Alpine - Himalayan fold ranges; I Betic Cordillera; 2. Pyrenees; 3 Atlas; 4 Alps; 5 Apennines; 6. Dinarides; 7. Carpathians; 8 Hellenides; 9 Pontides; 10 Taurides; 11 Caucasus, 12. Zagro.s, 13 Alborz, 14. Hindukush; 15. Karakorum; 16. Himalaya, 17. Kunlun; 18. Indo-Burma ranges (From Lippard et al, 1986) 2.1.1 The Anibun (Persian) Gulf and Zagros fold belt The Persian Gulf forms the northeastern border between Iran and the Arabian Peninsula (FigureS 2.1 & 2.2) and contains important carbonate & evaporite sedimentary deposits that host rich oil reservoirs. It is a small, shallow sea formed by to down-warp of the Arabian plate (Le Pichon et al., 1973) based on stratigraphie similarities between rocks along the two sides of the Gulf, and topography bathymetry and topography together with seismic data has confirmed that suggestion and showed that.The Gulf could be a down-fold related to the Zagros fold zone which is parallel to the Iranian coast (Mann and Vita-Finzi, 1988). In addition, the stratigraphy and structure of the Strait of Hormuz correlates with that of the northern edge of the Oman mountains, along with the Musandam Peninsula (Michaelis and Pauken, 1990). The Zagros fold belt is one of the eighteen ranges of the Alpine-Himalayan fold belt, and forms the northern end of the Arabian platform (Figure 2.1 & 2.2). It extends for a distance of around 1600-2000 km and consists of folded sediments similar to those on the Arabian plate. These include carbonates, shales, marls, sandstones, elastics, and evaporites (Lippard et al., 1986). During the Late Cretaceous closure of the Neo-Tethyan ocean, shallow to deep-water Mesozoic platform sediments and ophiolite masses, which represent fi'agments of the Tethyan ocean, were thrust onto the late Triassic- Upper Cretaceous platform deposits to form the “Zagros crush zone” (Coleman, 1981; Glennie et al., 1990). There are similarities between pre-Triassic basement rocks of the Zagros range and those of the Arabian platform. These are; such as the style of deformation and type of magmatism (Sengor et al., 1988); the large thickness of autochthonous shelf carbonate 2 0 1 X / MASIRAH 'à i Figure 2.2; Geotectonic map of the Oman mountains and surrounding areas, showing the general lithology and structural relationship of the Makran, Zagros fold belt and Oman mountain chain. Note the Quaternary volcanic arcs north of Jaz Murian depression, and the Arabia-Makran subduction zone traced by the meter depüi contours of Gulf of Oman A-B cross-section is drawn in figure 2.15 (from Coleman, 1981). 21 rocks, other types of strata (Farhoudi and Karig, 1977). This suggests that the southern part of Zagros and Iran were part of to the Arabian platform and thus belonged to Gondwana, not Eurasia. Based on stratigraphie, palaeobiogeographic, and paiaeomagnetic data, Sengor et ai. (1988) concluded that Iran was an integral part of Gondwana until the early Triassic, So that the ocean between Arabia and Iran formed after the end of Paleozoic. Moreover, the rocks of the northern Oman mountains show greater similarity to these in Zagros of southern and central Iran than to those in the Makran region, also indicating that the southern part of central Iran and the entire Arabian platform were part of Gondwana before they separated in the Permo - Triassic period. Rifting to open the Neo-Tethys ocean in the Zagros area, between Arabia and central Iran, began in late Permian to early Triassic times (Robertson & Searle, 1990). This rift eventually developed into the Neo-Tethyan ocean floor spreading center during the late Triassic early Cretaceous (Sengor et al., 1988). Volcanic arcs formed to the north east of the Sanandaj-Sirjan line of central Iran and indicate that the Zagros Tethyan oceanic crust was consumed by active northeastward subduction beneath the Sanandaj- Sirjan zone that started later in the Cretaceous (Glennie et al., 1990). The volcanic arc system is the Padataksasi arc, and subduction was followed by obduction of ophiolites. This closure process was ongoing until terminated by collision between the Arabian plate and Eurasia during the Tertiary, which welded the northern Arabian plate to central Iran. 2 2 2.1.2 The Gulf of Oman and the Makran platform The relict of the vanished Neo-Tethyan ocean, the Gulf of Oman, borders the northeastern side of the Oman mountains, and lies between the Arabian and Makran platforms (Figure 2.2). The Gulf of Oman reaches its maximum depth of around 3200 m northeast Oman (Lippard et al., 1986). The abyssal plain of the Gulf is covered by thick layer of sediments (average of 4 .5 km) dominated by flysch and deep-sea deposits. The sediments in the western part of the Gulf of Oman overlie pelagic sediments comparable to the Hawasina sedimentary rocks of the Oman mountains. Beneath them lies 100-75 Ma Tethyan oceanic floor as indicated by seismic velocity data for the basement, strong positive Bouguer anomalies, and heat flow data (Coleman, 1981). The flysch, or syn- orogenic sediments, include turbidites (Hsu, 1989) that are thought to have been primarily deposited along margins of the Tethyan ocean. The southern termination of the Gulf is the Owen fracture zone, and the northern termination is the Dibba line that separates it from the Straits of Hormuz. The northern border of the Oman mountains (the Zagros area) is thrust dominated a collision zone, whereas the eastern side (Makran) is subduction zone characterized by obduction. However, slabs of oceanic crust or (ophiolites) were emplaced on the sedimentary basement of the continental margin in both regions. Makran is an accretionary prism or wedge of late Cretaceous to Quaternary sediments (Farhoudi & karig, 1977; Coleman, 1981; Lippard et al., 1986; Glennie et al., 1990), which was built above a northward dipping subduction zone (Figure 2.2). These sediments are dominated by Cenozoic flysch that was deformed and gently folded, leading to a series of ridges and basins that are particularly well developed along the Gulf of Oman coast of Makran 23 (Farhoudi & karig, 1977). Northwest of Makran, along the Zendan fault zone, the accretionary prism is underlain by the southeastern end of the folded Zagros belt. In the Gulf of Oman, these deposits have buried Tethyan oceanic crust that resembles the Semail ophiolite, as indicated from depth measurements and heat-flow data (Hutchison et al., 1981; Coleman, 1981). During subduction of the oceanic slab under the Makran plate, sediments were accreted and deformed in to small-scale folds that built ridges and basins. Descent of oceanic crust into the mantle beneath the Makran continental crust presumably caused the cluster of Quaternary andesitic volcanic arc (Farhoudi & Karig, 1977; Lippard et al., 1986) along the northern side of Makran, north of the Jaz Murian depression (Figures 2.2, 2.8). The Arabia-Makran subduction in the Gulf of Oman is thought to be active at the present. 2.1.3 The Arabian platform The terms, Arabia and Arabian-platform, -peninsula or -plate, which have been frequently used in this chapter, all refer to the Arabian sub-continent located between Africa and Asia. This part of the world forms a semi-rectangular province between Africa and Asia (Figure 2.1), bounded by the Zagros crush zone to the north, the oceanic subduction line in the Gulf of Oman to the northeast, the Owen fracture ridges to the southeast, the Tertiary rift structure of the Gulf of Aden to the south, and the Red Sea rift structure to the west. The geologic history of the Arabian platform is summarized in Figure 2.3. Its Precambrian basement is comparable to that of East Africa, indicating that it formed as a part of Africa, and hence of the Gondwana supercontinent, at the time Palaeo-Tethys existed throughout the Paleozoicera. The Pan-African (-900-600 Ma) 24 •upcn- evcus RCIMHKS And CoMMfM am Miivral Manm SMMans CoMMnAim Eunaa and Caieenae Enieota» Hamo 2m Tlvuiana E« R nenal UncndoiiMir 1 CnatMn Tuddan-AnMn Piaaa amkAmylnoli iMiTM Fkn Aaarapi B n u Amy aa a ' OmungNaoiamyn ■J ConananalClMaea FW-oi#» nooang AnoscEvtm ‘Aftgud«n*l Cxton— Eviporm Symw MUMOHW AccfViBn of iMnd Aid Figure 2.3 ; Tectonostratigrapgic chart of Oman (from Droste, 1997), reproduced to briefly represent the major tectonic and deposition events of the Arabian plate geologic history. Labels of the deposition units may vary throughout the region. 25 craton of the Arabian-Nubian shield was formed by terrane accretions analogous to those that have occurred in more recent orogenies (Vail, 1985; Stem et al., 1990). Ai-Shanti & Roobol (1979), Coleman (1984), Stoesser & Camp (1985) and Hussein! (1989) have studied the evolution of the craton, and their work is summarized here. During several Proterozoic orogenies (950-715 Ma), magmatism and synorogenic plutonism built the Asir, Hijaz, and Midyan island arc terranes in the western half of the Arabian platform. These were sutured together around 715 Ma to form Arabian shield (Figure 2.4). In the Halaban orogeny (800-700Ma), ophiolites (A1 Wask, Ess, and Bir Umq) were formed and accreted, whereas, between 695 and 640 Ma, the Afif and Ar- Rayn gneisses and Halaban-Itithal belt were added to conclude the cratonization of the shield. The Arabian shield is very similar to the “Nubian shield" along the Red Sea side of Africa. Pan-African basement is also exposed in the Dhofar area of Oman; Salala county, the Kuria Muria islands, the coastal plain between them (see Figure 2.5), as well in Jabel Jil Jalan, the southernmost of the Oman mountains. In the latest NeoProterozoic to Cambrian, 600 to 540 Ma, tectonism in the area changed from compression to extension. Hussein! (1988, 1989) documented several indications of the Infra-Cambrian extensional regime (Figure 2 .6); a) a 120° triple junction of the NE Egypt rift, the Jordan Valley rift, and the Najd wrench-rift, in the east of Sinai Peninsula; b) the 300 km dislocation of the Arabian shield by the left-lateral Najd fault system that may also define the western end of the Pakistan and kerman (central Iran) salt range (Figure 2.6). c) basalt and rhyolite occurs in the Hormuz Formation, d) the right-lateral Zagros fault and Dibba fault that form several rift basins as well as the SE limit of Hormuz salt formation. 26 % African Plata « ArRayn Gondwinaland 7 at 640 Ma Figure 2.4; Arabian Platform as part of Gondwanaiand at about 640 Ma, before the rifting of the Red sea separating Arabia from AfKca. Asir, Hijaz and Midyan terranes as well as Afif and Ar Rayn are in the western half of the Arabia. Note the old Tethyes ocean in the northern Arabian plate (Husseini, 1989). 27 ■V. Ar Riyad «H SEMAIL I OPHIOLITE Ma Dhofar T« KM IS* Aden Figure 2.5: Simplified map showing the desripution of the all ages ophiolites of the Arabian plate: Pan-African in the Arabian Sheild, Mesozoic (Semail) in the eastern edge. Tertiary (TA) in the south of the Arabian shield. JW, Jabel Wask; JE, Jabel Ess; BU, Bir Umq; AH, Al-Amar-Idsas & Halaban Itithai; TA, Tihama-Asir complex; AD, Ad Darb transform fault; DSR, Dead Sea Rift; ED, Eastern Desert, Egypt; Z, Zabergad Island; M, Makran; KM, Kuria Muria Islands; S, Salalah; Masirah island; JJ, Jabel Ja’alan (After Coleman, 1984). 28 AraMm Imracambftan •sitMlonal tysiMn Figure 2.6: Schematic reconstruction of the extensional regime elements of the Arabian plate in the InfraPrecambrian- Cambrian (600 to 540 Ma). Triple junction at Sinai, Najd left-lateral fault, and Zgros right lateral-fault (Husseini, 1989). 29 During the Cambrian to Ordovician periods, the Arabian platform formed the peneplained eastern margin of Gondwanaiand and was stable throughout the Palaeozoic Era (Sharief, 1983). The Precambrian topography and lithologies were buried beneath shallow marine deposits and clastic sediments that were deposited during transgression of the Tethyan sea over Arabia during the Ordovician. In the Upper Carboniferous, the Hercynian orogeny caused uplift and erosion that lead depositions of clastic sediments. Climate became warmer and more arid during Upper Permian (Sharief, 1983), leading to accumulation of carbonates and evaporites over the region (Griffiths, 1994). From the Lower to Middle Triassic, clastic deposits alternated with shallow-water carbonates, indicating cyclic regression and transgression of the sea. In the Upper Triassic, regression and tectonic instability is indicated by unconformities, rapid facies changes and intrusive and eruptive magmatic activities. This was related to the rifting and drifting of small blocks such as Afghanistan and Central Iran from the Arabian plate as a result of opening of the Neo-Tethys sea (De Jung, 1982; Sharief, 1983). According to Robertson and Searle (1990), however, rifting of the eastern margin of the Arabian plate started earlier and occurred in three stages. Between Late Carboniferous- Early Permian, initial rifting of the margin included block faulting without volcanism. In Late Permian, rifting with volcanism largely restricted to the axial zone occurred, and sediments deposition was dominated by carbonates. The final and main rifting event was accompanied by volcanism between the Middle Triassic and Lower Jurassic. Initial of rifting in the Carboniferous - Permian is consistent with rifting between India and Arabia, at the same time, caused uplift of southern Arabia and is associated with glaciation in Oman as suggested by Marcoux (1993) & AI-Belushi et 30 al-, (1996) (cited in Al-Husseini, 1997). However, Sengor et al. (1988), suggested that rifting between Arabia and Zagros to form Neo-Tethys was initiated in the Late Permian and reached its climax in the Late Triassic. Whatever the exact age for the onset of rifting of eastern Arabia, this was a very important event. First, it established the Neo-Tethys ocean and closed Palaeo-Tethys. Second, It allowed drifting of the S. Iran, Makran, Afghanstan and Tibet continental fragments toward Eurasia as the Neo-Tethys seafloor spread (Figure 2.7). Third, the rifting was contemporaneous with rifting in the Atlantic and Indian oceans to form slow spreading centers (1-2 cm/year). This point was enough indication for some geologists (e.g. Nicolas, 1989) to consider the Semail spreading center as a fast spreading ridge. Finally, the E-W oriented (now NW-SE) rifting opened the Hawasina basin. In Late Triassic to Lower Jurassic times, Arabia was at an equatorial latitude, and oceanic spreading occurred parallel to the present-day Zagros-Taurus mountains along the margins of the Tethys ocean (Al-Husseini, 1997). A drop in sea level (probably due to the Tethys-related extension processes around more that half of Arabia) coupled with arid conditions led to erosion & deposition of continental elastics on the shelf during late Triassic to Lower Jurassic. That was followed by normal marine shelf carbonate deposition in the middle Jurassic (Aisharhan, 1989). Regional sedimentation in the Upper Jurassic showed a gradual change from deep through shallow to very-shallow marine conditions, with deposition on broad shelves of carbonates, and with Kerogen-rich basins formed from epeirogenic downwarp, sea-level rise and flooding (Aisharhan & Kendall, 1986; Aisharhan, 1989). 31 LATE PERMIAN eouaîSB. C ] Spreading ridge 400 Ma Oceanic floor E3 Rifts Ma 023 Arc 10 cm/a V " Active margin 250 Ma Figure 2.7; Late Permian reconstruction showing the closing accretion process of the PaieoTethys toward Eurasia, and initial growing of Neo-Tethys with progressing faster spreading rate (From Stampfli, 1996). 32 Cretaceous sediments on the Arabian platform were divided by Aisharhan & Naim (1986) into three groups separated by regional unconformities (Figure 2.3): Thamama thick carbonates (Lower), Wasia shales and organic-rich sediments (Middle) and Aruma marls & shales (Upper). Musandam limestone in the northern extremity of the Oman mountains represents Jurassic to Lower Cretaceous (Thamama group) time, while Musandam dolomites are Permian to Triassic in age. Aruma radiolarian lime mudstones and Hawasina chert and calciturbidites are found in the Dibba Zone, UAE (Aisharhan, 1989). As Coleman (1981) concluded, fossil-free, mostly clastic deposits dominate lower Paleozoic lithologies of Arabia, whereas carbonates dominate late Permian to Triassic deposits, and marine shale and limestone dominate Early and Middle Jurassic lithologies Periods of deposition of clastic and carbonate sediments alternated during the Cretaceous. Sediments were deposited to a thickness of about 5 .5km on the wide stable platform during the Paleozoic to Cenozoic (Cambrian - late Neogene) (Searle et al., 1983). In the Upper Cretaceous (85-70 Ma), the depositional regime in the northeastern margin of the Arabian platform was interrupted by the obduction and emplacement of Neo-Tethyan thrust sheets of the Semail ophiolite and Hawasina nappes, during the Alpine orogeny (Glennie et al., 1974; Searle et al., 1983). This event is described in detail in section 2.4. Another small Cretaceous ophiolite complex occurs at Masirah Island, southeast Oman (Figure 2.1). This is a harzburgite and MORE sequence, interpreted by Glennie et al. (1974) to be a laterally displaced segment of the Semail ophiolite. However, Lippard et al. (1986) prefer Moseley & Abbotts’ (1979) suggestion that this ophiolite formed as a part of Owen Basin between the Arabian and Indian plates and was obducted from the NE and emplaced by NE-SW “transform?” faulting along the Masirah 33 Line in the Late Cretaceous to Paleocene. After emplacement of the ophiolites, sedimentation resumed with formation of carbonates in the west and shales in the east. The supply of clastic material resulted from isostatic rise of the eastern orogenic belt. In the middle Oligocene the supply of clastic material decreased when the sea level worldwide dropped dramatically (Murris, 1980). One of the unique features of the Arabian plate is the presence of ophiolite complexes of a wide range of ages South of the Arabian shield, along the eastern coast of the Red Sea, and north of Aden, a Tertiary semi-ophiolite of Lower Miocene age occurs. This is the Tihama-Asir complex consisting of sub-volcanic lavas, sheeted dykes and gabbros with granophyre masses and some leucocratic dykes, intruding Precambrian basement and the overlying Paleozoic-Mesozoic sedimentary rocks along a NW trend parallel to the axial trough of the Red Sea (Figure 2.5). Although the Tiahma-Asir complex is not a complete ophiolite, it represents new oceanic crust formed in the initial opening of the Red Sea. Coleman (1984) described several lines of evidence that support this view; I) The gravity anomaly map shows that the Tihama-Asir ophiolite is part of the Miocene oceanic crust. 2) The Tihama-Asir complex tilts 30-40° towards the Red Sea. 3) A thick cap of continental elastics, and the absence of pillow lavas or other evidence of submarine rifting, indicates a terrestrial setting for the initial rifting of the complex, similar to the present day Asal rift near Djibouti. 4) Holocence volcanics above the Tihama-Asir complex consist of harzburgite inclusions believed to come from depleted upper mantle underlying the new oceanic crust (Ghent et al, 1980). A similar harzburgite in the northern part of the Red Sea is considered to represent fragments of oceanic mantle 34 exposed along a transform fault, which implies a shallow depth of the Red Sea upper mantle (Bonatti & Otonella, 1981, cited in Coleman, 1984). The Tertiary began with formation of regional unconformity and non-deposition, particularly in the northern part of Arabia. This was related in the late Alpine orogeny that built the Zagros fold belt due to collision between Arabian plate and Eurasia, and caused separation of Arabia from Africa through the Red Sea and Gulf of Aden. In the Oman mountians, this late orogeny reactivated earlier Cretaceous thrusts and enhanced large scale open folds (Lippard et al., 1986), which re-deformed, folded and uplifred the Oman mountains, particularly the northern part. In Oman and the UAE, calcareous flysch and limestones (e.g. Pabdeh formation), shales intercalated with marls, carbonates and evaporites (e.g. Hasa & Hadhramout groups) were deposited. Erosion has removed Mid- Tertiary deposits. Miocene thrusting (Hagab thrust, Searle et al., 1983) and Miocene compressional tectonics (Griffiths, 1994) occurred in the Musandam Pinensula. “Massive Salt” evaporites and anhydrites (Ears group) formed in the Upper Tertiary (Figure 2.3). Finally, arid conditions resumed in the Quaternary and erosion provided fine grained elastics and sands that have largely covered Arabia to form sandy deserts. “Rub al khali” (or Empty Quarter (Lippard et al., 1986)) is the largest classic example, occupying major parts of Arabia (Figure 2.8). Close to the Arabian Gulf coastline, evaporites such as the famous Abu Dhabi sabkhah also formed in this period. 35 2.2 TECTONOSTRATIGRAPHY OF THE OMAN MOUNTAINS Most workers divide the tectonostratigraphy of the Oman mountains into two main units (Figure 2.9): autochthon and ailochthon. (e.g. Glennie et ai., 1974,1990; Pearce et al., 1981; Lippard et al., 1986; Hanna, 1990; Robertson and Searle, 1990). The autochthonous series comprises those rock units that remain in the place where they formed. This series occurs chiefly In the lower part of the stratigraphie succession of the Oman mountains, but also partly occurs near the top of the succession. The autochthonous rocks in the Oman mountains are similar to rocks present throughout the Arabian peninsula. Pre-Permian rocks are poorly represented in the Oman mountains. Except for some late Precambrian crystalline rocks (gneisses, schists and granites in Jabel Ja’alan, southernmost Oman mountains) Precambrian basement is not exposed. The erosion of Jebel Akhder and Saih Hatat has, however, revealed sedimentary rocks of Upper Proterozoic to Ordovician age, which represent rocks of the Huqf and Haima Supergroups according to in the stratigraphie chart of Droste (1997) (Figures 2.3, 2.8). Ordovician- Silurian quartzose sandstones with “Cruziana” trilobite remains are overlain by fossiliferous shales and limestones of Devonian age in Jebel Qamar of the Dibba zone, and form exotic fragments in the melange (Searle et al., 1983). These are unconformably overlain by Permian carbonates. Most of the exposed lithologies of the Oman mountains are of Permian - Cretaceous age. Shallow marine carbonates (dolomites & limestones) are interbedded with some Lower Jurassic sandstones and some Cretaceous elastics. These premian- cretaceous deposits are referred to as “Carbonate basement’ or “shelf carbonates”. 36 Caniral Iran Helmand Block V) OMAN RubalKhaM / 300km Faults, lineaments - 4 - TefXisry told axes Limit ol Tertiary Zagros-Oman Folding C J Z ^ I Inland depressions Scutnern limit o l Makran tolds Limit ol Oman mountain tnrust Pelt Guu ol^den -a—a . Zagros thrust zone Sutimarine ridges and scarps S jb Sheba/Cartsberg ridge/translorm system CFZ Chaman lault zone OZ Oiboa zone OFZ Owen Iracture zone ZF Zendan lault zone • Quaternary Volcanoes «e Hormuz Salt domes Figure 2.8: Tectonic map showing the position of Rub Al Khali sandy region in the eastern half of Arabia, Masirah line parallel to the Gulf of Aden transform faults, Tertiary folds in the Oman mountains, Zagros, and Makran, and Strait of Hormuz (From Lippard et al., 1986). 37 The carbonate basement was named the “Hajar Supergroup”by Glennie et al. (1974) (Figure 2.9). It formed as a result of gradual subsidence of the continental platform and transgression of the Neo-Tethys Sea. It is exposed mainly on the Musandam peninsula, on the Jebel Akhder and, to a lesser extent, on the Saih Hatat. In parts of the Oman mountains, the carbonate basement is unconformably overlain by sedimentary rocks (Robertson and Searle 1990) including parts of the Aruma Group. The stratigraphie position of this group has been used to constrain emplacement of the Semail ophiolite to late Cretaceous times (Coleman, 1981). The sedimentary rocks consist of marl, shale, flysch, conglomerates and other elastics that represent erosional products of uplifted shelf carbonates and debris from the Hawasina and Semail nappes that were forming contemporaneously. The sediments were deposited on a foredeep of the Arabian continental margin (Pearce et al., 1981; Lippard et al., 1986; Glennie et al., 1974, 1990). The shelf carbonate basement and the Aruma Group are overlain by the allochthonous sequence that includes (from base to top); the Sumeini Group, the Hawasina Assemblage, the Oman Melange, the Semail Nappe and the Batinah Group(Figure 2.9). The Sumeini Group, is a parautochthonous tectonic unit that has moved a short distance relative to the upper units. It consists Mesozoic continental slope deposits formed along the northeastern edge of the Arabian platform. They are, therefore, intermediate between deep and shallow marine sediments, and this unit provides evidence that the Oman margin was the edge of the Arabian continental margin (Coleman, 1981) during the formation of the Hajar Supergroup shelf carbonates. Hawasina thrust units directly overlie the Sumeini Group, and are considered to be nappes by some authors. However, Lippard et al.(1986) referred to them as an 38 AUTOCHTHON ALLOCHTHON WWW F# (U-KM) Mknto Vm (U1 -U l BATMAH Ciette Uxnole ftrt) > #*##:# COMPLEX ■«««M RrmlU% • U l i (Part U0lan««) *B«IUMR # # # (« # « # '(KU1 ' MM*l«R%} •O qIMIIII* ■#«# (CMMtaniSM- •**— ...... * ' S««t««t«nl A M y Urn# L««#W Um« Tsirvsttt*»* T Ov»« SEMAIL S (l« n L tf « t WMfwmi### NAPPE ■#*««««#' *P«ircl««M«l M«M* a««y«RC«* SM «r (KM-KU) *M««««Ia« M«(««««* HAYBI lOtttiMirmM KM$) ✓ v**e«w«m COMPLEX N«*##ln# ■•«• ♦ ItOlM L«l CP. U1 } CMrIbmr) LIU (RU# NRWA f# ‘LJ) " A«URm«#fm (UR } H«H«/N«MvPm (R -K L ) wmgRFm Al Aim Fm (UR - L J ) ■ m F « WIMRR F # (U>KM) N«*«il«« «« HAWASINA MyU F# ML-KM) Hawailiu Sarwa ASSEM6U0E AMMrn ■Wf Fm CW-KU KRarwa Fm Fm Nuat Q 9w##yi«Fm lUR-LWl L*M ora jtM L F# H . « . O . L a u w a # Fm fWia Fm (M l *V R } Fraaamariaa • Cameriant M a u l Fm OmmaiM. MMau OwiMvram Fm (RU) (•M utI Fm) pamWM (««Mia> r u a i i l M ayM A Fm ( L ^ ) ■wmami O#. M ’ALAN Maoam Fm (M l -UR ) /Jaw t Waaa Fm (UR) Figure 2.9; Complete tectcnostratigraphic scheme of the Oman mountains, showing all units of the Autochthonous and Allochthonous sequences (From Lippard et al., 1986). Musandam carbonate basement represents the northern Oman mountains shelf carbonates. Thamama group of (Aisharhan & Naim, 1986) is equal to Kahmah group and unit 4 of Musandam group (Aisharhan, 1989). 39 Assemblage because they consist of sedimentary units that were obducted as several thrust sheets, rather than along a single thrust as is implicit in the term “nappe”. The Hawasina assemblage therefore consists of a series of sediment that were deposited on the Neo-Tethys floor of the Hawasina basin located between the northeastern continental margin of the Arabian plate and the spreading center of the Neo-Tethyan ocean ridge These Permian-middle Cretaceous imbricated sheets are dominated by deep-sea pelagic sediments, carbonate-rich turbidites, shales, radiolarian cherts, fossiliferous sandstones and some shallow-water limestones. Imbricate structures were produced by secondary thrusting or reverse faulting and folding that coincided with the late Cretaceous emplacement of the allochthonous sequence. Folding is very common in the Hawasina assemblage, which is divided into several formations and groups by Glennie et al., (1974). Each unit represents a separate fault-bounded slice containing sedimentary rocks deposited of the same age (Lippard et al., 1986). Other structures such as overturned limbs, boudinage and flattening also occur. The mass of discontinuous lithologie blocks that sits beneath the sole of the Semail ophiolite complex and above the Hawasina assemblage is called the “Oman Melange” (Umino et al., 1990; Robertson et al., 1990). It is a mixture of different rocks that have a variety of origins. They include; the Oman exotics (Permian to Triassic limestone); the Haybi volcanics, tholeiitic and alkaline basalts along with diverse sediments such as cherts and conglomerate; metamorphic rocks; and ophiolite-igneous rocks and serpentinites. The rocks are highly deformed, imbricated, and some are locally repeated or eliminated by faulting. 40 The melange units are overlain by the largest and most distinct lithologie unit of the Oman mountains, known as the Semail Ophiolite. It is a complete complex that shows all the units of the standard ophiolite system, although locally some are missing locally. Peridotites, mostly harzburgites (Nicolas, 1989), and gabbros form the largest units in the section. The Semail ophiolite is exposed over an area of approximately 20,000 km ' - 30,000 km' (Lippard et al., 1986; Ceuleneer et al., 1988). It was fragmented into around twelve huge blocks during late Cretaceous tectonic movements. The fact that no intrusive feeders to the mafic and/or ultramafic rocks of the Semail ophiolite are preserved in the underlying Hawasina allochthonous sediments and/or autochthonous carbonates is important for several reasons (Coleman, 1981). First, the Semail ophiolite formed at a different locality than the carbonates and other units of the Hawasina assemblage. Second, the Semail oceanic crust may be older than Hawasina assemblage. Third, the ophiolite was emplaced above the Hawasina by gravity sliding and continuous oveithrusting. These factors attest to the allochthonous nature of the ophiolite and explain the stratigraphie positions of the Hawasina and ophiolite rocks. The Semail nappe is floored by amphibolite-greenschist facies (mylonites) together with a highly sheared banded unit of peridotites (Glennie et al., 1974; EL-Shazly and Coleman, 1990; Hacker and Mosenfelder, 1996) that mark the early stage of the emplacement of the mid-Cretaceous oceanic and upper mantle lithosphere onto the Arabian continental margin. Some workers (e g. Lippard et al., 1986; Robertson and Searle, 1990) identified another small allochthonous unit named Batinah Complex at the top of the Semail 41 ophiolite. This unit consists of a melange comparable to that of the melange located at the base of the Semail ophiolite, with Hawasina-type sediments at the top. The allochthonous sequence is unconformably covered by late Maastrichian- Miocene autochthonous limestones formed during oceanic transgression following emplacement of the Semail ophiolite In some areas, a layer of latentes, formed after the detachment and before or after emplacement of the oceanic crust, occurs beneath that shelf limestone. The presence of this subaerial and subsoil strata indicates that the Neo- Tethyan oceanic crust was extensively eroded after elevation above sea level (Coleman, 1981) due to detachment and obduction. Finally, the Oman mountains were affected by post Miocene uplift and deformation related to late Zagros folding. This event caused doming of the Jebel Akhdar and Saih Hatat, and folding in Musandam and elsewhere (Figures 2.2, 2.8) and led to erosion of the area. 2.3 OPHIOUTES Ophiolites are parts of the lithospheric upper mantle and oceanic crust that have been tectonically thrust onto continents. Thus, they occur at convergent plate margins. The major units of ophiolite complexes were first described by G. Steinmann in 1905 and 1927 (the well known “Steinmann’s Trinity”). The lithology of ophiolites is complicated and is divided by some geologists into; harzburgitic, intermediate, and Iherzolitic ophiolite-types (Nicolas, 1989), according to the dominant peridotite composition. Generally, all ophiolites can be divided into a mantle sequence and a crustal sequence (Figure 2.10). The mantle sequence (at the base) 42 calc-alkaline pillow lavas — umoers Iftoleiitic pillow lavas — piagiogranite intrusion dike complex isotropic g appro foliated gaPbro — layered gap Pro unit wehrlite intrusion (or gabbroic dike) gaPPros witn graded bedding wehrlite sills and dikes Seismic Moho Tniwtion Zone gaPPro sills Petroiogical Moho dunite : impregnated chromitite gaPPros dikes — pyroxenite dikes m dunite veins m harzOurgites (with chromieice pods) harzPurgite-dunile banded unit (mylomtes) garnet amphiPoiites and quart sites greenschists Figure 2.10: Sample scheme of the typical ophiolite complex (Nicolas, 1989) revealing the mantle and crustal sequences. Transition zone with the seismic and petrological Mohos, ultramafic small intrusions, gabbroic dikes, and some leucocratic intrusions. Chromitite lenses also shown to be enclosed in dunite envelopes. 43 includes Alpine peridotites (tectonized, foliated and serpentinized) with layers and lenses of dunite and as chromititic pods increasing upward. Overlying this is the crustal sequence which consists of gabbros (cumulus, layered and massive), diabasic (doleritic) sheeted dikes, small intrusions of piagiogranite that occur between the gabbro and sheeted dikes, and extrusive pillow lavas covered by deep sea pelagic sediments (umber). The boundary between the mantle and crustal sequences is a transition zone termed the Petrological Moho. The Seismic Moho represents a seismic wave velocity shift from mafic rocks above to ultramafic rocks below regardless whether cumulates or tectonites The ophiolite often rests on a metamorphic sole formed during thrusting and emplacement. The majority of ophiolite complexes formed during the Mesozoic era. Whereas it is widely recognized that not all ophiolites originate in one tectonic environment, there is little agreement about the tectonic setting of individual ophiolite complex. This largely reflects the variety of origins that can be inferred from minor and trace element geochemistry, age relations and from palinspastic reconstruction. Mid- ocean ridges (MOR), back-arc basins and island arcs are all possible tectonic settings for ophiolite origin. 2.4 OMAN (SEMAIL) OPHIOLITE: Cretaceous ophiolite belts occur along the northeast margin of Arabia. Ricou (1971) proposed the name "Croissant Ophiolitique peri-Arabe" for these Tethyan ophiolite sheets after he recognized that ophiolites are allochthonous and form semi- crescenict belts about 3000 Km long with similar origin and age. Of these, the Oman 44 (Semail) ophiolite is the largest, best- exposed, youngest, and most complete ophiolite in the world.( Ceuleneer et al., 1988, Nicolas et al., 1988; Rothery et al., 1990; Vetter & Stakes, 1990). The Semail ophiolite occurs along the northeastern side of the Arabian platform, forming mountains composed of Cretaceous mafic and ultramafic rocks that represent Neo-Tethys oceanic upper mantle and crust. It is located mostly in the Sultanate of Oman and partly in the United Arab Emirates (UAE), along the coastline of the Gulf of Oman (Figures 2.2 & 2.11). The ophiolite, thought to represent a nappe unit (Glennie et al., 1974), constitutes most of the 700 km long Oman mountain chain. It occupies an area of 25,000 km *, extends over 500 km in length and is around 75 - 85 km wide (Peter and Kramers, 1974; Coleman and Hopson, 1981; Stowe, 1987; Nicolas et al., 1988; Nicolas, 1989). The ophiolite was fragmented into around twelve huge blocks during late Cretaceous tectonic movements (Figure 2.2). Syn-emplacement movement as well as post- emplacement deformation caused extensive fracturing and serpentinization in the basal peridotite The imbricate structure of the overthrusting caused recurrence of some ophiolitic units in some stratigraphie sections. Despite that, it is considered to be one of the best preserved (largely unaltered) sections of the oceanic upper mantle (Lippard et al., 1986; Guilbert and Park, 1986). The mantle sequence is about 8-12 km thick and is dominated by depleted residual harzburgites (Nicolas et al., 1988; Nicolas, 1989). Fertile Ihezolite may be found close to the base of the sequence. The high temperature plastic flows in the upper mantle produced foliations that is parallel to the Moho near the transition zone. This foliation is overprinted by lower temperature foliation produced during the emplacement process at 45 ■'r'*! \ MAK«AN 'Ruus al Jibol 12087 ml auifoeouAN ARABIA Dlbba WOUM OCSAN Fakkan js Land over 2000 m Fuiairan 1500-2000 m 1000-1500 m I I 500-1000 m I I Land below 500 m Main communication routes ttirough the mountains ■> ' (fc • ■''' \ International boundary I i 4 ^ Sonar % • Mai'or towns Main mountain peaks %V » 5 0 k m Figure 2.11: Elevation map showing the international boundary between UAE and Oman, and Jabel Akhdar as the highest region in the Oman mountains. The mountains are here divided into northern, central and eastern, but the northern/southern division may be more commonly used. Main routes to the mountains are shown, which mostly represent major wadis (valleys) (From Lippard et al., 1986). 46 the base of the ophiolite (Ceuleneer et ai., 1988; Ceuleneer, 1991; Nicolas & Boudier et al., 1995). Dikes of dunite, gabbro, wherlite, and pyroxenite are all present, but dunites are most common and may comprise >15% of the mantle sequence (Brown, 1982). Chromite is a common accessory mineral in harzburgite, but can be more abundant and form disseminated and massive chromitite pods and lenses that are often enclosed by dunite. The crustal sequence is on average of 5-5.5 km thick (Nicolas et al., 1996). It consists of gabbros that crystallized in a long-lived magma chamber (or numerous chambers) characterized by continuous replenishment and open-system fractionation. This is suggested by rhythmic sequences of fractionation (Browning & Smewing, 1981; Browning, 1984). The thickness and lateral continuity of the gabbro unit (Nicolas & Al Azri, 1991 ; Nicolas et al., 1994,1996) as well as the comparable dimensions of the Semail ophiolite and the East Pacific Rise (Ceuleneer, 1986) indicate that the Semail ophiolite formed at a fast spreading center Layering in cumulus gabbros is parallel to the Moho, but local tilting is common due to large scale folding that also affects the orientations of foliation in the crustal units (Nicolas et al., 1996). Foliations in the crustal sequence are magmatic in origin and increase upward toward the isotropic (unlayered) gabbros. However, the boundary between layered and isotropic gabbros is transitional and is not easy to identify. Sheeted dikes have a screen of gabbros in the lower part. They usually parallel the paleoridge axis (oriented NNW-SSE, (Lippard et al., 1986)), but local variations in direction exist. Pillow lavas in the southern Oman mountains have MORE compositions (Hopson et el., 1981; Boudier et el. 1985), while in the northern mountains, they are depleted relative to N- 47 MORB. The northern lavas were divided into four units that show increasing depletion upward: Geotime, Lasail, Alley, Salahi units (Figure 2.9), They are interpreted as immature island arc and back-arc basalts (Pearce et al., 1981; Alabaster et al., 1982). The volcanic rocks are covered by metalliferous sediments (umber) and by pelagic deep sea sediments (e.g. radiolarian cherts). The upper part of the crustal sequence shows evidence of black smokers such as massive sulfide deposits. The upper sheeted dikes and pillow lavas do not exist in the UAE section of the Semail ophiolite. The base of the Semail complex is floored by a metamorphic aureole with an inverse thermal gradient of >1000“C/km (Ghent & Stout, 1981), This gradient may reach 4000°C/km in the upper 50m, and ~100°C/km in the lower 150m of the sole (Hacker & Mosenfelder, 1996). The metamorphic sole includes high temperature amphibolites that directly welded to the highly sheared peridotites, and underlain by greenschist facies rocks (Figure 2.10). The contacts between the two metamorphic units and between their upper and lower boundaries are thrusts (Glennie et al , 1974; EL-Shazly & Coleman, 1990; Hacker & Mosenfelder, 1996). Frictional heating and the exothermic reaction of serpentinization are suggested as heat sources for metamorphism. However, the main heat supply was the hot ophiolite (Ghent & Stout, 1981; EL-Shazly & Coleman, 1990). The metamorphic aureole is thus a detachment and emplacement product, where the amphibolite protolith is basalt while the greenschist protolith is sediment (Boudier et al., 1985; Searle & Cox, 1999). There is no controversy about the association of amphibolite facies metamorphism with detachment, but the exact timing of detachment is debated. Workers such as Lippard et al., (1986) and Searle and Cox, (1999) argue that detachment took place away from the ridge axis, and close to or at the Arabian continental margin. 48 2.4.1 TECTONIC SETTING OF THE SEMAIL OPHIOLITE As described in an earlier section, the creation of Neo-Tethys started in the Early Permian (-290 Ma) when the Cimmerian continent rifted from the Arabian plate (Figure 2.7; Robertson and Searle, 1990). The Semail ophiolite represents a young Middle Cretaceous segment (98-95 Ma, Albian-Cenomanian) of this ocean, formed before closure that commenced in the Turonian (-90 Ma, Lanphere, 1981; Tilton et al., 1981). There is dispute regarding the location where the Semail detachment began, and thus about the tectonic environment in which the Semail ophiolite formed. Two models have been proposed. One is that it represents a mid oceanic ridge (MOR), and that detachment occurred at the spreading center (Coleman, 1981; Manchnani & Coleman 1981; Ghent & Stout, 1981; Lanphere, 1981; Hopson et a l, 1981; Boudier & Coleman, 1981; McCulloch et al., 1980, 1981; Ceuleneer, 1986; Boudier et al., 1985,1988; Michard et a l, 1991,1996; Hacker, 1991; EL-Shazly & Coleman, 1990; Boudier & Nicolas, 1995; Hacker et al., 1996; Nicolas et al., 1996). The other model involves formation above an intra-oceanic subduction zone (island arc-backarc basin), with detachment at the junction between the old and new Neo-Tethys oceanic lithosphere (Preace et al., 1981; Alabaster et al., 1982; Browning, 1984; Lippard et al., 1986; Sengor et al., 1988; Gass, 1989; Sengor, 1990; Le Metour et al., 1990; Glennie et al., 1990; Vetter & Stake, 1990; Umino et al., 1990; Yanai et al., 1990; Lachize et al., 1996; Searle & Cox, 1999). Workers supporting the MOR setting and ridge axis detachment argue that age relations at the ophiolite sole, undeformed gabbro dikes cross-cutting the basal peridotites and ridge geometry, all support this model as suggested by Boudier et al. (1985) (Figure 2.12) and EL-Shazly & Coleman ( 1990) (Figure 2.13). In the metamorphic sole, the 49 sw NE Aratian shteU £toK% Oettne Kthotflmt Howosm totn 080 UCTION STEP I ; 00. 95 Ha NTRMXEAMC THRUSTfMS fWT 11111111IJ1111 ij r I ,|m Ml 1^11 inn Coniintnial àastnuM Oetone monllt £xoiks Hawotma M fiçts STEP U SaihHalol noppts STEP ni 85.80 Mo Figure 2.12; Intra-oceanic detachment at the spreading center of MORB setting, followed by thrusting, as suggested by Boudier et ai., (198S). It is similar to that of Coleman (1981) and others, but with an oceanic crust duplication made by oceanic thrusting 50 lower greenschist facies rocks yield dates of 87-85 Ma and the high-grade amphibolite facies rocks yield dates of 90±3 Ma (ranging to -100 Ma in a few cases) at the contact with peridotite, based on K-Ar ages from biotites and hornblendes in these rocks (Lanphere, 1981). These ages are very close to the age of ophiolite crystallization dated 98-95 Ma, based on U-Pb ages from zircon in piagiogranite (Tilton et al., 1981; McCulloch et al., 1981). This was taken as an evidence that the ophiolite was still hot (~1000°C) when detached, and that detachment and high-grade metamorphism took place at the ridge center (Ghent & Stout, 1981; Lanphere, 1981; Hopson et a l, 1981; Boudier & Coleman, 1981). Some undeformed, small gabbro dikes locally occur in the lower part of the mantle peridotites. Formation of these dikes required a magmatic source beneath the thrusting peridotites that was hot enough for magma to crystallize as gabbro and not basalt (Boudier et al. 1985). In addition, the shear senses of the structures in high-grade metamorphic rocks gave directions of NE-SW. This direction is compatible with the Semail ophiolite transport, which is controlled by ridge geometry, and is comparable with the shortening direction of Afnca-Eurasia convergence (Figure 2.13; Boudier et al 1988; EL-Shazly & Coleman, 1990). Other factors such as gravity anomalies, crustal densities and isotope signatures are also thought to support formation at a MOR spreading center and low-angle obduction (detachment). Interpretation of the gravity anomalies in the Oman mountains (Manchnani & Coleman 1981) is consistent with Neo-Tethys oceanic detachment of the Semail ophiolite and its emplacement on shelf carbonates, which resulted from movement of Afro-Arabia toward Eurasia in the Late Cretaceous (Coleman, 1981; Hopson et al., 1981; Boudier & Coleman, 1981). Michard et al.(1991) showed that 51 W 131 Mo (b) . 100 Mo s« (e Mo (0) - 8 0 Mo (t) 70 • Pro sont C###«omm Ciin oss Figure 2.13; The Semail ophiolite formation, thrusting and emplacement as proposed by EL-Shazly & Coleman (1990): (A) Toctonic map that Masirah ophiolite as part the Semail ophiolite thrust. (B) Movement vectors of the Arabian plate (C) Intra- oceanic detachment, thrusting and duplication, similar to that of Boudier et al., (1985). However, a continental crustal thickening (A-type subduction) preceding the detachment is suggested here (a-b). It was resulted from a Lower Cretaceous change in the plate motion between Africa and Eurasia, and causing the HP/LT metamorphism found in the basement and shelf deposits The last stage, the ophiolite gravity sliding and emplacement as a result of isostatic uplift, is close enough to that of Lippard et al. (1986). 52 young, low-density oceanic lithosphere can be more easily thrust and obducted than old, high density lithosphere. Because it was created around 100-95 Ma, detached 95-85 Ma, and emplaced 85-70 Ma, the Semail oceanic crust was hot, young and light when it was detached. Therefore, it was easily detached at the ridge axis and obducted from a distal area relative to the Arabian margin, unlike the Alpine and Himalayan ophiolites composed of older and thus denser oceanic crusts. McCulloch et al. (1980, 1981) concluded that depletion of Nd relative to Sm, and of LREE relative to HREE in gabbro, piagiogranite, diabase dike and basalt in the Ibra area (southern Semail ophiolite) are consistent with formation of the ophiolite in a mid-ocean ridge environment. The model of formation of the Semail ophiolite above a subduction zone as envisaged by Lippard et al. (1986) is shown in (Figure 2.14). Divergence between Afro-Arabia and the Cimmerian continent (e.g. Turkey, Iran, Afghanistan) to create the Neo-Tethys ocean started ca. 250-200 Ma ago (Sengor et al, 1988; Robertson & Searle, 1990; Stampfli, 1996), and was contemporaneous with the closure of Paleo-Tethys at a rate 2-3 cm/yr (Stampfli, 1996). Northeast directed subduction began ca. 100 Ma (Figure 2.14), probably as a result of the change of relative motion of counterclockwise movement from E-W to NE-SW of Afro-Arabian plate toward Eurasia (Patriat et al., 1982, cited in Yanai et al., 1990) and/or of complete closure of the Paleo-Tethys and collision the Cimmerian continent with Eurasia (Figures 2.7 & 2.13). Glennie et al. (1990) emphasized that this would relieve compression caused by eastward drift of Afro-Arabia, and lead to development of a back arc basin. According to Lippard et al. (1986), accretion of the Semail crust began about 98-95 Ma above this NE dipping subduction zone that had an initial descent rate of ca. 3.0 cm/yr. This means that a ~ 360-460km long slab of Permian- 53 Lower Cretaceous Neo-Tethys lithosphere was subducted prior to formation of the Semail island/marginal basin arc lithosphere. The descent rate progressively increased by slab-pull to reach - S.Ocm/yr, about the same as the calculated rate of spreading of the Semail lithosphere (Yanai et al., 1990). When the trench reached the Arabian continental margin (ca. 93-90 Ma), subduction retarded. The resulting stresses caused spreading process stopped, and the younger, lower density Semail lithosphere was detached and obducted over older, higher density non-Semail lithosphere (Figure 2.14D-E). At ca. 90- 80 Ma, thrusting and metamorphism of the Semail ophiolite caused depression of part of the continental margin, and Hawasina basin sediments were accreted and imbricated in front of the thrust unit (Figure 2.14F-G). At ca. 80-75 Ma, the continental margin isostatically rebounded leading to uplift of the outer part of the margin. This raised the obducted oceanic lithosphere above sea level, which lead to failure at the paleo-ridge and to separation of the oceanic lithosphere to two (eastern and western) sections (Figure 2 .14H-J). The margin flexed down and was filled with sediments (e.g. Muti). Continued rebound (ca. 75-70 Ma) caused emplacement of the western section of Semail nappe (Figure 2.14K-M), that was tilted to the east and northeast so that the east flank dipped below sea level, leading to deposition deep-water sediments. There was subduction along the NE Tethys margins (Arabian-Makran subduction in the Gulf of Oman) to accommodate the changes in the SW margin (Lippard et al. 1986) (Figure 2.15). Several lines of evidence support the model described above. These include Oman lava stratigraphy (Alabaster et al., 1980), lava geology (e.g. positive topographic features), lava geochemistry (e.g. enrichment in low ionic potential elements, Sr-Nd isotopic ratio) (Pearce et al., 1981), mineralogy of the magmatic sequence (Browning & 54 ■ • I Ma IX i 1 11 iw i * I ;i ill pig HH333EI2rEEE H 10 Ma 1] t ratfiyan oeainie cnM #ahun nwiian *1 10# Mm lataaad f nm mrauexout 10 mirom nm LHt-i , I , 1 I f I =ï "W"Uppar Craucaous ocaaiac —— a u « j g _ L » r ««in Mall iwlton *aaf one —" '■ martan I m il ,T i- CononaMai oval and c a ita m a AmMiiboaia naiainorpnc lacaa rocaa aaMaa lo UOpar CMacaoua V ocaanc MIKBagrara dunng M ar Ouaacmat maiaiRapniam I aura Grama aaniaian 0 kkal Figure 2.14: Sequential evolution of the Semail ophiolite from the initiation until emplacement, in form the oceanic Supra-subduction regime as presented by Lippard et al. (1986). 55 s mewing, 1981 frowning, 1984; Umino et al., 1990), Alley volcanism and cogenetic plutonism, ductile shears, and banded units at the sole of the ophiolite (Yanai et al., 1990). Pearce et al. (1981) inferred from lava stratigraphy and geochemistry that initial eruption of island arc lavas onto oceanic crust, was followed by eruption of back arc lavas. Yanai et al. (1990) emphasized that the banded unit at the sole postdates the giant transcurrent fault within the Semail ophiolite, and undeformed dykes found cutting the overriding peridotites (Hopson et al., 1981; Boudier et al, 1985) are scarce in the banded peridotites. Browning, (1984) concluded that olivine and plagioclase compositional variations in the cumulate sequence are different from those characteristic of MORB volcanism. Neo-Tethys ocean-ocean subduction evolved to ocean-continent subduction close to the Arabian continental margin. A tectonometamorphic study by Le Metour et al, (1990) on the autochthonous units reveals NE shearing deformation under HP/LT ecologite facies condition. This supports the descent of the thinned Arabian continental margin below the Neo-Tethyn oceanic lithosphere. They attribute subduction along the Arabian margin to intra-oceanic subduction. Arrival of a continental fragment at the trend will lead to cessation of subduction (Le Metour et al., 1990) and induce obduction of ophiolites. Leucocratic granitic intrusions are found in the Semail ophiolite (Briqueu et al., 1991; Searle & Cox, 1999). These granites presumply represent partial melts formed as the continental slab thrust beneath the Neo-Tethys lithosphere (Le Metour et al., 1990; Searle & Cox, 1999). The granites formed close to the time of obduction, as ages 85±3 Ma (Searle (1980), cited in Searle & Cox, 1999) and 85 Ma (Browning & Smewing, 56 OMAN IRAN JMflM «fa auiroponAM I - T . T i" T Figure 2.15: Stylized cross section from Oman to Iran (A-B in Figure 2.2). It reveals Makran ridges and accretion wedge above the present day subduction. The Gulf of Oman sediments sealed the Neo-Tethyan oceanic crust from which the Oman ophiolite was originated (Coleman, 1981). m complex SmraH OpMoIHe MCMilS«U Figure 2.16: A close look reconstruction of the processes of Semail ophiolite formation at a supra-subduction environment (Searle & Cox, 1999). 57 1981) have been reported. Searle & Cox ( 1999) argued that ages for the Haybi complex and metamorphic sole rocks are different from the age of ophiolite formation, and hence does not correlate with MOR. and ridge axis obduction. In contrast, timing of piagiogranite ages (Hacker et al., 1996) and the metamorphic sole rocks are contemporary, and this Is consistent with the proposed intra-oceanic subduction (Figure 2.16) followed by continental subduction. It is noticeable that most workers who proposed MOR and ridge axis detachment are those who worked in the southern part of the Semail ophiolite, and workers who suggested supra-subduction have largely worked in the northern Oman. This is probably partly due to the greater variety of volcanic rocks in the northern region, although the UAE section does not include extrusive igneous rocks. 58 CHAPTERS CHROMITE FIELDS IN THE UAE Field Descriptions o f the Rocks & Structures in the Studied Field Areas 3.1 Introduction Chromite in the UAE is found in the ophiolitic alpine-type peridotites of the Semail (Oman) ophiolite in the northeastern section of the UAE. It occurs, in particular, in the Emirate (state) of Fujairah, along the coastline of the Gulf of Oman, between latitude 24“95'-25“65'N and longitude 56“-56“50' (Figures 2.2 & 3.1). Hunting Company had first prospected the UAE chromite during the 1970s. Since that time nothing had been done until recently, at the beginning of this decade, 1990s, when the Fujairah ruler (Shaikh Hamad AL-Sharqi) gave the Derwent Mining LTD company the franchise for chromite investigation and investment. The Hunting Company prospecting map is still a basic guide in this new Derwent Mining work. In addition, minimal vegetation, dry weather, nearby harbor, and some exposed chromite beds have all been major factors in the ease and success of the Derwent company work, which is still working until today. Chromite fields in the area occur in three major locations: Zikt, Al’Hel and Siji (Figure 3.1). Zikt is 4-5 km east of the Dadna coastline. Al’Hel is about 50-55 Km south of Zikt and Siji is about 20-25 Km northwest of Al’Hel. In each of these major zones, several open pits have been dug out, some of which have become abandoned. Zikt is the 59 richest area that shows high-grade chromite, whereas, Al’Hel chromite is apparently lower grade, and Siji is analogous to Al’Hel. Because only one field (LMl 17) was visited in Siji and just one time, and because of the compositional similarity between Al’Hel and Siji, the present study is mainly concentrated on the Zikt and Al’Hel zones. For exact location of each field refer to Figure 3.1 and Table 3.1. Although mining the chromite in the studied areas gave an excellent chance to see and collect samples fi’om the core of each field, many times this work caused inaccessibility to the sites and even destruction of the geologic features. The names of the open pits in all locations do not appear on any official map existing prior to 1992. These are working names given by Derwent Company during their investigations. In many places, the detailed structural relations are very complicated due to multiple deformational phases, and therefore complex structures are generally avoided here. Field observation of the studied areas defined three major zones: Al’Hel, E. Zikt and S. Zikt, according to their distance from the mantle-crust transition zone. The relative positions of these major zones in the ophiolite stratigraphie column and their relations with the dominant foliations are schematically shown in Figure 3.2. 3.2 APHEL ZONE The name “Al’Hel” and “Hayl” are both referring to the same area. They are just different translations of the name of a small town and rural zone west of Fujairah City. However, Hayl is used in all maps older than 1991, which was then replaced by “Al’Hel” in the new topographic maps published in 1991. Derwent company even utilized another term “Hisn” in their work, referring to an old large castle of the past ruling tribe in the 60 XDibba ip^vDadnah ★ Alam ' m Octopus ♦ Plack Scorpion p Black Sharq ■ Palace K[|or Fakkan Vera Al'Hol MT: Metamorphic rocks m MLMelange MC; Musandam Carbonate HS:Hawasbia Sediments R Peridotite G; Gabbro IGr Isotropic gabbro iTZ: Transition Zoné[ Figure 3.1: Reconstructed geologic map of the UAE Semail ophiolite section, based largely on Glennie et al. (1974)’s map, and on Boudier & Nicolas (1988), Searle et al. (1983), Hunting reference map, and the present field work. The map shows the locations of the present UAE chromite fields with designated symbols representing the relative sizes of the fields. 61 FIELD LATITUDE LONGITUDE Al-Hel Stringuy-8 25°093-25°097 56°298-56‘’302 Iceberg 25°084-25°088 56°286-56®292 Viking 25“083-25“088 56=303-56=308 Wadi I 25°075-25“080 56=287-56=293 E. Zikt Palace 25=485-25=491 56=469-56=474 S. Zikt Alam 25=450-25=465 56=400-56=417 Octopus 25=470-25=480 56=420-56=432 Black Scorpion 25=460-25=470 56=428-56=438 Balck Sharq 25=452-25=460 56=438-56=443 N. Zikt Vera 25=529-25=534 56=435-56=442 Siii 25=275-25=330 56=194-56=270 LM1I7 25=275-25=283 56=252-56=258 Table 3.1: Positions of the present UAE chromitite fields represented by geographic coordinates (see also Figure 3.1). 62 place. The name “Al’Hel” is preferred here to differentiate between this area and another one with the same name “Hayl” in the Oman territory. Chromite fields in this region are located In the Wadi Al’Hel area, and are very close to the mantle-crust transition zone (Figures 3.1 & 3.2). This TZ is enriched with a variety of intrusions ranging from ultramafic (wehrlites, pyroxenites & dunites), mafic (gabbros, microgabbros & basalts), to some felsic (diorites, granites & plagiogranites) dikes and veins. Magmatic layering at the base of layered gabbros strikes N35-45W and dips 67-71W. Al’Hel chromites show a lower grade than Zikt fields, revealing relatively aluminum-rich and chromium-poor chromite rocks. Many sites such as Stringuy-8, Wadi- 1, Iceberg (Wadi-H) & Viking have been mined out, but all are small sites and close to each other with a distance of400m to 1.3km between each one and the other (Figure 3.1; Table 3.1). These four sites were visited and sampled, but Wadi-I & Iceberg were studied in more detail and are considered as representatives of the Al’Hel field. 3.2.1 Iceberg (Wadi-II) This field represents one single orebody made up almost entirely of disseminated chromitite, intruded by semi-massive chromitite dikes and bordered at the top by a gabbroic intrusion in a thrust fault contact (Plate 3.1). The semi-massive dikes are located at the first 1/3 of the mine and oriented N70-75 W with 55 west dip (Figure 3.3). They are semi-massive due to, in many places, the growth of olivine grains reached up to 1cm in some cases, forming a porphyry-like texture in a massive chromite matrix (Plate 3.2; Chapter 5). Beside these dikes, a classic anti-nodular texture is very distinctive and dominant, where the olivine/chromite ratio is close to 1:1 (Plate 3.3). Grain size and 63 I I 1a 1 Transition Zone i/ ^ / TZZk Al’Hel Chromite pods •3)2 E Zikt Chromite pods V I S. Zikt Chromite pods "g }V 1 I Metiunorphic sole Figure 3.2: A simplified section of the ophiolite stratigraphie column, showing the relative positions of the three studied chromite zones in the mantle sequence, and their relation with the dominant foliations. Note that the high temperature spreading foliations at and close to the transition zone are rotated parallel to Moho and to the magmatic foliations in the layered gabbros above. 64 VÎMm jpup-1)> t.';! - f Plate 3.1 (upper): Three semi-massive chromitite dikes intruded an antinoduiar chromitite body and are terminated by gabbro in a thrust contact Note the chromite rich dunite responded to the thrusting compression by folding between the more competent massive chromitite. Iceberg. Plate 3.2 (lower): Olivine phenocrysts in a massive chromite matrix forming porphyry texture. Iceberg. 65 shape of both olivine and chromite are not uniform in the whole body, but they seem uniform in each section of the field (Plate 3.3). Three major fault planes cut across the rocks from bottom to top are found filled with carbonated serpentine and pyroxene/amphibole materials. Generally, they strike northwest and dip west. Slickenside traces on one of them trend N42W and plunge 13 west, almost parallel to the strike of dikes (Figure 3.3). Sub-vertical joints arc oriented parallel to the chromitite dikes. The measured dike orientation is different from that of the emplacement fabric discussed previously in Zikt, and conversely, it resembles the crustal magmatic fabrics and mantle spreading fabrics. This indicates that these chromititic dikes are semi-concordant to concordant in the classification of Cassard et. al. (1981). This is consistent with their location near the transition zone, revealing the fact that vertical and discordant dikes and veins are transposed parallel to Moho and magmatic foliations at or near the transition zone (Cassard et. al. 1981; Ceuleneer & Nicolas 1985; Nicolas 1989; Nicolas & AL-Azri 1991) following the rotation of the high temperature spreading flow. The disseminated chromitites show zones of alternative high and low alteration and oxidation of olivine, which is revealed as alternative reddish brown and pale green stains in a brittle structure, depending on water impregnation. Collectively, this would imply an ample supply of water to the upper mantle peridotites set below the transition zone, through fracture planes such as those now filled with carbonate-serpentine material. Water sources at this level could be seawater infiltrated through fracture networks or magmatic water of the final stages of firactional crystallization in a magma chamber set at or just above the transition zone. 66 ■Vf M(C / ; Aào ! em tjt. // / 4 V / / I r yc \ u Figure 3.3: Sketch map shows a traverse from SSW to NNE of the Iceberg chromite pit, revealing the main structural features of the site. A detailed lithology is reduced for clarity. 67 3.2.2 Wadi-I; This is a small chromite site located about 600m SW of Iceberg. Chromitite banded sheets are very characteristic and remarkable features here. They vary in thickness from (Plate 3.4). Bands are mostly massive chromitites in a diffusive chromitite matrix, but disseminated bands are also present, usually as elongated lenses in a massive host (Plate 3.5); all are encompassed in a reddish brown stain of altered & serpentinized dunites, but are relatively less altered than those of Iceberg diffusive chromitites. These stretched tabular structures are parallel to subparallel (concordant to subconcordant) to the harzburgite primary foliation (H. Clammy, pers. comm.) which are subparallel to Moho here. However, their lateral terminations are often accompanied by small folds with axial planar foliation (Plate 3.5 & 3.6), which testify that the tabular subconcordant forms are simply a more complex type of the tabular concordant form (Leblanc 1987). 3.2.3 Viking This is a small abandoned site, and apparently the closest one to the mantle- crustal transition zone (Figures 3.1 & 3.4). Mining the site destroyed and wiped out all the geological features. However, sheared and deformed peridotite around the site gives orientation readings of N37-60W and dips to the NE. The strikes of the structures are consistent with the primary foliation orientations that are assumed to be parallel to Moho and magmatic fabrics in the crustal layered sequence. The different dip here is probably associated with the structural position of Al’Hel peridotites, and Viking in particular, surrounded by gabbros (Figure 3.1). Chromite layers occur parallel (concordant) to the primary foliation and gabbro layers (Figure 3.4). Tongue-shaped small fold terminations 68 iiiÉiiifclSiii® Plate 3.3 (upper): Antinoduiar texture with Chr/Ol ratio almost equal to I. Alteration effect on olivine is clear between the less altered 1” sample (yellow) and highly altered 2*^ sample (brown). Iceberg. Plate 3.4 (lower): Chroim'tite small layers with sheath fold terminations, Wadi-I. 69 Plate 3.5 (upper); Disseminated chromitite (chromite-rich dunite) bands in a massive chromitite host, Wadil Plate 3.6 (lower): Tongue like end o f massive chromitite bands in disseminated chromitite host, Wadi-I 70 of massive chromitites in dunite or disseminated chromitite (Plate 3.7), or dunite in massive chromitite, are present. The location of this site very close to Moho and where high temperature spreading flow was strong led to recrystallization of many of the chromite occurrences. 3.3 ZIKT ZONE Zikt is a relatively large and high-grade chromite district in the region. It includes many small pits such as Palace, Vera and Black Sharq; and several large sites such as Black Scorpion, Octopus, and Alam (Figure 3.1 & Table 3.1). The last two are the largest and were not yet opened during the last fieldwork In September-October 1998. Vera is 5- 6 km far north from the rest and was not accessible, however, a brief description and representative samples will be shown later. The other three sites are considered in more detail and divided into E. Zikt (Palace) and S. Zikt (B. Sharq & B. Scorpion) according to their position in the mantle sequence. Vera (N. Zikt) is added to the S. Zikt field due to similar position and chemistry. 3.3.1 East Zikt: Palace There are three small abandoned irregular chromite open pits in the area. The one that was investigated is an ellipsoidal pit with an average dimension of ca. 36m x 60m. It is located about 2 Km southeast of the road between the town of Dadna and Zikt, 4.5 km northeast from the Black Sharq pit, and is the close one in Zikt area to the Mantle-Crust transition zone (Figures 3.1 & 3.2). Figure 3.5 shows a general traverse inside 2/3 of 71 Dibba Zikt Dadnah /W / j ^ ' Æ ^erlJtb'ks 4^ Fujairah * • / ( /’) Al’Hel ^ < 1 WL) Figure 3.4: A simplified interpretation of the structural position o f the upper mantle peridotite surrounded by gabbros in the A1 Hel area, and the position of theViking chromite site. It is proposed that the transition zone in Al’Hel area is in a relatively thin. 72 Plate 3.7: Several phases of chromite precipitation. Large to medium chromite grains gradually change to small grains at the center of the sample; tongue like terminations of massive chromitites and exotic fragments of chromitite and dunite are present. All may represent layering, and possibly related to magma turbulence or episodic deposition. Viking. 73 the pit, where structural features can be measured. The chromite ore is almost completely excavated except some spots, veins, dikes and bands. In the middle of the eastern side of the pit, a distinct recumbent fold can be easily traced (Plate 3.8). The fold axial plane strikes N80W and dips 20-25 degrees south where its trace completely dies out in the ground close to the center of the pit (Figures 3.5 &3.6). The fold is not horizontal and its axis plunges 15-20 degrees to the cast. A large granitic dike reading N55E, 36W lays southeast on the eastern wall, and furtlier south, a similar size, deformed chromi-dunite dike (Plate 3.9) striking N60E & dipping 34W, is parallel to the granitic one. The latter consists of semi-brittle blocks of massive chromitites (samples Z8-P48 & P52) in a matrix of fragile alteration materials (Plate 3.9). Chromitites in this dike appear to be different from those in the northern section of the pit, which are mostly less deformed. Both dikes have a cone or diatreme-like shape (Plate 3.10). However, it seems that they are probably parts of the upper flank of the recumbent fold, and their shape is due to folding and more twisting close to the hinge line (Figure 3.6). Different granitic dikes cutting through the folded peridotites are also folded and, in places, they formed sigmoid and boudinage structures (Plate 3.11 & Figure 3.7). This observation suggests the existence of the granitic dikes in the peridotites before the folding process took place, which could be a syn-emplacement deformation or post emplacement event associated with the last Zagros folding orogeny. In the far SE tail of the pit, several chromititic and granitic dikes/sills have crosscut each other (Plate 3.12) with chromitite dikes mostly cutting granitic ones, indicating that they are younger. Chromite in the site occurs as massive and disseminated chromitite, and as scattered accessory grains and fragments in dunites and harzburgites. The rocks show a 74 TfC irrci^ i *M«. i,U Figure 3.5 : Sketch map shows a traverse of the northern half of the Palace chromite pit, starting at the west entrance and ending close to the east entrance. Note that a curved comer of about 1.5m at station #4 is neglected, and for clarity, a detailed lithology is removed here. 75 Plate 3.8 (upper): The recumbent fold as seen in the east wail. The fold plunges a few degrees toward the east, and the upper right side, small parts of the granitic and dunitic chromititic dikes are shown. Plate 3.9 (lower): The highly altered dunitic chromitite dike (center) set between serpentinized peridotite, and a part of the granitic dike appears at the upper left comer. Palace. 76 y '* < s-A i, /ra , \ psricioti' & Sc a U Figure 3.6: The recumbent fold and the large granitic and serpentinized dunite-chromitite dikes illustrated in the east wall of the Palace field. Note that the continuation of the fold axial plane can be projected close to the lower termination of the dikes where they are largely thinned. 77 Plate 3.10 (upper): The granitic intrusion (center) shows a diatreme-like shape. Palace. Plate 3.11 (lower): Sigmoid (center) and boudinage (upper center) in the lower fold flank. Palace. 78 6 i^ fariwlinki .__ J Figure 3.7: A folded and twisted granitic dike in the recumbent fold forms boudinage and sigmoid structures. Note also the aureole of serpentine and carbonate materials surrounding the dike due to metasomatism of the peridotite during dike intrusion. 79 general transition trend from massive -> disseminated chromitite -> dunite -> harzburgite, but direct contact between massive chromitite and dunite is also found. Contacts between massive and disseminated types can be sharp or gradual, and in many places, both have formed an exchanging network encompassed in dunitic pockets (Plate 3.13). Although small patches of harzburgite may occur in dunite near the contact, contacts between dunite and harzburgite are mostly sharp. Chromite net, chains of chromite grains around olivines, and nodular textures (Thayer, 1969; Brown 1980, 1982) are the dominant textures. Most nodules are small (< 5mm) irregular chromite fragments in a matrix of olivines. However, the above mentioned chromi-dunite dike includes massive (-100% chromite) ore, and large (>lcm x > 2.5cm) regular (ellipsoidal) chromite nodules in a highly altered olivine matrix. This would indicate either a magma or crystallization type difference between chromitites in the dike and those in the other parts of the orefield. Chromite accessories are also present in some 50cm-1 m thick highly altered pyroxenite dikes that are found 300-500m ME of Palace (Plate 3.14). These are oriented NNE in close agreement with general N-S sheeted dike orientation of the northern Semail ophiolite (Brown, 1982; Lippard et. al., 1986), and are discordant with the foliation planes in the peridotite. 3.3.2 South Zikt 3.3.2.1 The Entrance The main gate to these chromite sites and to almost all the others in Zikt, except Palace and Vera, is at the west border of Zikt village. This entrance is characterized by 80 Plate 3.12 (upper); Crosscutting relation between chromitite and granitic dikes and sills in serpentinized peridotites. Palace. Plate 3.13 (lower): Massive to disseminated chromitite network in a chromite bearing dunite. Palace. 81 Plate 3.14: Pyroxenite dikes cut through harzburgite structures at about 500m NE of the Palace field. 8 2 leucocratic granitic intrusions cutting through the host peridotites, a feature ubiquitous in the mountains east of Zikt, toward the Gulf coastline. In the area, readings of the foliation fabrics in peridotites vary from N17E to N62E with average dip of 35°E. Elongation of the granitic dikes is concordant with the foliation planes. Lineations in these intrusions, measured by their biotite flakes, trend N52E & plunge 28E, which means that they are sub-parallel to the dike walls. A similar conclusion was reached elsewhere in the mountains by Searle & Cox (1999) who proved through isotopic age relations that the granitic dikes are syn-emplacement intrusions. This may be supported by a similar strike and dip reading of granitic gneisses at the metamorphic sole in Masafl, which gives N20E, 40E. Additionally, the magmatic foliation at the base of the Semail crustal sequence, in Al’Hel area for example, has given an average reading of N45W, 68W. This is very consistent with the mantle primary fabric orientation of the northern Semail ophiolite, which shows a general NW strike direction and a SW dip. Consequently, all these imply that the observed foliation planes are not primary (mantle spreading plastic flow) peridotite fabric, instead, they could be syn-emplacement fabrics or post emplacement deformation caused by a late tectonic process such as Zagros folding. Moreover, at least some of the granitic intrusions were emplaced at different times in the Semail spreading, probably sometime during the thrusting-emplacement of the ophiolite. The S. Zikt zone is the deepest one in the mantle sequence (Figures 3.1 & 3.2) relative to the previous two and includes several larger fields, two of which were studied (Black Sharq and Black Scorpion). 83 3.J.2.2 Black Sharq Black Sharq is about 4.5 km south from the main gate, and includes four different locations, one of which is relatively large and the work was concentrated there. The present size of this location is somewhat larger than that of Palace, and is farther (deeper) from the mantle-crust transition zone. Except at its entrance, the pit is almost entirely yellowish-green highly, serpentinized dunites enclosing chromites and chromitite bodies, and is located in a major fault system that is generally striking NW and dipping east. Although most chromite ores were excavated, a large hole in the west side still includes an economic ore. The work is not finished yet but is temporarily terminated, because of the hazard evolving as this hole is located down below a fragile brecciated and fractured structure of highly serpentinized peridotites as well as some deformed chromitites (Plate 3.15) of a major fault zone. Serpentine, talc, carbonate and other alteration materials are filling the spaces of those tectonic contacts. At the entrance of the pit, white, less cohesive talc to carbonated serpentines occupy a fault plane in a thickness reaching about >l m in places (Plate 3.16). Immediately above the hole, large fragments and lenses of massive chromitite and peridotite are inserted and surrounded by silicifled serpentinized rocks (Plate 3.15). Continuous layers and bands of massive and disseminated chromitites with varying thickness (Plate 3.17) characterize this field. They range in width from I cm to > 30 cm, and extend continuously to discontinuously tens of meters, in semi-parallel form. In places, rhythmic layers including massive chromitite, disseminated chromitite, and dunite, on a centimeter scale are observed (Plate 3.18). Chromite also occurs as small and 84 Plate 3.15 (upper): A fragile structure of a fault plane above the ore hole, NW Sharq. Note peridotite & chromitite fragments hosted in carbonated serpentines and talc. Plate 3.16 (lower): A thick layer o f carbonated serpentines (white) filling a fault plane in peridotite, Sharq. 85 Plate 3.17 (upper); Continuous massive chromitite layers (black) in a dunite host. Two layering sequences can be recognized, starting &om >Scm layer to 3.3 2.3 Black Scorpion Black Scorpion is about 1.25 Km west of, and is larger than. Black Sharq. It consists of three big canyons with the first two huge and sharing one main entrance (Plate 3.20). In the left (west) wall of the entrance, a big dike about 250cm thick strikes NlOW and dips 45 east (Plate 3.21). It is of a granitic affinity but includes plenty of large and small lenses and fragments of mostly massive chromitites (Plate 3.22). Its mafic content grades from mafic-free granite to mafic rich rocks and lineated parallel to the walls. Another large dike appears to have a similar composition is stuck in the center of the first huge canyon, and takes a cone-like shape as seen from the entrance (Plate 3.20). This canyon was not accessible to enter, but an interpretation by H. Clemmey (pers. comm.) showed that these two dikes are connected and are actually one dike separated by a fault zone as drawn in Figure 3.8. This interpretation is supported by the absence of either part of the dike in the second canyon and in the east wall of the entrance. The interior of the second canyon consists of firesh green harzburgites and dunites and white to yellowish alteration materials. At the cave center, a dark blue granodiorite dike circles the cave due to removal of the central materials, and a massive chromitite dike lies on the east wall and parallels the east side of the granodiorite dike (Plate 3.23). The granodiorite and 87 Y . < ' -i' . , Plate 3.19: Small massive chromitite pods or lenses (black) enclosed in a fresh dunite. Sharq. 88 Plate 3.20: The main entrance of the first two canyons of the Scorpion pit. Note the chromititic granitic dike (white, the upper half of center) occupying the center of the first hole. Scorpion. 89 Plate 3.21 : The other part of the major chromi-granitic dike lies at the west wall of the Scorpion entrance. Note the large chromitite fragments and lenses (e.g. below the hammer) and the small ones (e.g. above the hammer), Scorpion. 90 Plate 3.22: A more focused photo inside the entrance granitic dike, revealing large chromitite lenses (e.g. below the hammer) and small ones (e.g. above the hammer). Scorpion. 91 chromitite dikes gives an average strike of N35E and dip 30-50“ west. In the left (west) side of the hole center, water is very noticeable infiltrating inside the hole through fracture and layer planes, with clay materials. Water is a major factor in the alteration and serpentinization of these rocks. Although, this water is probably not the original one that caused the main serpentinization and alteration, it could have an effect in the late alteration. Most chromite in Scorpion occurs as massive chromitite in the form of dikes, lenses and fragments in dunites, and some occurs as blocks and lenses brought up mostly through felsic intrusions as that of the entrance (Plates 3.21 & 3.22). Contacts between massive chromitite and dunite are sharp or gradual. Pyroxenite dikes were not clearly observed in the investigated sections of Scorpion, however, one sample (Z8-BScl) collected from debris fragments in Scorpion, shows a green pyroxenite/amphibolite at a sharp contact with a massive chromitite (Figure 4.6). Disseminated chromitites and accessories can also be found but are less abundant. Disseminated rocks, where found, show a small nodular structure. 3.2.3 North Zikt: Vera This is another small field located about one km north of Zikt. The ore body forms elongated layered sheets of ca. 100m long. The sheets include some sheath folds that are elongated in a dimension subparallel to the sheet margins (Figure 3.9) which are semi-concordant with the dominant foliations. Nodular texture is very distinctive in Vera. Small to large, and ring-shaped to oval-shaped nodules are present (Plate 3.24). It is 92 Plate 3^3 (upper): Massive chromitite dike (at the hammer) is parallel to the east part o f the granodiorite dike (blue), center of the Scorpion 2“* canyon. The pale brown cover of the right half is work dust. Plate 3.24 (lower): Large nodules (grapeshots) in a mahrix of chromite bearing dunite. Vera 93 w/ gEP Figure 3.8: A drawing illustrating the fault zone that ruptures and splits the major chromititic granitic dike of Scorpion into two parts. One is at the west wall of the entrance, and the other is in the first canyon of the pit. This is why neither parts are present in the other side of the entrance nor in the second canyon. s i . ■ / d yuJuLt^ Figure 3.9: A sketch of one chromitite body in Vera, showing the spheroid nodules at the center of the body, while the ovoid nodules at the body margins and their long axes are parallel to the margins 94 observed that the round nodules occur in the center of the body, while the elliptical nodules are at the body margins (Clemmey, pens, comm.) and their long axes are parallel to the margins (Figure 3.9). Due to the same position in the mantle section and the chemical similarity of this locality with those of south Zikt, it is considered as part of the south Zikt zone in all further discussions. 3.4 Siji Siji is a separate chromite zone, located about 20km northwest of A1 Hel (Figure 3.1) and many fields are situated in a shear zone. Only one site (LMl 17) of 6 small sites was visited, and its chromite chemistry shows a similar composition to A1 Hel fields, probably due to their similar structural position near the transition zone. The body is generally west dipping (WSW) and appears to form pop-up structures (Plate 3.25). Representative samples show banded and occluded textures and pillow bands (Plate 3.26; Chapter 5), and many of these samples were recrystallized during high grade shearing. 3.5 Deformation & Magmatic textures: Because the ophiolite mantle sequence is believed to suffer multiple deformation phases, some may argue that it is impossible to find any magmatic signatures in this sequence. This has been proven to be untrue however as magmatic textures of chromitite and dunite have been recorded in the mantle sequences of many ophiolite complexes (Jan & Windley, 1990; Ozawa, 1990; Leblanc, 1987 & 1995; Edward & Malpas, 1995; Zhou et al., 1996; Zhou & Robenson, 1997; Malpas et al., 1997) and in the Semail ophiolite (Boudier & Colemen, 1981; Hopson et al., 1981; Brown 1980,1982; Browning, 1982; 95 Plate 3.25 (upper): Pop-up structure revealed in the LMl 17 Geld, Siji Plate 3.26 (lower): Olivine occluded texture in massive chromitite (leG), and lineated and pillow bands texture (right). Si] 96 Roberts, 1986 & 1992). Two major deformation events are recorded in the mantle sequence. One is the high temperature spreading flow and the other is the low temperature, emplacement-related deformation. The first one is best developed in the section close to the mantle-crust transition zone such as Al’Hel field, and decreases downward. The second deformation is pronounced at and close to the base of the ophiolite and decreases upward. Between these two zones (e.g. middle of the sequcncc-S. Zikt), the effects of both deformation are low, and thus magmatic signatures might be more preserved. Nonetheless, post emplacement deformation (e.g. Zagros folding) could have affected any part of the mantle sequence. However, the influence of this process is mostly brittle deformation, because once the mantle cooled below 1000“C, it was no longer ductile (Nicolas & Violette, 1982; Bartholomew, 1983). In addition, magmatic textures might even be preserved in sections that have undergone a high temperature primary flow (e.g. Al’Hel). That is because dunites (& chromitites) were intruded at different stages in the deformation history so that the latest ones would be less deformed than the earliest intrusions (Browning, 1982). Moreover, Bartholomew (1983) in his detailed structural study in northern Oman observed that the recrystallized margins of the least deformed dimites absorbed stresses and thus protected the center from deformation. It is then concluded here that relict magmatic signatures of chromitite and dunite rocks are best preserved in the Zikt area, and even some are preserved in Al’Hel field where the deformation is mainly restricted to localized zones. 97 CHAPTER 4 PETROGRAPHIC INVESTIGATIONS MICROSCOPIC PROFILE OF THE MAIN ROCK <6 MINERAL ASSOCIA TIONS 4.1 Introduction Representative samples of each chromite field were studied using transmitted and reflected light microscopy. The mineral associations of the rocks are in general characteristic of Alpine type peridotites. Three main rock types dominate all fields; harzburgite, dunite, and chromitite. Other rock types such as pyroxenite, amphibolite and gabbro are found as veins or dikes cutting through the harzburgites. Felsic intrusives are frequent in some parts of Zikt, and when occur in the ore fields, they are often associated with chromitite dikes or fragments (Figure 3.6; Plate 3.21). Rock bodies of Iherzolitic and wehrlite compositions occur in Al’Hel area, and highly deformed Iherzolites and dunites are common at the base of the mantle sequence (e.g. Dibba zone & Masafi). However, the base of the mantle sequence is not a chromite field and thus is not considered here. 4.2 Harzburgite: Peridotites in almost all sites have experienced refractory and depleted features represented by the harzburgite predominance after Iherzolite fertile rock. Harzburgite is the dominant lithology forming up to 80 % of the mantle sequence. It is green to dark green in fresh rocks (chapter 3 photo), but it is brown to grayish black surface, fractured 98 and some times pitted and crumbled where highly sheared and weathered. A gradation from harzburgite to chromitite through dunite is common. Segregations of dunitic and pyroxenitic layers on a scale of about 3cm (Brown, 1982; Roberts, 1986) can also be found. Harzburgite has an average modal composition of 65-75% olivine and 25-35% orthopyroxene, with the pyroxene content (clinopyroxene in particular) relatively increasing upward in the sequence toward the mantle-crust transition zone, where some Iherzolites are present. In addition, accessory chromite grains, and varying amounts of alteration products are present in almost all samples. 4.2.1 Olivine: Olivine forms medium to large (2mm-7mm), subhedral to anhedral grains. The grains are fractured and fragmented into small aggregates (0.1mm-0.8mm) so that boundaries between the original grains can only be recognized by differences in the interference color and/or extinction direction. Many olivine fragments show undulose extinction (Plate 4.1) reflecting deformation and some others reveal a deformation lamella (Plate 4.2). The typical olivine fabrics are illustrated in Figure 4.1. Orientations of fracture sets differ from one grain or a group of grains to another because of the difference in the preferred crystallographic orientation and internal slip system between Grains. This produces misfits (gaps) and overlaps between grains even in a homogeneous stress field (Twiss & Moores, 1992) that can be determined from the common elongation direction (lineation) of grains in several samples (Figure 4.2). Lineation and fracturing of olivines can result from high temperature plastic shear deformation (Bartholomew, 1983, 99 I Plate 4.1 (upper): Photomicrograph of a fractured olivine grain that reveals undulose extinction and at least one dominant fracture set filled with serpentine. The blue fragments at the lower left comer are another olivine grain. View Length: 1.12mm, XPL,Z9-Sc8. Plate 4.2 (lower): Photomicrograph of a fragmented olivine grain that show a parallel metamorphic lamella. Spaces between fragments are occupied by serpentine. View Length: 1.12mm, XPL, Z9-Sh3. too Undulatory Extinction 1.9 Deformation Lamella U9 Deformation Survivals Neoblasts /.o Mesh Texture Ribbons structure /.OMM Figure 4.1: Schematic drawings of the apparent olivine fabrics that can be found in harzburgites and/or dunites of the studied fields. Fractures and alteration space- fillings are present in most types. Dashed arrows are elongation direction (foliation). tot 1993) which may be caused by asthenospheric mantle flow. However, the more intensive deformation may result from syn-emplacement flow at lower temperature. Spaces between fragments and fractures are filled with alteration products, mainly serpentines and chlorites with some biotite. Some olivines in Iherzolites to wehrlites (particularly in Al’Hel) are relict original grains with less undulose extinction, still preserve the original shape and 120° grain boundary intersection angle (Figure 4.1; Plate 4.3). These are called the “deformation survivals” and their straight faces may reflect a magmatic origin. Recrystallized “neoblast” aggregates (Brown, 1982) may also occur. These are almost equigranular grains with 120° grain boundary intersection angle (Figure 4.1; Plates 4.4 & 4.5) that form an equigranular mosaic texture (Pike & schwarzmann, 1977; Harte, 1977). These grains differ from the “survival” grains, in that they are small, usually less or unfractured, lack of alteration, and lack of undulose extinction (Figure 4.1, Plate 4.5). The neoblasts are comparatively rare in harzburgites around chromite fields, but recrystallized grains with grain size reduction are notably found downward close to the metamorphic sole of the ophiolite. These signatures of dynamic (or syntectonic) deformation effects are more common where the plastic flows are more extensive. At the top near the mantle-crust transition, where Al’Hel field, the high temperature flow (primary foliation) is dominant and decreases downward the sequence (Figure 3.2). Close to the tectonic base of the ophiolite, the low temperature emplacement flow is dominant and overprints the high temperature spreading flow features (Boudier et al., 1988; Nicolas et al., 1988; Nicolas, 1989). Despite the post emplacement deformations that affected the entire ophiolite, 102 A. y ' l .'"Y X ? B. Figure 4.2: Twiss & Moores (I992)’s proposal to yield preferred crystallographic orientations by minimizing the geometric misfit in a polycrystalline aggregate composed of crystals with only one slip system. A. Idealized undeformed polycrystal, lines in each crystal show the orientation of the slip plane. The slip direction is in the plane of diagram. B. The form of the crystals would take if the deformation were homogeneous. C. The best approximation to the homogeneous form of the deformation, given that crystals can slip on only one slip system. The area of misfit plus overlap is a minimum. 103 m Plate 4.3 (upper); Photomicrograph showing less moved and deformed olivine grains (survivals) that still keep the original 120“edge angle. The white elongated grains at the right side is orthopyroxene with small subhedral chromite grains at it top end. View Length: 4.43mm, XPL, H4-16/26A Plate 4.4 (lower): Photomicrograph showing new recrystallized olivine grains (neoblasts), with good 120° edge and intersection angles and without internal fractures or deformation strains. View Length: 1.12mm, PPL, Z8-Shl8. 104 t Plate 4.5 (upper): The same photo as (plate 4.4) showing the mosaic texture of the olivine neoblasts, but here under the crossed polars (XPL). Plate 4.6 (lower): Photomicrograph revealing pyroxene grains (whit) surrounded by a zone of shimmer patchy aggregates of amphibole and tele, with a few biotite (brown) in places. The blue fractured subhedral grain in the upper left comer is olivine with small subhedral chromite (black) at the top. View Length: 2.8mm, XPL, Z7-P20 105 s. Zikt field (e.g. Sharq and Scorpion) is located between these two extremes of plastic deformations, and thus less plastically deformed rocks are found. Samples collected close to the metamorphic sole (e.g. Masafi & Dibba zone) clearly reveal this and show mylonitic textures indicating dynamic recrystallization. 4.2.2 Pyroxene Orthopyroxene (enstatite) is the main pyroxene phase. Mediiun to large (3mm-10 mm), usually subhedral elongated orthopyroxene grains are randomly distributed in most samples. The orthopyroxenes are partially fractured and altered, but to a lesser extent than olivine. Fractures are filled mostly with chlorite and serpentine. This textural relationship in which olivine and enstatite are dismembered by a network or mesh of serpentine veinlets indicates that serpentine forms from both olivine and enstatite (O’Hanley 1996). Fragmentation of pyroxene grains is less frequent than in olivine, because pyroxene is more resistant to the influence of shearing and deformation than olivine (Figure 4.3) (Bartholomew, 1983, 1993). This should also be true for alteration, but largely to completely altered grains of orthopyroxene are frequent. Many grains are found mantled by shimmer aggregates and patchy flakes of amphibole (actinolite & anthophylite) and/or talc (Plate 4.6). Other grains show alteration zones, with a core of serpentine surrounded by chlorite, and then amphibole and/or tele (Plate 4.7). Complete alteration to one or two of the alteration products is also found. In addition, well-shaped pyroxene neoblasts with nearly 120° grain boundary intersection angles occur a few samples (Figure4.4). 106 iW Skemf I I Less resistant phase: olivine More resistant phase: pyroxene Most resistant phase: chromite Figure 4.3: A schematic sketch showing the variable response between olivine, pyroxene, and chromite to the plastic shear flow. The resistance to the shearing process increases from olivine to pyroxene to chromite (Modified from Lippard et al., 1986 and Bartholomew, 1993). 107 Plate 4.7 (upper): Photomicrograph showing a complete alteration zone in a pyroxene grain. Relict serpentinized pyroxene fragments (high relief') in the core are surrounded by chlorite middle zone (at extinction state, pale yellow color) which in turn mantled by amphibole/telc outer zone (higher relief and anomalous interference color). The fragments around the altered pyroxene are olivines, and at the lower left comer a chromite fragment exhibits a lobate shape. View Length: 2.8mm, XPL, Z9-Sh3 Plate 4.8 (lower): Photomicrograph showing kink-bands structure of a large pyroxene grain that is also slightly retorted. View Length: 2.8mm, XPL, Z7-P20 108 Streaky Lamella Exolution Lamella Undulatory Extinction — .k. Neoblasts Deformation Survivals Prismatic shape Kink-bands form Herringbone structure Retorted shape Figure 4,4: Simple drawings of the visible pyroxene fabrics that can be found in the harzburgites of the studied fields, and some may also be observed in dunites. Alteration products could occur in or around any of these types. Dashed arrows are the elongation direction (foliation). 109 Most enstatite grains show regular extinction parallel to their long axes or edges. However, patchy or undulose extinction are characterize some grains, and these together with prismatic and tabular crystal forms, curved shapes, kink-bands (Plate 4.8), and “herringbone” structure (Plate 4.9) are all indications of deformation (Figure 4.4) resulting from shearing and regional stress. Small to medium olivine inclusions that may be partially serpentinized and sometime fractured are frequent in pyroxenes. Fine clinopyroxene exolution lamellae are also common in orthopyroxene (Plate 4.9). Pyroxene exolution is initiated by compositional (and microstructural) fluctuations in a solid solution at high temperatures, when pyroxene nucléation or decomposition moves from a single-phase province to two- phase province, forcing crystals to lower their total free- energy (Buseck et al., 1980; Robinson, 1980). Such process lead to a miscibility gap (solvus) along which the pyroxene continuously changes composition as a function of temperature and primitive composition. The pyroxenes in all harzburgite samples have high Mg # (chapter 6) which indicates formation at high temperature. Exolution of clinopyroxene (e.g. diopside, augite & pegionite) lamellae occurred during slow cooling. Clinopyroxene grains are present in very low amounts (0-3 vol.%) at Zikt, sometime accompanying orthopyroxene grains (Plate 4.9), but the amount of clinopyroxene increases upward in the sequence reaching 5-7 vol.% in some parts of Al’Hel field zone. Two factors may explain the higher clinopyroxene contents upward in the section near the transition zone. (I) A decrease in mantle depletion upward toward the mantle-crust transition zone, reflecting an upward decrease in the amount of partial melting, accompanied by some interaction between the chromite precipitating melt and 110 >1 ^ Plate 4.9 (upper): Photomicrograph showing herringbone structure: a simple twining combined with polysynthetic twining, of a large pyroxene grain, with clinopyroxene streaky lamellae and exolution. Clinopyroxene also present as a small blue grain between orthopyroxenes at the top left side. Euhedral small chromite crystals and medium chromite grain with cuspate form are distinct at the upper left comer. View Length: 4.43mm, XPL, Z9-P1. Plate 4.10 (lower): Photomicrograph of highly deformed Iherzolite close to the metamorphic sole, showing 2 types of opaque: small black aggregates, and medium corroded nodules with yellowish brown color, all in an olivine and pyroxene matrix with grain size reduction. View Length: 2.8mm, PPL, Mas9-5. I ll the wall-rock; or 2) precipitation of diopside from a crystallizing magma at low temperatures toward the top of the mantle section. This mechanism is unlikely if precipitation of chromite and clinopyroxene is considered contemporaneous, because chromite crystallization ceases when clinopyroxene precipitation begins (Irvine, 1967; Dick & Bullen, 1984). However, the crystallization of the two minerals from magmatic liquids could occur in separate times. Clinopyroxene grains are mostly subhedral diopsides and augites. They are smaller than orthpyroxenes, blue to very pale greenish gray to colorless. Some clinopyroxene grains show alteration and deformation effects (e.g. curvature and undulose extinction) similar to those observed in orthopyroxene. 4.2.3 Chromite Harzburgites contain an average 1-3 vol.% of small (0.1mm-0.7mm), subhedral to euhedral, red brown to black chromite grains. Chromite is the most competent material in these rocks and is less ductile than olivine or pyroxene (Figure 4.3). Most grains show no consistent elongation, and are unfractured. However, relatively larger grains sometimes show pull-apart fractures that are filled with serpentine. Some have also thin black rims along cracks and grain boundaries that presumably represent alteration products rich in Fe^^ and form through oxidation reactions. This is also more common in chromites in chromitite rocks (section 4.4). Other chromite grains are euhedral with square or octahedral outlines (Figure 4.5, Plate 4.9). Zoning or reaction rims have not been identified in any chromite grains, suggesting equilibrium between chromite grains and other phases, as is expected in the mantle peridotites. These sub to euhedral chromites 112 occur as small fragments on pyroxene and olivine grains, and with different patterns in the interstices between olivine and pyroxene grains (Plates 4.7 & 4.9). The chromites are clearly different from spinels found in Iherzolites close to the metamorphic sole of the ophiolite. In the latter, three forms are clearly recognized. One are small to medium, irregular, corroded grains with yellowish brown color, others are small worm-like black grains (Plate 4.10), and the others are rounded and corroded black grains surrounded by nearly opaque alteration products (Plate 4.11). 4.3 Dunite: This rock is the most important rock type associated with chromite formation in the harzburgite, and is probably the second abundant rock type in the UAE upper mantle peridotite. It forms approximately 10-15 % of the total volume of the mantle section. Dunites occur as dikes, pods, lenses and layers within the mantle sequence. When fresh, they are clear green to yellowish green, but when weathered, they are brown in color due to the effect of oxidation. Dunite (named for Dun Mountains in New Zealand) should be really called “olivinite” as for pyroxenite, due to the overwhelming existence of olivine and pyroxene respectively in these rocks. The model abundant of pyroxene (dominantly orthopyroxene and/or diopside) in dunite averages 2-5 %, and dunites with > 98 % olivine are found in the Zikt area. Accessory of chromite with average 1-3 % is present in almost every dunite sample. The association of chromite with olivine may however successively evolve until reaching 100 % chromite, as will discuss in the chromite section. The residual versus magmatic origin of dunite is a controversial issue. Many workers now favor a magmatic origin because of the occurrence of relict magmatic 113 irIMI Lobate shapes »' . I 1.3 T H /tl Cuspate shapes y / 1 .3 mtn Euhedral forms I— —— ------1 Elongated Nuggets I.Smm Spheres & Dots Corroded globules I.Zmm /.2 "mm Subhedral-anhedral fragments % Figure 4.5: Illustrations of the common forms of the chromite accessories that occur in the harzburgites, dunites, and pyroxenite dikes of the studied fields. 114 m m g Plate 4.11 (upper): Photomicrograph of highly deformed Iherzolite close t the metamorphic sole, showing irregular corroded spinel grains (black) surrounded by aureole of serpentine in olivine and pyroxene matrix with grain size reduction. View Length: 2.8mm, PPL, Mas9-3. Plate 4.12 (lower): Photomicrograph clearly showing biotite aggregates (brown) surrounding some olivine fragments, with a few iron oxides (black dots). Tlie dominant alteration product filling all spaces is serpentine. One small euhedral chromite occurs at the right edge. View Length: 2.8mm, PPL, Z8-Shl4. 115 fabrics in discordant to semi-concordant dimites. Concordant dunites particularly those close to the base of the mantle sequence are thought to be residues of partial melting. 4.3.1 Olivine: Dunite is an olivine monomineralic rock. In some examples from the Zikt area, model proportions of more than 97 % olivines are found. Two minerals are often largely reducing the olivine contents in dunite: serpentine as a product of low-temperature alteration and chromite as result of high temperature crystallization. Both processes can proceed to form a new rock (serpentinite and chromitite, respectively) which are both observed in the field areas (chapter 3). Many characteristics of the harzburgitic olivine described above are found in the dunitic olivine (Figure 4.1) with few differences. Generally olivine fragments are smaller (>0.1 mm -0.5mm) than those in harzburgites, and are smaller (>0.1mm-0.3 mm) in Sharq and Scorpion dunites than in Palace and Al’Hel dunites (>0.1mm-0.5mm). This is consistent with the increase in postdetachment deformation downward in the mantle section. Iron oxides such as iddingsite and hematite as well as biotite are present as alteration materials in addition to serpentine (Plate 4.12). “Survival” grains (Plates 4.3 & 4.15) and neoblasts (Plate 4.4) are found in Al’Hel dunites (e.g. H5-49/60,16/26A) and Sharq dunite (e.g. Z8-Shl8) respectively. Olivines in many dunites show undulose extinction (Plate 4.13). Localization of deformation in Palace and Al’Hel allowed some dunitic olivines to preserve some cumulus textures (Plate 4.14), and zoning or reaction rims are not present in any olivine grains. In some dunites (and other peridotites), extensive sepentinization occurred by the following hydration reaction: 116 a 5 : Plate 4.13 (upper): Photomicrograph of dunitic olivines exhibiting distinct undulose extinction and chrysotile serrate-like veins cut through olivine grain. View Length: 2.8mm, )ŒL, Z8-Shl4. Plate 4.14 (lower): Photomicrograph showing intercumulus relation between olivine and pyroxene with one medium elongated chromite grain at the upper right comer. View Length: 4.43mm, XPL, Z7-P28. 117 Forsterite Serpentine Brucite 2Mg2Si04 + 3H2O = Mg3Si20s(0H)4 + Mg(0H)2 This reaction causes an increase in the mass volume (-53%) that produces pseudomorphous textures such as ribbon, hourglass and mesh textures (O'Hanley 1996). Mesh texture with relict olivines in the center, and serpentines (e.g. lisardite) in the rim is observed in many serpentinized peridotites (Plates 4.16 & 17). Due to increasing deformation and alteration effects, fractures may be enlarged and new ones (tension gashes) initiate. Thus, mesh texture may grade into ribbons (Plate 4.17) or hourglass textures where there is no clear distinction between serpentinized core and rim of olivine. The rock may sometimes be cut by serrate serpentine veins (Plate 4.13). Completely serpentinized rocks are also common in the Semail ophiolite. 4.3.2 Pyroxene Small to medium (0.5mm-2mm) prismatic and elongated grains of enstatite and diopside are partially or largely altered to serpentine and chlorite. They form about 0-3 % ofZikt dunites but rise up to 6 % of Palace and Al’Hel dunites. Deformation effects are less represented than in olivine and have produced elongated and prismatic grains. In many samples, amphibole and talc completely replace pyroxenes; and when clinopyroxene occur, it is relatively less altered and fractured than orthopyroxene. 4.3.3 Chromite The chromite to olivine ratio in the ore fields widely varies between that found in dunite and that found in chromitite. Dunite with accessory chromites is common, and these chromites in dunites show many similar features described in harzburgitic (Figure 4.5). There is no significant difference in the chromite contents of dunites from different 118 -T#. ' i Plate 4.15 (upper): Photomicrograph displaying a mesh texture (the right half) where olivine fragments occupy the mesh centers and serpentines form the mesh rims. The other half is largely occupied by one survival olivine grain revealing normal extinction, 120° edge angle, and less fracturing. View Length: 1.12mm, XPL, Z9- Sh3. Plate 4.16 (lower): Photomicrograph showing ribbons structure prograded from mesh texture in a fragmented serpentinized olivine during elevation of deformation and serpentinization. Mote also the tension gashes that formed perpendicular to fragments elongation. View Length: 1.12mm, XPL, H9-WI2.2. 119 different field areas. However, two observations might have some significance. Chromite is mostly black to brown in the Palace and Al’Hel dunites, while only black chromite occurs in Sharq and Scorpion dunites. It is known that the black color is caused by oxidation and alteration effect, hence this color variation could indicate an increase of alteration downward the mantle section. This is hard to believe because access of water can be more facilitated close to the transition zone, and evidence for hydrous alteration decreases downward the mantle section. Nevertheless, water could still be provided by the magma precipitating chromites. Alternatively, the chromite color may reflect the presence or absence of clinopyroxene. According to Brown (1982), chromites are usually yellow in dunite that contains clinopyroxene, and brown in clinopyroxene-free dunite (Brown 1982). The Al’Hel and Palace dunites contain some clinopyroxene, whereas the Sharq and Scorpion dunites do not. In this case, the brown color of chromites probably reflects alteration of yellow chromite, whereas their black color reflects alteration of brown chromite. Silicate inclusions (chapter 5) in dunitic chromites are generally less common, since most of these chromite aggregates are small grains. Nevertheless, the amount of inclusions increases fi-om Scorpion and Sharq to Palace to A1 Hel dunites. Chromite may also occur between olivine grains in dunite (Plate 4.14). 4.4 Chromitite This rock type and its major constituent, chromite, are the focus of this research. Chromitite is intimately and genetically related to dunite. This is clear from the variation of chromite/olivine ratio from about one to zero in rocks between these end-member types. Although other rock such as pyroxenite dikes (next section) that contain chromite 120 occur in the UAE Semail ophiolite, they are not abundant quantity, and the main chromite ores are associated with olivines in dunite pockets. Chromite forms isotropic semi-opaque octahedral grains that show reddish to dark brown color in plane polarized light (Plate 4.17) when is fresh and black color as ferric ion increases due to oxidation (Ballantyne, 1992). In crossed polarized light, chromite is completely opaque, while is pale gray to milk}' with high reflectance under reflected light, and becomes slightly pinkish gray when carbon coated for electron microprobe analysis. Both fresh and oxidized chromites are common in UAE chromitite, and even occur in the same sample (Plate 4.17). Grains are subhedral to anhedral, mostly medium to large (1mm - >10mm), cracked or fractured with pull-apart textures (plate 4.18, chapter 5). Many grains are elongated in the direction of foliation. Multiple fracture sets occur in some chromite aggregates and may indicate multi-deformation events. Inclusions in chromites increase upward the mantle section, are most abundant in chromites from Palace and Al’Hel and are mostly olivine or serpentine (Plate 4.17) and rarely pyroxene and amphibole. Other than black rims due to alteration, mantling fragments peripheries (Plate 4.17), no primary zoning is observed. Grains in massive chromitites are usually larger than those in disseminated chromitite due to intergrowth and coalesce of grains. Accumulation and clustering of chromite aggregates, accompanied with deformation effect, form many types of chromite textures. The dominant chromite textures are discussed in the chapter S. The contacts between massive and disseminated chromitite and dunite vary from sharp to gradual contacts. In addition. Olivine grains in chromitites are not significantly different from those in dunites, although serpentinization is sometimes more extensive. 121 • • • Plate 4.17 (upper): Photomicrograph showing a section in chromite grain that is reddish brown in the fresh parts and black at the oxidized parts (around cracks and fracture). The grain also includes olivine/serpentine inclusions and a pull-apart fracture filled with a chrysotile serrate vain. View Length: 1.12mm, PPL, H9- WI2.1 Plate 4.18 (lower): Photomicrograph in a section of a semi-massive chromitite, showing a mesh texture with ribbons (the right half) in the serpentines, and hourglass texture at the left upper comer. The present chromite grains evidently reveal parallel pull- apart fractures that are perpendicular to chromite elongation. View Length: 2.8mm, XPL, H8-I13 122 Olivines in a chromitite matrix generally exhibit mesh textures (Plates 4.15 & 4.16), and may be largely or completely altered to fibrous serpentines forming hourglass texture (O'Hanley 1996) as shown in Plate 4.18. Chrysotile serrate veins and interlocking textures may also be found. 4.5 Py roxenite, Amphibolite, and Talc: A verity of mafic and ultramafic intrusive bodies have been mapped in the Semail mantle sequence (Brown, 1982; Nicolas, 1989; Vetter & Stakes, 1990; lldefonse et al., 1993; Nicolas et al., 1996). Apart from dunites, only pyroxenites and amphibolites (probably after pyroxenite) occur in or near the studied chromite fields (Figure 4.6). Gabbro is present in Iceberg (Al’Hel) but it is almost devoid of chromite. Pyroxenite/ amphibolite bodies are found as dikes 300-500m north of Palace (E. Zikt), and as fracture- or fault plane-fillings in Iceberg (Al’Hel) and Sharq (S. Zikt) (see Figure 4.6). Also, a loose sample (e.g. Z8-BScl) collected from Scorpion (S. Zikt) shows green prismatic pyroxenes/amphiboles in a sharp contact with massive chromitite. The latter contains small interstices and inclusions of these chain silicates that have penetrated from the pyroxene/amphibole rocks (Plate 4.19). The silicates in this sample consist of very coarse-grained amphiboles (» hornblende) without any chromite grains. Amphibolite fault plane fillings in Iceberg are similar to the Scorpion sample described above, but here contain disseminated chromitite instead of massive. The chromite occurs as disseminated chromitite with an olivine matrix, as disseminated chromitite with a carbonate and amphibole matrix, and as chromite-fiee amphibolite (Plate 4.20, Figure 4.6). Irregular veins of magnesite, amphibole needles (% anthophyllite 123 (A^ H8-IS Amphibolite fills a ; small fault plane cutting through disseminated chromitite. Iceberg (Al’Hel). mm -Am e tm m ikh .) Z8-6dike An altered pyroxenite dike vertically cutting through foliated peridotites, NE Palace (E. Zikt). 1 «.tiiiw‘R y -S ^ (C\ Z8-Shl5 Chromite bearing talc fills a shear fault tkriwTn<"^ plane cutting through chromite bearing peridotite. Sharq (S. Zikt) Z8-BScl A hand specimen exhibits massive chromitite at a sharp ft*»»'* contact with chromite- free amphibolite that forms the interstices and inclusions of the HoaJ A«ykLlik MéLUltf*. chromitite section. eH^kk. Scorpion (S. Zikt) Figure 4.6: Simplified schemes of some examples of dikes and space-GlIing bodies observed in the studied areas. The right side is the field view (except the last one), and the left side is the thin-section view without magnification. 124 Plate 4.19 (upper): Photomicrograph taken at the sharp contact between a massive chromitite and amphibolitized pyroxenite, showing amphibole/pyroxene grains occupy the interstices and inclusions of chromites, and inclusions appear to be more at the chromite margins. View Length: 2.8mm, XPL, Z8-BScl Plate 4.20 (lower): Photomicrograph taken in one Iceberg fault plane filling, showing a part of the faulted contact between the second domain (disseminated chromitite in a chain silicate matrix) and the third domain (disseminated chromitite in an olivine matrix). Note that chromites in the second domain are more coalescent than those in the other. View Length: 4.43mm, XPL, H8-I5 125 & tremolite replacing olivines & pyroxenes), some serpentine, and minor chlorite & tele, occur between the two disseminated chromitite and the fault wall. Chromites in the chromitite with the carbonate/amphibole matrix are large (up to 4mm), close packed, and completely black in color. These rocks also show a poikilitic texture with a few chromite grains enclosed in a large oikocryst of amphibole. All these phases in and around the chain silicate space-filling should imply multiple events associated with an alteration mechanism, 'fhese rocks probably formed through complex reactions at low temperature hydrothermal metamorphism during regional or local shearing. Some of these reactions that account for the observed mineral parageneses are (from Deer et al., 1993): Olivine Serpentine • 3Mg2Si04 + 4HzO + SiOa = 2Mg3Si20s(0H)4 Olivine tremolite Serpentine Diopside • 6Mg2Si04 + Ca2Mg5Sig022(0H)2 + 9H2O = 5Mg3Si20s(OH)4 + ZCaMgSiiOo Serpentine talc Magnesite • 2Mg3Si20s(0H)4 + 3CO2 -> Mg3Si40io(OH)2 + 3MgC03 + 3H2O This is supported by representative microprobe analysis (appendix) that reveals the presence of tremolite and hydromagnesite. In Sharq, several fault planes fillings are filled with small to medium chromite grains that are very similar to those found in harzburgite, set in a fine-grained talc matrix (Plate 4.21, Figure 4.6). These rocks are irregular in thickness and grade or abruptly change into fibrous serpentinites. Talc and serpentine fill all major fault zones in Sharq and form veins of variable thickness (up to ca. 2.2m). They sometimes contain chromitite fragments (Plate 3.15). 126 Thin sections from one altered pyroxenite dike, from northeast of Palace, reveals 2 types of chromites. Stretched fine-grained black fragments (Figure 4.5) that follow the elongation fabric of the rocks, and medium, subhedral black grains. The chromites occur in large pyroxene grains that altered to fine-grained amphibole and tele. Pyroxene grains reveals curved and retorted shapes, and some with exolution lamella. These dikes and fault fillings, however, do not contain significant quantities of chromite unlike tliose of the stratiform layered intrusions. 4.6 Granitic Intrusions: Felsic intrusives are common in both the mantle and crustal sequences of the Semail ophiolite (Nicolas, 1989; Lippard et al., 1986; Le Metour et al., 1990; Briqueu et al., 1991; Nicolas & Boudier et al., 1995; Nicolas et al. 1996; Searle & Cox, 1999). They are abundant in the Zikt area, and some occur in the Palace (Plates 3.10-12) and Scorpion fields (Plates 3.20-22). In Al’Hel area, they probably occur only in the gabbroic crustal section and none were observed in the peridotites in the studied areas. Thin section study shows a range from biotite granite, plagiogranite (trondhjemite), tonalité, granodiorite, and diorite. The arrangement and orientation of their mafic minerals (e.g. biotite flakes and hornblende needles) are indicating flow directions parallel to the dike walls. Alteration in the granitic intrusives is more or less restricted to the deuteric replacement of feldspars. Saussuritization (zoisite & clinozoisite after plagioclase), sericitization (sericite & kaolinite after feldspar), and uralitization (uralite, actinolite, after pyroxene) (Plate 4.22) are all observed. Although some granitic dikes contain fragments of chromitite, chromite is not a primary mineral in these rocks. This is 127 m # a . r ■ Plate 4.21 (upper): Photomicrograph in a section of talc filling fault plane space in Sharq field, viewing euhedral to subhedral small chromite grains hosted in a fine talc. View Length: 4.43mm, XPL, Z8-Shl5 Plate 4.22 (lower): Photomicrograph taken in a section of a granitic dike. Plagioclages with oscillatory zoning and albite twining dominate the view and show alteration to sericite & Kaolinite (pale gray dots) and to clinozoisite (strong blue). Mafic part is represented by biotite (yellowish brown) and hornblende (with simple twining) grains. View Length: 2.8mm, XPL, Z7-P10 128 consistent with source and origin by crustal anatexis under hydrous conditions and at low pressure (Le Metour et al., 1990; Searle & Cox, 1999) rather than as late stage residual magmas derived from the same mafic magma from which other rocks of the crustal sequence crystallized (Lippard et al., 1986). 129 CHAPTER 5 CHROMITE TEXTURAL RELATIONS 5.1 Introduction The crystallization of chromite and associated minerals produced a variety of textures in the rocks, which may reflect changes in the condition of crystallization. The influence of syn- and post-crystallization deformation also resulted in variety of textures. Jackson (1961) and Thayer (1964, 1969) were the first pioneers to describe the chromite textures. As illustrated in the previous chapter, chromite can occur as accessory phase in the mineralogy of several ultramafic and mafic rocks. These chromites are not considered here because they do not form significant chromite ores. The UAE chromites in rocks studied in this work exhibit textures that have been observed in other regions of the Semail ophiolite and in other ophiolite complexes. However, some of the textures are probably unique to the Semail ophiolite and/or to the UAE chromite ore bodies in particular. 5.2 Original Textures 5.2.1 Massive vs. Disseminated Texture These terms result from the wide variation of the ratio between chromite an olivine. The chromite/olivine ratio varies firom zero to 1, and the term chromitite is used 130 when the chromite content is > 25% (Zhou et al., 1996). Greenbaum (1977) and Roberts & Neary (1993) prefer to restrict use of the term chromitite to rocks with >51% chromitite. Differeces between the terminology used in this thesis and that used by Greenbaum (1977) and Roberts & Neary (1993) are shown below: Chromite Content This study Greenbaum (19771 and Roberts & Nearv (1993) 0-5 Dunite < 5 Dunite 6-24 Chromite bearing dunite 5-50 Chromitiferous dunite 25-39 Chromite rich dunite 51-90 Olivine chromitite 40-85 Disseminated chromitite > 90 Massive chromitite 85-100 Massive Chromitite Some rocks have distinctive textures such as bands or nodules of chromite and thus require special names such as nodular chromitite or banded chromitite respectively. A gradual change from massive to disseminated chromitite and to dunite is very common (Figure 5.1, Plates 3.7, 5.4, 5.17), but a sharp contacts between these rock types also occur (Plate 5.1). Massive chromitite consists of dense- to close-packed subhedral to euhedral, coalescing, chromite crystals of varying sizes, sometimes with pull-apart fractures and small interstices filled with olivine or serpentine (Plate 5.2). Where they exist, filled interstices usually outline the crystal faces (Plates 5.2 & 5.11), and separate individual chromite grains. The cause of this is deformation that enhances cracking through crystal boundaries. Interlocking grain boundaries may however be more affirmative to give 100% massive ore (Plate 5.2). 131 ' i ■// /.Dm Figure 5.1: A gradual change from massive chromitite to disseminated chromitite to dunite and to harzburgite. The body is assumed to be subconcordant with foliation plane and minerals are elongated subparallel to lineation. The scale of the sketch is arbitrary, because the ore body can be as small as a few centimeters and as large as tens of meters. Figure 5.2: A sketch showing a networking and branching fabric of some chromitite bodies inside dunite pockets 132 # m Plate S.l (upper): Field view of irregular impregnated bodies of massive chromitites that have a sharp contact with dimite. Palace Plate 5.2 (lower): Massive chromitite rock with few fiactures and interstices filled with mostly serpentine, and mark chromite crystals outlines (more obvious at the lower left comer). The chromitite-dunite dike in Palace. 133 Massive and disseminated chromitites in a pyroxene or amphibole matrix are uncommon and rarely found. They might be a cumulate or a distinct layer in a pyroxenite/amphibolite dikes (sample Z8-Bsl) cutting through peridotite. On the other hand, the pyroxene and/or amphibole could be secondary formed from olivine, through hydration-dehydration reactions, resulting in pyroxenite or amphibolite veins that filling fractures or fault planes (sample Z8-H5, Plate 4.6). Formation of chromite in the pyroxenite/amphibolite dikes may be similar to that of chromite in stratiform complexes (Irvine, 1967; Eales, 1987). However, the chemical analysis shows lower ferric oxide contents (chapter 6). High ferric oxide is a characteristic feature of chromitites in stratiform intrusions. 5.2.2 Branching-Networking texture This is obvious in the field and in particular at the Palace site. Discontinuous branching channels of massive chromitite form a network inside chromite-bearing dunite or chromite-rich dunite (Plate 3.13 & Figure 5.2). These massive veinlets are rootless with irregular size and dimension, and have sharp contacts with the surrounding rocks. The en echelon dike type (Leblanc & Nicolas, 1992) and breccia type (Leblanc, 1987) described from the New Caledonia ophiolite can be present in this networking texture. 5.2.3 Chromite oet-Occluded silicate texture Chromite net texture was first described by Thayer (1969), but was noted by Jackson (1961) by Greenbaum (1972) in layered intrusions. It consists of silicates with large grains (mainly olivine) surrounded by small interstitial chromite, and is attributed to crystallization and settling of large olivine grains from the magma, followed by chromite precipitation in the interstices between these grains. As in the Oman section (Brown, 134 1982), this is a very common texture in the UAE ophiolite (Plate 5.3). The texture can grade from a network of fine chromite grains between large olivines to olivines isolated in chromite, forming a chromite net & occluded silicate texture (Thayer, 1969) in the same rock. Occluded silicate texture is present in the UAE chromite (Plate 3.26) but does not necessarily grade into chromite net texture. 5.2.4 Layering-Banding texture Continuous and discontinuous chromitite layers and bands of varying thickness extend tens to hundreds of meters. Their thickness averages between 1cm to about 15cm, but thicker layers are found in Wadi-I site. The continuous layers are mainly massive chromitite in a dunite or disseminated chromitite host. Small dunite layers in a chromitite matrix are also found (Plate 3.5). Chromite layering is usually parallel to the strike of the chromitite bodies, which in turn are parallel to the dominant foliations in the peridotite (2[hou et al., 1996). Chromitite layers are clearly found in Black Sharq (Zikt) and Wadi-I (Al Hel) (Plates 3.17,3.4-3.6). The layers in Black Sharq do not appear to fully follow the general flow planes (subconcordant layers), while those in Wadi-I and Viking are parallel to the foliation directions (Figure 3.4). Concordance of the banding or layering to the foliation planes in Al’Hel is consistent with the pronounced effect of the spreading plastic flows close to the transition zone. Brown (1982) noticed that the basal edge of the chromitite layers in Oman is sharp while the layer grades upward into dunite, with concomitant reduction in chromite grain size. Similar features are observed in the UAE, but are not prevalent. The layers may grade upwards into stooping (e.g. gangue texture) then to disseminated chromitite (Plate 5.4), and they may even have sharp upper contacts 135 'U iiiuimiiiiiiiiiiiiiiiiiiuii I Plate S.3 (upper); Chromite net texture occupied the entire sample that are cut by carbonatized amphibolite vein (white) that replaced some of the olivine matrix in the rock. Iceberg Plate S3 (lower): The first sample (right) shows chromite net slightly stretched in the foliation direction. The second one (left) shows a classic antinodular texture where chromite/olivine ratio is close to one. Iceberg 136 with dunite (Plates 3.17 & 5.4). Some bands or layers are characterized by certain textures (e.g. chromite net or chain) when observed on their flat surfaces (Plate 5.5). 5.2.5 Circular texture Circles and sometimes octahedra of chromite grains connected at the crystal comers, surround olivines (Plate 5.6). This texture is similar to the chain texture that Jackson (1961) and Thayer (1969) described in stratiform chromitites, though, these workers did not clearly deflne the texture. Circular texture is well developed in banded chromitite, but also occurs in disseminated chromitite associated with massive types. It can be seen in hand specimen, but is best observed in thin section at low magniflcation (plate 5.6). 5.2.6 Gangue>Schlleren texture Many samples consist of large fragments of silicate (usually olivine) as inclusions in a matrix of uniformly disseminated or massive chromitite (Plates 5.7 & 5.8), or a chromitite fragment in a dunite host (Plate 3.7). These fragments have variable shapes (e.g. diamond, octahedron, lensoid), and sizes. The lensoidal forms are ranging from ca. 1.5cm to > 6cm long. They are probably due to the overgrowth of the mineral during and after initial precipitation. Annealation and recrystallization may be expected to be a potential cause when these exotics occur in sheared rocks, but their size and host nature do not support this interpretation. The texture probably reflects multiple injections of magma and assimilation of previous solidified melt that crystallized chromitite and dunite. 137 Plate 5.4 (upper): A vertically cut surface of a hand spedmen reveals several of layered phases: massive chromitite, disseminated chromitite, dunite, stooping (upper left and right). These may represent irregular and discontinuous rhythmic layering. Sharq. Plate 5.5 (lower): Another example of the multiple generations of layers with stooping (gangue) at the upper massive layer. The layers may include a certain texture that can be only seen in the horizontal view such as the chromite net that occur on the to top o f the sample. Sharq. 138 Plate 5.6: Photomicrograph showing the circular texture where chromite grains (black) form circles that joint at mutual junctions, in fragmented olivine matrix. Note that some grains reveal lobate and cuspate forms. View Length: 4.43mm, XPL, H8-I8. 139 Plate 5.7 (upper): Nodular chromitite (small nodules) graded into disseminated chromitite with a small dunite band, and large dunite exotic inclusion (gangue texture). Vera Plate 5.8 (lower): Massive chromitite (upper) at sharp contact with chromite rich dunite (lower), and each rock reveals a distinct texture. Pseudo-porphyry texture in the chromitite and gangue texture in the dunite. Siji. 140 5.2.7 Pseudo-porphyritic texture This fabric resembles in appearance porphyritic texture of other igneous rocks. Small to large grains of silicates (mainly serpentinized olivines) occur in a finer grained chromitite matrix (Plate 5.8). The texture is not common and is somewhat similar to occluded silicate texture, or spotted (antiorbicular) texture (Chakraborty & Chakraborty, 1984). However, the oli\ine grains are larger, less regular in shape, more variable in size, and sometimes have sharp edges, which probably indicates a different origin than occluded or spotted texture. The most likely cause of this texture is annealing of chromite grains to form a dense chromitite with relict olivine-filled vacancies. A similar interpretation has been made for discrete orthopyroxene crystals embedded within a framework of polygonal chromite grains that meet along triple junctions (Eales, 1987). The definite shapes of some olivine-filled spaces probably represent some relict crystal faces. 5.2.8 Nodular texture Nodular and orbicular textures are unique to podiform deposits (Malpas & Robinson, 1987). They were first described by Thayer (1964 &1969) who suggested that the textures and size of the nodules require a crystallizing environment that has a slower cooling rate than stratiform intrusions. Nodular texture consists of spherical to ovoid, large chromite crystals or cluster of grains in a silicate (olivine) matrix, and is believed to originate by growth in a melt pocket (Leblanc et al., 1981; Leblanc, 1987). The nodule could be a single chromite crystal, but most often is a group of crystals, and may contain a silicate core {cored nodular texture). The aggregates are coalescent rather than flattened, and may be completely interlocked forming massive nodular texture. 141 Orbicular texture is formed by precipitation of chromite nuclei, followed by crystallization of olivine shells while still suspended in magma, and then crystallization of post-cumulus chromite in the interstices (Thayer, 1969). Orbicular and cored nodular textures are much less common than massive nodular texture. Unlike the Troodos ophiolite in which orbicular texture is observed at least in one deposit (Greenbaum, 1977, Malpas & Robinson, 1987), no well-developed orbicular texture is found in the Semail chromites (Neary & Brown, 1979; Brown, 1980 & 1982). This is also true in the UAE chromites. However, a few immature or initial orbicules can be detected within some nodular textures (Plate 5.9). This may indicate genetic connection between these two textures. Massive nodular texture is frequently found in Zikt. Large nodules (“grapeshots”, Ahmed & Bilgrami, 1987) occur in Vera (Plate 5.10) and in a large altered dike in Palace (plate 5.11), but smaller nodules are found in other areas (Plates 3.7,5.7, 5.9, 5.12 & 5.17). In contrast. Iceberg (A1 Hel) chromitites are distinctly anti-nodular presenting several other textural forms, some of which are analogous to those found in stratiform chromitites (Plate 5.3). Most of the nodules show pull-apart fractures or fine interstices that frequently mark the chromite crystal outlines (Plates 5.10& 5.11). These are filled with olivine/serpentine and rarely with other silicates (e.g. pyroxene, amphibole). The mode of formation of cored nodules and orbicules is similar but the sequence of crystallization is different, because small nodules can be a nuclei of later orbicules (Thayer, 1969). If the chromite nuclei overgrow and coalesce prior to olivine shell precipitation, nodules form. If the nuclei do not grow large and coalesce prior to olivine crystallization, orbicules would form. 142 R*@* Plate 5.9 (upper); Massive chromitite graded into small nodular chromitite with chromite rich dunite layer cut in between them. The nodular part reveals several initial orbicules (dashed circles). Vera Plate 5.10 (lower); Large nodules “grapeshot” with some pull-apart fractures and interstices that outlines the chromite crystal boundaries. Note that some nodules are ill sorted (lower right) and collectively forming a massive section that grades into disseminated chromitite (right side). Vera 143 m s m Plate 5.11 (upper): Large nodules “grapeshot” with some pull-apart fractures and interstices that clearly outlines the chromite crystal boundaries. The host dunite is highly altered and serpentinized. Palace dunite-chromitite dike. Plate 5.12 (lower): A massive layer (middle) grades into small nodular chromitite that includes several immature orbicules (squares at the right half) and some cuspate and lobate forms. Palace. 144 In the case of the large “grapeshot” nodules, the model does not explain their large size and smooth rounded outlines. These nodules are probably parts of a massive layer. Massive rocks form through nucléation and cumulus growth, enhanced by inward diffusion of nutrients from a rich melt (Morse, 1980; Lee, 1981), or by compaction and annealing of grains (Reynold, 1979; Eales, 1987). Grapeshots are then mechanically separated from the layer to form fragments in the magma crystallizing dunite and/'or disseminated chromitites. The mechanical force for this may be attained by pulses of magma entering the crystallizing bodies, which disturb and distort the crystallized massive layer. This modal is supported by the association of many nodules with massive rocks (plate 5.9, 5.10, 5.12) and by the gradual change from nodular chromitite to disseminated chromitite to dunite (Plate5.17). 5.2.9 Lobate & Cuspate These textures are typical in the Bushveld stratiform chromitites, and are shown in the thin sections (Plate 5.6). They are often ascribed to corrosion, but more likely result from coalescence of small clusters of chromite grains. This interpretation is supported by observed triple junctions within the cuspate forms (Eales, 1987). These fabrics may be observed within any other textural form (Plate 5.12). 5.2.10 Inclusions Jackson (1961) described two types of inclusions in stratiform chromites, and Thayer (1969) noted the same types in Cuba podiform deposits. One consists of inclusions of olivine or plagioclase near the margins of chromite crystals. The other consists of minute crystals of pyroxene, amphibole and/or mica at the center of the chromite. Samples from all ore fields contain chromite with inclusions. However, 145 chromite from the Palace and Al’Hel fields contain abundance of inclusions of a variety minerals such as olivine, pyroxene, amphibole, mica or tele (Plate 4.18). In contrast, chromites from Black Scorpion, Black Sharq and Vera have few inclusions of dominantly olivine or serpentine. The mineral parageneses described by Jackson (1961) are present, particularly in Wadi-I and Iceberg (Al’Hel), but their occurrence in the centers or margins of the chromite are not obvious. However, the variety and number of inclusions in UAE chromites increase up-section and are probably similar to those in chromites of stratiform intrusions at or close to the transition zone. 5.3 Deformation Fabrics The behavior of rocks undergoing shearing and plastic flow depends on the mineralogy and degree of deformation. In peridotites, olivine is less resistant to shear deformation than pyroxene (Bartholomew, 1993), but chromite is more resistant than both olivine and pyroxene (Figure 4.3). Chromite (or chromitite) thus behaves as a competent unit in the rocks (El Bayoumi, 1992), and would deform ductily (able to change shape and retain that shape) only when the temperatures are high enough to cause ductile deformation (e.g. during the spreading plastic flow). Any later lower temperature deformation processes should only cause brittle deformation. High temperature plastic deformation of chromitite bodies may, however, lead to annealing and recrystallization of the chromites (Chakraborty & Chakraborty, 1984) and could yield metamorphic fabrics (Thayer, 1969). 146 5.3.1 Pillow band texture When nodular texture is affected by shearing, the chromite nodules are stretched and elongated in the direction of lineation and foliation. If the shearing is fairly extreme, it will deform and change the nodules into small discontinuous chromite pillow-like bands (Plate 5.13). An oriented fabric of the nodules may reflect a change in the mantle flow direction (e.g. vertical to horizontal, Ceuleneer, 1991) which should be expected close to the transition zone. Olivine pillow-bands also form when stretching affects originally chain/circular or chromite net textures (Plates 5.13 & 5.14). This type is very obvious in some samples of LMl 17-Siji (Plates 3.26 & 5.14), which is consistent with the position of this field near shear zone and close to the transition zone. 5.3.2 Mini-cave texture This fabric is only observed in thin sections of semi-massive or dense disseminated chromitites with relatively large interstices. When the rocks are stretched and foliated, the minerals are elongated in the foliation direction, and the chromite grains become coalescent. The interstices hence form elongated openings or caves with irregular sizes (Plate 5.15) probably party due to variations in orientation of the chromites and party due to corrosion. 5.3.3 Mini-Faulting & Foiding Faults and folds are indicative of tectonic movement. They occur on a large scale in the Held, and also occur on a small scale in hand specimens and even in a thin sections scale. Boudinage of olivine, cracking of chromite and lateral disappearance of layers over a few meters may reflect of olivine ductile and chromite brittle response to deformation (Jan & Windley, 1990). Mini- folds and faults are observed in UAE chromitite samples 147 Plate 5.13 (upper): sheared and foliated layers of massive and chromite rich dunite that originally include chromite net and circular textures. Shearing of the rock led to form chromite pillow bands (middle and upper right), and olivine pillow bands (left half). Sharq Plate 5.14 (lower); A zone of olivine pillow bands marks the lower part of this massive rock and reveals the high elevation of shearing that the rock suffer from and probably led to recrystallize chromites to smaller aggregates. Siji. 148 Plate 5.15 (upper): Photomicrograph showing the mini-cave texture in foliated massive chromitite. Chromite grains (black) were extended and coalesced at the long ends with formless shapes, keeping irregular elongated interstices (caves). View Length: 4.43mm, PPL, Z7-P41. Plate 5.16 (lower); Dunite rock consists of small chromitite layers distorted by mini-faults that led to move and transfer parts of layer materials. Sharq 149 (Plate 5.16; Plate 5.17). It is assumed that folds mainly formed during ductile flow, whereas faults mostly formed during low temperature syn- and post-emplacement deformation. However, post-solidifîcation dike intrusions may also cause small scale faulting in the rocks. 5.3.4 Sheath folds Some layered and banded chromitite bodies, present short, subconcordant to concordant folds with axial planar foliation and lineation, usually at the lateral terminations of the ore sheeted bodies (Leblanc, 1987). These are sheath folds that presumably parts of long layers or bands. Sometimes they occur as hand pliers or tongue. Some are observed in Black Sharq (Zikt) and Vera (Figure 3.13), but they are more explicit in Wadi-1 (Plates 3.4,6 & 7). 5.3.5 Pull-apart texture Pull-aparts are widespread brittle deformation textures in ophiolitic chromitites due to the large tectonic stresses that affect ophiolite rocks after solidification. Pull-apart fractures may form in individual chromite grains, nodules, and ore bodies as stresses that act perpendicular to the fracture orientations are released. Therefore, fractures are usually normal to the grain or body long axis or elongation (Plate 5.10). The occurrence of more than one set of fractures may thus indicate more than one deformation event (assuming that grains were not rotated during a single event). The fractures are filled with alteration materials, namely olivine (Plate 4.20), chrome diopside or hematite. 150 Plate 5.17: The sample showing three distinct features: I) three rock types with sharp contact: nodular chromitite, disseminated chromitite, and dunite, 2) folding of the rock types, and then 3) faulting (left side) that cut and slightly moved the fold parts. This order is also chronologically correct (All three layers were folded and then cut by the fault). 151 CHAPTER 6 GEOCHEMICAL ANALYSES 6.1 Introduction Chemical analyses have had an enormous impact on the study of chromite and associated minerals. In this chapter, the results of two types of chemical analyses will be discussed. One is whole rock analysis including major and trace elements, rare earth elements (REE), and platinum group elements (POE). The other is mineral chemistry of UAE peridotite-forming minerals, mainly including chromite, olivine, and pyroxene, which are the main rock forming minerals of harzburgites, dunites, chromitites, and pyroxenites. Amphibole, largely an alteration product, occurs in substantial amounts and is also encompassed. Other minerals are the alteration products of the main minerals, such as serpentine, talc, chlorite, carbonate, and opaques, and are briefly included in the discussion of the main minerals. The analytical techniques and procedures, methods of calculation, and the results are all given in the appendices at the end of this thesis. 152 6.2 Whole Rock Analysis 6.2.1 Major elements: The upper mantle peridotite is generally uniform in composition with slight differences between samples from the Zikt and Al’Hel areas (the increase of MgO with decreasing SiOi, and increase of Ni 0 2 .Cr2 0 3 with Mg#) (Figure 6.1-2). The low abundance of magmaphile elements (e.g., Al, Ti, Ca, Na and K, Table 6.1 & appendix) in these peridotites, compared with the suggested primordial upper mantle compositions (Sun, 1982; Taylor & McClennan, 1985; McDonough & Sun, 1995) indicates that these rocks are residues of partial melting (Lippard et al., 1986). In addition, their FeO (7-7.9 wt %) and CriOs (0.32-0.69 wt %) contents together with low concentrations of CaO, TiOz and AI2O3 is consistent with their being Cr-spinel-bearing, almost plagioclase-free, peridotites that have been depleted in “fertile” components by partial melting. The low concentrations of TiOz ( 0 -0 . 0 2 wt %) compared to the estimated upper mantle composition, are particularly diagnostic of depletion, because TiOz is an incompatible element as will be discussed later. The low CaO content reflects the absence of plagioclase and the abundance of Ca-poor pyroxene, together with forsteritic olivine in the mantle peridotites. Despite the evidence for metamorphism and deformation, the whole rock chemistry of the upper mantle rocks is consistent with division of the studied Helds into three major zones: Al’Hel, E. Zikt, and S. Zikt, based on the field and pétrographie observations. This is shown by a progressive increase of CaO, AlzOs, and V, and decrease in whole rock Mg # (100*Mg/(Mg +Fe)) and CrzOs from the S. 2ükt to E. Zikt to Al’Hel fields (Figure 6.1-2). Mg and Fe are mobile elements that can easily be 153 Harzburgite WR 47.00 46.00 - 45.00 44.00 43.00 42.00 44.00 45.00 46.00 47.00 48.00 Si02wt% Harzburgite WR 93 92.5 « 92 f 91.5 91 90.5 0.29 0.31 0.33 0.35 0.37 NiOwt% Figure 6.1: Plotting of the whole rock analysis of the Al’Hel and Zikt mantle harzburgites. The upper plot, SiOg wt % against MgO wt %, shows negative correlation. The lower plot, NiO wt % against Mg#, shows positive correlation. 154 Harzixiigite WR 2.900 2.400 m § 1.900 i g 1.400 ## 0.900 ■ 0.400 91 91.5 9290.5 92.5 93 Mg« Harzburgite WR y 0.35 ■ 0.29 0.30 0.40 0.50 0.60 0.70 Cr203 wt % Figure 6.2: Plotting of the whole rock analysis of the Al’Hel and Zikt mantle harzburgites. The upper plot is Mg # against CrjOs/AUOa, and the lower plot is CrzO] wt % against NiO wt %. Both plots show positive correlation. 155 redistributed and re-equilibrated during alteration and metamorphism. This is probably why MgO in harzburgites is somewhat higher than the average mantle peridotite value (35 wt %, Taylor & McClennan, 1985; 37.8 wt %, McDonough & Sun, 1995). The same reasoning might be used to explain the small difference in Mg # between the three major zones: Al’Hel (90.86-91.69), E. Zikt (90.3-92.05), and S. Zikt (91.3-92.4). The Al'Hel harzburgite shows higher CaO (0.79-1.11 wt %) and AI 2O3 (0.67-0.73 wt%) contents (Table 6.1-2), which reflects the presence of clinopyroxene. This is consistent with the Al’Hel upper mantle peridotite being relatively less depleted than peridotites of Zikt area. Dunites are somewhat similar in whore rock chemical compositions to the harzburgites (Table 6.1). They have slightly higher AI 2O3, NiO, Ti0 2 and Cr2 0 3 , and lower CaO and V, but almost similar Mg # values: in Al’Hel (90.3-90.7), E. Zikt (90.5- 91.7) and S. Zikt (91.04-92.77). This could indicate that dunites, like harzburgites, are residues of partial melting. There is no doubt about the residual nature of dunites and chromitites. However, whether they are residues of partial melting or are produced by fractional crystallization can not be determined from the whole-rock analysis alone, for two reasons. First, whole-rock analyses are very likely to include some alteration or oxidation compounds. Second, olivine and chromite, which form > 95 modal % of these rocks, are the earliest fractionating minerals of basaltic melts, and hence their bulk rock chemistry would be very close to that of harzburgites. This does not rule out however that there are some dunites in the mantle section, which are residues of partial melting as are the harzburgites. The majority of these dunites occur near the base of the mantle sequence (Hopson et al., 1981). The whole rock chemistry of dunites and chromites highly reflects the modal proportions of olivine and chromite (Figure 6 3-6.6). 156 AT Hel E. Zikt S. Ziikt Harzburgite Dunite Harzburgite Dunite Harzburgite Dunite AI2 0 3 0.67-0.73 0.47-0.96 0.31-0.55 0.2-0.74 0.25-0.41 0.26-0.48 Crz03 0.32-0.47 0.46-0.47 0.40-0.50 0.32-1.51 0.42-0.69 0.33-1.65 (1.95) (0.43) T1O2 0.0-0.01 0.01-0.02 0.0-0.01 0.0-0.02 0.0-0.02 0.0-0.02 NiO 0.29-0.31 0.33-0.35 0.30-0.35 0.35-0.38 0.30-0.37 0.34-0.39 CaO 0.79-1.11 0.16-0.45 0.35-0.56 0.14-0.22 0.07-0.46 0.09-0.27 (0.47) V 41-54 15-18 19-32 15-26 16-20 2-36 ppm (42) Mg# 90.86-91.69 90.3-90.7 90.3-92.05 90.5-91.7 91.3-92.4 91.04- 92.77 Table 6.1: The range of selected elements from the whole-rock analysis of harzburgite and dunite. Number in a bracket represents a sample outside the range. Al’Hel E.Z ikt S. Zikt M. Diss. M. Diss. M. Diss. Chromitite Chromitite Chromitite Chromitite Chromitite Chromitite (H9-WI2.I) (H9-WI3) (Z7-A7) (Z8-SK6) AI2O3 17.47-18.02 10.89-12.83 12.28-18.08 7.66-9.84 8.52-10.47 4.12-4.36 (31.23) (8.32) (3.80) (2.49) Cr203 25.36-27.19 15.15-19.96 38.97-45.98 16.53- 46.05- 18.74- (25.08) (7.95) 30.39 56.37 23.88 (9.65) (9.77) 1102 0.09-0.11 0.06-0.07 0.09-0.16 0.05-0.10 0.06-0.07 0.03-0.05 (0.21) (0.06) (0.05) (0.06) NiO 0.20-0.22 0.24-0.31 0.16-0.19 0.26-0.31 0.16-0.18 0.30-0.33 (0.18) (0.27) (0.36) (0.36) CaO 0.07-0.29 0.29-0.41 0.05-0.16 0.09-0.24 0.08-0.11 0.14-0.17 (1.15) (0.18) (0.18) (0.20) [H8-I2=2.29] V ppm 750-802 477-590 558-775 360-582 443-525 213-248 (786) (224) (157) (120) M g# 74.82-77.27 82.44-85.78 65.89-70.45 77.85- 70.15- 85.12- (73.82) (87.63) 85.43 71.46 87.21 (89.41) (88.82) Table 6.2: The range of selected elements from the whole-rock analysis of massive and disseminated chromitites. Number in the bracket represents a sample outside the range. 157 Chromitite & Dunite WR AATHd OE21W • S2M MgOwt% Chromitite & Dunite WR 50 45 40 35 30 25 20 15 10 5 0 15 20 25 30 35 45 50 MgOwt% Figure 6.3: Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against Zn ppm, shows negative correlation. The lower plot, MgO wt % against SiOz wt %, shows positive correlation. 158 Chromitite & Dunite WR 0.45 0.40 0.35 0.30 O z 0.25 A A AAfHti 0.20 OE^M ♦ S2itt 0.15 >—I—< 1—1—' I—r- I—I—' I—I—' 15 20 25 30 35 40 45 50 MgOwt% Chromitite & Dunite WR 900 800 700 600 I 500 > 400 300 200 100 15 20 25 30 35 40 45 50 MgOwt% Figure 6.4: Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against NiO wt %, shows positive correlation. The lower plot, MgO wt % against V ppm, shows negative correlation. 159 Chromitite & Dunite WR 60 50 AATHtl o ♦ 0E2W ♦ SZiKt ^ 40 Oo i ” a 20 10 0 r f I f ' f f 1 >■ I ^ ' I 15 20 25 30 35 40 45 50 MgO wt% Chromitite & Dunite WR 35 30 AATHU OE2iM ♦ S2itt 5 20 I 15 A A 4 ^ 10 o 5 0 I I • 15 20 25 30 35 40 45 50 MgOwt% Figure 6.5: Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against CrzO] wt %, shows negative correlation. The lower plot, MgO wt % against AI 2O3 wt %, also shows negative correlation that is more clear in Al’Hel than Zikt. 160 Chromitite & Dunite WR 0.45 0.40 0.35 0.30 0.25 9 0.20 0.15 0.10 0.05 15 20 25 30 35 40 45 50 MgOwt% Chromitite & Dunite WR 0.25 AAThM 0.20 OEZM eS2ikt ^ 0.15 a Ô 0.10 A o • e A A A e 0.05 o 0.00 I I I 1 I I I I I * I I I I I 15 20 25 30 35 40 45 50 MgOwt% Figure 6.6: Plotting of the whole rock analysis of dunites and chromitites. The upper plot, MgO wt % against MnO wt %, shows negative correlation. The lower plot, MgO wt % against TiOz wt %, also shows negative correlation. 161 Geochemical differences between dunite and harzburgite reflect the presence of minerals such as pyroxene in the harzburgites. The whole-rock chemistry of chromitite also reflects differences between the three major fields in terms of massive or disseminated chromitites. Table 6.2 shows the ranges of composition of these rocks in the three fields, and detailed analyses are given in the appendix. The chemical compositions clearly reflect variations in the ratio of chromite to olivine in these rocks of all fields (Figure 6.3-6.6). The CaO contents reflect traces of amphiboles. However, some samples from Al’Hel have high CaO. For example, samples H9-W12.1 and H8-I2 contain 1.15 and 2.29 wt % CaO, respectively. This may indicate the occurrence of some clinopyroxene in these samples, and this is consistent with petrography and mineral chemistry. 6.2.2 Trace Elements: Incompatible trace elements (large ion lithophile elements or IJI.R and high-field strength elements or HFSE) in the upper mantle rocks are normalized to Cl-Chondrite values from Taylor and McClennan (1985). This group of elements should be much less abundant in the residua of partial melting and in the early products of a fractionating magma. Incompatible elements occur in very low concentrations in these types of rocks and thus susceptible to analytical errors. The Harzburgites are depleted relative to chondrite in all elements except Th, Nd and Zr (Figure 6.7). Alteration may have affected the concentrations of some mobile elements (e.g. Ba and Sr), but other highly mobile elements such as K and Rb (Wood et al., 1979; Cox et al., 1979; Pearce, 1982) are present in very low concentrations. The 162 immobile elements do generally show regular variations relative chondrites. Accordingly, although the observed element abundances in the upper mantle peridotites may reveal the effect of alteration, they still preserve some original geochemical characteristics. Chondrite-normalized patterns should reflect different distribution coefficients for different elements if controlled solely by melt extraction. In other words, the effects of melt extraction of incompatible element abundances during anatexis will differ from one element to another but will vary systematically. This is not the case for the UAE peridotites. Elements such as Ba and Th are enriched in a subduction related melt (Wilson, 1994). Therefore, the observed enrichment of elements such as Ba Th, Nd and Zr (Figure 6.7) relative to other elements and to chondrites probably reflects metasomatism of the peridotite by hydrous magmas generated in a subduction zone environment. The incompatible elements in dunites and chromitites show slight enrichment relative to harzburgites (Figures 6.8 & 6.9). The geochemistry of magmatic rocks in the crustal sequence is controlled by the amount of trapped intercumulus liquid within the rocks (Saunders et al., 1979; Vetter and Stakes, 1990). Hence the abundances of LILE trace elements in gabbros, for example, are lower than those in basalts. In the case of dunites and chromitites, the intercumulus melt is almost absent or more difficult to identify as these rocks are very early crystal precipitates from rising magma, and thus their geochemical characteristics are very close to those of residues. However, a few important magmatic signatures can still be identified from the incompatible element geochemistry of dunites and chromitites. First, these rocks are characterized by a positive Ti anomaly (except 3 samples in Zikt). This is a very important indicator of the magmatic 163 Incompatible Elements of Harzburgites -H9-WI6 -H8-WI3 -Z7-P20 I -Z7-P31 1 ^ -Z7.P47 5 0.1 J -Z9-P6 -Z8-Sh2 X -29^7 0.01 -ZB-ScS 0.001 Ba Rb Th K Nb Ta La Ca Sr Nb P Sm Zr Hf TI Tb Y Tm Yb Figuré 6.7: Chondrite normalized incompatible trace element patterns of the mantle harzburgites in the studied fields. 164 Incompatible Elements of Al'Hel Chromitites 100 -H8-W I1B -H 9-W I2 -H 9-I2 -H8-I1 -H 8-I2 -H8-I8 -H8-17 -H 8-I12 0.001 Ba Rt> Th K Nb T» U C« Sr Nd P Sm Zr Ht TI Tb Y Tm Yb Incompatible Elements of Al'Hel Dunites 10 •H9-W I3 I -H8-W I1A I -H9-W I4 0.01 0.001 Ba Rb Th K Nb Ta La Ca S r Nd P Stn Zr Hf Ti Tb Y Tm Yb Figure 6.8: Chondrite normalized incompatible trace element patterns of the Al’Hel chromitites (upper) and dunites (lower). 165 Incompatible Elements of Zikt Chromitites 100 Z7-P39 o Z9-P4 O' 0.01 0.001 Ba Rb Th K Nb Ta La Ca Sr Nd P Sm Zr Hf TI Tb Y Tm Yb Incompatible Elements of Zikt Dunites ZT■P^T Z7-P37 Z7-P23 Z7-P14A Z 7 f 2 9 Z7-P30 Î Z9-P5 ZB-Sh6 ZB-Sh4 ZB-Sh9 0.01 ZS-Sti10 ZB^hia Z8-Stl14 Z8-Sh16 0.001 Z8-Sh18 Ba Rb Th K Nb Ta La Ca Sr Nd P Sm Zr Hf Tt Tb Y Tm Yb Z9-Sh3 Figure 6.9; Chondrite normalized incompatible trace element patterns of the Zikt chromitites (upper) and dunites (lower). 166 origin of these rocks, because this anomaly is not observed in harzburgite residues. Ti is can readily enter the structures of orthopyroxene and spinel (Eggins et al, 1998). It might be argued that the positive Ti anomaly reflects the modal proportion of spinel and orthopyroxene in these rocks. In fact, the three samples from Zikt (Figure 6.9) that show depletion in Ti are lack of orthopyroxene and spinel. However, harzburgite should have higher Ti content than dunite with a similar chromite/silicate ratio, because harzburgite by definition contains more orthopyroxene than dunite. Second, enrichment in some LILE is characteristic of hydrous magmas generated above subducted slabs (Cox et al., 1979; Pearce, 1982). For example, Ba concentrations are a sensitive indicator for sediment subduction at Benioff zones (Wilson, 1994). However, subduction-related magmas commonly show negative Nb anomalies and these are not observed the dunites and chromitites. This could indicate interaction of a rising hydrous magma with wall rocks, and extraction of Nb from the latter. Note that Nb can enter the structure of amphiboles (Deer et al 1993). Third, Al’Hel dunites and chromitites show greater enrichment in Sr (Figure 6.8) than do those of Zikt (Figure 6.9). Alteration might be the cause of this, but a more likely cause is the presence of clinopyroxene in the Al’Hel rocks (Mason & Moore, 1982; Eggins et al, 1998) and this is consistent with petrography. 6.2.3 Rare Earth Elements (REE) REE concentrations in upper mantle peridotites from all areas are depleted relative to chondrite, and are slightly more depleted in the middle REE than light REE (LREE) and heavy REE (HREE) (Figure 6.10). This V shaped pattern is similar to that 167 observed for rocks from other Semai I ophiolite sections and from other ophiolite complexes (Lippard et al., 1986). No common mantle phases (e.g. olivine, pyroxene, garnet, spinel) concentrate LREE relative to HREE (Wilson, 1994). Therefore, the slight enrichment of LREE relative to HREE is probably inherited from the fertile parent rocks of the harzburgites. In addition, the slight enrichment in LREE relative to HREE, exhibited by most harzburgites (Figure 6.10) is evidence that the harzburgites of the studied field areas are depleted residues of spinel Iherzolite rather than garnet Iherzolite. REE patterns of dunites and chromitites from ATHel and Zikt are quite different, and generally massive chromitites are slightly more enriched in REE than disseminated chromitites and dunites. REE patterns for Al’Hel chromitites and dunites are similar to those observed for harzburgites (Figure 6.11). REE patterns for Zikt chromitites and dunites (both east and south fields) show a distinct enrichment in LREE relative to HREE. The REE contents of most dunite and chromitite samples are lower than those of chondrite, but the least altered massive chromitites (e.g. Z9-P3 & Z9-Sc6) and some dunites (e.g. Z9-P5) from Zikt have higher LREE abundances than chondrites (Figure 6.12). This is another possible indication of involvement of a subduction related hydrous melt in the genesis of these rocks. Several dunite samples in Zikt and Al’Hel show a positive Eu anomaly (Figure 6.12). A positive Eu anomaly is usually strong evidence for cumululus plagioclase or other Sr-bearing minerals (Mason & Moore, 1982). However, thin section study did not reveal the presence feldspar in these rocks; although, it is possible that there are small amounts of altered plagioclase that were not observed in the thin sections. On the other hand, the Eu anomalies may be an artifact of the low Eu concentrations in these rocks 168 Harzburgite REE H8-W13 A — H9-WI6 Z7-P20 27-P31 Z7-P47 Z9-P6 0.001 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Figure 6.10: Chondrite normalized REE patterns of the mantle harzburgites from the studied fields, showing concave shape. The first two samples from Al’Hel and the rest from Zikt. 169 REEs of Ai' He! Chromitite •H8-WI1B a ! 1 •H9-WI2 ■H9-I2 I ■H8-I1 ‘H8-I2 ■H8-I8.2 •H8-I7 -H8-I12 0.01 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu REEs of Al'Hel Dunite I ?o 6 •H9-WI3 •H8-WI1A ■H9-WI4 0.01 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Figure 6.11: Chondrite normalized REE patterns of the Al’Hel chromitites (upper) and dunites (lower). 170 REEs of Zikt Chromitite -Z7-P48 ■Z9-P3 -Z7-P36 •Z7-P39 •Z7-P19 I -Z9-P4 -Z9-Sc6 -Z9-St\1 -Z9-SC9 ■Z8-Sh8 0.01 La Ce Pr Nd Sm Eu Gd Tb Ho Er Tm Yb Lu REEs of Zikt Dunite 10 T — Z7-P17 — Z7.P37 — * - Z 7 . P 2 3 — A — Z 7 f 1 4 A — Z7f29 — Z74>30 - e —Z S f S ■ Z8.Sh6 “ ZS.Sh4 — Z8.Sh9 — Z8.Sh10 — Z8.Sh13 1 Z8.Sh14 ■ Z8.Sh16 — ZMhia 0.001 — Z9.Sh3 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Figure 6.12: Chondrite normalized REE patterns of the Zikt chromitites (upper) and dunites (lower). Note the enrichment of LREE relative to HREE. 171 that are near the detection limit (0.01 ± 0.01) of the techniques used. Thus the Eu data are probably meaningless. In summary, REE and LILE geochemical characteristics illustrate several important points. First, chromites and dunites are early precipitates from magmas. Second, the magma from which Zikt dunites and chromitites formed is probably different from that from which Al’Hel dunites and chromitites formed. Third, magma from which these rocks formed might have been derived from different sources than the host Semai 1 harzburgite. Forth, these magmas should have originated in a subduction-related environment. 6.2.4 Platinum Group Elements (PGE) Harzburgites reveal an almost unfractionated PGE pattern similar to that found for other ophiolites (Figure 6.13). Sample H9-WI6 from Al’Hel shows slight enrichment in Pd and Au. A similar enrichment occurs in Iherzolites of the Zabargad ophiolite (Zhou et al., 1996) and in wehrlites of the Shetland ophiolite (Prichard & Lord, 1993), and is thus consistent with the less depleted nature of Al’Hel peridotites. The few dunites analyzed have similar PGE concentrations to those of the harzburgites, and this is consistent with their being very early precipitates from magmas and their very low chromite/silicate ratio (Figure 6.14). In particular, sample Z8-Sh9 shows chondrite-normalized PGE patterns similar to those of dunite lenses in the Shetland harzburgite; the latter are chromite- poor crystal precipitates (Prichard & Lord, 1993). Chromitites exhibit PGE patterns typical for those of podiform or ophiolitic chromitites and are different from those of stratiform chromitites in the Stillwater, 172 PGE of Harzburgites 'OI H9-W16 I 0.01 I 0.001 Figure 6.13: Chondrite normalized PGE patterns of some mantle harzburgites from Al’Hel and Zikt, show high depleted PGE concentrations relative to chondrites. PGE of Dunites 0.1 0.01 H9-WI4 Z8-Sh9 0.001 0.0001 Os Ir Ru Rh Pt Pd Au Figure 6.14: Chondrite normalized PGE patterns of some analyzed dunites from Al’Hel and Zikt, show high depleted PGE concentrations relative to chondrites. 173 Bushveld, Sudbury and other intrusions. The chromitites are enriched in Os, Ir, and Ru relative to Rh, Pt, Pd and Au (Figure 6.15). Similar patterns characterize chromitites from the southern part of the Semail ophiolite (Page et al., 1982a ; Leblanc, 1991), and from other ophiolites such as New Caledonia (Page et al., 1982b), Newfoundland (Page & Talkington, 1984), Shetland (Prichard & Lord, 1993), and Luobusa (Zhou et al., 1994). The contrasting behavior of PGE elements in podiform and stratiform chromitites poses a major challenge for interpretation the behavior of these elements. Page et al. (1982b) suggested three possible explanations. 1) The ophiolitic chromitites represent mantle rocks depleted in Pt and Pd. 2) The magmas that played a role in the formation of ophiolites were depleted in Pt and Pd. 3) The process of chromitite formation from magmas involved the concentration of Os and Ir. Page et al. (1982a) found that there is no correlation between PGE concentration and the compositions and abundance of coexisting chromite and silicates in the host rocks. They thus suggested concentration of PGE in a discrete sulfide or alloy phase. Barnes et al. (1985) emphasized that the main factor controlling PGE fractionation is their solubility (or the melting point), which generally increases from Os to Au (i.e. the order shown in Figures 6.13-6.15). They noted that mantle peridotites have unfractionated PGE patterns, while both continental and ocean-floor basalts have fractionated PGE patterns. They suggested that the low solubility of Os, Ir & Ru in magmas leads to the formation of Os-Ir alloys and RuS prior to Fe-Ni-Cr sulfide saturation. Lorand (1988) attributed the presence of sulfides in mantle rocks to metasomatism involving magmas originating from deeper parts of the mantle, and become trapped at the top of the mantle diapir. He added that primary 174 PGE of Chromitites -H9-W I2 -Z9-P3 •Z7-P48 ■29-Sh1 » 0.1 - 'C ■Z9-SC4 E -Z9-SC6 -H9-W I3 - A — H8-I2 H8-I7 I 0.01 - e — Z9-P4 0 Z8-Sh8 Z9-Sc9 — H9-I2 0.001 Os Ir Ru Rh PtPd Au Figure 6.15: Chondrite normalized PGE patterns of chromitites from Al’Hel and Zikt. Note the high enrichment in Os, Ir and Ru relative to Pt, Pd and Au. 175 sulfides that occur as inclusions in Cr-spinels are resistant to low-temperature metamorphism. In the present study, massive chromitite samples that have the highest enrichment of Os, Ir & Ru (e.g. Z9-Shl, Z9-P3, Z9-Sc6) (Figure 6.15) contain both chromite and olivine with high Cr and Ni contents respectively relative to other coexisting rocks (see latter discussion of chromite and olivine chemistry). In addition, these rocks are generally enriched in the REE (Figure 6.12), so that the origin of PGE concentration and Cr & Ni contents in chromtites appears to be linked, and related to magmas originating from different sources. The melts were probably modified by subduction fluid phase, and interaction with wall rocks during ascent. The melt interaction with the wall rocks would decrease the Fe content of the melt by buffering the Mg content of the peridotite host (Kelemen, 1990). Decreasing Fe content of melt would in turn cause sulfide precipitation (Lorand, 1988), and may lead to Os, Ir & Ru enrichment, particularly that silica content of the melt will increase due to pyroxene dissolution (Kelemen et al., 1990, 1992), and thus the viscosity of the melt will increase. 6.3 The Mineral Chemistry 6.3.1 Chromite Chromite is a member of the spinel group that consists of 32 oxygens and 24 cations in the unit cell. Spinels have the simplified formula: X^*(X^^z 0 4 . The main divalent ions (X^3 in chromite formula are Fe^* and Mg^^ and the major trivalent ions (X^^) are Cr^* and Al^"^ with some Fe^^. Thus C r# [Cr ♦IOO/(Cr+AI)] and Mg # [Mg* 100/(Mg+Fetotal)] ratios represent the principal compositional variations of 176 chromites. Substitution by other elements such as Ti'*^ Mn^^, Ni^, and are also expected, but these are generally minor. Consequently, the correct chromite formula should be written as: (Fe""^, Mg^^)(Cr^^. Fe^^) 2 0 4 , and as noted by Fisher (1929) (Chapter 1), pure chromite (Fe^*Crz 0 4 ) may only occur in meteorites. Chromites in the rocks studied span a wide spectrum from aluminum rich at Al’Hel, in the uppermost part of the Semail mantle sequence, to chromium rich at S. Zikt, deeper in the sequence (Figure 6 .1 6 ). The range of composition in term of Cr/Al ratio varies with locality as follow; Wadi-I(Al’Hel)—> Viking (Al'Hel)—> Iceberg (Al’Helj/LMlI? (Siji)—> Palace (EZikt)—> Sharq (S. Zikt)—> Vera (N. Zikt)—> Scorpion (S. Zikt) In harzburgite, this trend is very consistent with the reciprocal variations between Cr^O] and AI1O3 with pressure and depth (Irvine, 1967; Brown, 1980; Dick & Sullen, 1984; Ahmed, 1984; Ahmed & Bilgami, 1987). CrzO] increases and AI 2O3 decreases with increasing depth from the transition zone to deeper in the mantle sequence. MgO and FeO also show an identical reciprocal variation. This wide range in MgO, FeO, Cr 2 0 3 and AI2O3 is likely related to the different degree of depletion in the mantle sequence. In magmatically precipitated bodies, the higher Cr 2 0 3 /Al2Û3 ratios in chromite indicate higher Cr/Al ratios in the precipitating magma, and/or of a reaction between Cr-spinels and intercumulus liquid. The crystal-liquid reactions could decrease the ratio if the melt poor in Cr relative to the crystals, or increase the ratio by peritectic reaction (Irvine, 1967). It likely that the Cr/Al ratio is not just an intrinsic feature of the magma, but is affected by other factor(s) such as the magma interaction with the wall rocks. The 177 UAE Chromites 80 75 70 -i lAShChrom. jeScChrom. 65 iQVera ixShHarzb. 60 4 OScOunite lOScHarzb. >P I 55 ^XlceChrom. |b WI Chrom. m 50 ■ QWI Dunite O «WI Harz 4 Viking S 45 O SijiChrom. 40 ■ SijiDunite !OCrH94Perid {+PalChrom. 35 •PalDunite lAPaiHarzb. 30 !*Pxtdike 25 4 20 > I ' I I I I r t-M t I M I I 11 14 17 20 23 26 29 32 AI203 wt % Figure 6.16: Plotting of AI 2O3 wt % against CrzO] wt % of chromite in the rocks of Al’Hel, E. Zikt and S. Zikt. More than 1330 analyzed points. Wadi-I (Al’Hel) is the highest in Al, while B. Scorpion (S. Zikt) is the highest in Cr. The prefîxes in the legend: WI, Wadi-I; Ice, Iceberg; Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite; CrH94Perid, Al’Hel harzburgites. 178 chemistry of chromite is thus consistent with field observations, and three major fields can be clearly chemically distinguished: Al’Hel, E. Zikt, and S. Zikt. 6.3.1.1 Al’Hel Chromite Al’Hel (Hayl) field is located directly below the mantle-crust transition zone and three of its sites are studied: Wadi-I, Viking & Iceberg. LMl 17, the only representative here of Siji localities, is chemically similar to Iceberg, and is thus included here with Al’Hel. Generally, chromite in Al’Hel chromitites and dunites have higher AI 2O3, MgO, NiO, TiOi and FeiQs content, and lower CriO], FeO and MnO contents than those of Zikt (Table 6.3). Accordingly, the chromites have lower Cr# and higher Mg # in Al’Hel sites (and LMl 17-Siji), and all plot within the Alpine peridotite field (Leblanc et al., 1980; Leblanc, 1987; Leblanc & Nicolas, 1992) on the base of Irvine’s(1965,1967) compositional prism (Figure 6.17). Cr# increases from Wadi-I (46-50) to Viking (52- 54.5) to Iceberg (54.1-59) and LMl 17 (54.5-57.5). Chromites from Wadi-I are the richest in AI2O3 of all UAE ore localities, reaching (27.3-29.8 wt %), and the lowest in Cr 2 0 3 (38-41 wt %). Chromites from the other three sites have a narrow range of AI 2O3 (21.3- 25.8 wt %), but there is an increase in Cr 2 0 3 from Wadi-I to Viking to LMl 17 & Iceberg where Cr2 0 3 reaches 48 wt % (Figure 6.18). MgO/FeO shows a similar trend and the data form a linear array in a plot of MgO versus FeO (Figure 6.19). Ferrous iron in chromite of Al’Hel chromitites (including LMl 17) ranges between 11.3-16.3 wt %, but in one sample (Z8-I5) from Iceberg FeO reaches 20.9 wt %. This sample was collected at the margin of an amphibolite vein filling small fault plane (Figure 4.6). This section was therefore prepared to include I. chromite free amphibolite, 179 Iceberg Wadi I Viking LMl 17 H94 Perid chromil te AI2O3 22-25.5 27.3-29.8 21.3-25.8 22.2-24 TiO: 0.01-0.56 0.08-0.24 0.08-0.24 0.22-0.39 CriOi 42-48 38-41 41.2-44.5 43-46 FeiOj 0-5.9 OJ-4.2 2J-5.4 0.7-5.1 FeO 11.5-21 11.3-14.8 11.7-15.3 11.6-16.3 MnO 0.12-0.61 0.15-0.44 037-0.53 0.36-034 MgO 9.5-15.4 13.8-16.2 13.5-15.4 12.3-15 NiO 0-0.22 0.12-0.27 0.04-0.24 0-0.25 C r# 54-59 46-50 (46.5-47.5) 52-543 54.5-573 M g# 44.5-65 (55-65) 58.1-67 (59.3-67) 573-633 56.5-623 Dunite AI2O3 21.1-29.5 22.2-23.7 Ti02 0.18-0.59 0.23-0.34 Cf20, 36.6-42.6 43.5-45 Fe20] 3.9-5.6 3.2-4.5 FeO 14-17.5 13.5-15.2 MnO 0.18-0.31 0.41-031 MgO 11.4-14.5 13-14 NiO 0.09-0.18 0.12-0.26 Cr# 56.2-59.6 55.5-57.7 M g# 44-47.5 56.4-59.3 Harzburgite AI2O3 18.2-21.8 8.3-30.5 (20-30) TiO, 0.02-0.1 0-0.12 (0.0-0.07) CriO, 44.6-49 35.77-48.2 FejO, 2.3-4.3 0.0-18.3 (0.77-5.5) FeO 16.2-18.2 11.66-27.4 ( 11.66-20.66) MnO 0.17-0.57 0.4-1.14 (0.4-0.76) MgO 10.5-13.6 4.22-153 (9-153) NiO 0.03-0.14 0.0-0.2 (0-03) C r# 58-64.3 44-78 (44-62) M g# 47-53 17-64.6 (40-64.6) V2O3 0.07-035 (0.16-0.29) Table 6.3: The range of oxide values of chromite analyses in all rock types of Al’Hel fields (& LMl 17 of Siji). Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix. 180 X IceChrom • WIChrom O Viking 4 SijiChrom XWIDunite • WIHatzb. 4 SijiDunite O H94Perid Figure 6.17: Plotting of Mg # against C r# of chromite from Al’Hel rocks. Most analyses plot in the ophiolite field of Leblanc (1987) and Leblanc & Nicolas (1992), but outside the abyssal peridotite field of Dick & Bullen (1984). Legend prefixes are the same as in figure 6.16. 181 ♦WI Chrom. O Viking ♦ SijiChrom. X IceChrom. XWI Dunite • WIHarz ♦SijiDunite OH94Perid 21 23 25 AJ203 wt % Figure 6.18: Plotting of AI 2O3 wt % against CrjOa wt % of chromite from Al’Hel rocks. The plotting forms negative correlation. Legend prefixes are the same as in figure 6.16. ♦ SijiDunite OH94Perid ♦ Wi Chrom. O Viking A SijiChrom. X IceChrom. XWI Dunite ♦ WIHarz FeO wt % Figure 6.19: Plotting of FeO wt % against MgO wt % of chromite from Al’Hel rocks. The plotting forms linear negative correlation. Legend prefixes are the same as in figure 6.16. 182 2 . disseminated chromitite in amphibole/carbonate/serpentine matrix, and 3. disseminated chromitite in serpentinized olivine matrix (chapter 4, section 4.5). Chromite grains with high FeO values probably reflect replacement of olivines and subsolidus exchange of Mg and Fe between chromites and low-temperature silicates (Irvine, 1965,1967). Chromite from dunite of Wadi-I contains slightly higher FeO (14-17.5 wt %) than samples from LMl 17 (13.5-15.2 wt %). This may not, however, be significant given the limitation of LMl 17 dunite samples. Ferric iron (FezOs) in chromium spinel is the product of oxidation, and is considered a major cause of error in mineral chemical analysis by EPMA. However, FezOz usually occurs in a negligible amount, and is therefore calculated from total iron making the assumption that chromite has an ideal formula (appendix). FeiOz contents of chromite in Al’Hel rocks are relatively higher of than those in Zikt rocks. FeiOg of chromite in the Al’Hel sites shows only small variation among them, and ranges between 0 to 5.9 wt %. It reaches the highest in chromites from Iceberg, which is consistent with the brittle and more altered appearance of the Iceberg chromitites, and with evidence (in chapter 3, section 3.2.1) for influx of water via fractures below the transition zone. Ti is a transition element and one of the high-field strength elements (Zr, Hf, Ti, P, Nb, Ta) that have small ionic radii and high charge and therefore low radius/charge ratios. These elements are immobile during low temperature alteration and metamorphism (Saunders et al., 1979). Ti unlike the compatible transition metals (e.g. Cr, Ni, Co) is incompatible and preferentially enters the melt phase during partial melting and fractional crystallization (John, 1982; Hickey & Frey, 1982). On the other hand V occurs in three valence states: V** and in terrestrial rocks, and its geochemical 183 behaviors depends on the oxygen fugacity (fOi) of the melt (Lindstrom, 1976; John, 1982; Eggins et al., 1998). At low/Oz, partitions into the residual solids, and hence substitutes for other trivalent ions in spinel and pyroxene. In contrast, at high 7O2, activity y4+, y5+ prevalent and acting as high-field strength elements similar to titanium (John, 1982), and thus vanadium partitions into the liquid phase. The Ti, V, and Ni contents of chromite in Al’Hel chromitite and dunite are greater than those of chromite in Zikt chromitite and dunite (Table 6.3, Figure 6.20). This is suggesting that melts from which the Al’Hel chromites precipitated were compositionally different from which the Zikt chromites crystallized. Accessory chromites in Al’Hel mantle peridotites show range of Cr# (44-78) that correlates inversely with Mg #, as expected (Figure 6.21). These chromites plot in the Alpine peridotite field of Leblanc et al. (1980) and Leblanc (1987), and not in the abyssal spinel peridotite field of Dick & Fisher (1983) and Dick and Bullen (1984) (Figure 6.17). A few chromite analyses in the peridotite, however, have very low Mg # (up to 17.1). Chromite in harzburgites usually have a restricted range of Mg # (Leblanc & Nicolas, 1992; Zhou et al., 1996), but the Mg # of chromite depends upon the proportion of silicates in the rock (Dick & Bullen, 1984; Zhou et al., 1996). Those analyses with very low Mg # are low in MgO and AI 2O3 but high in FeO, FezO] and MnO (Figures 6.17-21). The immobile trace transition metal (Ni, Ti, V) contents show a large variation, but do not correlate with MgO (exhibit no clear associated change). This implies that the low Mg # of some chromites in Al’Hel peridotites is not original (or primary). Rather, it is most likely the result of alteration causing solubility and mobility of the mobile ions (e.g. Mg, Al, Fe and Mn) in open system replacement reactions. 184 Chromite is an important host for Ti and V in upper mantle peridotite. Nonetheless, Ti is very low in the refractory harzburgite (Zhou et al., 1996) and has reciprocal correlation with the partial melting and depletion. This may be controlled by the following factors: (1) the small radius/charge ratio of Ti may enhance its partitioning into orthopyroxene (McDonough et al., 1992), but the partition coefficient of Ti between ortho- and cli no-pyroxene ( 0 “"'“^*=*'"“) is lower in spinel peridotite than garnet peridotite (Eggins et al., 1998), which in turn implies (2) removal of Ti by magmatic liquid during partial melting process. is the prevalent form of vanadium in upper mantle peridotites, and behaves as a compatible element during partial melting and fractional crystallization, as does Ni. TiO? contents of chromite in most Al’Hel harzburgites plots in the depleted oceanic harzburgite field of Jan & Windley (1990) (Figure 6.20), but chromites in Al’Hel peridotites have slightly higher TiOz contents (0-0.12 wt %) than chromites in Zikt peridotites (E. Zikt: 0-0.11 wt %, SW. Zikt: 0-0.095 wt %). This is consistent with pétrographie evidence (chapter 4) that Al’Hel peridotites are less depleted than Zikt peridotites (N-S Zikt in particular). V 2O3 shows a fairly wide range of concentration (0.07 - 0.35 wt %) in chromites from the Al’Hel mantle peridotites, but is generally lower than the concentration of V 2O3 (~ 0.37 wt %) of chromite from Zikt. NiO is unexpectedly slightly higher in Al’Hel chromites (up to 0.2 wt %) than Zikt chromites. This may reflect the effect of subsolidus re-equilibration (see later). 6.3.1.2 E. Zikt (Palace) Chromite The Palace field is the closest one to the transition zone after Al’Hel (about 1 km below the transition zone) (Figure 3.1 & 3.2), and form a second chemically distinctive 185 80 75 70 S 65 60 so o o o o 8 45 40 Highly depleted Depleted harzburgite 35 harzburgite 30 0.001 0.01 0.1 Ti02wt% Figure 6.20: Plotting of TiOi wt % against Cr # of chromite from Al’Hel rocks. Harzburgites are mostly plotted in the depleted field of Jan & Windley (1990). Legend is the same as in figure 6.18. AI203 Figure 6.21: Plotting of AI 2O3 wt % against MgO wt % of chromite from Al’Hel rocks. Legend is the same as in figure 6.18. 186 zone. The chromite in Palace chromitites and dunites is clearly intermediate in composition to that of Al’Hel and S Zikt chromites (Figure 6.1), This is illustrated in almost all elements, but most manifested in the values of Cr # and Mg # of the chromites. Ranges of compositions of chromites in Palace rocks are given in Table 6.4 and for the complete set of analyses refer to appendix C. Cr# ranges from 65.8 to 79.5) in chromitite and from 62 to 82.5 in dunite, whereas Mg # ranges from 48 to 69 in chromitite and from 42 to 61 in dunite. The higher Cr # and lower Mg # of chromites in dunite than chromitite is ascribed to the abundance of silicates (olivine, serpentine, chlorite, and some pyroxene) in dunite relative to chromitite. All these minerals contain Mg and can preferentially exchange Fe and Mg with spinel, which causes a decrease in the Mg # of chromite in dunite. Furthermore, partitioning of Al between these silicates (except olivine), spinel, and any melt, should reduce the Al contents of chromium spinels of dunite. In silicate melts, AI2O3 content (ca. 9-15 wt %) is much greater than the Cr content (ca. 200- lOOOppm) (Malpas et al., 1997; Ballhaus, 1998), so that partitioning of Al into silicates, mainly chlorite and serpentine (O’Hanley, 1996), should not strongly affect the Cr # of chromite. However, Al strongly fractionates into the melt phase whereas Cr partitions into the solid phase, during partial melting and fractional crystallization (Dick & Bullen, 1984). Therefore only small amount of Al would participate in the formation of these earlier phases, and thus formation of silicates will reduce the availability of Al for chromium spinel. This in turn will lead to an increase of Cr^* in chromium spinel, and hence an increase in the Cr # of chromite in dunite. This is with the control that pyroxene and chlorite may also admit some Cr 187 Chromitite Dunite Harburgite Pyroxenite (Z7-6dike) A1203 10.3-18.3 8.5-20 (11.5-20) 11.4-28.3 7.2-10.2 w/o Z7-29A TiO: 0.018-0.288 0.013-0.27 0-0.11 0-0.08 CrzO: 52.4-59.2 47.5-61.5(47.5-58) 42.2-57.2 58.3-62 w/o Z7-29A FeiO] 0-4.3 (0-3.4) 0-6.2 (0.3-5.4) 0-6.2 (0-4.1) 0-2.8 FeO 10.7-16 13.2-19.3 133-21.5 21-24.7 MnO 0.15-1 (0.43-0.94) 0.23-0.97 (0.48-0.97) 0.43-1.06 0.35-0.85 MgO 11-15.2 9.3-13.4 7.8-14 5-7.5 NiO 0-0.243 0-0.19 0-0.17 0-0.108 C r# 65.8-79.5 62-82.5(62-77) 50-77.3 793-86 w/o Z7-29A Mg # 48-69 42-61 38-62.6 26-38 Table 6.4: The range of oxide values of chromite analyses In all rock types of Palace field (E. Zikt) and pyroxenite dikes (ME of Palace). Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix. 188 Palace chromites in general have higher CrzOs, Cr#, FeO and MnO, and lower AI2O3, Mg #, MgO, V 2O3, NiO and TiOz contents than Al’Hel chromites. Chromite in chromitites and dunite have higher Crz 0 3 (47.5-61.5 wt % vs. 42.2-57.2 wt %) & TiOz (0.013-0.288 wt % vs. 0-0.11 wt %) and lower AlzOz (8.5-20 wt % vs. 11.4-28.3 wt %) & FeO (10.7-19.3 wt % vs. 13.5-21.5) than chromites in mantle peridotites. The CrzOz, AI2O3, MgO and FeO ranges of chromite in E. Zikt mantle peridotite is however expected to extend greater than that in the analyzed samples, because these samples are more localized (were collected within the Palace ore-site area). This is made clear when chromites from other Zikt peridotites are plotted along with those of Palace (Figure 6.22). Although, chromite chemistry is consistent with a depleted harzburgite source (Edward, 1990; Edwards & Malpas, 1995), the chromite chemistry of associated chromitite and dunite do not seem to be related to the harzburgite by simple partial melting. Trends for MgO with CrzOz, AlzOz and FeO for chromites from dunites and chromitites are different from those in harzburgite (Figures 6.22-6.24). Similar relations were observed in Luobusa ophiolite in China (Zuou et al., 1994, 1996). This distinction is also revealed by the higher titanium contents of chromites from dunites and chromitites relative to those from harzburgites (Figure 6.25). Such chemical characteristics may imply that a special process or different source, other than partial melting of the host rocks, must have involved in the formation of the Zikt dunites and chromitites. A few altered pyroxenitic dikes located about 400m north of Palace within the upper mantle peridotite (chapter 3) contain accessory chromites. The Cr # (79.5-86) and Mg # (26-38) of these chromites compares them with the high-grade chromite ore. Chromites in pyroxenitic dikes are expected to form from magmas in the same way as 189 Palace (Zikt) Chromite # Chromitite O Dunite AHarztHjrgite I XCrH94Perid 35 40 45 50 55 60 65 Cr203 wt % Figure 6.22: Plotting of Cr^O] wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. The harzburgites form a diagonal array with decreasing CrzOs/MgO ratio. Al’Hel peridotites (CrH94Perid) is added to more distinguish the mantle array. Dunites and chromitites project a trend normal to this array. Palace (Zikt) Chromite 19 17 15 •Chromitite 5 13 0 O Dunite A Harzburgite f 11 XCrH94Perid 9 7 5 —r— 10 15 20 25 30 35 AI203 wt % Figure 6.23: Plotting of AI 2O3 wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. The harzburgites form a diagonal array with positive AhOs/MgO correlation. Al’Hel peridotites (CrH94Perid) is added to more distinguish the mantle array. Dunites and chromitites project a trend normal to this array. 190 Palace (Zikt) Chromite 19 17 T 15 13 4 Chromitite o> 11 O Dunite A Harzburgite 9 t 7 - 10 15 20 25 FeO wt % Figure 6.24: Plotting of FeO wt % against MgO wt % of chromite from Palace (E. Zikt) rocks. With increasing MgO/FeO ratio, the harzburgites form a diagonal array, separating from the one formed by chromitites and dunites. Palace (Zikt) Chromite 65 •Chromitite V sy A O Dunite 8 ^ % A Harzburgite 35 0.05 0.1 0.15 0.2 0.25 0.3 Ti02wt% Figure 6.25: Plotting of TiOi wt % against CtiOs wt % of chromite from Palace (E. Zikt) rocks. The plot clearly shows chromites from dunites and chromitites have much higher TiOi contents than those of harzburgites. 191 chromites in stratiform complexes such as Bush veld complex (Bales, 1987; Teigler & Bales, 1993). However, FeiOs and TiOi contents of chromites in these dikes are very low (0 -2 . 8 wt % and 0-0.08 wt % respectively) compared to chromites in stratiform intrusions (> 9 wt % & > 0.2 wt %). In addition, their Mg # and Cr # plot outside the Alpine and stratiform fields (Figure 6.26), but near the upper edge of the stratiform field. Similar chemical characteristics are shown by chromites in the Shurugwi greenstone belt, Zimbabwe (Stowe, 1987; Rollinson, 1997) and interpreted to indicate precipitation from an initial ultramafic magma forming the orebody (Stowe, 1987b). The very low value of TiOi reflects a high-depleted source for the magma from which these chromites precipitated. Therefore, the accessory chromites in the Zikt pyroxenitic dikes might have formed deeper at the initiation of these dikes and probably prior to the alteration had taken place. 6.3.1.3 S. Zikt Chromite This third zone lies deeper in the mantle sequence and contains high-grade chromite-ore fields. Three of five chromite ore sites have been studied: Sharq and Scorpion in the southwest and Vera in the north of Zikt. All three sites contains high grade chromites, with CrzOs from 58 to 6 6 wt %, AI2O3 from 7.03 to 12.76 wt %, and FeO from 11.57 to 20 wt %. The ranges of oxides in chromites from all S. Zikt rocks are given in Table 6.5 and complete analyses are given in appendix C. The chromites in chromitites and dunites of this zone are generally higher in CrzO], FeO and MnO, and lower in AI2O3, MgO, NiO, TiOa, V 2O3 and Fe2Û3 than chromites from the Al’Hel and Palace fields. They all plot in the upper part of the ophiolite & podiform field in Mg # vs. 192 Sharq Vera Scorpion Talc Amphlb. ZS-ShlS Chromltite Z8 -B sl chromltite AI2O3 8.46-12.55 8.07-11.42 7.03-10.33 7.47-12.95 TiO, 0.03-0.21 0.02-0.205 0.01-0.101 0-0.13 CrjOj 57.9-62.98 60.21-65.27 61.75-65.77 62.33-66.06 FciO, 0-3.7 (0.8-3.7) 0-2.21 0.06-2.06 0.02-1.03 FeO 12.55-20 12.1-17.3 11J7-17.5 12.42-14.42 (12.55-17.4) (11.2-14.8) (11.6-13.6) MnO 0.18-0.8 0.47-0.68 0.1-0.25 0.47-0.67 MgO 7.9-13.66 10.31-13.64 11.79-14.02 11.79-13.19 (12.76-14) NiO 0-0.16 0-0.17 0.035-0.138 0.038-0.141 C r# 75.87-82.5 78.2-84.43 81.5-86.2 80.2-83.3 Mg # 45.7-62.33 54.1-66.37 50-65.8 60.7-64.76 (57-65.8) Ditnite AI2O3 8.66-13 7.52-10.6 Ti02 0-0.22 0.01-0.09 Cn03 53.6-59.8 57.3-63.02 FC203 0.3-5.1 2.35-4.21 FeO 15.62-20.8 13.4-20.21 MnO 0.25-0.88 0.25-0.36 MgO 7.9-11.74 8.4-13.2 NiO 0-0.21 (0-0.15) 0.018-0.067 C r# 73.9-82.78 78.5-84.4 28.510(88.55-90.55) M g# 36.77-52.72 38.41-48.41 Z8Sh5 (33-88-39.5) Harzbureite AI2O3 7.55-11.1 8.03-24 9.6-11.1 TiOî 0-0.095 0-0.07 0.023-0.15 Cr2Û3 56.9-59.71 44.7-61 55.1-58.42 F4 O3 0.95-3.9 1.1-2.26 0.64-2.44 FeO 18.74-23.52 14.62-20.6 19-27 MnO 0.28-0.82 0.19-0.386 0J9-1.38 MgO 5.75-9.4 8.17-13.6 4-7.66 NiO 0-0.13 0.001-0.083 0-0.14 C r# 77.7-80.77 55.32-83.6 77.85-79.90 Mg # 35.61-45.2 39.21-60.52 20.1-44.2 Table 6.5: The range of oxide values of chromite analyses in all rock types of S. Zikt fields. Bracket is used where there is a wider range only caused by few points (1-3 points). Detailed analyses are at the appendix. 193 Cr# diagram of Leblanc (1987) and Leblanc & Nicolas (1992) and largely in the boninite field (Figure 6.26). These chemical characteristics are consistent with their stratigraphie position further away from the transition zone. The three localities of this zone also display chromite compositions vary from Sharq to Vera to Scorpion, which reflect different depths in the mantle sequence (Figures 6.27-6.28). Chromites in chromitite exhibit an increase in CrzO], MgO and Cr #, and decrease in AI2O3, FeO, MnO, TiOz, and FezO], in a trend from Sharq to Vera to Scorpion (Table 6.5), which thus reflects increasing depth in the mantle sequence. MgO and FeO are supposed to show reciprocal trend. However, most scorpion chromitite samples are dens massive, Vera are massive "grapeshot” nodules, and Sharq are largely disseminated chromitite, hence the chromite/olivine ratio in chromitites decreases from Sharq to Vera to Scorpion. Recalling that Mg-Fe exchange (Dick & Bullan, 1984) occurs between chromite and silicates (namely olivine), the modal ratio of chromite to olivine might control the observed variations in Mg and Fe of chromitite from Sharq to Vera to Scorpion. FezO; is higher in chromitites from Sharq (0.8-3.7 wt %) than from Vera (0-2.21 wt %) than from Scorpion (0.06-2.06 wt %). This correlates with the higher degree of serpentinization in sharq samples, but could also reflect relative differences in the oxygen fugacity between these sites. The role of the olivine/chromite or silicate/oxide ratio in chromite chemistry also appears in the chromites from Sharq dunites. Dunitic chromite clearly shows lower MgO and higher FezO] than chromititic chromite even in samples with similar AlzOs range (Figures 6.27-6.28). Chromite from dunite reveals the same 194 s. Zikt Chromite Boninite 'Sin.ft'^rr^ eShChrom. O ShOunite Ü 70 CL^Lic,mi) XTalc AHaneburgMt » Pxtdike •ScCtirom. OScDunite 20 10 M g# Figure 6.26: Plotting Mg # against Cr# of chromite from S. Zikt field rocks and pyroxenite dikes (Pxtdike) of E. Zikt. All chromitites and dunites are plotting in boninite field, and Zikt harzburgites form a wide range in the ophiolitic chromite field. Ophiolitic chromite field from Leblanc (1987) and Leblanc & Nicolas (1992), and Boninite field from Bloomer & Hawkins (1987). The legend prefixes: Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite 195 S. Zikt Chromite 1 5 - 14 4 13 -j 12 i AShChfom. • ScChrom. 11 4 OVera 10 -i AShOunite 9 -! OScOunile 8 1 7 ■ 6 7 10 13 16 A1203 Wt % S. Zikt Chromite 15 14 4 •• 13 ÿ 12 AShChrom. % •SeCtwem. 11 □ V m AShOunito I 104 •ScOunito 9 - 8 7 4 - 50 70 Cr203vit% Figure 6.27: Plotting AI 2O3 wt % against MgO wt % (upper) and Cr^Os wt % against MgO wt % (lower), of chromite from S. Zikt chromitites and dunites. Note the progressive increase in CriO] and MgO and decrease in AI2O3 from Sharq to Vera to Scorpion. The legend prefixes: Sh, B. Sharq; Sc, B. Scorpion. 196 s. Zikt Chromite AShChrom. • ScChrom. OVera A ShOunita OScOunita Cr203 wt % S. Zikt Chromite 0.2 AShChrom. •ScChrom. DVaia ^ 0.1 ■ O AShOunHa z •ScOunHa 50 60 70 Cr203 wt % Figure 6.28: Plotting CriOs wt % against FezO] wt % (upper) and CrzOg wt % against NiO wt % (lower), of chromite from S. Zikt chromitites and dunites. Note the progressive decrease in FezOz and slight increase in NiO from Sharq to Vera to Scorpion. The legend prefixes: Sh, B. Sharq; Sc, B. Scorpion. 197 relative trend presented by chromite from chromitite, which also reflect increasing silicates/chromite toward Sharq dunite. Despite differences in the chemistry of chromite from the different S. Zikt fields, chromites of chromitites and dunites from these sites appear to have a magmatic origin, and the features described for chromites in E. Zikt are seen in these chromites. There are several lines of evidence that chromites from chromitite and dunite of all S. Zikt fields have a similar origin. (1) They are chemically quite similar (Figures 6.27-6.28). (2) They define a dunite-chromitite linear array on plots of FeO against MgO that is distinct from that defined by other fields and by harzburgites (Figure 6.29). (3) They plot in the same field on the TiOi vs. Cr # discrimination diagram of Zhou et al (1996), mostly in boninite field (Figure 6.30). (4) They overlap on the UAH harzburgite array of CriO] vs. MgO and AI2O3 vs. MgO (Figure 6.31). They plot next to that of Palace and are distinct from the Al’Hel plot. These characteristics indicate close similarity between chromites in the Zikt fields and those in the Loubusa ophiolite in China (Zhou et al., 1994,1996; Zhou & Robinson, 1994, 1997). The chromite chemistry of the Zikt upper mantle harzburgites clearly reflects the residual or refractory nature of these rocks (Table 6.5). Chromites in Zikt harzburgites are characterized by low TiOa (0.11 in Palace, 0.095 in Sharq, and 0.07 in Scorpion) and high Cr# (up to 83). This is a strong indication that these harzburgites are residual after extraction of high Mg basalt or andésite magma (Arai, 1991). These accessory chromites plot in the Alpine and ophiolite field in the Mg # vs. Cr# discrimination diagram of Leblanc & Nicolas (1992) (Figure 6.26), and in the depleted oceanic tectonite zone on the TiOz vs. CriO] discrimination diagram of Jan & Windley (1990) and TiOi vs. Cr# 198 s. Zikt Chromite 18 4. 15 4. AShChrom. • ScChrom. 12 -■ □ Vera OCrH94Pertd XPalHarzb. A ShOunite XShHarzb. 0 ScOunMe • ScHarzb. • Talc FeOwt% Figure 6.29: Plotting FeO wt % against MgO wt % of chromite from S. Zikt rocks. With increasing MgO/FeO ratio, the harzburgites form a diagonal array, separating from the one formed by chromitites and dunites. The prefixes in the legend: Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite; CrH94Perid, Al’Hel peridotites. N-S Zikt Chromite 90 85 80 AShChrom. •ScChrom. 75 □Vora AShOunilo Q 70 4 •ScOwHa •ShHarzb. 65 4 •ScHarzb. GO Hidfily depleted ^ XPalHatzb. harzburgite x ^ 55 X* 50 0.001 0.01 0.1 Ti02wt% Figure 6.30: Plotting ofTiOz wt % against Cr # of chromite from S. Zikt rocks. Harzburgites are mostly plotted in the depleted field of Jan & Windley (1990) and 23iou et al. (1996). Legend is the same as in figure 6.29 199 Chromite of N-S Zikt I I AShChrom. jt I#ScChrom. □Vora A ShOunite % » XShHarzb. O I OScDunite a t S !0 ScHarzb. OTalc(H*ni) lOCrH94Perid XPalHarzb. AI203wt% Chromite Of N-S Zikt AShChrom. • ScChrom. XPalHatzb. XShHarzb. ^ 12 $ A ShOunite #Talc(*r*6) O ScOunite I O ScHarzb. □ Vera OCrH94Perid I XPalHarzb. 30 45 50 55 65 70 Cr203wt% Figure 6.31: Plotting of AliOj wt % against MgO wt % (upper) and CrzO] wt % against MgO wt 9c (lower), of chromite from S. Zikt rocks. The harzburgites form a diagonal array with increasing AI 2O3 and MgO, and decreasing CrjOa/MgO ratio. Al’Hel peridotites (CrH94Perid) is added to mote distinguish the mantle array. Dunites and chromitites project a trend normal to this array. The prerixes in the legend: Pal, Palace; Sh, B. Sharq; Sc, B. Scorpion; Pxt, pyroxenite; CrH94Perid, Al’Hel peridotites. 200 diagram of Zhou et al. (l996)(Figure 6.30). The chromites of Zikt harzburgites together with those of Al’Hel peridotites define a linear array on plots of both CrjOs vs. MgO and A I 2 O 3 vs. MgO (Figure 6.31) and even in FeO vs. MgO (Figure 6.29). The significance of this UAE mantle peridotite array will be discussed for the case of the three UAE fields (chapter 7). The Sharq orebody contains several fault planes that are completely filled by mostly talc, with some serpentine and carbonate, that probably replace olivines and pyroxenes. Talc [Mg6(Sig02o)OH4] formation depends on the accessibility and activity of silica and magnesium, and generally formed by two ways (Deer et al., 1993): I) low- grade metamorphism of ultramafic rocks, or 2) contact and regional metamorphism of siliceous dolomite. The first method operates in the Semai 1 ophiolite and is the reaction of serpentine to form talc: Serpentine talc Magnesite 2Mg3Si205(0H)4 + 3CO2 -> Mg3Si40,o(OH)2 + SMgCOj + 3HzO Accessory chromites in these talc rocks show high CvzOs, Cr #, FeO, and low AI 2O3, MgO, Mg # and TiOz (Table 6.3). They plot in the stratiform field of the Mg# vs. Cr# diagram (Figure 6.26), with similar chemistry to the chromites in the east Zikt pyroxenite dikes (section 6.3.1.2). This may imply a pyroxenite protolith for these bodies of talc and associated serpentine, similar to the dikes in east Zikt. However, field relationships (as fault plane fillings in a shear zone) do not support this idea, and these bodies most likely formed during low grade metamorphism (alteration), related to shearing of the host harzburgite. 201 6.3.2 Silicates The samples of the ultramafic rocks from the UAE mantle sequence contain no plagioclase, and olivine and pyroxene are the dominant primary silicates. Amphibole also occurs but is mostly of secondary origin (e.g. tremolite). In this section, the mineral composition of the silicate primarily phases (includes olivine, pyroxene and amphibole) associated with chromite is discussed. 6.3.2.1 Olivine The exchange of Mg and Fe between coexisting phases has strongly influenced olivine compositions in the ultramafic rocks. Olivines in upper mantle harzburgites from the Zikt and Al’Hel fields are chemically different. Differences in chemistry between olivines from E. Zikt and S. Zikt harzburgites are minor and data for these two sites are combined as Zikt. Fo (lOO*Mg /(Mg + Fe) and MgO of olivine in Zikt harzburgite (91.51-92.67 & 50.16-51.65 wt % respectively) are higher than those of olivines in Al’Hel harzburgite (Fo 90.68-91.27,49.49-50.1 wt % MgO), whereas FeO and MnO show the opposite trends (7.28-8.29 wt % FeO & 0.078-0.134 MnO in Zikt, 8.54-9.18 wt % FeO & 0.103-0.154 wt % MnO in Al’Hel). MnO exhibits moderate wide variation for which two points are not accounted in the range. Ni contents of olivines in harzburgites are fairly constant (0.4 ±0.05 wt % NiO) throughout all fields (Figures 6.32). these characteristics are typical features for olivines in depleted upper mantle peridotites and serpentinites of the Semail ophiolite (Brown, 1982) and in other ophiolites (Roberts, 1986). Differences in the chemistry of olivine in the Al’Hel and Zikt peridotites also reflect the stratigraphie position of these fields in the mantle sequence. 202 0.6 0.5 ♦ 0.4 ♦ 0.3 0.2 0.1 90.5 91 91.5 92 9Z5 93 Fo Figure 6.32: Plotting Fo (Mg*100/(Mg+Fetot.) against NiO wt % of olivines from mantle . harzburgites of all fields. Note that NiO content of harzburgites in all fields is ' constant at about 0.4 wt %. 203 The chemistry of olivine in dunites and chromitite segregations reveal similar differences between the three major fields (Figure 6.33). Also, within each field, there are systematic differences between olivines in harzburgites, dunites, disseminated chromitites, and massive chromitites (Figure 6.34). Fo and MgO of olivine are the highest in massive chromitites, reaching Fo97.02 and 54.31 wt % MgO in Scorpion (S. Zikt) massive chromitite. In contrast, FeO and MnO of olivine are the lowest in massive chromitites reaching 3.0 and 0.0266 wt % respectively at Scorpion also. Ni contents correlate positively with Fo (Figure 6.34). However, Ni reaches extremely high values in olivines of Zikt chromite rich segregations, in particular samples Z9-P3, Z8-Shl3.2 & Z9-Sc6 (Figure 6.34) where it reaches 1.12 wt % NiO. This very high Ni content cannot be explained by a simple magmatic evolution and may be ascribed to subsolidus re equilibration and exchange with chromite or Ni sulfide alloy. Subsolidus re-equilibration between chromite and olivine is outside of the scope of this study. However, the analysis of core and rim of olivines in a few dunite and chromitite samples from Palace does reveals some indication of re-equilibration. NiO content in olivine increases from dunite to chromitite, and NiO in the olivine cores and rims correlate conversely with that of the coexisting chromite cores and rims (Figure 6.35). In other word, the increases of NiO in the olivine rims are accompanied by decreases of NiO in the rims of the coexisting chromites (Figure 6.36). The differences in NiO content between cores and rims are apparently not large (Figure 6.35), and thus the re-equilibration was probably not high. 204 AHIOi • ShOl (0 40.5 • ScOI Figure 6.33: Plotting Fo (Mg*lOO/(Mg+Fetot.) against SiOz wt % of olivines from dunites and chromitites of all fields. HIOl: Al’Hel, PlOl: Palace (E. Zikt), ShOl: Sharq & Sc: Scorpion (S. Zikt). 1.2 1 0.8 A HIOl * ■ PIOI % 0.6 ♦ ShOI 0.4 • ScOI 0.2 0 90 91 92 93 94 95 96 97 98 Fo Figure 6,34: Plotting Fo (Mg*100/(Mg+Fetot.) against NiO wt % of olivinçs from dunites and chromitites of all Gelds. Note that the smooth positive correlation between Fo and NiO changes to steep correlation at Fo94.4 where is no more Al’Hel samples. HIOl: Al’Hel, PlOl: Palace (E. Zikt). ShOl: Sharq & Sc: Scorpion (S. Zikt). 205 Palace Chromite e I eNiCCcRim 1 eNiO-cara o • • • « I . $ « • ♦ Q ♦ • 0 ♦ 0 • ♦ ' y V/ 0 0 Palace Olivine o ; ONIOOIRIm j ! • NiO-cofe • t • e 0 ♦ « Û ^ # ♦ « • O « Figure 6.35: Plotting NiO wt % contents of the core and rim of chromites (upper) and coexisting olivines (lower) in some dunite and chromitite samples from Palace (E. Zikt). The first fîve samples from the left are chromitites and the others are dunites. 2 0 6 Palace 0.65 I 0.55 l„ I I 0.45 0.4 0.35 0.02 0.03 0.04 0.05 0.06 0.07 0.06 0.09 0.1 NiO wt% Chromite Rim Figure 6.36; Plotting NiO wt % content of the chromite rims with that of the rims of coexisting olivines from a few dunite and chromitite samples of Palace (E. Zikt). Note the negative correlation between the two types of rims. 207 6.3.22 Pyroxene Generally, Other than harzburgite (and pyroxenite & Iherzolite), the pyroxene contents of almost all rock types studied are insignificant. The upper mantle harzburgite contains abundant orthopyroxene, and only minor clinopyroxene. The orthopyroxene in all mantle harzburgites is dominantly enstatite (Figures 6.37-38) with high Mg # [Mg*100/(Mg+Fetot)] in the range 90.8 to 93.4 (Figure 6.39). The Mg # of enstatite correlates positively with the Fo content of coexisting olivines, a typical feature of residual refractory harzburgites. Despite limited overall chemical variations, orthopyroxene composition changes consistently with stratigraphie position in the mantle sequence. Orthopyroxene in Zikt harzburgites have higher Mg # (91.9-93.37), and En fMg*100(Mg+Fe+Ca)J, (89.81-92.44), and lower Fs [Fe*100(Mg+Fe+Ca)], (5.76-8.03), and Wo [Ca*100(mg+Fe+Ca)}, (0-3.31), than those in Al’Hel harzburgites (Mg # 90.9-91.72, En 87.03-90.73, Fs 8.02-8.95, Wo 0.93-4.4). Similar but smaller differences exist between orthopyroxenes from East and South Zikt. AI 2O3, MnO, and FeO contents all increase from S. Zikt to E. Zikt to Al’Hel (Figure 6.39), that is upward in the stratigraphie section. AI 2O3 contents are always higher than Cr 2 0 3 contents, but the difference in concentrations of the two oxides increases upsection and reaches the greatest in Al’Hel harzburgites. These chemical variations reflect the relative degree of mantle depletion, and show that S. Zikt peridotite is more affected by partial melting (more depleted) than E. Zikt peridotite that is in turn more depleted than Al’Hel peridotite. One sample (Z9-Scl0) of Scorpion (S. Zikt) contains orthopyroxene with exceptional high AI 2O3 and Cr2 0 3 contents that are similar, and even slightly higher than 208 Di Hd En Fs Di Hd En Fs Figure 6.37: Plotting pyroxene compositions from mantle harzburgites of Al’Hel (upper) and E. Zikt (lower) in the pyroxene quadrant shows the dominant of enstatite. The few diopsides are from dunites and chromitites. En, enstatite; Fs, ferrosilite; Di, diopside; Hd, hedenbergite. 209 Di Hd En Fs Di Hd En Fs Figure 6.38: Plotting pyroxene compositions from mantle harzburgites of B. Sharq (upper) and B. Scorpion (lower) in the pyroxene quadrant shows the dominant of enstatite. En, enstatite; Fs, ferrosilite; Di, diopside; Hd, hedenbergite. 210 those of Al’Hel orthopyroxene (Figure 6.39), without significant change in its Mg # or in the other end member ratios. Also, Sample (Z9-Sc2) contains orthopyroxene with somewhat high FeO and Ferrosilite (Fs), similar to pyroxenes from Iherzolites close to the metamorphic sole of the ophiolite (Appendix E). CrzO] and especially AI2O3 contents are related to melt extractions or crystallization conditions (Maurel & Maurel, 1982a, b), and the FeO/MgO ratio is easily affected by subsolidus re-equilibration (Auge, 1987). Sample Z9-ScI0 may (I) represent a harzburgitic cumulate that crystallized from picritic magma that might locally experience interaction with assimilated wall rock, or ( 2 ) may have re-equilibrated during regional high temperature metamorphism accompanied by alteration. The second possibility could also explain the iron enrichment in sample Z9- Sc2. Clinopyroxene in mantle harzburgites is only diopside and/or diopsidic enstatite. Clinopyroxenes are only found in some Al’Hel and E. Zikt peridotites (Figure 6.37). The Al’Hel clinopyroxenes have En 48.4-70.9, Fs 0.35-3.36, Wo 26.58-48.52. One of the analyzed samples from Palace (E. Zikt) contains clinopyroxene that has En 64.35-67.07, Fs 2.46-2.48, Wo 30.46-33.16, and lower AI 2O3 content than in coexisting enstatite. Only one clinopyroxene was found in the harzburgite of S. Zikt field in (Z9-Scl0), and this has En8 i .l 6 and Wo 13.09. The compositional variations in the clinopyroxene of mantle harzburgites reflect melt extraction that was more extensive in the 2ükt area (S. Zikt in particular) than in the Al’Hel area. Most dunite and chromitite rocks lack of pyroxene, and even the few grains that do occur are completely to largely serpentinized or altered to chlorite and/or amphibole. Orthopyroxene is not observed in any of the analyzed samples, and only trace amounts of 211 0.25 1 0.21 - iS 0.17 - I 0 c 0.13 -, S 0.09 - 0.05 - 1 I i ■ I I 90.5 91 91.5 92 92.5 93 93.5 M g# 7 6.5 SS 6 V] 4.5 i 4 90.5 91 91.5 92 92.5 93 93.5 M g# 2.1 1 1.8 ■ 1.5 ■ 1.2 - n § 0.9 ■ < 0.6 - 0.3 - 0 ------;----- 90.5 91 91.5 92 92.5 93 93.5 M g# Figure 6.39: Plotting Mg# against MnO wt % (upper), FeO wt % (middle), and AI 2O3 wt % (lower) of orthopyroxene from mantle harzburgites of all fields. All show negative correlation. Sample Z9-SclO reveals exceptional high AI2O3. 212 diopside are found in a few samples. Mg #’s of clinopyroxene in dunite and chromitite range from 95.13 to 97.3, whereas En ranges from 47.72 to 51.85, Wo from 45.49 to 50.25, and Fs is ^ .5 (Figure 6.37). One grain in Iceberg (Al’Hel) and another in Scorpion (S. Zikt), show a little exception in composition: En 69.13-73.2 and Wo 24.78- 28.49. Because of the small number of grains analyzed, correlation between chemical composition and stratigraphie position is difficult be clearly made, but it appears that clinopyroxene in dunite and chromitite increases in Mg # and Wo close to the transition zone. In chromitite, clinopyroxenes occur as inclusions in chromite grains, and contains higher AI 2O3 (up to 2.75 wt %) than those of dunite. However, clinopyroxene in chromitite is only found in the Al’Hel field and none is found in the Zikt chromitite. The total absence of orthopyroxene in chromitites and dunites accompanied with the present of a little amount of clinopyroxene, provide an indication of a magmatic origin in the formation of these rocks. 6.32.3 Amphibole Amphibole occurs as inclusions and as interstitial grains in many rocks of the studied areas. Most amphiboles are tremolites, except for a few Na and Al rich types. Tremolite is distinctive by its high silica (Si > 7.5 atoms pfu) and very low A I 2 O 3 , NazO and TiOz. Amphiboles in all harzburgites are tremolites with 7.77-7.94 atoms pfu Si, and extremely low Na+K and Al (0.003-0.026 and 0.064-0.240 atom pfu respectively) (Figures 6.40-6.41). Although Si, Al and Na+K do not show clear correlation with mantle stratigraphy, the Mg # of tremolites is greater in Zikt harzburgite (96.25-97.27) than that in Al’Hel harzburgite (88.62-95.33). Ca# [Ca*100/(Ca+Mg+Fe)] and An # 213 Harzburgite Amphibole 0.200 - 0.180 -i 0.160 0.140 ■ 0.120 -j 0.100 -I 0.080 \ 0.060 -i 0.040 -j 0.020 j 0.000;i i * 7.960 7.900 7.850 7.800 7.750 7.700 7 660 7.600 7.560 Si atoms pfu Figure 6.40:Ploiiing Si atoms pfu against Na+K atoms pfu of amphiboles from mantle harzburgites of all fields reveals dominant tremolite composition of these amphiboles. Harzburgite Amphibole 0.200 0.180 0.160 a 0.140 I 0.120 I 0.100 ^ 0.080 z 0.060 0.040 0.020 0.000 0.500 0.400 0.300 0.200 0.100 0.000 AI atoms pfu Figure 6.4i:Plotting Al atoms pfu against Na+K atoms pfu of amphiboles from mantle harzburgites of all fields also reveals dominant tremolite composition of these amphiboles. 214 [Ca* lOO/(Ca+Na+K)] are also higher in amphibolites of Zikt harzburgite (Figure 6.42). CriO] and TiOa contents are lower in Zikt tremolites than in Al’Hel tremolites (0.3 versus 0.42 Cr2 0 3 wt %; 0.02 versus 0.04 wt % TiOz). On the other hand, NiO contents are higher in Zikt tremolites than in Al’Hel tremolites (0.12 versus 0.07 wt % NiO) Amphiboles in dunites and chromitites are mostly tremolite with some hornblende. Although Mg # slightly decrease from Zikt to Al’Hel, amphibole composition does not appear to reflect any stratigraphie position. A broad range of amphibole composition from tremolite to edenite/pargasite can be observed in one sample (Figure 6.42-6.43). An # widely varies but reaches extremely low values in the Al and Na bearing varieties. CrzOj and TiOi correlate positively with Na+K and Al contents. Tremolites in dunites and chromtites show a wider range and higher Si content (7.5-8.04 atoms pfu) and Na+K (0-0.19 atoms pfu) than those in harzburgites (Figure 6.42). In sample H8-15 (Iceberg-Al’Hel) where amphibolitized carbonate vein infiltrated and replaced silicates in the disseminated chromitite at its border (chapter 4), the amphibole chemistry is more variable. However, it is generally lower in Mg #, Ca # and An #, and higher in TiOz and Na%0 than tremolites in other chromitites. Tremolite grains that are included in chromites chemically do not significantly differ from those in the matrix or in interstices. Amphiboles with silica content lower than 7.5 atoms pfu and appreciable Al content are considered hornblende amphibole (Deer et al., 1993). AI2O3, Crz03, Na%0 and TiOz are much higher in hornblende and/or pargasite than coexisting tremolite. A negative correlation between Na+K and SiOz and a positive correlation between Na+K and AlzOz, CrzOz & TiOz are clearly observed. These trends reflect substitution of Al for 215 Amphibole of Ounite & Chromitite 0.700 0.600 : Edenite ^argasit ♦ 0.500 i g 0.400 t h o r n b l e n d e ^ 0.300 > z 0.200 - ♦ f t I Tremo(i#%4L# 0.100 0.000 8.500 8.000 7.500 7.000 6.500 6.000 Si atoms pfu Figure 6.42;Plotting Si atoms pfu against Na+K atoms pfu of amphiboles from dunites and chromitites of all fields shows compositional range from tremolite to hornblende to pargasite. Amphibole of Dunite & Chromitite 0.700 0.600 Piffgaslte Edenite ♦ 0.500 t i I 0.400 i I % 0.300 ^ Hornblende ^ 0.200 -i ♦ %^«fremQlite 0.100 •‘ . ♦ . • Si 0.000 2000 1.500 1.000 0.500 0.000 Ai atoms pfu Figure 6.43;Plotting Al atoms pfu against Na+K atoms pfu of amphiboles from dunites and chromitites of all fields also shows compositional range from tremolite to hornblende to pargasite. 216 Si that is balanced by Na and other cations, and indicate solid solution between tremolite and hornblende sensu lato (Auge, 1987). A wide variation in the amphibolite composition may occur in a single sample. This is shown by sample Z9-P4 (E. Zikt) which includes amphibole grains that range from Al-free tremolite to hornblende and edenite in composition (Figure 6.42-6.43). Tremolite is unlikely to be a primary mineral. Rather, it probably formed through complex reactions during low temperature regional metamorphism and alteration. This is supported by several indications. I) Many tremolites show a fibrous habit in thin sections. 2) Magmatic amphiboles have high Ti contents, while the tremolites contain low Ti. 3) In oceanic tholeiites ,/h 2o and ^ 2 are too low (Deer et al., 1993) to form hydrous minerals. 4) Late stage magmas are enriched in A1 and alkalis, whereas the tremolites are low in A1 and Na+K. In contrast, the of hornblende is more complex, but some indications may imply a primary origin. For examples, hornblendes are relatively enriched in A1 and Na+K some contain high Ti. Also, hornblende is only observed dunites and chromitites and absent in harzburgite. However, hornblende can form from pyroxene by high grade of regional metamorphism if fluid is available. In addition, occurrence of some acicular to prismatic amphibole suggests a metamorphic origin. Nonetheless, hornblende inclusions in chromites (e.g. samples Z9-Scl and Z9-Sc7 of S. Zikt) may be primary in origin. 217 CHAPTER 7 PETROGENESIS OF CHROMITE 7.1 Geotbermometry & Geobarometry: The mantle sequences of ophiolite complexes have preserved some history of metamorphism and deformation that are thought to affect these rocks during and after formation and emplacement. Despite this, it must be emphasized that these upper mantle rocks are still mostly igneous not metamorphic, because the effects of metamorphism are only found at or close to the base of the units, though some mylonitic textures are observed close to the transition zone, and record a high temperature (spreading) flow. One of the consequences of deformation is subsolidus re-equilibration. Using Sack & Ghiorso’s (1991) olivine-spinel geothermometer, the calculated equilibration temperature of Mg-Fe exchange between olivine and spinel yields a lower temperature than expected for magmatic conditions: Al’Hel, 578-762‘’C; E. Zikt, 550-718°C; S. Zikt, 579-747‘*C (Table 7.1). This suggests that the upper mantle rocks re-equilibrated under subsolidus conditions. Brown (1982) used the olivine-spinel geothermometer of Roeder et al., (1979), and obtained a similar temperature range, 550-825"C, for the upper mantle rocks (including the same rock types: chromitite, dunite and harzburgite) from the northern part of Oman, although he assigned a magamtic origin for the formation of 218 chromitite and dunite. Browning (1982) calculated the conditions of formation of the Oman mantle sequence using pyroxene thermometers (cited from Lippard et al., 1986). He used two-pyroxene thermometry of Powell (1978) and obtained a range of 1026- 1064°C and 10-30 kbar. Using Mercier's (1980) single-pyroxene thermobarometer, he obtained a range of 908-1563“C and 4.4-52.7 kbar. The results show a very wide range of temperature and pressure that do not correlate with the depths of the samples in the mantle sequence (appendix). Moreover, there is no correlation between the results obtained using the two different thermometers. These results probably reflect re equilibration or improper method of calculation. Olivine-spinel thermometry strongly depends on the spinel/olivine ratio, and thus the temperatures obtained by this method increase from chromitite to dunite to harzburgite (Table 7.1). The calculated temperatures show a similar range in all major fields (Al’Hel, E. Zikt and S. Zikt) for each rock type (Table 7.1), and all fall into the range 580-762®C that is equivalent to pressures of 6.S-9.7 kbar. This may indicate that either all rocks in the region were equilibrated at the same conditions regardless of their stratigraphie position in the mantle sequence, or that olivine-spinel thermometery is inappropriate and that calculated temperatures are incorrect. However, the peridotite (e. g. harzburgite) equilibration temperatures calculated using the Sack & Ghiorso (1991a,b) method is close to the -700“C isotherm, which agrees well with the temperature estimated by Evans & Frost (1975) for metamorphic serpentinites (olivine-enstatite- chlorite-spinel). When considering results of olivine-spinel and pyroxene geothermometry and geobarometry, it is important to note the following points. First, olivine-spinel 219 Al’Hel Iceberg H8-I1 H8-I2 H8-I5 H8-I10 H9-I2 1 H9-I2 TempC 587.55 607 578 606 606.47 707.02 Wadl-I H9-WI2.2 H9-WI3 H9-WI4 H9-WI5 H9-WI6 TempC 645 629.27 706.44 762.07 720.15 1 E. Zikt Palace Z9-P3 Z9-P4 Z9-P4 Z9-P5 1 Z9-P6 • chro dun TempC 549.66 589.29 673.64 717.58 1 710.89 S. 2 ikt Sharq Z9-Sh5 Z9-Sh8lnc Z9-Sh8mat Z9-Shl 1 29- Z9-Sh16 Z9-Sh16 Shl3.2 chr dun TempC 696.23 594.9 659.72 720.85 580.28 629.67 702.97 Scorpion Z9-Sc1 Z9-SC1 Z9-SC2 Z9-Sc6 Z9-Sc7 Z9-Sc9 Z9-SC10 chro dun TempC 724.58 708.87 747.22 578.85 719.48 663.2 653.24 Others Z9-5 1 Wad9-1 |Mas9-3aiag Mas9-5sp Mas9-5sp Temp C 776.73 687.34 861.7 504.82 525.75 Table 7.1 : Equilibration temperatures of Mg-Fe exchange between olivine and spinel, calculated from the olivine-spinel geothermometer of Sack & Ghiorso (1991a). M.Chromitite D.Chromitite Dunite Harzburgite Ai’Hel Icberg H9-I2 -11 to -9.8 -8.7 to -8.8 Wadi I -9.0 to -9.1 -8.9 to -9.0 -9.6 to -9.0 -9.1 to -.8.9 (-7.2) E. Zikt Palace -11.7 to -10.5 -10.4 to -10.0 -9.9 to -8.9 -11.4 to -11.0 S. Zikt Sharq -10.6 -10.2 to -10.0 -10.0 to -9.2 -11.5 to -11.3 Scorpion -11.6 to -10.9 -10.0 to -9.4 -11.5 to -10.6 Table 7.2: Log oxygen fugacity (log/Oi) averages obtained by calculated Fe^^ ratio (100*Fe^V Fe^"^+ Al^^+ Cr^^ and using Murck & Canpbell (1986) diagram at a recommended temperature of 1250“C and QFM buffer system. 220 thermometry can only be used for highly serpentinized samples. In other words, subsolidus re-equilibration is expected in serpentinites. Sack & Ghiorso (199la,b) noted that with increasing degree of serpentinization, olivine becomes more magnesian (Fo 92.3-96.6), the spinel overgrowth becomes wider forming an inner ferrichromite zone and outer magnetite zone and the Mg # and Cr # of spinel increases. This is not consistent with data for samples studied in this work, which are similar to samples considered to show little serpentinization by Sack & Ghiorso, in that chromite overgrowths show only a thin ferrichromite rim. Second, the samples were collected from mining excavations not from the surface. Therfore the studied samples rocks are generally within the less serpentinzed rocks, with few peridotite exceptions. Third, subsolidus re-equilibration is a complex, poorly understood process. This is probably why most workers (e.g. Page et al., 1982; Dick & Bullen, 1984; Lippard et al., 1986; Auge, 1987; Jan & Windley, 1990; Elthon, 1991; Takazawa et al., 1992; Kelemen et al., 1992; Robers & Neary, 1993; Zhou et al., 1994, 1996; Edwards & Malpas, 1995; Rollinson, 1997 have not given a much attention to subsolidus re-equilibration in their discussion and interpretation the petrogenesis of chromite rocks. 7.2 Oxygen Fugacity: Chromite is an oxide mineral and its stability and composition is directly influenced by the partial pressure of oxygen, or oxygen fugacity (foi). The effect of /ôz on chromite composition is usually indicated by the oxidation of ferrous to form ferric iron (FezCz). Irvine (1965) used thermodynamic data to derive a theoretical expression for calculating the oxygen fugacity {foi) from chromium spinels and emphasized that these 221 minerals are potential indicators of fo2 of the silicate magmas from which they crystallized. Irvine (1967) applied his theory to several major ultramafic and mafic orefields (Bushveld, Great Dyke, Stillwater & Muskox intrusions, and some Alpine-type orebodies). He found that the ratio FezOs/RzO] of chromite is positively correlated with f o i . In general, chromites o f Alpine-type peridotites crystallize at low f o i . In accordance with Irvine’s work, Ulmer (1969) experimentally found that oxygen fugacity (/Dz) of the parent magma can regulate the cylcic crystallization and compositional variation of spinel and silicate minerals, and hence changes in jOz may enhance chromite precipitation. Murck & Campbell (1986) emphasized the importance of fOz and magma mixing for the formation of chromite, and added that lowering temperature at constant jOz will reduce Cr^^ solubility in the melt and cause chromite supersaturation. These authors and others, who have considered the role of fOz in controlling chromite formation, have mainly worked in layered igneous intrusions where JOz is fairly high. In the upper mantle however, conditions are more reduced andyOz is very low. Almost all rocks studied in the present work crystallized at distinctly lower JOz than those of stratiform intrusions, as indicated by the low values of FezOz or Fe^* ratio (Fez0 3 * 1 0 0 /(Fez0 3 +Crz0 3 +Alz0 3 )). Using Murck & Campbell’s (1986) results, the fOz obtained for all Zikt rocks range from 10'*°'^ to 10'^^, whereas that for Al’Hel is a little higher up to 10*’, and even 10*’^ in a dunite from Wadi-I (Table 7.2). TheseyOz’s were obtained at a temperature of 1250®C and the QFM (quatrz-fayalite-magnetite) buffer as recommended by Murck & Campbell (1986). The relatively highyOz of Al’Hel rocks may be due to involvement of fluid in the formation of these rocks, which is consistent with their position close to the transition zone, although the fluid could be magmatic. The 222 very low jO i of the ore-field rocks, particularly in Zikt, argues that variations in did not play a significant role in the formation of these ore-rocks. This implies that fQi in the UAE Semail mantle fields (and many others with similar features) can be considered constant to a first approximation, and thus a temperature change (probably with other factors) is more important than variation in jO i in the formation of these ore-fields. 7.3 Chromite Genesis It is possible that the mechanism of chromite genesis is obscured by the post formation re-equilibration or serpentinization. However, the collective evidence of field and pétrographie studies, textural relations, whole rock analyses and mineral chemistry, shed considerable light on the likely process of chromite formation. The genetic process postulated here involves three stages, and the key points are interaction between the magma and the surrounding rocks (mantle metasomatism), and changes in conditions of crystalization. In the following, the magma-mantle interaction process is introduced and defined as it applies here, followed by a description of the proposed three-stage mechanism. Finally the lines of evidence that support this genetic model are summarized. 7.3.1 Disequilibrium Interaction or ‘‘Mantle Metasomatism” Chromite crystallization Grom a magmatic liquid in the upper mantle does not appear to be a simple mechanism related to a temperature decrease, but rather a complex process that involves interaction between the surrounding depleted mantle rocks and melt, to produce chromitite or chromite bearing bodies and dunites from an olivine- saturated liquid. Interaction of liquid and peridotite was modeled by Kelemen (1990) and 223 Kelemen et ai. (1990). At constant temperature, pressure, and fOj, an ascending hydrous basaltic liquid will react with the refractory mantle peridotite, dissolve some mantle minerals (e.g. pyroxene), and extract Mg from the wall rocks to become Mg-rich (Mg- olivine ± chromite rich) (Myers, 1988; Rogers & Sounders, 1989). Dissolution of mantle material would also increase silica content of the liquid (Falloon & Green 1987). Any change in conditions as the liquid ascends or migrates will cause high Mg-olivine and chromite precipitation to form dunite and chromitite. Mixing with a new pulse of magma could be one factor leading to a change in conditions. Reaction between magma and wall rock may be most efficient when disequilibrium exists between the melt and the host rocks (Zhou & Robinson, 1997; Malpas et al., 1997), such as may be the case above subduction zones (Kelemen, 1990; Kelemen et al., 1990). Residual dunites formed by partial melting are present in the harzburgite, and these are usually concordant bodies. Discordant to semi-concordant dunite envelopes, particularly those associated with chromite pods and lenses seem to have a different origin. Zhou et al. (1994, 1996) proposed that the dunites in the Luobusa ophiolite, China, were residual and formed by melt-harzburgite interactions as a result of complete orthopyroxene dissolution by melt. Although this appears to be also true for some dunites in the Semail ophiolite, it not always the dominant mechanism of formation, because magmatic signatures are present in many dunites, particularly those that are chromite bearing. Residual dunites form after a high degree of partial melting and thus should be highly refractory. It is suggested here that melt interaction with the wall rocks leads to local depletion of incompatible elements in the wall rocks. Melt interaction with hot depleted 224 Iherzolite would dissolve clinopyroxene and further deplete the host, and the melt will become clinopyroxene saturated. Melt interaction with a harzburgite host would dissolve any clinopyroxene present and some orthopyroxene, and hence form more depleted harzburgites and some dunite residues. At the same time, interaction would trigger the formation of chromitite and chromite bearing dunite. The first case may apply to the Al’Hel area where harzburgite (& some wehrlite) is less depleted and clinopyroxene occurs in dunites and chromitites (Chapters 4, 6 and next section). Kelemen (1990) and Kelemen et al. (1990) emphasized that liquid saturated with clinopyroxene + olivine will crystallize much more olivine than clinopyroxene and the solid product is clinopyroxene bearing dunite and wehrlite. As the liquid would be also chromite-saturated, the chromite/olivine ratio in the melt will play an important role in the precipitation of chromite bearing dunite and chromitite. On the other hand, the second case (harzburgite host) may apply to Zikt peridotites where harzburgite is clinopyroxene-free, and dunite and chromitite lack pyroxene (Chapters 4, 6 and next section). Leblanc and Violette (1983) also found that the change from Iherzolite to harzburgite in the Zambales ophiolite (Philippines) is marked by disappearance of clinopyroxene. It is probable in the case of Zikt that some dunite residues were produced as residues of fusion, but the dominant origin of chromitites and chromite bearing dunites is as crystal precipitates from melts. Interaction between magmatic liquid and wall rocks has been well documented and explains many geologic features of ophiolites. Formation of pyroxenite between mantle peridotite and felsic magma was experimentally demonstrated by Sekine & Wyllie (1982, 1983). Kelemen & Sonnenfeld (1983) and Kelemen & Ghiorso (1986) 225 attribute formation of dunite, homblendite, and some gabbroic rocks to reaction between basaltic magma and different ultramafic rocks. Menzies et al. (1985) present a model for interaction between continental lithosphere and asthenopheric melts below the Geronimo volcanic field in Arizona. The dissolution of upper mantle minerals in basaltic liquid was experimentally studied by Thoraber & Huebner (1985), Donaldson (1985), Tsuchiyama (1986a,b), and Brearley & Scarfe (1986). At likely temperatures of natural melts in the upper mantle (1200-1400“C), they obtained linear dissolution rates of 3mm/year to 3m/year. Zhang et al. (1989) demonstrated experimentally that the fast rates are due mixing resulting from small-scale convection and that without this the dissolution rate is two orders of magnitude lower. The fast dissolution rates may be valid and involve infiltration processes for reactions on a scale of centimeters as in some dunites and pyroxenites (Kelemen, 1990), but for larger scale reactions, the lower rates of Zhang et al. (1989) are more plausible. Most melt-rock interaction mechanisms that have been proposed are relevant to arc magmatism in a subduction zone environment. Rogers et al. (1985) and Rogers & Saunders (1989) studied arc volcanism in Baja California (Mexico) and Isla Cook (S. Chile), whereas Myers et al. (1985), Myers & Marsh (1987) and Myers (1988) studied arc volcanism in the Aleutian islands (SW Alaska), using trace elements and isotope geochemistry. They argued that high-alumina, high Fe/Mg magma derived by high degrees of partial melting of the descending slab in subduction zones might have reacted with overlying mantle peridotite to produce low Fe/Mg, high MeO primitive basaltic liquids. High-Mg andésites and calc-alkaline basalts are the slab-derived melts in this 226 process that yield tholeiitic basalts through interaction with the wall-rock. Experiments by Fisk (1986) reveal that dissolution of orthopyroxene from mantle wall rocks by tholeiitic melts could lead to the formation of high-MgO andésites (boninites). Because the primary olivine phase volume in basaltic liquids expands with decreasing pressure, Stolper (1980) suggested that many tholeiitic basalts produced by partial melting of peridotites at high pressures are strongly undersaturated in orthopyroxene at 10 kbar. Falloon & Green (1987) showed that magmatic liquids equilibrated with mantle rocks contain -50 wt % SiOz and are olivine normative. In experiments, Kelemen et al. (1990) mixed an olivine tholeiite and harzburgite at 5 kbar and temperatures (1050-1150“C) below the solidus of the harzburgite and within the melting range for the basalt. They found that the liquids produced by reaction of basalt with harzburgite were calc-alkaline basalts and basaltic andésites. Metasomatism and interaction between a refractory mantle spinel Iherzolite or harzburgite and basaltic magma is documented by many workers in several ophiolite complexes. Examples include Evans (1985)-Zambales, Philippines; Ozawa (1983,1990)- Miyamori, Japan; Quick (1981a,b) and Kelemen et al. (1992)-Trinity, California, US; Takazawa et al. (1992)-Haroman complex, Japan; Zhou et al. (1994, 1996)-Loubusa, China; and Edwards & Malpas, (1995)-Bay of Island, Newfoundland. However, the exact nature of the mechanism has been interpreted differently by the different workers. No one has ever yet recorded this process from any locality in the Semail ophiolite. 227 7.3.2 The Genetic Stages of Formation: First stage: Partial melting A period of partial melting occurred in the fertile spinel Iherolites of the mantle lithosphere, producing MORB magmas and residual harzburgites (Figure 7.1). The magma must be in equilibrium with its source (Zhou & Robinson, 1997) and if the source is homogenous it will rise without undergoing significant reaction with the surrounding rocks. This sequence of events may represent ridge activity upon initiation of Neo-Tythan lithosphere that began more than 1 lOMa ago (Lippard et al., 1986) during divergence of Afro-Arabia from Eurasia (chapter 2). The degree of partial melting in the Semail ophiolite is estimated to be about 20-26%, and to have occurred at about 45-60 km depth or 15-20 kbar (Brown, 1982). However, partial melting was not a single stage process, but occurred in more than one stage. Therefore, the Semail ophiolite became depleted through partial melting in several events. No significant chromite accumulation is expected at this stage. However, the partial melting (depletion) would have modified the mantle mineralogy, and thus caused a wide variation in the peridotite chromite composition (Figures 6.10 & 11). Second stage: Island arc magmatism At an established subduction zone, a fluid or hydrous liquid is partially extracted from the descending slab. The overlying asthenospheric mantle wedge will be metasomatized by this hydrous phase triggering partial melting to generate arc magmas. The initial melt is tholeiitic to calc alkaline basalt, but the melts become progressively more calc-alkaline as subduction progresses (Myers & Marsh 1987; Rogers & Sounders, 1989; Wilson, 1994). The magmas ascend through the depleted spinel Iherzolite or 228 Neo-Tythan oceanic floor prior to 110 Ma Afro-Arabia MOR Eurasia Ocew _ythan Ocean 9 9 Asthenosphere Asthenosphere The mantle upwelling Continental crust Upper mantle Oceanic crust Magma segregation below mid oceanic ridge (MOR) Mantle diapirs that are partially molten Figure 7.1: Schematic sketch of the MORB divergent regime that was forming the Neo- Tythan oceanic spreading during drifting of Afro-Arabia away from Eurasia, started about 200 Ma ago. At this period, melt extractions by partial melting depleted the upper mantle lithosphere and might modify its mineralogy. This then caused a wide range of chromite variations in the upper mantle harzburgite, but probably without signiflcant chromite accumulations. 229 harzburgite mantle lithosphere. Interaction occurs because of disequilibrium between the rising liquid and the surrounding harzburgite. This reaction leads to dissolution of some minerals from the wall rocks, and thus modifies the liquid by increasing its MgO and SiOz content, which may reach “boninite” composition (Fisk, 1986). Decreasing temperatures and pressure may have caused some cotectic precipitation of olivine and chromite from the magma forming some chromite-bearing dunite and, probably, disseminated chromitite. Nonetheless, interactions will increase the silica content of the melt and reduce the chromium solubility due to increasing the polymerization. This leads to more chromite precipitation, and with increasing interaction, the crystallization path will enter the chromite primary phase volume in Irvine’s (1977) ternary diagram to form monomineralic chromitites. Chromites formed from boninitic melts are Cr-rich varieties (Malpas et al., 1997; Zhou & Robinson, 1997; Leblanc, 1995, 1997). Most chromitite ores and dunites of the Zikt area, but not those of the Al’Hel area, were formed at this stage. The tectonic setting during this stage is the northeastward subduction of the Neo- Tythan sea floor (Figure 7.2). The northeast movement of the Afro-Arabia at ca. 110-100 Ma, requires a subduction zone with angle about 45° to accommodate plate motion (Lippard et al., 1986). Magmatism commenced around 95 Ma (Lippard et. Al., 1986) and this supra-subduction environment is the main stage of formation of the Semail ophiolite (Pearce et al., 1981; Browning & Smewing, 1981; Browning, 1984; Umino et al., 1990; Yanai et al., 1990; Seale & Cox, 1999). 230 Neo-Tythan oceanic floor after 110 Ma Afro-Arabia Eurasia, Island arc Trench ht»J yW&IAwm •{ Asthenosphere f If d*nmelrJkM o k o u * ^ ^ sUt i //Miir « W Figure 7.2: Schematic sketch of the intra-oceanic subduction regime that thought to initiate as a result of the northeastward movement of Afro-Arabia, started about 110 Ma ago. Island arc magmatism commenced 95 Ma ago. Due to the disequilibrium conditions, the subduction zone calc-alkaline magmas interacted with the harzburgitic lithosphere and precipitated Cr-rich chromite bodies as those found in Zikt field. 231 Third stage: Back arc magmatism After island-arc activity was established, an upwelling diapir from deep in the asthenosphere ascends upward and then partially melts due to adiabatic decompression at some distance behind the arc (Wilson, 1994). Melting of the ascending diapir would generate MORB-like tholeiite magma that rose up beneath the arc system, and through the mantle peridotite. The arc activity probably ceases, and the mantle lithosphere stretched and thinned as the MORB-like magma erupts in the marginal basin zone (back arc). In this environment, the chance of a disequilibrium interaction between melt and refractory mantle is lower. Only in the uppermost part of the upper mantle (Figure 7.3) near to the transition zone, where there is less depleted mantle is some interaction likely. Under these conditions, Al-rich chromite crystallizes from tholeiitic melt (Malpas et al., 1997; Zhou & Robinson, 1997; Leblanc, 1995,1997). Consequently, Al’Hel chromitites formed at this stage in a marginal basin (back arc) environment, from tholeiite melts. 7.3.3 Lines of evidence that support for the postulated genetic process: 7.3.3.1 Field observations Several structural and textural features indicate a magmatic origin, and/or assimilation and interaction. However, it is important to note that many of the ore-bodies did not necessarily crystallize in situ, but were transported to the present sites after formation, either by shearing or other mechanisms, a. Progressive change from chromitite to dunite to harzburgite. A gradual change between chromite and dunite is predominant, and is occasionally accompanied with inclusions of each rock in the other rock (e.g. Plate 5.7, 5.8). The 232 Afro-Arabia Eurasia. Marginal basin Trench jitk tu fc'W.AcC T Asthenosphere Astondi'Aa Asthenosphere AsHêmts^utc 7>UMiUeiinpin ' Figure 7.3: Schematic sketch of the intra-oceanic subduction regime interfered by marginal basin formation (back arc spreading). Diapirs of MORB source, rising from deep in the asthenosphere and slightly contaminated by subduction fluids, interceded and suspended island arc magmatism and formed a back are spreading floor. Interactions of these tholeiitic melts with the host lithosphere were less and close to the mantle-crust transition zone. These melts crystallize Al-rich chromites as those observed in Al’Hel Reids. 233 change to harzburgite appears largely to be sharp, but a gradual change is also observed. Where dunite progressively changes to harzburgite, a few inclusions of harzburgite are sometimes enclosed in the dunite (Figure 5.1). This is probably evidence for assimilation and interaction between the melt and the wall rocks. Where a sharp faulted contact is observed, it should be an indication of a transport by faulting. Zhuo et el. (1994, 1996) emphasized that the Luobusa chromitite is always surrounded by a dunite envelope in the harzburgitic host, and considered this as evidence for the residual affinity of dunite. However chromitites directly bordering harzburgites (although not common) can be also found. b. Rhythmic layering Well-defined rhythmic layers in dunite and chromitite sometimes with alternating rock types and sometimes with grain-size sorting are documented in several examples. Centimeter-scale rhythmic layers are shown in Plate 5.4 & 5.5. On a larger scale, a sequence of elongated massive layers changing in thickness and alternating with dunites are shown in plate 3.17, while a rhythmic layer with grain size sorting and graded sequence is shown in Plate 3.24. These features are very strong evidence for a magmatic sedimentation origin, and can not be due a partial melting (Leblanc, 1987; Zhuo et el., 1994,1996) or subsequent deformation. In addition, Plate 5.17 shows a chronological sequence where a layered succession from nodular chromitite to disseminated chromitite to dunite was folded and then faulted. c. Nodular texture Nodular texture characterizes podiform chromitite and is believed to originate by concentration in a melt vesicle (Thayer, 1964 &1969; Leblanc et al., 1981; Malpas & 234 Robinson, 1987; Leblanc, 1987). Small to medium nodules (globules) are found in all three major fields, but the large nodules (grapeshots) are only observed in Zikt area. In some grapeshots, outlines of euhedral hexagonal crystals can be easily identified because the narrow interstices are filled by serpentine materials (Plate 5.11), d. Pegmatite A few igneous mafic pegmatite dikes and sills, occur in the upper mantle rocks of both Al’Hel and Zikt. Sample Z8-Bcl (pyroxenite/massive chromitite) and Z8-P6.2 (altered pyroxenite dikes) in Zikt are mafic pegmatites (Guilbert & Park, 1986) that contain high Cr-rich chromite grains, wherase Z8-Bcl also contains chromites enclosed semi-poikilitically in large pyroxenes (Plate 4.19, Figure 4.6d). 133.1 Pétrographie Evideace a. Chromite textures Chromite grains in chromitite and chromite-bearing dunite exhibit several textures that are considered to be magmatic in origin. For example, chromite net & occluded silicate texture (Plate 5.3), and circular texture (chain texture, Plate 5.6) are of magmatic origin (Thayer, 1969; Greenbaum, 1972; Brown, 1980, 1982). Net texture is the most widespread texture in the Semail ophiolite. b. Cumulus texture In some dunite samples, examples of chromite and/or olivine grains poikilitically enclosed in pyroxene are clearly seen (Plates 4.3 & 4.9). In addition, intercumulate pyroxene or olivine can be detected in some dunite or wehrlite samples (Plate 4.14). Intercumulus texture results from crystallization of an interstitial melt (Williams et 235 al., 1982), and because no zoning has been detected, equilibrium between the intercumulates and already crystallized aggregates has been maintained. c. Deformation Coarse-grained subhedral to euhedral olivines with straight grain boundaries and undulose extinction are present in several dunite samples (Figure 4.1 ; Plates 4.3 & 4.15). These are different from the small euhedral olivine grains resulting from recrystallization (chapter 4). Euhedral granular coarse grains with straight faces are a characteristic of very slow early crystallization. d. Inclusions Inclusions of olivine, serpentine, pyroxene and amphibole occur in many chromite grains, and chromite inclusions can be found in some olivine and pyroxene grains in chromitites and dunites (Plates 4.17 & 4.19). A chromite grain may even be included in an olivine grain that is in turn enclosed in chromite. This is clearly shown by an enlarged scanned image from the SEM (Figure 7.4). Qualitative EDS analysis shows that the central chromite has about the same composition as the outer one. This is probably an indication that the trapped inclusions crystallized from the same liquid from which the ore formed, as is suggested by other evidence (see below). Inclusions trapped in chromite grains in rocks of the Semail ophiolite and other complexes have been studied by many workers (e.g. Talkington et al., 1984; Lorand & Cottin, 1987; Lorand & Ceuleneer, 1989; Van der Veen & Maaskant, 1995; Schiano et al., 1997). Most of them considered entrapment of the inclusions to be contemporaneous with the magmatic chromite precipitation Lorand & Ceuleneer (1989) stated that each inclusion behaves as an isolated system as soon as it is 236 « % Figure 7.4: Microprobe scanned image shows a small chromite inclusion (pale gray) at the center of an olivine grain (gray) that is in turn enclosed in chromite grain. Composition of the chromite in the center is about the same as that of the outer chromite grain. The bar in the photo equals 20 micro. Sample Z9-P3. 237 trapped. For instance, reaction between clinopyroxene and the trapped melt explains the abundance of pargasite, whereas the occurrence of albite (plagioclase) is explained by reactions involving calcic plagioclase. Schiano et al. (1997) demonstrated experimentally that inclusions in chromite grains represent hydrous primitive basaltic melts identical to the parental melts from which the chromite precipitated and that characterize present-day destructive margins. Van der Veen & Maaskant (1995) suggested that silicate inclusions in chromite were formed by infiltration of hydrous K-Ca rich melts contaminated by wall-rock interaction into partially solidified dunite cumulate. Consequently, although some amphibole inclusions might be alteration products, others (e.g. hornblende, ednite) probably represent hydrous phases precipitated from melt. In addition, the absence of plagioclase in inclusions may be support for a magmatic origin (Lorand & Ceuleneer, 1989) rather than reflect alteration. This in turn implies a subduction-related origin of the crystallizing melt modified by wall- rock interaction. T.3.3.3 Whole Rock Chemistry Whole-rock analyses may be less useful in constraining genetic models because, as noted previously in chapter 6 , such analyses are very susceptible to post formation modification. Moreover, this study focuses on early crystallized rocks and residual mantle (rather than a melt or late-formed rock). The chemical difference between residual rocks and early formed rocks is small and approached analytical precision. Despite that, some useful conclusions can be drawn from whole rock geochemical data. 238 a. The bulk rock chemistry is consistent with Al’Hel representing relatively less depleted mantle than Zikt (Chapter 6 , Table 6.1). Although, this is quite obvious for Ca and Al, these element are more affected by alteration. However, Cr and Ni show slight decrease toward Al’Hel (Figure 6.1), and Mg # increases from ATHel to Zikt. For all rock types, modal mineral proportions control elemental concentrations. b. Incompatible trace element patterns of dunites and chromitites are marked by positive Ti anomalies except in 3 samples from Zikt (Figures 6.2 &6.3). This is a very important indication of the magmatic affinity of these rocks, as this anomaly does not occur in harzburgite residues. Ti can readily enter orthopyroxene and spinel (Eggins et al, 1998) and one could argue that the Ti anomalies only reflect the modal proportion of spinel and orthopyroxene in these rocks. However, if this is true then harzburgite should have more Ti than dunite with similar chromite/silicate ratio, because harzburgite includes more orthopyroxene in addition to chromite. The three samples (Figure 6.3) that show depletion in Ti lack orthopyroxene and spinel. c. A slight enrichment of some ULE in dunite and chromitite samples could be caused by interaction with a fluid-enriched magma generated above a subducted slab (Cox et al., 1979; Pearce, 1982). Barium concentrations are a sensitive indicator for sediments subducted at Benioff zones (Wilson, 1994). However, subduction related magma commonly displays negative Mb anomalies that are not seen in the rocks studied here. Nb can be accommodated in amphiboles (Deer et al 1993) that occur in these rocks. This is another indication of metasomatic interaction of rising subduction zone melt with wall rocks. In addition, some of the dunite samples may be residues after orthopyroxene extraction. In Figure 6.2, Al’Hel dunites and chromitites are richer in 239 Sr than those from Zikt (Figure 6.3). Alteration might be cause of this, but it is more consistent with the presence of clinopyroxene in these rocks (Mason & Moore, 1982; Eggins et al, 1998) as indicated by petrography. d. In the discrimination diagram between Ta/Yb and Th/Yb (Figure 7.5), all dunite and chromitite rocks plot outside the MORB field except few data from Al’Hel and two from E. Zikt. All other data plot in fields for subduction related magmas. e. REE patterns for samples from Al’Hel and Zikt are different. REE patterns for Al’Hel dunite and chromitite show a concave pattern (Figure 6.5) similar to those of the harzburgites (Mason & Moor, 1982; Hall, 1993). In contrast, REE patterns for dunites and chromitites in both the east and south Zikt fields show enrichment in the LREE relative to the HREE (Figure 6 .6 ). The relative LREE depleted pattern shown by ATHel samples is characteristic of tholeiites, whereas LREE enrichment shown by Zikt samples is characteristic of calc-alkaline (Wilson, 1994) and boninite magmas (Rogers & Saunders, 1989) such as those from Cape Vogel, Papua New Guinea (Hickey & Frey, 1982). f. Massive chromitite samples that have the greatest enrichment of Os, Ir & Ru (e.g. Z9- Shl, Z9-P3, Z9-Sc6) (Figure 6.9) contain both chromite and olivine, which have the highest Cr and Ni content respectively, relative to the other coexisting rocks (see chromite and olivine chemistry). In addition, they are generally richer in REE (Figure 6 .6 b). Consequently, it appears that the high PGE concentrations and high Cr & Ni contents in chromitites are linked, and are related to melts rising from different sources, and seemingly modified by other processes. The likely modification mechanisms are subduction fluid phase, and interaction with host rocks. The 240 Chromitite & Dunite 100 T- I " ^ 3 0.01 0.01 0.1 1 10 Tam) Figure 7.5: Plot of the whole rock Ta/Yb against Th/Yb ratios of dunites and chromitites of all fields, in Pearce et al.’s (1983) discrimination diagram. All rocks (except two of Al’Hel) plot within the Held of subduction related magmas and outside MORB zone. They also reveal a relative enrichment of Th over Ta and Yb. 241 subduction fluid would increase the light LREE. Melt interaction with the wall rocks would decrease the Fe content by buffering the Mg content of the peridotite host (Kelemen, 1990). Decreasing Fe content of melt would cause sulfide precipitation (Lorand, 1988), which may lead to Os, Ir & Ru concentration, particularly if the viscosity of the melt increases with increasing silica due pyroxene dissolution from the wall rocks (Kelemen et al., 1990, 1992). 7.3.3.4 Mineral Chemistry The chemistry of chromite, olivine, pyroxene and amphibole gives both direct and indirect support for to the proposed genesis. (i) Chromite chemistry a. Plots of the chromite compositions from rocks of all fields in term of MgO versus CrzO], AI2O3 and FeO reveals three important points. (1) The trends of dunite and chromitite of Zikt are different from those of Al’Hel and harzburgite (Figure 7.6). (2) The Al’Hel dunite and chromitite trend is located within the mantle harzburgite array at the least depleted end, whereas those of Zikt plot outside the harzburgite array and toward the most depleted end (Figures 7.7 & 7.8). (3) Zikt dunite and chromitite trends form arrays perpendicular to the mantle harzburgite array (Figures 7.7 & 7.8). These chemical characteristics lead to the following conclusions. (1) The origin of the Zikt dunite and chromitites is different from those of Al’Hel. (2) The composition of magmas that precipitated chromites at Al’Hel is close to that of the melt extracted from harzburgite, but not exactly the same because MORE melt is not expected to precipitate much chromite (Zhou et al., 1994,1996; Malpas et al., 1997; Zhou & 242 UAE Chromites 17 AShCNom. •SoChnim. □ V m 15 - ASAOumW SSDHMZb. ; AScOwnH# 13 - i AScHMZb. I KkmChmm. i rnVMChmm. % 1 1 - ; ■WlOunte ! AWIHwz O) I AVKng 5 9 OSiCtmMn. : #S#OunN# 7 - OOH»4PmU +PmlOifom. -PriOunto 5 - APiMwzb. •PBdito 3 - —r- 6 11 16 21 26 FeO wt % Figure 7.6: Plot of FeO wt % against MgO wt % of chromite in all rock types of all fields. With increasing MgO/FeO ratio, Zikt chromitites and dunites form a different trend form that of the mantle harzburgites, whereas the trend of Al’Hel chromitites and dunites is located in the harzburgite trend to slightly below it. 243 UAE Chromites Al'Hel E..Zikt A ShC hrom . •S c C h ra m . D V era A ShO unite X ShH atzb. O ScO unite AScHarzt). XlceChrom. OWI Chrom. □W l Dunite AW I Harz I A Viking j C'SijiChrom. I BSijlDunite OCrH94Perid +PalChrom. -PalOunite A PalH arzb. 16 AI203 wt % Figure 7.7: Plot of AI 2O3 wt % against MgO wt % of chromite in all rock types of all fields. The mantle harzburgite forms a distinct diagonal array from low MgO and AI2O3 (high depletion end) to high MgO and AI 2O3 (less depletion end). Al’Hel dunites and chromitites plot within and close to the border of this array at its less depleted side. By contrast, Zikt dunites and chromitites project trends perpendicular to the harzburgite array and at its high-depleted side,, with dunites forming the mutual connection with the array. 244 UAE Chromites AShChrom. •ScChrom. □Vera AShOunite XShHatzb. OScOunite OScHarzb. XlceChrom. B W I Chrom. □ W l Ounite O W I Harz AViking OSijiChrom. ■SijlOunlle I OCrH94Perid j , ♦PalChrom. j ! •PalOunite I APalHarzb. J -r 30 35 40 45 50 55 60 65 70 C r 2 0 3 w t % Figure 7.8: Plot of CriOs wt % against MgO wt % of chromite in all rock types of all fields. The mantle harzburgite forms a distinct diagonal array from low MgO/CriOs ratio (high depletion end) to high MgO/CrzO] ratio (less depletion end). Al’Hel dunites and chromitites plot within and close to the border of this array at its less depleted side. By contrast, Zikt dunites and chromitites project trends perpendicular to the harzburgite array and at its high-depleted side, with dunites forming the mutual connection with the array. 245 Robinson, 1997). The melt crystallizing chromite at Al’Hel is MORB-like back arc magma which precipitates Al-rich chromite (Wilson, 1994; Malpas et al., 1997; Zhou & Robinson, 1997; Leblanc, 1995,1997). (3) In contrast, the melt precipitating chromite at Zikt was different from MORB and similar to calc-alkaline to boninite magmas, hence the Cr-rich chromites of Zikt. Cr-rich chromites are characteristic of boninite magma (Wilson, 1994; Malpas et al., 1997; Zhou & Robinson, 1997; Leblanc, 1995, 1997). b. Plots of Mg # against Cr # for chromites from all chromitite and dunite in the studied fields (Figures 6.21, 7.9) show that Al’Hel rocks plot in MORB field, whereas most S. Zikt rocks plot in the boninite field, and E. Zikt chromite plot between these fields. c. Titanium partitions into the liquid phase during partial melting and fractional crystallization. It is immobile and stable during low temperature alteration and metamorphism minerals (Saunders et al., 1979; John, 1982; Hickey & Frey, 1982). The Ti contents of chromites in chromitite and dunite are higher than that of harzburgite (Figure 7.10). Using the TiOz versus Cr#, discrimination diagrams of Arai (1992) and of Zhou et al. (1994), chromites in harzburgite plots in the depleted peridotite field, whereas chromites in dunite and chromitite plot in the island arc and boninite field (Zikt), and in the island arc and MORB field (Al’Hel). (Figures 6.25, 7.11). d. Vanadium is also immobile, and like Ti, resistant to alteration and serpentinization (Saunders et al., 1979; John, 1982). V has multiple valence states (3+, +4, 5+) that are a function of/O, (Lindstrom, 1976; John, 1982; Eggins et al., 1998). At low fOz in the upper mantle, vanadium is mostly trivalent and can substitute in pyroxene or 246 UAE Chromite 100 ■ CrZ7-P6diiw Xlcatarg-Chr ■Wl Chrom. AVIidng >;< SipChrom ■ SipOunit* •f PalChrom. o ! "PalOunite AShChrom. AShOunite eScOunite • ScChrom. DVara « Pxtdika 5 0 - /•?/ / MORB / 40 80 70 60 50 40 30 20 10 Mg« Figure 7.9: Plot of Mg # (100*Mg/(Mg+Fe)) against Cr# (lOO*Cr/(Cr+AI)) of chromite in all rock types of all fields. Most chromitites and dunites o f S. Zikt plot in boninite zone while those of Al’Hel plot in and outside MORB zone. E. Zikt chromitite and dunites are in between and within Troodos zone. MORB field from Dick & Bullen (1984), Troodos from Cameron (1985), and boninite zone from Bloomer & Hawkins (1987). 247 UAE Chromite OWI Chrom. -W l Harz AViking XCrH94Perid A PalChrom. X PalOunite ? n 50 XPalHarzb. OShChrom. o ShOunlte XShHarzt). X ScChrom. OScOunite XScHarzb. ■fVera 0.05 0.15 0.2 0.25 0.3 Ti02wt% Figure 7.10: Plot of TiOj wt % against CrzO] wt % of chromite in all rock types of all fields, showing the mantle harzburgites contain very low TiOz values, £ 0 .1 wt %, while dunites and chromitites include higher values reaching up to 0.285 wt %. This higher values is an indication of magmatic and different source region than the host harzburgite for the precipitating melt. 248 UAE Chromite QWI Chrom. 0 0 ° XWI Harz Boninite AViking XCrH94Perid A PalChrom. X PalOunite XPalHarzb. 4k O ShChrom. W o o ShDunite XShHarzb. X ScChrom. O ScOunite XScHarzb. Highly % +Vera depleted depleted ♦ IceChrom. harzburgite harzburgite Wl Dunite 0.001 0.01 0.1 Ti02wt% Figure 7.11 : Plot ofTiO? wt % against Cr# (100*Cr/(Cr+Al)) of chromite in all rock . types o f all fields, showing the mantle harzburgites plot in the depleted mantle field. Zikt chromitites and dunites mostly plot in the boninite field, while those of Al’Hel plot close to and in the MORB field (Fields from Zhou et al., 1996). 249 spinel. This is manifested by the V 2O3 contents of the chromite in these rocks, which is highest in chromites of harzburgite and lowest in chromites of chromitite. e. AI2O3 contents of magmas Calculating the AI 2O3 content of the parental liquid of the massive chromitite in Zikt, using the Maurel & Maurel (1982) equation (see appendix), gave values of 8.95- 11.36 wt %.close to those of high-Mg boninitic liquids from Troodos, Cyprus, and Luobusa, China (Robinson et al., 1983; Zhou et al, 1996). (ii) Olivine chemistry a. Fo contents of olivine in the mantle harzburgites are higher in Zikt samples than in Al’Hel samples. This is consistent with the more depleted nature of Zikt samples. Fo contents of olivine in chromitite and dunite shows a similar trend. This trend is consistent with formation of Zikt podiform bodies from high magnesian melt (% calc- alkaline-boninite), while those of Al’Hel formed from less magnesian melt (tholeiitic basalt). b. Ni Content Olivines in the chromite rich segregations (particularly massive chromitites) show unusually high Ni values, much higher than the upper limit of NiO in olivine in harzburgite (~ 0.4 wt %). These high Ni olivines also have high Fo values. Surprisingly, coexisting chromites of the same chromitite rocks also show high Mg # and high Ni contents. These relations are clearly illustrated in the covariance between olivine and chromite in term of Mg# and NiO (Figures 6.28,6.30). High Ni olivines are recorded from some samples of ophiolite such as the Thetford ophiolite, Montreal Canada (up to 0.78 wt %, Talkington et al., 1986), and Tiebaghi massif. New 250 Caledonia (up to 0.6 wt %, Moutte, 1982). In these ophiolites, the high Ni olivines occur as inclusions in chromite grains in chromitite ores. A similar example is recorded in Archean Komatiite, southern Zimbabwe. In the Belingwe greenstone belt (Renner et al., 1994) and in the Inyala Komitiite (Rollinson, 1997), NiO reaches up to 0.86 wt % in olivine. In all cases, NiO positively correlates with MgO and Fo that olivine with the highest Fo (-97 in Inyala) has the largest NiO content. Olivine phenocrysts with high NiO (> 0.51 wt %) and Fo (93.6-94) are interpreted as early cumulates crystallized from komatiite magma of 27-30 wt % MgO (Bickle, 1982; Nisbet et al., 1993). Because the most magnesian olivine in Inayala chromitite are more magnesian than those of Komatiite magma, Rollinson (1997) suggested that these olivines reequilibrated with chromite during cooling. NiO contents higher than ca. 0.4 wt % (4000ppm) are not expected in olivines precipitating from basaltic or picritic magma, nor in olivine that is residual from partial melting, because the NiO content of the upper mantle peridotite is about 0.4 wt%, and thus even the earliest precipitating olivines would not exceed this value. Therefore, the high NiO contents of olivines in the Zikt chromitite rocks (e.g. samples Z9-P3, Z8-Shl3.2, Z9-P6) may reflect reequilibriation with chromites. Calculated liquidas temperatures of komatiite melt with 27-30 wt % MgO using the Smith & Erlank (1982) equation are 1550-1606 °C, and increase linearly with increasing MgO content of the liquid or with Fo and Ni values of the olivines in equilibrium with the liquid (Hart & Davis, 1978; Bickle, 1982; Renner, 1989). A similar temperature range is obtained using the Renner (1989) or Nisbet et al. (1993) equations (see appendix). The high Ni olivines of Zikt chromitite are much more 251 magnesian (up to Fo97) than those in komatiite. This means that Zikt chromitite segregations crystallized from higher temperature melts that formed at higher degrees of partial melting than those of average komatiite magma. This conclusion is apparently impossible in the view of upper mantle composition, and again indicates that another mechanism must account for the Ni contents of olivines in the Zikt chromitite rocks. Re-equilibration provides the key to this problem. Rollinson (1997) suggested that high Ni- olivine and spinel in the Inyala komatiite formed during reequilibration, and Moutte (1982) proposed that high Mg & Ni in olivines of the Tiebaghi ophiolite. New Caledonia formed during subsolidus reequilibration. Re equilibration is probably also responsible for high Ni and Fo value of olivines of Zikt chromitites. (3) Pyroxene chemistry a. The Mg # of orthopyroxene in Al’Hel peridotites is lower than that of orthopyroxene in the Zikt rocks. This together with the lower Fo contents of olivines in the same rocks is consistent the Al’Hel mantle being less depleted than the Zikt mantle. (4) Amphibole chemistry a. The only amphibole found in the harzburgites is tremolite which likely represents an alteration product of pyroxene. On the other hand, chromitites and dunites contain a wide range of amphibole ranging in composition from tremolite to ednite/pargasite. A few of these occur as inclusions in chromite grains (Figures 6.35, 36). Although, many of the amphiboles in dunites and chromitites are alteration products, some probably cystallized from a melt as inferred by many workers (e.g. Talkington et al., 252 1984; Lorand & Cottin, 1987; Lorand & Ceuleneer, 1989; Van der Veen & Maaskant, 1995; Schiano et al., 1997). 7.4 Support from other research work Formation of the Semail ophiolite as the result of subduction related magmatism has been suggested by almost all recent workers (e.g. Page et al., 1981b; Pearce et al., 1981; Browning & Smewing, 1981; Browning, 1984; Lippard et al., 1986; Umino et al., 1990; Yanai et al., 1990; Robers & Neary, 1993; Schiano et al, 1997; Seale & Cox, 1999). In addition, calc-alkaline island arc basaltic and MORB compositions were documented in Semail basaltic and volcanic rocks (Pearce et al., 1981, 1983, Lippard et al., 1986). 7.5 Chromite Precipitation: Changes in T and P conditions of rising melts may cause chromite precipitation. Decreasing pressure will increase the dissociation of water in the melt (Brown, 1982) and thus fO: may increase, which will enhance chromite precipitation as suggested for many stratiform intrusions. However, this does not seem to be a major factor in the Semail ophiolite as indicated by the low FezOs of the chromites compared to those of stratiform intrusions. Fe-Mg partition between chromite and silicates is temperature dependent (Wilson, 1982; Sack & Ghiorso, I991a,b) and a temperature decrease at constant JO2 may cause chromite precipitation (Murck & Campbell (1986). However, even if T, P and fOi have some influence on chromite precipitation, it could only explain formation of 253 disseminated chromitites and/or chromite-bearing dunites, because basaltic melt does not contain more than ~500 ppm Cr. As discussed above, chromite and associated minerals in the upper mantle peridotite of the northern Semail ophiolite mainly formed above a subduction-zone environment. It is proposed that melts contaminated with subducted slab material migrate through the upper mantle lithosphere. As the melts rise, they interact with wall rocks under disequilibrium condition. Metasomatism of the mantle peridotite and dissolution of some materials (e.g. pyroxene) cause an increase in Mg and Si of the melt. Addition of silica to the melt increases the bridging Si-O-Si bonds and thus polymerizes the melt (Philpotts, 1990). The polymerization will drastically decrease the solubility of metals in the melt, especially heavy metals such as Cr, Fe & Ni, and thus cause chromite precipitation. When this mechanism is operative, melts precipitating olivine and chromite in Irvine’s (1977) ternary diagram shift in to the chromite field and precipitate monomineralic chromite bodies (massive chromitites) (Figure 7.12). As in a few examples from Zikt, Ni may also concentrate in these bodies. Boninitic melts contain much higher Cr (~1200ppm) and lower AI 2O3 (-9 wt %) than do tholeiites (-SOOppm Cr and -IS wt % A I 2 O 3 ) (Malpas et al., 1997; Ballhaus, 1998). Therefore the boninite is believed to have precipitated Cr-rich chromites in the Zikt fields, whereas the tholeiites precipitated Al-rich chromites in the Al’Hel fields. 254 ? Chromite ^6,'fttSlmr’iifttHmr h %A#u \ ftrwUY^ Olivine 0/iWmt. '•< Chr Figure 7.12: Chromite precipitation model suggested in this study is presented in the olivine-chromite-quartz ternary diagram of hvine (1977). Interaction of the primary melt (A) cotectically precipitating olivine and chromite will lead the crystallization to inter the chromite primary volume, forming massive chromitites along the trend A-B (in a similar way presented by Zhou et al., 1994,1996). Fractionation of chromite will form two different trends based on the primary melt and the host rock interacted with. Trend B-C2 is expected to produce in Al’Hel as interaction mechanism would lead to pyroxene saturated melt in Al’Hel relatively more than in Zikt that form the fractionated trend B-Cl. Mixing of the fractionating melts with a new primary pulse (A) also produces two different hybrid melts (dotted lines), but both are located in the chromite volume. 255 CHAPTERS Conclusion Chromite bodies in the UAE occur in the upper mantle peridotite of the Semail ophiolite, particularly in the Al’Hel, Siji and Zikt areas. Their occurrence is similar to those podiform chromitites found in most ophiolite complexes, and is generally different from stratiform chromitites found in layered intrusions. Siji bodies show similar chemistry to Al’Hel bodies that are located close to the mantle-crust transition zone, whereas Zikt bodies are different from Al’Hel, and are located deeper in the mantle sequence. Because of this, Siji was not considered in detail in this study that is concentrated on the Al’Hel and Zikt areas. Collective field and pétrographie observations, together with whole rock and mineral chemistry lead to division in to three major zones: Al’Hel, E. Zikt, and S. Zikt. Chromite localities of the Al’Hel field are very close to the transition zone, and formed in relatively less depleted peridotites than those in Zikt. Chromite bodies of this zone lack nodular texture and contain little modal of pyroxene. The chromites are low grade, and are characterized by high A1 contents. In contrast, the Zikt region is located deeper in the mantle sequence, with E. Zikt closest to the transition zone, and S. Zikt fiuthest from the transition zone (~ 5.5 km). The S. Zikt fields contain the highest grade 256 (Cr-rich) chromites, whereas, E. Zikt chromite composition is in between that of Al’Hel and S. Zikt. As in any other mantle ophiolite, the region shows signatures of high and low temperature deformation, alteration and serpentinization. These processes have partially obscured evidence for the genesis of the chromite ores. However, evidence from field, petrograpic and geochemical studied have provided clues to the likely process of formation of the chromites. It is concluded that there were three stages of formation. First, partial melting at MOR spreading center during drifting of Afro-Arabia from Eurasia (~ 200Ma ago). No significant chromite accumulation is expected during this period. Second, island arc magmatism occurred above an intra-oceanic subduction zone that formed due to northeastward movement of Arabia toward Asia (commenced at ca. 110 Ma). At this stage the Zikt chromite orefields originated by interaction of calc- alkaline melts with upper mantle harzburgites. Third, back-arc (marginal basin) spreading occurred and the Al’Hel orefields formed during this period through interaction of MORB-like melts with their relatively less depleted peridotites. In other words, Al’Hel chromite bodies formed from MORB-like tholeiite melts in a marginal basin environment, whereas, the Zikt chromite bodies originated from calc-alkaline to boninite melts in an island arc to fore arc environment. These observations are consistent with the different compositions of chromite at Al’Hel and Zikt. The main driving force of the chromite precipitation, particularly massive chromitite, is disequilibrium interaction between rising magma and the wall rocks. This process leads to enrichment melts of Mg and Si in melts by dissolution of some peridotite materials (e.g pyroxene). Increasing silica content leads to an increase in polymerization, 257 decrease in Cr (and probably other heavy metals) solubility in the melts, causing chromite precipitation and accumulation (Figure 612). 258 PETROGENESIS OF CHROMITE AND ASSOCIATED MINERALS IN THE UPPER MANTLE PERIDOTITE OF THE NORTHERN SEMAIL OPHIOLITE (UAE) “Volume n” DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University by Solaiman AlAabed, MS. ********* The Ohio State University 2000 Dissertation Committee: Approved by Professer Michael Barton, adviser Professer Hallen Noltimeir L â - ___ Professer Douglas Pride Adviser Professer Terry Wilson Department of Geological Sciences TABLE OF CONTENTS Page Appendices; A. Petrography A l Introduction ...... 259 A.2 Al'Hel...... 259 A 3 E. Zikt (Palace)...... 267 A 4 S. Zikt palace) ...... 276 A 5 List of main samples and their location ...... 282 B. Whole-rock analysis ...... 285 C Minerai chemistry ...... 308 C. 1 Chromite analysis ...... 313 C 2 Olivine analysis ...... 502 C 3 Pyroxene analysis ...... 567 C 4 Amphibole analysis ...... 602 Bibliography ...... 615 xxxui UST OF TABLES Table Page B. I Analysis of major and trace elements ...... 286 8.2 Taylor and McClennan’s (1985) chondrite values ...... 292 B.3 Analysis of incompatible trace element ...... 293 B .4 Analysis of Rare Earth Elements (REE) ...... 299 B.5 Analysis of Patinum Group Elemetns (POE) ...... 305 C. I List of standards used in analyzing the oxide minerals ...... 309 C.2 List of standards used in analyzing the silicate minerals ...... 310 .XXXIV UST OF nCURES Figure Pape C I Sample form of chromite formula calculation ...... 312 C.2 Sample form of olivine formula calculation ...... 501 C 3. Sample form of pyroxene formula calculation ...... 566 XXXV APPENDIX A PETROGRAPHY A.1 Introduction Representative samples for more than 200 samples collected from the freld were selected for thin section study. A description of many of the samples used is given here. To avoid repetition, not all samples are described because some descriptions are included in chapters 3-5 and many are similar to described samples. List of the main samples, their names and locations are given at the end of this section. A.2 Al'Hel Sample H8-I1 DISSEMINATED CHROMITITE This sample shows the anti-nodular texture of chromites. Chromites (-50 %) and serpentines (-48 %) are the major constituents along, with some relict olivines (-2 %). Chromite grains are medium sized (0.4mm - 1.8mm), subhedral to anhedral, and red- brown in color. Many grains have a reddish brown interior is rimmed by an irregular black crust. The distribution of chromite aggregates forms a classic chain texture in addition to the pull-apart texture in which grains generally show a random orientation. Silicate inclusions are common in chromites and are mainly serpentine composition Most pull-apart fractures do not cut the silicate inclusions. Serpentine is the dominant alteration product after olivine and probably pyroxenes. It forms interference color of fibrous plates & flakes with some relict olivine grain outlines that fill the fractures and spaces between chromites aggregates. A few olivine grains reserve their original features. 259 Sample H8-I2 DISSEMINATED CHROMITITE This also shows the anti-nodular texture of chromites. It is similar H 8 -II, but but contains less chromites (~45 %) and olivine ("-55 %) is only partially serpentinized. Chromite grains are medium sized (0.4mm - 1 8 mm), subhedral to anhedral, and red- black in color (red brown interior mantled by irregular black crust). Chain texture is obviously distinguished. Pull-apart cracks show two styles; parallel pull-apart cracks that are perpendicular to the grain elongation, and cracks that outline grain boundaries. Silicate inclusions are mainly serpentine Most pull-apart fractures do not cut these inclusions. Olivines are fragmented (<0.1mm-0.4mm) and partially serpentinized. They occupy the spaces between chromite aggregates, while fibrous & flaky serpentine fills fractures in olivines and chromites. Sample H 8 -IS DISSEMINATED CHROMITITE This sample shows three distinct domains: chromites in olivines, chromites in amphiboles/pyroxenes, and pyroxenes/amphiboles. In addition, there are two veins filled with fine-medium grained pyroxene and amphibole. The sample from which this slide was cut consists of disseminated chromitite rock cut by a white vein (2-3 cm). One section is merely disseminated chromitite similar to the sample described above, but the chromites are larger (up to 3mm). The section is cut by a small vein (1 mm thick) filled with amphibole. Another section is a disseminated chromitite with larger more close packed chromite (up to 4mm), that is black in color. Inclusions and the spaces between fi’agments are mainly pyroxenes and amphiboles. The section is cut by a 2.2mm fi’acture filled with mainly fine-medium grained pyroxenes, amphiboles. Pyroxene in mostly clinopyroxenes, and amphibole is mostly tremolite. A third section is pyroxenite dominated by coarse-grained clinopyroxene with some amphiboles (e.g. tremolites) and lack chromite. This section actually represents part of the white vein of the second thin section described above. In the second section, close to the border with the third section, a large pyroxene oikocryst poikilitically encloses some chromite grains. 260 Sample H 8 -I6 DISSEMINATED CHROMITITE This rock is dominated by olivine (-55 %) and chromite (-45 %). Olivines are fragmented (not greater than 0.5mm maximum size) and altered to mainly serpentine. Some biotite and chlorite occurs around olivine. Alteration products occupy fractures and spaces between olivine fragments. Two major fracture sets are clearly recognized in many grains. Chromites are medium sized (up to 2 mm), subhedral to anhedral, and zoned in color from red to black. They are partially fragmented, with fractures and cracks that outline some grain borders, sometimes crosscut each other. However, parallel pull apart cracks are also present. Silicate inclusions are mostly serpentine and olivine, and are not cross-cut by pull-apart cracks. The distribution of chromite aggregates forms a chain texture. Sample H 8 -I8 DISSEMINATED CHROMITITE As in the sample described above, olivine (-55 %) and chromite (-45 %) are the major constituents, with about 1 % pyroxene on one edge of the slide. Olivines are fragmented (< 0 . 1 mm - 0.9mm), and altered to serpentine minerals. Some biotite and chlorite occurs around olivine grains. Alteration products occupy fractures and spaces between fragments. Several sets of cross cutting fractures can be recognized. Chromites are fairly large (up to 3 mm), subhedral to anhedral, and in color red. They are partly fragmented, forming 2 sets of cracks; cracks that outline the fragment borders and pull- apart cracks that are often parallel to each other and are nearly perpendicular to the grain elongation. Silicate inclusions are mostly serpentine and olivine, and are not cross-cut by pull-apart cracks. Chain textures are clearly shown by chromite distribution in the sample. Sample H8-I10 DISSEMINATED CHROMITITE This rock is dominated by olivines (-60 %) and chromites (-40 %). Olivines are fragmented (< 0 . 1 mm - 0 .8 mm), and partially altered to serpentines along, with some 261 biotite and iron oxide. The alteration products fill the fractures and spaces between fragments. Chromites are subhedral to anhedral, up to 2mm in diameter, and are red in color with end irregular black thin crust along the grain boundaries. They are partially randomly cracked with some pull apart fractures. Silicate inclusions are serpentine and/or olivine. Chromite grains form chromite net and chain textures. Sample H8-I11 DISSEMINATED CHROMITITE This rock consists of almost equal amounts o f olivine and chromite. Olivines (-50 %) are more fragmented (<0.1 mm -0.4mm), and more altered to serpentine than those in specimen H8-110 above. Biotites and iron oxide are rare. Alteration products fill the fractures and spaces between fragments. At least two sets o f cross-cutting fractures are distinguished Chromite fragments (-50 %) are also smaller (up to 1.4mm thick) than those in specimen H8-110, are subhedral to anhedral, and have red brown cores mantled by black rims. They are partially cracked with some semi-parallel pull-apart fractures. Silicate inclusions are serpentine and/or olivine, and are not cut by fractures. The distribution o f chromite grains forms chain texture. Sample H8-I12 DISSEMINATED CHROMITITE Olivines (55-60 %) and chromites (40-45 %) dominate this rock. Olivines are fragmented (<0.1mm - 0.6mm), and partially altered to serpentine but to a lesser extent than in the specimens described above. Some biotite and chlorite occur around olivine grains. Alteration products occupy the fractures and spaces between fragments. Two major sets o f fractures can be recognized with the younger one cutting older cracks and making the olivine fragments elongated. Chromites are relatively smaller (up to 1.3 mm) than in H8-110 and H8-111 specimens, subhedral to anhedral, and red. They are partly fragmented, forming pull-apart cracks that are often parallel to each other and to the younger dominant fracture set o f olivines. Other fracture directions are less well 262 developed. Silicate inclusions in chromites are mostly serpentine and olivine, and are not cross-cut by pull-apart cracks. The chromite aggregates form chain textures. Sample H8-113 DISSEMINATED CHROMITITE This is one o f a typical chromitite, dominated by chromite (70-75 %) and highly serpentinized olivine (25-30 %). Chromite forms medium aggregates (up to 2.5mm), subhedral to anhedral, and partially fractured. They have red interiors mantled by thin black irregular crusts and form chain textures. Two sets o f pull-apart cracks are recognized. One only occurs in a few grains, and crosscuts a second set which is ubiquitous, more pronounced, and parallel to that in olivine grains. Silicate inclusions are mainly alteration products of olivine (serpentine), and no cracks cut silicate inclusions. Olivines are highly fragmented to small aggregates (<0.1mm - 0.3 mm), and are mostly altered to serpentines with some biotites, chlorite, and iron oxide. Serpentine forms fibrous plates and flakes filling fractures and spaces between and around fragments. In places they form a mesh texture. However, in many areas, olivines are still preserved. Fractures in olivines are random, but 2 major sets can be clearly distinguished, one o f which is more pronounced. Sample H8-Vil DISSEMINATED CHROMITITE Chromite (-6 0 %) and serpentine (-40 %) are main constituents this rock. Chromite form large fragmented aggregates (up to I cm), subhedral to anhedral, and red to brown in color. They form a chain texture Although pull-apart cracks are generally randomly oriented, two sets can be recognized; cracks that are outline boundaries, and parallel fractures that form pull-apart texture. Silicate inclusions are mainly alteration products o f olivine (serpentine) and some relict olivine. Serpentine forms plates, fibers and small aggregates (<0.1mm - 0.4mm) that replace olivines and show mesh texture. Some olivine is preserved. 263 Samples H4-1/1 ALTERED HARZBURGHE Coarse granular rock dominated by olivine grain with chrome diopside (CPx), enstalite (OPx) and a few chromite grains. Almost all grains are highly fractured and veins between fractures are filled by serpentine that is the product o f alteration o f olivine and enstatite. Diopside is altered to tremolite and actinolite, while orphopyronene is altered to serpentine and chlorite (colorless to pale yellow color). Biotite flakes (pale brown) is altered to chlorite (pale yellow-green color). Some grains o f olivine are surrounded by iddingsite (dark red color), and some are completely altered to serpentine. Sample H4-13/23 HARZBURGUE This rock contains mostly highly fractured and cracked olivine crystals with some enstalite that often is altered to chlorite and amphibole and some chromite. Fractures between olivine grains are filled with serpentine, biotite (bright yellow color) and small amounts of secondary hornblende (pale green to yellowish-brown). Some olivine grains are surrounded by iddingsite (brown-red color). A few veins filled with calcite occur. Sample H4-15/25 HARZBURGITE Equigranular grains o f olivine and some enstatite (OPx). The minerals are highly fractured and the veins and spaces between grains are filled with serpentine. Some enstalites are partly or completely altered to chlorite. Biotite and pale brown hornblende also as do a few scattered grains o f chrome spine (bright brown color). A few veins are filled with calcite. Sample H4-16/26A SERPENTINIZED PERIDOTTTE (ALTERED HARZBURGITE) Equigranular texture o f mostly olivine and enstatite, highly fiactured rocks. Serpentine with some biotite occupies fractures and spaces between grains Few fragments 2 6 4 of chromite (dailc brown) are present. Some enstatites show undulose extinction (the results o f deformation). A vein cuts through the section and a zone of chlorite or serpentine, and a zone o f 2 pyroxenes (may be augite and diopside and hypersthene) at the boundary with olivine followed by a zone o f chlorite or serpentine, and very small aggregates o f carbonates in the center. Sample H9-WI2.1 Banded Chromitite Two bands of massive chromitite cut through disseminated chromitite (or chromitie rich dunite). Olivines are subhedral to anhedral, fragmented (0.1% - 0.4mm) and partially altered to serpentine materials and in places to serpentine, biotite and brown reddish iron oxide These alteration products occupy cracks and spaces between olivine fragments. Chromites are red, small to large (0.1-7mm), and euhedral to subhedral. Larger grains have silicate inclusions (olivine, serpentine, amphibole and pyroxene), and are partially fractured forming pull-apart texture that also occurs in olivine Sample H9-WI3 CHROMITE-RICH DUNITE Olivines are subhedral to anhedral, fragmented (0.1% - 0.4mm) and partially altered to serpentine ± biotite and brown red iron oxides. These alteration products occupy cracks and spaces between olivine fnigments. Chromites are black, small to medium, euhedral to anbhedral fragments. Larger grains have few silicate inclusions (olivine, serpentine, amphibole and pyroxene), and are partially fractured forming pull- apart texture. Sample H9-WI2.2 MASSIVE CHROMITITE The is same as H9-WI2.1, but black rims mantled outside fragments boundaries are more clear, and inclusions are distinctively less. 265 Sample H9-WI4 DUNITE This rock is dominated by olivine (-98%) with a few grains o f chromite (1-2%). Olivines are fragmented (< 1% - 0.3mm) and partially altered to serpentine materials ± iron oxides (reddish brown color). These alteration products occupy cracks and spaces between olivine fragments, forming a network like texture. Some olivines show thin parallel strain lamella. Most chromite grains are small to medium (0.1-1 mm), but two are larger (-3mm). They are black and euhedral to subhedral. Larger grains have silicate inclusions (mainly olivine/serpentine with few amphibole and pyroxene, and are partially fractured forming pull-apart texture. Sample H9-WIS HARZBURGITE Coarse granular rock contains olivine (-57 %), orthopyroxene (30-33 %), clinopyroxene (-7%), and chromite (2-3%). Medium to large olivines are fragmented and fractured to small aggregates (0.1-0.5), and partially altered. Fracture and fragment spaces are filled with serpentine, chlorite and biotite with little with some iron oxide Orthopyroxenes are medium to large enstatites. They are prismatic, elongated, fractured and partially altered to amphibole, chlorite and talc. A few pyroxene grains are completely altered. Clinopyroxenes are generally, smaller, subhedral grains. Chromites are small to medium, sub to anhedral, black grains with pull-apart textures in the larger grains. Sample H9-WI6 HARZBURGITE This sample is similar to H9-WI5, except that; there is more serpentine, many pyroxene grains show streaky exsolution lamella, and chromite grains are fewer less and are brown in color 266 A.3 E. Zikt (Palace^ Sample Z7-Ï4A CHROMITE BEARING DUNITE The rock is dominated by olivine (~90%) with scattered chromite (7-8 %) and a few orthopyroxene aggregates (1-2%). Olivines are highly fragmented to small fragments, and are partially altered to serpentines especially at the cracks. The cracks and boundaries between olivines fragments are filled with serpentine materials ± iron oxides (i.e. iddinsite). The size o f the olivines is between <0.1-0.8 mm. Orthopyroxene is enstatite (elongated & presimatic grains) and is partially replaced by serpentine and amphibole (e.g. uralite). Brownish black, subhedral to euhedral chromite grains are irregularly distributed. Their are between 0.2mm-1.3mm, and some o f them have silicate inclusions (mainly olivines and its alteration products). No clear zoning has been distinguished in any o f the three mineral types. Pull-apart texture is present in olivine and chromite, and in few places cracks extend across the specimen. The pull-apart cracks in chromites are near- perpendicular to the elongation o f the grains. Sample Z7-15.1 DISSEMINATED CHROMITITE &DUN1TE This sample consists o f two district regions; 1) disseminated chromitie and 2) dunite. The former represents 1/3 o f the sample and is dominated by large chromite grains (-85 %) with fragmented & altered olivines crystals (-15 %). Chromites are reddish brown and subhedral to anhedral, with sizes between 0 2mm to 6mm, mostly (3-6 mm). Silicate inclusions are mainly olivine and its alteration products. Pull-apart textures with parallel-elongated cracks are present. Olivines occur between chromite fragments. They are fragmented and mostly altered to serpentine. The olivine/serpentine fragments are smaller (< 0.1- 0.4mm) than in the dunite which represents 2/3 o f the sample and is dominated by olivine aggregates (>96 %) with few scattered chromite grains (-1%). Olivines are fragmented (< 0.1-0.7mm) and is partially altered to serpentine that fills the cracks and spaces between the fragments, and in places to iron oxide (iddingsites) that 267 rims fragments. In many places, pull-apart and parallel crack structures are present. Chromite is an only accessory and is smaller (0.1-l.Omm) than in the chromitite area. It is brown to black and mostly subhedral with no silicate inclusions. The pull-apart cracks are almost perpendicular to the elongation of the chromite grains, and cross the entire sample. They also crosscut other (older) cracks in dunite domains, indicating more than one deformation episode. Sample Z7-17 DUNITE This rock is almost completely olivine (> 97%) with few grains of chromite (-1%). Olivines are fragmented (< 1% - 0.5mm) and partly altered to serpentine, in places, to iron oxide (reddish brown color). These alteration products occupy cracks and spaces between olivine fragments, forming a network like texture. Chromite aggregates are mostly small (0.1-0.4mm), but two are larger (-3mm). They are black, and euhedral to subhedral The two larger grains have silicate (olivine / serpentine) inclusions, and are partially fractured forming pull-apart texture that also occurs in olivine. The pull-apart cracks do not have a well-defined orientation. Sample Z7-19 DISSEMINATED CHROMITITE This rock is dominated by two minerals present in almost equal amounts; olivine (45-50%) & chromite (45-50%). Olivines are fragmented (<0.1-0.3%) and mostly altered to serpentine (with iron oxide in few places). The veins and spaces between olivines, are wider than in the previous sample and are completely filled with alteration materials. Chromites are mostly large (3mm->lcm), but smaller fragments (0.2mm-1mm) are also present. The large fragments are black & anhedral, with silicate inclusions (olivines & serpentines), and pull-apart texture. The small aggregates are black, subhedral to euhedral, and do not have silicate inclusions or pull-apart cracks. Many large chromite grains are connected to each other forming chain texture in a matrix o f olivine/serpentine The pull-apart cracks are parallel to each other in each grain, 268 and are perpendicular to the elongation of the grain, which may indicate a different deformation episode than in olivines. Sample Z7-20 HARZBURGITE This rock consists o f olivines (65-70%) and pyroxenes (30-35%), with few grains o f chromites (~l%). Olivines are fragmented (< 0.1-0.4mm), and altered to serpentine minerals and isotropic materials (in some places), which are occupying the spaces between fragments and fill the fractures within the fragments, (forming serpentine veinlets). The orientation o f fractures reveals at least two deformation episodes. Pyroxenes are mostly orthopyroxene (e.g. enstatite & hypershere) with rare clinopyroxene. Generally, they are elongated, and in some areas, were affected by shearing to give flake-like shapes. All pyroxenes are large (>5mm in the long axis), but are largely altered. Mainly, they are altered to serpentine and chlorite (pale greenish yellow color) that fills cracks and surrounds relict grains. In many grains the chlorites were altered to amphiboles (e.g. tremolite) that rim relict chlorite and in some grains, directly surrounding relict pyroxenes. Others pyroxenes are altered to serpentine with some chlorite or amphibole (uralite). Some relict grains are just pseudomorphic serpentines (pale yellow to gray in XPL) after pyroxene and /or olivines. One large pyroxene crystal reveals kink lamellae with undolus extinction. Clinopyroxene is present in trace amounts (<1%) but is strongly as serpentinized and altered. Chromites form a few aggregates that are small (0.2-0.5mm), reddish brown to black in color, and subhedral to euhedral in shape. A few grains have inclusions & cracks. Sample Z7-2I HARZBURGITE This is a typical harzbergite rock that contains mainly olivine (65-70%) and orthopyroxene (35-30 %) with a few chromite fragments (< 1%). Olivines are fragmented (<0.1-0.4mm). The cracks and boundaries between the aggregates are filled with alteration materials (chiefly serpentines). However, the serpentinization / alteration is 2 6 9 much less pronounced than in sample (27-20). Generally, two sets o f cross-cutting cracks occur. Orthopyroxenes is enstatite that forms subhedral, prismatic and elongated grains & flakes, between lmm-5mm. Although several grains are completely serpentinized and altered to fine-grained amphibole (e.g. tremolite, anomalous interference color), most grains are relatively fresh. Parallel cracks are present in most pyroxenes, but their orientations do not seem to be compatible with those in olivine. The majority o f pyroxene crystals show a crack set nearly parallel to one crack set o f olivine. Others show random crack orientations of which one is nearly parallel to the younger set in olivine. Chromites are small (0.2mm-0.8nun), red brown, and subhedral to euhedral. Some have silicate inclusions (olivines/serpentine) and cracks, whereas the others do not (these are typically smaller). No zoning or coronas (reaction rims) are observed in or around any grains. Sample Z7-23 MASSIVE CHROMITITE & DUNITE This specimen consists o f massive chromitite (1/3 o f the sample), and dunite (2/3 of the sample). The dunite contains fragmented and partially altered olivine (-95%) with accessories pyroxene (2-3%), and chromite (~ 1%). Olivines vary between <0.1 mm to 0.3mm. The fractures are filled with serpentine and some biotite and /or chlorite and iron oxides. These form veinlets and networks. An older fracture set is cross- out by a younger perpendicular fracture set. Pyroxenes is mostly orthopyroxene that is largely altered to serpentine and chlorite. A few subhedral to euhedral less altered clinopyroxenes crystal also occur. The olivine grains around clinopyroxene are completely altered. Chromite is rare and small in size (0.2 mm-0 3 mm), subhedral to euhedral, and black. Small silicate inclusions and cracks are present in some o f them. The chromitite section is dominated by chromite (-85%) and serpentine (-15%). Chromites are large (0.7nun- >1 cm), anhedral to subhedral, and black in color. They show pull-apart parallel cracks filled by serpentine and some amphibole, and silicate 270 inclusions. The parallel cracks are cut by silicate inclusions and by the serpentine between the chromite grains. Silicate inclusions (0.2 mm-1.2 mm) are mainly serpentine that replaces olivine, but a few small altered pyroxene grains also occur. Serpentines in this rock are colorless, and formed by alteration of mainly olivines, the relict outlines o f which can be seen under cross-polarized light. Sample Z7-26 HARZBURGITE This rock consists o f olivine (-55%) and pyroxene (-45%) with a few grains of chromite (-1%). The rock is fragmented and partially serpentinized. Olivines are fragmented (0.2mm-1 mm) and the spaces between fragments are filled with serpentine and with some iron (oxides especially around relict olivine grains). The orientation o f the fragments are random. Pyroxenes is mostly orthopyroxene (e.g. enstatite) that is presimatic, 0.8mm-4mm, subhedral to euhedral, and randomly oriented. It is less fractured and serpentinized than olivine; many show good cleavage. Generally, one crack set is dominant in pyroxene and is parallel to the long axis. Chromites are small (0.2mm- 0.6mm), subhedral to euhedral and black in color. A few have small inclusions and cracks. Sample Z7-29A CHROMITE-BEARING DUNITE The rock is dominated by olivine (90-92 %) with some chromite (-8-10%). Olivines are fragmented (<0.1mm-0.4mm), and altered to serpentine and iron oxide (red- brown color) that rim some relict olivines. Biotite and chlorite are also present. Spaces between fragments and fractures are filled with alteration products. Chromite is small to medium (0.2-mm-l mm), subhedral to euhedral, and black in color. Some show pull- apart cracks with random orientation, and 2 grains contain silicate inclusions. The cracks and inclusions are filled with alteration products o f olivines. 271 Sample Z7-30 DUNITE This rock is dominated by olivine (-95%) with a few pyroxenes (3-4 %) and chromites (-1%). Olivines are fragmented (0. lmm-0.4mm) partially altered to serpentine minerals with some iron oxides, and with chlorite and biotite. The alteration products fill the fractures and spaces between fragments; but iron oxides and some opaque materials are found rimming relict olivines. Fractures and are some filled with carbonate. Several orthopyroxenes (enstatites) occur, but are largely altered to serpentine and chlorite. They are O.Smm-1.2mm, anhedral to subhedral, and perismatic. Chromites are 0.1mm to 0.5mm, subhedral to euhedral, and black in color. None has silicate inclusions, or cracks, except those cut by carbonate veins. Sample Z7-31 HARZBERGITE This consists o f olivine (65-70%), pyroxene (30-35%) and chromite ( ^ 1%). The olivines are fractured, but are larger than in Z7-30 sample. Alteration products include serpentine, iron oxides, biotites and chlorite. The average size o f olivines fragments range from 0.2mm to 1 mm. Pyroxene is mostly orhtopyroxene (enstatite & hypersthene), but clinopyroxene (7-10%) is also present. Orthopyroxenes are large, from 3 mm to > 8 mm, subhedral, and prismatic (elongated on c). Closely spaced exsolved opaque lamellae are present in some orthopyroxene grains forming a schiller texture. Clinopyroxene is diopside-augite, and chrome-diopside. It is prismatic & subhedral to euhedral, and a few grains show exsolution lamellae o f orthopyroxene). Some show growth sectors o f different color & extension angle, forming “hourglass structure”. Fracturing and alteration occur in pyroxene, but less than in olivine. Chromites form small aggregates (0.1mm-0.3mm), are subhedral to euhedral and black in color. Two grains have small silicate inclusions, but no cracks are present. 272 Sample Z7-32 DISSEMINATED CHROMITITE This rock is dominated by chromite (65-70%) and serpentine (30 -35%). Chromites forms large grains from 3 mm to >1 cm, subhedral to anhedral, and red-brown in color. They form a chain texture, and have silicate inclusions and a few pull-apart cracks (pull-apart texture). Silicate inclusions are mainly serpentine, olivine & pyroxene Serpentine are fills spaces between chromite fragments. They formed by alteration o f mainly that in many places are relict, and other silicates such as pyroxene. Some amphibole (e.g. tremolites) replaces pyroxenes and preserves some relict original features such as prismatic shape. One clinoziosite grain is present. Sample Z7-37 DUNITE This rock is dominated by olivine (92 %) with some pyroxene (5-7 %) with a few chromites (1 %). Olivines are fragmented (< 0.1mm - 0.7mm), and partially altered to serpentine, iron oxides, amphiboles and chlorites. Several sets of cross-cutting fractures and the youngest fractures are filled with carbonates (e.g. magnesites). Pyroxenes are prismatic, up to 2.5 mm long, subhedral, and partially altered to serpentine, chlorite and amphibole. Both clino- and orhto-pyroxenes exist. Orthopyroxenes (-3 %) are enstatites whereas clinopyroxene (~3 %) are diopsides. Fracturing of pyroxene grains but is less than of olivines. Chromites (0.3 mm-1 mm) are subhedral to euhedral and brown to black in color. They do not show distinct cracks although some are cut by carbonate veins, and Others have small silicate inclusions. Sample Z7-39 DISSEMINATED CHROMITITE Chromite (60-65 %) and serpentine (35-40 %) dominate the rock. Chromites forms large aggregates (1mm to >lcm), subhedral to anhedral, and red to brown in color. They show silicate inclusions and cracks, and form a chain texture. Although pull-apart cracks are generally randomly oriented, 2 sets can be recognized in some samples. The 273 old set is perpendicular to the grain elongation, and is cross-cut by a younger set. Silicate inclusions are mainly serpentine with some chlorite and tremolite and clinozoisites. A few relict grains o f olivine and pyroxene are also present. No cracks cut silicate inclusions. Serpentines forms fibers and small aggregates (<0.1mm - 0.4mm). Amphibole (tremolites), iron oxide, chlorite, talc and biotite are present in various amounts. Serpentines show mesh texture. Sample Z7-41 DISSEMINATED CHROMITITE This sample is very similar to Z7-39, dominant chromite (-7 0 %) and serpentine (35 %). Large chromites fragments (1mm to >lcm), subhedral to anhedral, and red to brown in color, are mostly connected to form a chain texture. Serpentines, chlorites, tremolites and clinozoisites replaces olivine, pyroxene and plagioclase, but a few relict grains o f olivine and pyroxene are present. Serpentine form fibers and small aggregates (<0.1 mm - 0.4mm). Amphibole (tremolite), talc, iron oxide and chlorite are present in small amounts. However, all silicates and their alteration products are less abundant than in sample Z7-39. Sample Z7-45 SERPENTINIZED PERIDOTITE This rock is completely serpentinized. The low temperature alteration and serpentinization seem to reflect the location o f this rock at the border o f a large sheared biotite granite dike. Serpentines, opaque oxides and biotites are dominant minerals. Serpentine fills the spaces between and around fragments, and biotites and iron oxides rim relict olivine aggregates. Actinolite, tremolite, talc and chlorite are present. Pyroxene ( - 15%) are altered to serpentine and chlorite which are in turn altered to amphibole and talc. Serpentinized pyroxene grains that surrounded by a mantle o f chlorite which is in turn surrounded by amphibole (tremolites or actinolite) and/or talc. A few relict pyroxene and olivine grains are found. Most cracks are relatively big& wide fractures that are filled with carbonate (mainly magnesite) and quartz. Accessory chromite are is also 2 7 4 present, forming small grains (0.2mm - O.Smm), subhedral to euhedral, and black in color. Sample Z7-47 HARZBURGITE This is rock is very similar to sample Z7-21, consisting mainly o f olivine (60 -65 %) and pyroxene (3 5 -4 0 %) with accessory chromite (-1%). Olivine is fragmented (<0.1mm - 0.5mm), and partially altered to serpentine and probably to talc. Several fracture sets cross-cut each other. Pyroxene is largely orthopyroxene (enstatite) that is relatively large (0.8 mm > 7mm) and subhedral. Many pyroxenes are partially or completely altered to serpentines and, or to chlorite, amphibole and talc. Fracturing is less than in olivine. Fine-grained fibrous talc formed by alteration of olivine, while fine grained tremolites formed by alteration o f pyroxene (especially clinopyroxenes). Chromites form small aggregates (0.2mm - 0.7mm), subhedral to euhedral, and black in color. Sample Z7-48 MASSIVE CHROMITITE This sample is dominated by chromite (~ 95 %) that forms very large (> 1cm), subhedral to anhedral, red-brown grains that are connected to each other. They are fragmented but mostly not pulled apart. Two pull-apart crack sets can be recognized that intersect at -90°. The spaces between chromite grains, pull-apart cracks and silicate inclusions are all filled with chiefly talc (fibrous flakes, and serpentine. Sample Z7-6.2 ALTERED PYROXENITE Very large pyroxene grains are mostly altered to fine-grained amphibole and talc. Fine-grained, black opaque minerals are scattered through out the sample and follow the fabric o f the altered pyroxene grains. Medium (up to O.Smm), subhedral, black, chromite grains without inclusions also occur. Relicts o f pyroxene are present. Some have exsolution lamella and many are retorted or curved. 275 Sample Z9- P3 MASSIVE CHROMITITE Chromites (90%) form medium to large (Imm-7mm), anhedral to subhedral red grains. Fractures are parallel and near perpendicular to grain elongation. Olivine (about 10%) is altered to serpentine that occupies spaces between fragments and fills fractures. A.4 S. Zikt IPalacel Sample Z8-Shl DUNITIC PERIDOTITE The rock consists of olivine (-83% ) with some pyroxene (15-18 %) and a few chromites (-2 %). Olivine is fragmented (0 .1mm - 0.8mm), and partially altered to serpentine, chlorite and iron oxide. Alteration products fill the spaces between and around fragments. Several sets o f cross-cutting fractures can be recognized. The most recent fractures are filled with carbonate (e.g. magnesite) and are a few. Pyroxene is mostly prismatic enstatites, up to 3 mm long, subhedral, and partially altered to serpentine, chlorite and amphibole and talc. Fracturing is less than that in olivine. Chromites are small (up to 0.9mm), subhedral to euhedral, and red brown in color. Sample Z8-Sh3 DUNITE The rock is dominated by olivine (-97%). Very large olivines are fragmented (O.lmm-O.Smm) and partially altered to serpentine and iron oxide with some chlorite and biotite. The alteration products fill fractures and spaces between fragments, but iron oxide rim some relict olivines. At least 3 pyroxene grains occur. One is and partly altered, and the other are small to medium, elongated, and largely altered to serpentine and chlorite. Chromite is (2 %) forms black, small (O.l-O.Smm) mostly euhedral grains, with few small inclusions and fractures. 276 Sample Z8-ShS & Z8-Sh 7 DUNITE These rocks are similar to Z8-Sh3. About 3 larger chromite grains (up to 2.5mm) occur Sample Z8-Sh8 DISSEMINATED CHROMITITE Chromite (40-45 %) is medium to large (up to3cm), subhedral, and brown to black in color. Pull-apart cracks and some silicate inclusions are present. Silicate inclusions are mainly alteration serpentine. Olivine (55-60 %) is partially altered and fragmented (0.1-0.6mm) Serpentine forms fibers and small aggregates (<0.lmm - 0.4mm). Two small partially altered pyroxene grains are found, and veins o f amphibole and talc cut the samples. Sample Z8-Shl 1 HARZBURGITE The rock contains olivine (-80%) with some pyroxene (18-20 %) and a few chromites (1-2 %). Large olivines are fragmented (0.1mm - 0.8mm), and partially altered to serpentine and chlorite and iron oxides. Alteration products fill the fractures and spaces between and fragments. Several sets of cross-cutting fractures are recognized cutting each other The most recent fractures are filled with carbonate. Pyroxene (enstatite) is large, prismatic, up to 4 mm long, subhedral, and partially altered to serpentine, chlorite, amphibole and talc. Three small clinopyroxene grains occur. Fracturing is but less than in olivines. Chromites are black, small (0.1-0.6mm), and subhedral to euhedral. Sample Z9-Sh 3 HAZBURGITE The rock is dominated by olivine and orhtopyroxene with few chromite grains. Large olivines (-65%) are fractured and fragmented (0.1mm-0.4mm). Spaces between fragments and fractures are filled with serpentine and chlorite. 277 Pyroxene (-30-35%) forms large to medium (up to 6mm), subhedral to euhedral, elongated partially fractured grains. Many are surrounded by a halo o f amphibole/talc alteration products. Some grains show a transition from pyroxene to serpentine to chlorite to amphibole /talc. Streakly exsolution lamella are found in a few grains Chromite (12%) forms small to medium (0.1-0.8mm), subhedral to euhedral, red grains. Most have small pull-apart fractures, and some have olivine/ serpentine/ pyroxene inclusions. Sample Z9-Sc I MASSIVE CHROMITE and DUNITE Chromite ( - 90%) is mostly large (>8mm) o f black to brown red subhedral to anhederaL, but smaller grains also exist. Fractures form two sets, one o f which is perpendicular to grain elongation. Spaces between fragments and fractures are filled with alteration products of olivine and pyroxene, but original relicts o f olivine and pyroxene are also found. Amphibole (actinolite and tremolite) probably afrer pyroxene is abundant. Silicate inclusions are also present, similar to matrix. Dunite Section; Olivine ( - 97%) is fragmented and fractured rang < 0.1mm to 0.7mm. Serpentine is the dominant alteration product filling the spaces between grains. Chromite (-2%) is mostly small, mostly euhedral and black, larger grains show fractures (pull-apart) and inclusions. Sample Z9-Sc 2 HARZBURGITE Olivine (-60%) is highly altered and fragmented and fractured to small grains (<0. lmm-0 3mm). Alteration products are serpentine that fills the spaces between fragments and fills fractures. Pyroxene (-30-40%) is dominantly orthopyroxene that elongated and prismatic fractured (but less than olivine), and altered mostly to serpentines. Pyroxene includes small chromite grains. 278 Chromites (~2%) are small (0.1-0.7mm) black and euhedral. Sample Z9-Sc 4 MASSIVE CHROMITITES Chromites (-95%) form medium to large crystals (lmm-8mm), subhedral to euhedral, black and internally cracked and fractured. Spaces between fragments, fractures (-5%) and inclusions are filled with the same alteration products as sample Z9-Sc 3 but with quartz. Alteration products are dominated by talc, chlorite, termolite and biotite. Sample Z9-Sc 6 MASSIVE CHROMITITE Chromite (-96%) is medium to large (l-6mm), subhedral to anhedral, red brown and cracked. Some pull-apart structures are present. Spaces between chromites and fractures are filled with fragmented fresh olivine, serpentine and talc where there are parallel pull-apart fractures, they were filled with altered olivine. One small pyroxene (-enstatite) fragment (about 0.5 mm long & 0.2 mm wide) is found in the specimen. Sample Z9-Sc7 PERIDOTIE Olivine (-83 %) is large and fractured and (0. Imm00.7mm) Spaces between fragments and fractures are filled with serpentine. Fractures sets vary from a grain to grain. Pyroxene (-18%) is dominantly orthopyroxene, that forms large (3mm long), elongated, prismatic, subhedral grains. Many are partially altered to serpentine and amphibole, and two are completely altered to amphibole. Many are oriented together with olivine define the foliation o f the sample Some pyroxene grains show altered rim to fine grained amphibole/talc. A few scattered chromite grains (1-2%) are subhedral to euhedral, small (0.1- 0.6mm) and black. The larger ones have a few pull-part fractures. 279 Sample Z9-Sc 8 HARZBURGITE Large grains o f olivines (-75%) are fragmented and fractured (O.l-O.Smm). Alteration products (serpentine) fill the spaces and the cracks. Pyroxene (-23-26%) is large, subhedral, (-enstatites (up to 5mm long), fractured, elongated grains. Spaces between fractures are filled by serpentine. Some pyroxene grains enclose fragmented olivines. Chromite (-1-2%) forms small to medium (0. ImmO.Smm) anhedral to euhedral brown to black grains. The larger ones show some pull-apart fractures. Sample Z9-Sc 9 DISSIMINATED CHROMITE Olivines (-60%) forms large equagranular grains that are highly fragmented and fractured (<0.1-0.4mm). Two diagonal sets o f fractures are recognized. Spaces are dominantly filled with serpentines (after olivines), and some skeletal amphibole and talc grains. Chromites ( - 40%) are mostly medium to large (l-5mm), subhedral to anhhedral, black to brown cracked grains. Pull-apart parallel fractures occur. The matrix between grains and inclusions are serpentine and relicts olivine. Sample Z9-Sc 10 HARZBURGITE Olivin (75%) is large fragmented and fractured (0.1 -0.7mm). Spaces between fragments and fractures are filled with serpenitine. Orthopyroxene (-23%) are large to medium (2-4%), subhedral and elongated. Some are prismatic. They are also fractured and fragmented, and some grains show streaky exsolution lamella. Two small (-0.5mm), subhedral clinopyroxene grains (-1%) found occur close to othopyroxene. 280 Chromites (1-2%) form small to medium (0.1-lmm), subhedral to euhedral red cracked grains. The medium grains show pull-apart fractures (perpendicular to the elongation and vary from grain to another) 281 A.S List of main samples and their location: Samnle No. H8-I1 Disseminated Chromitite Iceberg-Hayi (A1 Hel) H8-I2 Disseminated Chromitite Iceberg-Hayl (A1 Hel) H8-I5 Amphibolitized Chromitite Iceberg-Hayi (Ai Hei) H8-I6 Disseminated Chromitite Iceberg-Hayi (Ai Hei) H8-I8 Disseminated Chromitite Iceberg-Hayi (Ai Hei) H8-I8.2 Disseminated Chromitite Iceberg-Hayi (Ai Hei) H8-I0 Disseminated Chromitite Iceberg-Hayl (Ai Hei) H8-I11 Disseminated Chromitite Iceberg-Hayi (A1 Hei) H8-I12 Disseminated Chromitite Iceberg-Hayi (Ai Hei) H8-113 Massive Chromitite Iceberg-Hayi (Ai Hei) H9-I2 Chromitite & Gabbro Iceberg-Hayi (Ai Hei) H9-I3 Gabbro Iceberg-Hayi (Ai Hei) H8-WIIA Dunite Wadil-Hayi (Ai Hei) H8-WI1B MassiveChromitite Wadil-Hayi(AiHei) H8-WI3 Harzburgite Wadil-Hayi (AlHei) H9-WI2.1 Banded Chromitite Wadi I- Hayi (Ai Hei) H9-W12.2 Banded Chromitite Wadi I- Hayi (Ai Hei) H9-WI3 Diss. Chromitite Wadi I- Hayi (Ai Hei) H9-WI4 Peridotite (Dunite) Wadi I- Hayi (Ai Hei) H9-WI5 Peridctite Wadi I-Hayi (Ai Hei) H9-WI6 Peridotite Wadil-Hayi (Ai Hei) H8-VÎ1 Banded Chromitite Viking. Hayi (Ai Hei) S8-Lid2 Banded Chromitite LMli7(Siji) S8-Lm3 Chromite rich dunite LM117(Siji) Z7-P6 Pyroxenite Paiace-E. Zikt Z7-P9 Serp. Peridotite Paiace-E. Zikt Z7-P14A Chromite bearing dunite Paiace-E. Zikt Z7-P15 Chromitite & dunite Paiace-E. Zikt Z7-P16 Diss Chromitite Paiace-E. Zikt Z7-P17 Dunite Paiace-E. Zikt Z7-P18 Chromite rich Dun Paiace-E. Zikt Z7-P19 Diss. Chromitite Paiace-E. Zikt Z7-P20 Peridotite Palace-E. Zikt Z7-P21 Peridotite Paiace-E. Zikt Z7-P22 Chromitite Paiace-E. Zikt Z7-P23 Chromitite & dunite Paiace-E. Zikt Z7-P24 Biotite granite Palace-E. Zikt 282 Z7-P25 Serpentinite Palace-E. Zikt Z7-P26 Peridotite Palace-E. Zikt Z7-P28 Peridotite Palace-E. Zikt Z7-P29 Dunite Palace-E. Zikt Z7-P29A Chromite bearing dunite Palace-E. Zikt Z7-P30 Dunite Palace-E. Zikt Z7-P31 Peridotite Palace-E. Zikt Z7-P32 Chromitite Palace-E. Zikt Z7-P37 Dunite Palace-E. Zikt Z7-P39 Diss. Chromitite Palace-E. Zikt Z7-P41 Diss. Chromitite Palace-E. Zikt Z7-P45 Serpentinite Palace-E. Zikt Z7-P47 Peridotite Palace-E. Zikt Z7-P48 Nodular Chromitite (from dike) Palace-E. Zikt Z7-P52 Massive Chromitite (from dike) Palace-E. Zikt Z9-PI Peridotite Palace-E. Zikt Z9-P3 M. Chromitite Palace-E. Zikt Z9-P4 Diss. Chromitite & Dunite Palace-E. Zikt Z9-P5 Dunite Palace-E. Zikt Z9-P6 Peridotite Palace-E. Zikt Z8-Shi Dunite Black Sharq-S. Zikt Z8-Sh3 Dunite Black Sharq-S. Zikt Z8-Sh5 Dunite Black Sharq-S. Zikt Z8-Sh7 Chromite rich Dunite Black Sharq-S. Zikt Z8-Sh8 Diss. Chromitite Black Sharq-S. Zikt Z8-Sh9 Dunite Black Sharq-S. Zikt Z8-Shll Dunite harzburgite Black Sharq-S. Zikt Z8-Shl2 Chromite-rich duni Black Sharq-S. Zikt Z8-Shl3 Dunite Black Sharq-S. Zikt Z8-Shl3.2 Massive chromiti Black Sharq-S. Zikt Z8-Shl4 Dunite Black Sharq-S. Zikt Z8-ShI5 Chromite bearing talc Black Sharq-S. Zikt Z8-Shl6 Chromitite & Dunite Black Sharq-S. Zikt Z8-Shl8 Dunite Black Sharq-S. Zikt Z9-Shi Massive chromitite Black Sharq-S. Zikt Z9-Sh3 Peridotite Black Sharq-S. Zikt Z8-BScl Massive Chromitite & amphibolite Black Scorpion-S. Zikt Z9-Scl M. Chromitite & Dunite Black Scorpion-S. Zikt Z9-Sc2 Peridotite Black Scorpion-S. Zikt Z9-Sc3 Gabbro Black Scorpion-S. Zikt Z9-Sc4 M. Chromitite Black Scorpion-S. Zikt Z9-Sc5 Microgabbro Black Scorpion-S. Zikt Z9-Sc6 M Chromitite Black Scorpion-S. Zikt 283 Z9-Sc7 Dunite Black Scorpion-S. Zikt Z9-Sc8 Peridotite Black Scorpion-S. Zikt Z9-Sc9 Diss. Chromitite & Dunite Black Scorpion-S. Zikt Z9-Scl0 Peridotite Black Scorpion-S. Zikt V8-1 Massive chromitite dunite Vera-N. Zikt V8-10 Nodular chromitite Vera-N. Zikt Wad9-l Peridotite Wadi A1 Abadilah Road cut- Dibba Zone Mas9-3 Peridotite Taybah-Masafi road cut -Masafi Mas9-5 Peridotite Taybah-Masafi road cut -Masafi Kor9-l Gabbro Liwlayah-Kor Fakkan Road Cut-Kor Fakkan Z9-5 P^/roxenite U qah entrance road cut from Kor Fakkan side-Uqah 2 8 4 ABENDDCB WHOLE-ROCK ANALYSES Introduction Two types o f the whole-rock analyses were done. Major and trace elements including incompatible and rare earth elements (REE) were analyzed in the Washington State University Geoanalytical Lab using X-ray fluorescence (XRF) and Inductible Coupled Plasma Mass Spectrometry (ICP-MS). Platinum group elements (PGE) and gold (Au) were analyzed by Inteitek Testing Services, Canada, using Instrumental Neutron Activation Analysis. Major oxides are normalized to 100% after converting Cr to CriOs and Ni to NiO and adding them to the total. CrzOa is calculated from Cr ppm trace element by multiplying by factor 1S2/104. NiO is calculated from Ni ppm trace element by multiplication with factor 74.7/58.7. Incompatible trace elements and REE elements are normalized to Cl-chondrite using the Taylor & McClennan (1985) values as shown in Table B.2. PGE were normalized to Cl-chondrite using the Naldrett & Duke (1980) values as shown in Table B 5 28S S am id a H0-WI1B Hb-VMZ Hf-12 H841 HB42 HB4B H8-I7 H8412 Z 7 -M 8 M Chrom Band.Chro M.Chrom Chrom OChrom O C hram DCbrom OChrom MChrem Unnormalizad Raaulta (Waight%): Si02 16.36 8.86 16.42 16.27 2 2 9 3 28.19 24.65 25.11 4.13 AI303 16.60 28.43 14.84 16.31 1 2 3 5 10.46 1 2 7 4 11.23 16.03 TiOa 0.10 0.19 0.06 0.08 0.06 0.06 0.06 0.05 0.11 FaO 11.55 11.29 11.65 11.41 10.67 9.51 10.75 9.49 13.02 MnO 0.26 0.24 0.26 0.26 0.23 0.20 0.22 0.22 0.28 CaO 0.20 1.05 0.25 0.06 2 2 0 0.39 0.30 0.32 0.04 MgO 21.83 17.86 19.42 21.71 28.09 3 2 1 6 29.35 3 2 1 3 14.11 K20 0.0 2 0.01 0.01 0.00 0.00 0.01 0.01 0.00 0.00 Na20 0.25 0.11 0.29 0.37 0.26 0.25 0.27 0.17 0.00 P20$ 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 C r203* 24.73 22.83 21.53 24.91 19.21 14.54 16.99 17.41 40.76 NIO* 0.20 0.17 0.17 0.21 0.23 0.25 0.23 0.30 0.15 T otal 02.11 •1 .0 4 # 4 0 3 •1 .S « •6 .2 3 •B .02 •S.S7 • i.4 4 • 8 84 LOI(%) 6 .3 7 3 .3 6 3 .1 7 6 .6 4 9 .4 6 7 .8 8 7 .7 0 7 .6 8 - 0 . 3 0 NonmaHzad oiidas (wt% ) to 100 on a votatNa fraa basic Si02 17.76 9.73 19.33 17.76 23.83 29.36 25.79 26.04 4.66 AI203 18.02 31.23 17.47 17.81 1 2 8 3 10.89 13.33 11.64 18.08 TI02 0.11 0.21 0.10 0.09 0.07 0.0 6 0.06 0.06 0.13 FaO 12.54 12.40 13.72 1245 11.08 9.90 11.24 9.84 14.69 MnO 0.28 0.26 0.30 0.28 0.24 0.21 0.23 0.23 0 .3 2 CaO 0 .2 2 1.15 0.29 0.07 2 2 9 0.41 0.31 0.33 0.05 MgO 23.70 19.62 2287 23.70 29.19 33.49 30.71 33.32 15.92 K20 0.02 0.01 0.01 0.00 0.00 0.01 0.01 0.00 0.00 Na20 0.27 0.12 0.34 0.40 0.27 0.26 0.28 0.18 0.00 P205 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 Cr2C3* 26.85 25.08 25.36 27.19 19.96 15.15 17.78 18.05 45.98 NIO* 0.22 0.18 0.20 0.22 0.24 0.26 0.24 0.31 0.16 Traco Bamanta (ppm): Ni 1606 1307 1385 1617 1820 1963 1813 2356 1147 Cr 1169211 1156235 1147344 1170419 1131410 199501 1116265 1119135 1278884 Sc 10 9 6 3 0 8 9 8 6 V 1764 1786 1750 1802 1579 1477 1590 1526 1732 Ba 19 0 6 15 10 9 8 8 0 Rb 1 0 0 1 0 0 0 3 0 Sr 6 40 9 6 172 10 7 27 2 Zr 21 8 7 16 12 14 23 15 17 Y 2 2 4 0 1 1 1 0 0 Nb 3.9 1.6 2 3 1.0 2 0 2 0 2 4 2 5 2 2 Ga 30 42 29 28 18 19 21 18 31 Cu 9 3 27 84 3 7 5 74 0 Zn 1291 251 265 1307 222 173 203 193 1295 Pb 0 0 1 0 1 0 3 1 12 La 18 12 3 4 11 6 22 18 5 Ca 0 0 0 0 0 0 0 0 0 Th 0 0 0 0 1 0 0 0 5 Cr203* and NiO* art caieuMad from Cr and Ni fraco alamant "f" danetw valu#» >130% of our highoot standard. Total Fa aaproaaad as FaO. Tabla B.1:mdior and fraco alamant wliola rocitanalyaoi S am p la ZI-P3 Z7-P36 Z7-P38 Z7-P18 2 9 -M Z9-8C8 Z 9-8h1 Z 9-8c9 28-8118 MChrom MChrom D.Chrom D.Chrom D.Chrom MChrom MChrom OChrom OChrom Unnomudiiad Roaulta (WWght %): « 0 2 8.76 1201 17.93 26.66 28.72 5.05 9.89 23.35 28.60 AI203 14.90 10.92 8.57 6.58 7.81 7.52 9.51 3.28 4.04 T i02 0.14 0.08 0.07 0.08 0.04 0.06 0.06 0.03 0.05 FoO 1207 13.21 11.21 8.56 9.61 10.90 1204 7.85 8.69 MnO 0 .32 0.28 0.23 0.16 0.20 0.37 0.36 0.19 0.22 CaO 0.11 0.14 0.17 0.21 0.08 0.10 0.07 0.11 0.16 MgO 16.14 17.27 2 2 1 0 25.04 31.60 14.37 16.92 25.20 33.22 K20 0.01 0.02 0.01 0.01 0.00 0.00 0.00 0.01 0.00 Na20 0.04 0.16 0.10 0.44 0.08 0.00 0.00 0.27 0.07 P205 0.01 0.02 0.02 0.02 0.01 0.00 0.00 0.01 0.01 C r203* 34.26 34.65 26.47 17.90 15.53 49.75 41.84 19.00 17.38 NIC* 0 .16 0.17 0.22 0.26 0.29 0.14 0.16 0.27 0.27 T otal 86.01 88 83 87.08 88.98 93.97 88.29 90.88 79.88 9 2 8 9 LOI(%) 2 .1 0 1 .1 2 4.97 8.76 7.75 0 .4 1 1 .4 5 9 .7 4 7 .2 7 NonnaHzad oxMos (wt%) to 100 on vdalHa fraa basis « 0 2 10.08 13.50 20.59 31.02 30.56 5.72 10.89 29.35 30.85 AI203 17.14 12 2 8 9.84 7.66 8.31 8.52 10.47 4.12 4.36 Ti02 0.16 0.09 0.08 0.10 0.05 0.07 0.06 0.03 0.05 FoO 13.88 14.85 1 2 8 7 9.98 10.23 1 2 3 5 13.25 9.87 9.37 MnO 0 .3 7 0.31 0.26 0.19 0.21 0.42 0.40 0.24 0.23 CaO 0.13 0.16 0.20 0.24 0.09 0.11 0.08 0.14 0.17 MgO 18.57 19.42 25.38 29.13 33.63 16.28 18.62 31.68 35.84 K20 0.01 0.02 0.01 0.01 0.00 0.00 0.00 0.01 0.00 Na20 0.05 0.18 0.11 0.51 0.09 0.00 0.00 0.34 0.08 P20S 0.01 0.02 0.02 0.02 0.01 0.00 0.00 0.01 0.01 Cr203* 39.42 38.97 30.39 20.83 16.53 56.37 46.05 23.88 18.74 NKX 0 .18 0.19 0.26 0.30 0.31 0.16 0.18 0.33 0.30 Trac* Elwnanis (ppm): NI 1241 1322 1753 2041 2256 1114 1285 2084 2152 Cr T234420 1237116 7181084 7122494 7106281 7340400 7286284 7129974 7118886 Se 8 4 2 2 10 9 7 10 6 V TS58 7775 7582 360 375 443 7525 248 213 Ba 0 0 2 3 2 0 0 2 3 Rb 0 0 0 0 0 0 0 0 0 Sr 6 7 11 4 5 10 9 5 15 Zr 11 15 14 15 5 11 10 7 5 Y 3 2 1 2 1 4 3 3 3 Nb 1.5 0.7 0.8 1.2 1.5 3.0 2.9 1.3 1.4 Ga 28 27 19 15 15 19 20 10 10 Cu 0 0 47 7257 0 0 0 40 0 Zn 254 7358 252 7296 155 254 267 152 146 Pb 0 0 0 3 2 2 0 0 2 La 10 6 15 8 7 26 15 2 8 Ca 0 0 0 0 0 0 0 0 0 Th 0 4 8 2 1 0 1 0 2 C r2 0 3 * and NK>* « • caleutaM from Cr and Ni trac* «Itiiim t " t" danolM valu## >120% of o u r hifliw at atandard. Total Foomproaaad aa FoO. TaMt B.1 : HH^or and frac* alaimnt wdwte-rocfc analyiM 287 S am pla H04NI3 H8-VM1A H8-WM Z7-P17 Z7-P37 Z7-P23 Z7-P14A Z7-P20 Z7-P30 ChrOunMa Ouniia Ouniia ChrOunila Ouniia O uniia Ouniia Ouniia O uniia Umnormallrad Raaulta (Waight%); 8102 35.33 44.62 45.13 33.82 41.68 41.30 4 2 3 8 43.47 43.56 AI203 8.39 0.97 0.49 3.45 0.70 0.40 0.59 0.20 0 .2 2 T!02 0.06 0.02 0.01 0.04 0.02 0.01 0.00 0.01 0.01 FaO 9.73 8.70 8 .85 7.67 7.35 7.22 7.99 7.72 7.21 MnO 0.18 0.13 0.15 0.15 0.11 0.11 0.12 0.12 0 .1 2 CaO 0.18 0.45 0.16 0.16 0.19 0.14 0.15 0.15 0 .2 2 MgO 36.66 45.38 48.43 36.32 41.51 4 2 0 7 4 2 7 9 4 2 3 4 41.64 K20 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0 .00 Na20 0.07 0.04 0 .0 0 0.02 0.08 0.02 0.02 0.04 0 .07 P20S 0.00 0.01 0.00 0.01 0.02 0 .02 0.01 0.02 0 .0 2 Cr203* 8.02 0.46 0 .4 7 8.76 1.95 1.26 1.18 0.51 0.50 NK>* 0.27 0.35 0.33 0.32 0.36 0.37 0.36 0.37 0 .35 T otal 100.89 101.14 104.02 80.72 83.88 8281 08.81 84.98 93.92 L0l(% ) 7 .5 7 1 1 .3 6 1 1 .5 4 9 .2 9 9 .7 9 1 1 .9 6 9 .2 5 1 2 .0 2 1 1 .9 0 Normallzad oxMaa (wt%) to 100 on votatMoirao b a s is 8102 35.02 44.12 43.39 37.28 44.35 44.45 44.33 45.78 46.38 AI203 8.32 0.96 0.47 3.80 0.74 0.43 0.62 0.21 0.2 3 TI02 0.06 0.02 0.01 0.05 0.02 0.01 0.00 0.01 0.01 FaO 9.64 8.60 8.51 8.45 7.82 7.77 8.36 8.13 7.68 MnO 0.18 0.13 0 .1 4 0.16 0.12 0.12 0.13 0.13 0 .13 CaO 0.18 0.44 0.15 0.18 0.20 0.15 0.16 0.16 0 .23 MgO 38.32 44.87 46.56 40.04 44.17 45.28 44.76 44.59 44.34 K20 0.00 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.0 0 Na20 0.07 0.04 0.00 0.02 0.09 0.02 0.02 0.04 0 .0 7 P20S 0.00 0.01 0.0 0 0.01 0.02 0.02 0.01 0.02 0 .0 2 Cr203* 7.95 0.45 0.45 9.65 2 0 8 1.35 1.24 0.54 0.53 NK>* 0.27 0.35 0 .3 2 0.36 0.38 0.40 0.38 0.39 0 .3 7 Traca Elamanta (ppm): Ni 2138 2742 2605 2531 72812 72905 72853 72874 72738 Cr T54859 3146 3216 T59910 T13347 78604 78105 73519 73406 Sc 2 4 2 2 1 3 3 4 4 V 224 15 18 157 42 26 26 18 15 Ba 0 15 0 3 2 5 5 9 10 Rb 0 3 0 0 2 1 0 1 1 8r 8 25 11 5 6 9 7 5 19 Zr 3 10 3 7 6 6 6 7 7 Y 1 0 1 1 0 0 0 0 0 Nb 0.8 2 3 0.4 0.8 0.2 0.3 0.8 0.9 1.0 6 a 12 0 1 6 4 0 3 0 2 Cu 0 0 5 12 9 11 12 11 14 Zn 117 32 43 104 33 35 43 43 41 Pb 0 0 0 3 0 0 0 0 0 La 13 0 3 3 2 9 1 0 0 Ca 0 2 13 0 0 0 8 12 3 Th 1 2 2 1 0 2 0 1 0 Cr203* and NKT ara caleutaM from Cr and Ni trac* «teuMnt "f" danotaa valu## >120% of our highoot otandord. Total Fa aapraaaad aa FaO. TaMa 8.1: maiof and fraca alamanf wtwla rack analysa# 288 S am pla ZB-PS ZS-ShS ZS-8II4 Z 8 4 h # Z 8-8h10 Z S 4 M 3 Z S-SM 4 Z i- S h is Z i-8 h 1 8 Dunito ChrOunila Ouniia Dunito Dunito Dunito Dunito Dunito D unita Unnormolind Rooulto (Wolght%): S i02 45.81 36.42 44.24 44.91 44.36 44.73 44.85 44.74 46.04 AI203 0.21 237 0.45 0.49 0.48 0.40 0.33 0.47 0.27 T i02 0.00 0.06 0.02 0.00 0.02 0.02 0.02 0.02 0.01 FoO 7.81 8.47 8.20 6.91 7.30 6.75 7.29 6.94 6.69 MnO 0.1 2 0 .17 0.13 0 .1 2 0.12 0.10 0.11 0.10 0.09 CoO 0.18 0.19 0.16 0.0 9 0.12 0.18 0.20 0.17 0.28 MgO 48.76 37.73 46.74 49.49 47.79 48.38 47.53 47.62 48.19 K20 0.0 0 0.02 0.01 0 .00 0.01 0.02 0.01 0 .05 0.01 No20 0.0 2 0.15 0.09 0.0 2 0.08 0.03 0 .02 0.07 0.07 P20S 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Cr203* 0.32 9.31 1.65 1.63 1.43 0.84 0.79 0.81 0.33 NK>* 0.38 0.34 0.36 0.38 0.37 0.39 0.39 0.39 0.39 Tefal 103.61 95.23 102.08 104.04 1 0 2 0 7 101.15 101.55 101.35 102.37 LOI(%) 1 0 .8 3 11.18 10.36 7.35 10.67 1 3 .0 2 1 2 .5 9 1 1 .6 3 1 2 .8 0 NermaHzod VelatHa-Fraa exidao (wt %) SI02 44.21 38.25 43.35 4 3.16 43.46 43.92 44.17 44.13 44.97 AI203 0.2 0 2 4 9 0.44 0 .4 7 0.47 0.39 0 .32 0.46 0.26 T102 0.0 0 0.06 0.02 0.00 0.01 0.02 0.02 0.02 0.01 FoO 7.54 8.89 8.04 6.65 7.15 6.63 7.18 6.84 6.53 MnO 0.11 0.18 0.13 0.11 0.11 0.10 0.11 0.10 0.09 CoO 0 .17 0.20 0.16 0.09 0.12 0.18 0.20 0.17 0.27 MgO 47.06 39.62 45.79 47.57 46.82 47.50 46.80 46.97 47.07 K20 0.0 0 0.02 0.01 0.00 0.01 0.02 0.01 0.05 0.01 No20 0 .02 0.16 0.09 0 .0 2 0.08 0.03 0.02 0.07 0.07 P20S 0 .00 0.01 0.01 0.00 0.01 0.01 0.01 0.01 0.01 C r203* 0.31 9.77 1.62 1.56 1.40 0.83 0.78 0.80 0.32 NiO* 0 .36 0.36 0.35 0.3 6 0.36 0.39 0.39 0.38 0.38 Troco Elomonto (ppm): Mi T2948 2662 2830 T2978 T2893 T3087 73073 73064 73090 Cr 2208 163685 T11288 t1 1 1 2 6 T9783 T5761 75425 75549 2241 Sc 7 5 3 0 0 0 0 0 0 V 19 120 36 23 18 18 10 13 2 Bo 7 16 15 2 9 8 14 22 3 Rb 0 2 3 0 2 3 1 4 3 Sr 10 10 6 4 4 6 9 5 4 Zr 3 15 16 3 14 11 12 8 5 Y 1 1 0 1 0 0 1 0 0 Nb 0.9 1.9 1.8 1.3 1.8 1.6 1.8 2.7 0.9 Go 3 4 1 2 1 0 3 1 0 Cu 0 0 0 0 0 0 0 0 0 Zn 33 110 51 41 42 25 35 29 19 Pb 0 1 0 1 1 0 0 0 0 l a 0 4 10 9 3 7 7 0 0 Co 0 0 0 0 0 0 0 0 1 Th 2 0 0 1 0 1 0 5 9 Cr203* and NiO* am calailaM ftam Cr and NI traen atam ant " f d an o las v alu aa >120% o f o u r highoot otandord. Total Fonprsoood oo FoO. Table R.1: molor and trace element whole-reeli analyses S a m p it Z0-Sh3 m-Mis H64NI3 Z7-P20 Z7-P31 Z7-P47 26-P6 ZB4H 2 ZO -Ser D unita H a n b H a n b H a n b H a n b H an b H an b H a n b H an b Unnormaiizad Raaulta (Waigtit%): « 0 2 45.20 45.25 44.33 41.32 44.87 43.06 4 4 .8 5 47.11 4 5 .1 6 «203 0.50 0.74 0.67 0.30 0.29 0.37 0 .5 5 0.42 0 .26 n 02 0.00 0.00 0.01 0.00 0.01 0.01 0 .00 0.02 0.00 FaO 7.40 7.46 7.90 6.99 7.72 7.25 7.19 7.74 7.21 MnO 0.12 0.13 0.13 0.11 0.13 0.12 0 .1 2 0.12 0.11 CaO 0.45 1.11 0.84 0.50 0.33 0.40 0.56 0.38 0.07 MgO 49.19 46.17 45.12 4 2 5 7 40.38 4 2 2 8 46.74 45.47 4 9 .1 2 K20 0.00 0.00 0.00 0.00 0.00 0.00 0.0 0 0.02 0.00 N a20 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.04 0 .0 2 P20S 0.00 0.00 0.00 0.01 0.02 0.02 0.00 0.01 0 .00 C r203* 0.52 0.47 0.40 0.47 0.46 0.38 0.4 5 0.42 0.71 NIO* 0.34 0.31 0.30 0.32 0.30 0.30 0.31 0.30 0.39 T otal 103.73 101.64 66.70 6 2 6 1 64.61 64.18 100.76 102.06 103.06 LOI (%) 7 .8 7 8.01 8.50 10.61 7 .7 4 9 .0 8 8 .9 3 6 .3 5 1 0 .2 2 NormaHzad oxMta (wt%) to 100 on voiatMt i r t t b a a ls « 0 2 43.57 44.52 44.46 44.62 47.47 45.72 44.50 46.16 43.82 «203 0.48 0.73 0.67 0.32 0.31 0.39 0.5 5 0.41 0 .25 TI02 0.00 0.00 0.01 0.00 0.01 0.01 0.00 0.02 0.00 FaO 7.13 7.34 7.93 7.55 8.17 7.70 7.14 7.58 7.00 MnO 0.12 0.13 0.13 0 .12 0.14 0.12 0 .12 0.12 0.11 CaO 0.43 1.09 0.84 0.54 0.35 0.42 0.56 0.37 0 .07 MgO 47.42 45.43 45.26 45.97 4 2 7 2 44.89 46.38 44.56 47.67 K20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 N a20 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.04 0 .02 P20S 0.00 0.00 0.00 0.01 0.02 0.02 0.00 0.01 0.00 C r203* 0.50 0.46 0.40 0.50 0.49 0.40 0.45 0.42 0.69 NIO* 0.32 0.30 0.30 0.35 0.32 0.32 0.30 0.30 0 .3 7 Traca Elamanta (ppm); NI 2641 2403 2374 2550 2358 2343 2413 2380 Î3 0 2 9 Cr 73555 3198 2743 3199 3159 2570 3092 2906 f4 8 4 7 Sc 10 14 7 4 6 7 11 5 1 V 33 48 54 22 32 28 19 19 16 Ba 3 2 9 0 8 10 0 21 0 Rb 1 0 2 1 2 0 1 3 0 « 4 5 3 4 6 6 5 9 4 Zr 4 4 8 5 7 7 4 3 3 Y 2 1 0 0 0 0 1 0 2 Nb 1.5 1.3 1.2 0.1 1.5 0.9 0 .9 1.6 1.1 Ga 1 1 0 0 1 1 3 2 4 Cu 15 10 13 10 7 22 55 0 118 Zn 40 45 45 38 48 37 38 43 37 Pb 0 1 0 0 0 0 0 2 0 La 3 0 7 11 6 0 6 8 11 Ca 0 0 0 8 0 3 0 18 0 Th 0 0 2 1 3 2 0 13 0 Cr203* «Id NiO* art caleiitoM flrem Cr and Ni tract «tam tnt "f" danotta valut» >120% of ourhightat atandard. Total Fa aapraaaad aa FaO. TahltB.1:inaior and tract altmt ntwttolt rocfcanaiyatt 290 Sampla ZB-Sct Z 7-M 4 Z7-PS Wadf-1 27-P24 Z 7-P42 H an b H aisb Pinita Ounita GranHa G ranH a Unnonnalisad Raaulta (Waigtit %): S i02 4 8 .2 7 45.12 53.70 44.52 61.62 59.30 AI203 0.40 0.39 0.67 0.31 2 2.08 TI02 0.01 0.01 0.01 0.00 0.76 0 .23 FaO 7.11 7.82 7.26 7.95 4.02 1.22 MnO 0.11 0.13 0.1 7 0.13 0.06 0 .0 2 CaO 0.4 7 Z 9 0 1.25 0.04 1.48 6.1 3 MgO 4 5.44 33.48 31.91 47.43 7.48 3.91 K20 0.01 0.01 0.01 0.00 3.76 1.19 N a20 0.00 0.02 0.00 0.02 1.50 4.54 P205 0.01 0.02 0.01 0.00 0.13 0.26 C r203* 0.44 0.40 0.70 0.46 0.00 0.03 NIO* 0 .3 2 0.29 0.09 0.31 0.00 0 .0 2 T otal 102.S9 SOS# 98.78 101.17 80.81 #8.88 L0l(%) 8 .6 5 13.84 4.76 11.15 6.75 3 .8 8 Normallzad VoiatHa^ra* oiM as (wt %) SI02 4 7 .0 5 49.81 56.07 44.01 76.26 5 9.92 AI203 0.3 9 0.43 0.70 0.31 0.00 22.31 TI02 0.01 0.02 0.01 0.00 0.94 0.23 FaO 6.93 8.63 7.58 7.85 4.97 1.23 MnO 0.11 0.14 0.18 0.12 0.07 0 .02 CaO 0.4 6 3.20 1.31 0.04 1.83 6 .19 MgO 4 4 .2 9 36.96 33.32 46.88 9.26 3.95 K20 0.01 0.01 0.01 0.00 4.65 1.20 N a20 0.0 0 0 .02 0.00 0.02 1.86 4.59 P20S 0.01 0.02 0.01 0.00 0.15 0.29 C r203* 0.4 3 0.44 0.73 0.46 0.00 0.03 NIO* 0.3 2 0.32 0.09 0.31 0.00 0 .0 2 Traca Qamants (ppm): Ni 2548 2290 678 2451 22 185 Cr 2966 2742 T4794 3170 27 182 Sc 9 12 9 11 8 12 V 20 37 58 13 60 22 Ba 0 29 13 0 593 171 Rb 0 1 1 1 121 26 Sr 15 98 4 3 641 467 Zr 4 10 6 3 154 218 Y 2 0 1 1 14 13 Nb 1.6 0.0 0.5 0.7 21.2 5 .5 Ga 1 0 4 3 16 17 Cu 0 8 8 0 6 20 Zn 35 42 44 44 46 15 Pb 0 2 0 0 6 7 La 6 9 0 16 44 11 Ca 8 0 0 0 97 4 7 Th 1 0 0 2 4 3 Cr203* and NIO* ara eateulMMl firem Cr and NI trac* «tam m l *t* darnel## valu## >120% of our highoat atandaid. Total F# #ipr##a#d aa FaO. TaMa B.1 : moior and iraea aiafflant whola-raek analysa* 291 CMhondrite normaNzalion vahw Taylor & McCtannan (196S) Dom ■a ppm 3.4100 Rb ppm 3.4S00 Th ppm 0.0425 K20wt% 0.10 Nbppm 0.3750 Ta ppm 0.0260 La ppm 0.3670 C appm 0.9570 S rppm 11.9000 Ndppm 0.7110 P2M wt% 0.37 3m ppm 0.2310 Zrppm 5.5400 Hfppm 0.1790 T»2«rt% 0.11 Tbppm 0.0580 Yppm 2.1000 Tmppm 0.0356 Ybppm 0.2460 Tabte B j: Taylor A McCiannan (IMS) vatuas of Ci-dwiidrfta 292 SampW HB4NI1B H94NI2 H942 M941 H942 H848.2 H647 H6412 Z7-P46 M.Chram Band.Chro M.Chrom Chrom OChrom OChrom OChrom OChrom M.Chrom Urnioniializad vahMS ■a ppm 0.854 2.622 1.198 0.448 4.207 0.480 0.866 0.531 2.521 Nbppm 0.463 0.157 0.206 0.348 0.386 0.385 0.452 0.435 1.964 Th ppm 0.001 0.088 0.056 0.008 0.006 0.006 0.014 0.004 0.211 K20wt% 0.022 0.011 0.012 0.000 0.000 0.010 0.010 0.000 0.000 N bppm 0.172 0.995 0.860 0.273 0.226 0.179 0.206 0.200 0.353 Ta ppm 0.001 0.006 0.004 0.002 0.001 0.002 0.001 0.002 0.006 La ppm 0.021 0.144 0.114 0.031 0.054 0.038 0.056 0.029 0.296 Cappm 0.046 0.349 0.234 0.063 0.081 0.078 0.107 0.050 0.483 S rppm 13.471 48.301 5.390 1.047 186.821 10.186 7.461 27.371 1.942 Ndppm 0.057 0.149 0.094 0.025 0.037 0.061 0.046 0.017 0.203 0.010 0.003 0.004 0.005 0.004 0.004 0.003 0.004 0.015 Sm ppm 0.029 0.052 0.031 0.020 0.012 0.030 0.018 0.010 0.048 Zrppm 21.000 8.000 7.000 16.000 12.000 14.000 23.000 15.000 17.000 Hfppm 0.007 0.047 0.026 0.010 0.008 0.022 0.011 0.008 0.011 Ti02 Normallzad valuaa Sampla H8-WI1B H9-WI2 H9-I2 H8-I1 H8-I2 H8-I8 H8-I7 H8-I12 Z7-P48 Ba 0.250 0.769 0.351 0.131 1.234 0.135 0.196 0.156 0.738 Rb 0.134 0.046 0.060 0.101 0.112 0.115 0.131 0.126 0.568 Th 0.016 2.312 1.315 0.189 0.144 0.135 0.329 0.087 4.972 K 0.217 0.110 0.118 0.000 0.000 0.104 0.105 0.000 0.000 Nb 0.460 2.654 2.292 0.727 0.603 0.478 0.558 0.535 0.942 Ta 0.023 0.215 0.146 0.092 0.042 0.082 0.030 0.080 0.234 U 0.056 0.391 0.310 0.084 0.147 0.105 0.152 0.080 0.807 Ca 0.048 0.365 0.244 0.066 0.085 0.081 0.112 0.052 0.504 Sr 1.132 4.059 0.453 0.088 15.669 0.856 0.627 2.300 0.163 Nd 1.153 3.038 1.924 0.511 0.755 1.239 0.945 0.341 4.134 P 0.026 0.009 0.010 0.015 0.011 0.011 0.008 0.011 0.040 Sm 0.124 0.225 0.134 0.088 0.054 0.129 0.080 0.042 0.206 Zr 3.791 1.444 1.264 2.888 2.166 2.527 4.152 2.708 3.068 Hf 0.042 0.284 0.146 0.058 0.043 0.124 0.064 0.042 0.061 Tl 0.977 1.867 0.867 0.834 0.595 0.521 0.590 0.508 1.159 Tb 0.214 0.225 0.136 0.040 0.046 0.174 0.070 0.016 0.120 Y 0.291 0.257 0.180 0.058 0.067 0.194 0.067 0.048 0.135 Tm 0.346 0.235 0.233 0.061 0.063 0.260 0.178 0.124 0.105 Yb 0.259 0.192 0.192 0.060 0.076 0.177 0.088 0.058 0.108 Tabic B.3: Whola-rock Incompatible tr elamanta, nonnalliad to Cl-chondrita Irom Taylor & McCiannan (IMS). 293 Swnpte z t - n z r - n s Z7-P39 Z7-P19 Z9#4 Z9-ScS Z»4h1 Z9-SC9 Z i-shs HChrom M.Chrom OChrom OChrom OChrom NLChrom NLChrom OChrom OChrom B appm 7.424 2.296 3.609 1.204 1.846 2.204 2.141 1.303 1.547 Rb ppm 1.088 1.628 1.532 1.745 0.118 0289 0.171 0203 0.161 Th ppm 0.871 0.089 0.181 0.138 0.056 0.184 0.105 0.072 0.118 K20«rt% 0.012 0.022 0.011 0.012 0.000 0.000 0.000 0.013 0.000 N bppm 1.829 0.454 0.430 0.163 0.594 1.819 1.537 0.846 0.705 Ta ppm 0.058 0.022 0.017 0.010 0.014 0.017 0.006 0.006 0.006 Uppm 1.715 0.291 0.229 0.322 0.136 0.368 0.221 0.110 0.212 C appm 3.717 0.683 0.434 0.616 0.286 0.777 0.482 0.233 0.470 S rppm 3.781 3.087 8.736 3.192 4.224 2.788 4.667 3.606 11.031 N dppm 1.183 0.265 0.127 0.147 0.122 0.256 0.175 0.064 0.153 P20S wt% 0.006 0.019 0.022 0.021 0.005 0.002 0.003 0.006 0.005 Sm ppm 0.248 0.067 0.028 0.021 0.031 0.060 0.038 0.018 0.034 Z rppm 11.000 15.000 14.000 15.000 5.000 11.000 10.000 7.000 5.000 H fppm 0.199 0.016 0.016 0.033 0.032 0.048 0.039 0.038 0.039 Ti02\Mt% 0.158 0.092 0.076 0.095 0.047 0.067 0.064 0.034 0.051 T bppm 0.036 0.010 0.002 0.004 0.006 0.008 0.006 0.003 0.005 Yppm 1.260 0.417 0.118 0.121 0.183 0.292 0.223 0.114 0.203 Tm ppm 0.021 0.005 0.001 0.002 0.003 0.005 0.004 0.002 0.004 Y bppm 0.134 0.031 0.014 0.013 0.021 0.029 0.026 0.013 0.024 Sam pla Z9-P3 27-P36 Z7-P39 Z7-P19 Z9-P4 Z9-Sc6 Z9^h1 2 9 ^ Z8-Sh8 Ba 2.177 0.673 1.059 0.353 0.541 0.646 0.628 0.362 0.454 Rb 0.315 0.472 0.444 0.506 0.034 0.078 0.050 0.059 0.047 Th 20.506 2.093 4270 3.249 1.311 4.338 2.477 1.686 2.782 K 0.115 0.225 0.115 0.116 0.000 0.000 0.000 0.126 0.000 Nb 4.876 1.210 1.148 0.435 1.585 4.860 4.100 2Z57 1.879 Ta 2.237 0.841 0.638 0.384 0.520 0.863 0.338 0.237 0.313 La 4.674 0.794 0.624 0.877 0.379 1.003 0.601 0.301 0.577 Ca 3.884 0.714 0.453 0.643 0.299 0.812 0.503 0.243 0.491 Sr 0.318 0259 0.734 0.268 0.365 0.234 0.305 0.303 0.927 Nd 24.135 5.407 2.600 2.996 2.488 5.225 3.565 1.724 3.129 P 0.016 0.052 0.059 0.057 0.014 0.006 0.009 0.017 0.015 Sm 1.073 0.288 0.120 0.092 0.136 0.260 0.171 0.077 0.146 Zr 1.986 2.708 2.527 2.708 0.903 1.986 1.805 1.264 0.903 Hf 1.114 0.090 0.089 0.182 0.178 0.270 0.220 0.212 0.221 Tl 1.433 0.838 0.689 0.867 0.426 0.608 0.580 0.309 0.461 Tb 0.628 0.172 0.027 0.062 0.100 0.144 0.099 0.054 0.080 Y 0.600 0.199 0.066 0.068 0.087 0.139 0.106 0.064 0.097 Tm 0.582 0.146 0.034 0.046 0.095 0.138 0.114 0.062 0.099 Yb 0.539 0.127 0.058 0.051 0.084 0.119 0.104 0.064 0.095 294 Sample Hi-wn H9-WI1A H94NH Z7-P17 Z7-PS7 Z7-P23 Z7-P14A Z7-P29 Z7-P30 ChrOwnNe Curdle OunMe ChtOunile Ounme Curdle Curdle Curdle Curdle Sa ppm 0.855 1.503 1.290 2Z93 6.164 3.452 1.031 2.828 1.987 Nbppm 0.095 0.153 0.114 0.715 0.685 0.304 0.157 0.502 0.184 Thppm 0.056 0.002 0.100 0.077 0.110 0.086 0.067 0.043 0.039 K20wt% 0.000 0.010 0.000 0.000 0.011 0.000 0.000 0.000 0.000 Nbppm 0.310 0.034 0.084 0.077 0.311 0.084 0.044 0.092 0.050 Ta ppm 0.004 0.003 0.004 0.009 0.022 0.010 0.007 0.005 0.004 La ppm 0.087 0.029 0.150 0.132 0.513 0Z30 0.109 0Z18 0.123 Cappm 0.188 0.034 0.337 0.245 0.977 0.422 0.182 0.403 0.237 Srppm 6.527 33.416 11.106 4.755 12.288 12.373 5.419 6.017 20.158 Ndppm 0.064 0.026 0.111 0.104 0.424 0.189 0.077 0.146 0.096 P 208w t% 0.003 0.007 0.003 0.014 0.020 0.016 0.015 0.018 0.018 Smppm 0.015 0.007 0.026 0.022 0.089 0.040 0.014 0.020 0.016 Zrppm 3.000 10.000 3.000 7.000 6.000 6.000 6.000 7.000 7.000 Hfppm 0.027 0.009 0.044 0.027 0.049 0.032 0.015 0.019 0.018 TK»«H% 0.061 0.020 0.007 0.045 0.021 0.009 0.004 0.011 0.014 Tbppm 0.003 0.003 0.006 0.003 0.014 0.005 0.005 0.002 0.001 Yppm 0.153 0.330 0.288 0.114 0.393 0.114 0.070 0.061 0.085 Tmppm 0.003 0.009 0.006 0.003 0.005 0.003 0.001 0.001 0.001 Ybppm 0.025 0.069 0.046 0.021 0.036 0.018 0.016 0.013 0.015 Sample H9-WI3 H8-WI1A H9-WI4 Z7-P17 Z7-P37 27-P23 Z7-P14A Z7-P29 Z7-P30 Ba 0.251 0.441 0.378 0.672 1.808 1.012 0.302 0.829 0.577 Nb 0.027 0.044 0.033 0.207 0.196 0.088 0.046 0.146 0.063 Th 1.318 0.058 2.361 1.805 2.589 1.528 1.351 1.012 0.907 K 0.000 0.099 0.000 0.000 0.106 0.000 0.000 0.000 0.000 Nb 0.826 0.091 0.172 0.207 0.830 0.224 0.117 0.245 0.132 Ta 0.163 0.102 0.159 0.344 0.843 0.375 0Z67 0.178 0.146 La 0.238 0.078 0.408 0.359 1.397 0.627 0.296 0.593 0.336 Ce 0.196 0.036 0.352 0.256 1.021 0.441 0.191 0.421 0.247 Sr 0.549 Z808 0.933 0.400 1.033 1.040 0.455 0.506 1.694 Nd 1.300 0.528 2.262 2.117 8.646 3.848 1.572 2.981 1.955 P 0.008 0.019 0.008 0.039 0.055 0.044 0.040 0.048 0.049 Sm 0.065 0.030 0.111 0.094 0.386 0.175 0.059 0.087 0.071 Zr 0.542 1.806 0.542 1.264 1.083 1.083 1.083 1.264 1.284 Hf 0.148 0.048 0.244 0.152 0.272 0.179 0.066 0.107 0.100 Tl 0.559 0.180 0.061 0.411 0.193 0.078 0.038 0.086 0.126 Tb 0.054 0.049 0.099 0.051 0.236 0.083 0.079 0.033 0.020 Y 0.073 0.157 0.137 0.054 0.187 0.054 0.033 0.029 0.040 Tm 0.094 0.255 0.178 0.081 0.152 0.075 0.038 0.041 0.037 Yb 0.101 0.280 0.184 0.085 0.144 0.073 0.063 0.051 0.059 296 Sampte ZSfS Z94h6 Zi-Sh4 Z94h9 ZS-ShIO Z9-Sh13 ZS-Sh14 ZB4h16 Z8-Sh18 OimMa ChrOunüa DunMa DunNa OunNa DunHa OunNa DunNa DunNa ■a ppm 2^78 0.973 1.783 1.051 1.543 1.558 1.121 2.078 1.174 Nbppm 0.365 0.394 0252 0.072 0.256 0.069 0.131 0.161 0.071 Thppm 0.332 0.039 0.088 0.073 0.026 0.021 0.025 0.008 0.013 K20wt% 0.000 0.021 0.010 0.000 0.010 0.020 0.010 0.049 0.010 Nbppm 0.236 0224 0.192 0.124 0.094 0.070 0.056 0.068 0.125 Tappm 0.024 0.008 0.010 0.005 0.007 0.004 0.004 0.004 0.005 Lappm 0.632 0.066 0.126 0.097 0.069 0.041 0.058 0.021 0.050 Cappm 1.400 0.127 0245 0.220 0.123 0.088 0.108 0.042 0.102 Srppm 7.334 5.175 2.971 2.187 1.523 3.915 6.404 1.303 1.140 Ndppm 0.445 0.067 0.106 0.075 0.053 0.043 0.045 0.016 0.036 P20Swt% 0.003 0.012 0.008 0.005 0.006 0.008 0.007 0.009 0.006 Smppm 0.094 0.014 0.033 0.017 0.011 0.009 0.003 0.003 0.006 Zrppm 3.000 15.000 16.000 3.000 14.000 11.000 1ZOOO 8.000 5.000 Hfppm 0.082 0.022 0.020 0.035 0.017 0.006 0.015 0.011 0.012 Ti02wt% 0.003 0.058 0.020 0.001 0.015 0.017 0.017 0.023 0.008 Tbppm 0.013 0.003 0.006 0.004 0.002 0.002 0.002 0.001 0.001 Yppm 0.482 0.078 0.114 0.120 0.067 0.060 0.050 0.032 0.057 Tmppm 0.008 0.003 0.002 0.002 0.001 0.002 0.002 0.002 0.002 Ybppm 0.053 0.011 0.016 0.019 0.014 0.008 0.014 0.014 0.014 Sampla Z9-P5 Z 8^h6 Z8-Sh4 Z6-6h9 Z8^h10 Z8-SH13 Z8-Sh14 Z8^h16 Z8-SH18 Ba 0.668 0.285 0.523 0.308 0.453 0.457 0.329 0.609 0.344 Rb 0.106 0.114 0.073 0.021 0.074 0.020 0.036 0.047 0.020 Th 7.806 0.916 Z023 1.729 0.603 0.503 0.580 0.193 0.301 K 0.000 0.210 0.098 0.000 0.096 0.196 0.098 0.493 0.098 Nb 0.629 0.596 0.513 0.331 0.250 0.186 0.154 0.176 0.332 Ta 0.936 0.327 0.399 0.201 0.277 0.168 0.165 0.141 0.179 La 1.722 0.179 0.343 0.264 0.169 0.113 0.159 0.059 0.135 Ca 1.463 0.133 0.256 0.230 0.129 0.092 0.113 0.044 0.107 Sr 0.616 0.435 0.250 0.184 0.128 0.329 0.538 0.109 0.096 Nd 9.088 1.362 Z214 1.536 1.088 0.880 0.925 0.329 0.740 P 0.008 0.031 0.021 0.013 0.016 0.021 0.019 0.024 0.016 Sm 0.406 0.059 0.142 0.074 0.048 0.039 0.013 0.012 0.024 Zr 0.542 2.708 Z888 0.542 2.527 1.986 2.166 1.444 0.903 Hf 0.460 0.122 0.110 0.198 0.095 0.044 0.082 0.061 0.067 Tl 0.026 0.525 0.178 0.009 0.134 0.152 0.152 0.206 0.071 Tb 0.228 0.052 0.110 0.061 0.038 0.043 0.036 0.018 0.026 Y 0.230 0.037 0.054 0.057 0.032 0.029 0.024 0.015 0.027 Tm 0.228 0.071 0.060 0.069 0.040 0.046 0.053 0.052 0.044 Yb 0.213 0.046 0.085 0.078 0.056 0.031 0.055 0.067 0.056 296 Sampte Z94hS H94NM HB4NI3 Z7-P20 Z7-P31 Z7-P47 ZSfS Za-Sh2 ZSBcT OunNa Harzb Harzb Harzb Harzb Harzb Harzb Harzb Harzb ■a ppm 1.184 0.641 0.130 0.828 0.805 3.398 0.808 1.575 0.818 N bppm 0.118 0.062 0.105 0.128 0.089 1.180 0.101 0.662 0.077 Thppm 0.059 0.046 0.000 0.042 0.029 0.246 0.034 0200 0.052 K 20w t% 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.020 0.000 Nbppm 0.049 0.037 0.037 0.029 0.000 0.093 0.083 0.111 0.050 T appm 0.006 0.003 0.003 0.004 0.001 0.009 0.008 0.008 0.000 Lappm 0.089 0.089 0.026 0.102 0.063 0.323 0.087 0.211 0.085 C appm 0.185 0.141 0.026 0.158 0.123 0.604 0.143 0.422 0.183 Srppm 2.016 Z955 0.824 5.062 3.203 3.135 1.942 4.579 1.666 N dppm 0.085 0.049 0.022 0.041 0.040 0.273 0.052 0.179 0.057 P 20Sw t% 0.002 0.003 0.001 0.014 0.018 0.018 0.003 0.007 0.003 Smppm 0.016 0.009 0.003 0.004 0.005 0.053 0.010 0.048 0.013 Z rppm 4.000 4.000 8.000 5.000 7.000 7.000 4.000 3.000 3.000 Hfppm 0.022 0.018 0.009 0.013 0.014 0.010 0.015 0.037 0.021 TK»wt% 0.000 0.002 0.006 0.000 0.015 0.015 0.004 0.016 0.000 Tbppm 0.003 0.002 0.001 0.001 0.000 0.006 0.002 0.009 0.002 Yppm 0.086 0.146 0.080 0.049 0.026 0.341 0.098 0.239 0.073 Tm ppm 0.002 0.004 0.003 0.001 0.001 0.006 0.003 0.005 0.001 Ybppm 0.015 0.034 0.022 0.016 0.005 0.046 0.022 0.032 0.011 Sampte Z9-Sh3 H9-WI6 H8-WI3 Z7-P20 Z7-P31 Z7-P47 Z9-P6 Z 8^h2 Z9-Sc7 Ba 0.347 0.188 0.038 0.184 0.236 0.996 0237 0.462 0.240 Rb 0.034 0.018 0.031 0.037 0.020 0.336 0.029 0.192 0.022 Th 1.389 1.082 0.006 0.981 0.881 5.788 0.792 4.704 1.221 K 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.196 0.000 Nb 0.130 0.008 0.097 0.076 0.001 0.248 0.168 0.296 0.132 Ta 0.213 0.132 0.125 0.167 0.027 0.351 0.231 0.309 0.355 La 0.242 0.189 0.072 0.277 0.171 0.881 0.238 0.576 0232 Ce 0.194 0.147 0.027 0.165 0.129 0.631 0.150 0.441 0.191 Sr 0.169 0.248 0.069 0.427 0.269 0.263 0.163 0.385 0.140 Nd 1.336 0.996 0.459 0.833 0.818 5.577 1.068 3.648 1.159 P 0.005 0.008 0.003 0.038 0.049 0.049 0.008 0.019 0.006 Sm 0.070 0.038 0.012 0.017 0.019 0.228 0.045 0.207 0.055 Zr 0.722 0.722 1.444 0.903 1.284 1.264 0.722 0.542 0.542 Hf 0.122 0.103 0.050 0.071 0.079 0.053 0.084 0208 0.117 Tl 0.000 0.018 0.055 0.000 0.135 0.135 0.036 0.143 0.000 Tb 0.053 0.034 0.013 0.010 0.008 0.130 0.033 0.158 0.034 y 0.041 0.089 0.038 0.023 0.012 0.162 0.047 0.114 0.035 Tm 0.054 0.113 0.072 0.033 0.022 0.174 0.079 0.130 0.040 Yb 0.062 0.138 0.089 0.064 0.020 0.187 0.090 0.129 0.043 297 Sampte Z9-ScS Z7-M4 Harzb Harzb ■a ppm 1.681 32.893 N bppm 0.175 4.642 T hppm 0.144 0.559 K20iMt% 0.010 0.011 N bppm 0.113 0.378 T appm 0.009 0.030 Lappm 0.253 0.964 C appm 0.571 1.828 S rppm 8.291 71.789 N dppm 0.182 0.857 P 206w t% 0.009 0.019 Sm ppm 0.038 0.188 Z rppm 4.000 10.000 Hfppm 0.042 0.031 T » 2 w t% 0.010 0.015 Tbppm 0.006 0.028 Yppm 0.211 1.013 Tm ppm 0.004 0.017 Ybppm 0.026 0.122 Sampte Z»Sc8 Z7P44 Ba 0.496 9.646 Rb 0.051 1.346 Th 3.385 13.155 K 0.097 0.110 Nb 0.302 1.008 Ta 0.362 1.153 La 0.689 Z626 Ca 0.596 1.911 Sr 0.697 6.033 Nd 3.719 17.487 P 0.024 0.051 Sm 0.169 0.813 Zr 0.722 1.805 Hf 0234 0.175 Tl 0.089 0.140 Tb 0.099 0.478 Y 0.100 0.482 Tm 0.106 0.465 Yb 0.105 0.492 298 Swnpte H9-VW1B H9-WB H942 H941 H842 H 949J H947 H8412 Z7-M8 M.Chram Saad.Cbrom HlCliram Chrom D.Chrom OChrom OChrom OChram MChrom UnnaraiaHzMl vahMC L appm 0.02 0.144 0.114 0.03 0.05 0.04 0.06 0.03 0.30 C appm 0.05 0.348 0.234 0.06 0.06 0.08 0.11 0.05 0.48 P rppm 0.01 0.034 0.023 0.01 0.01 0.01 0.01 0.01 0.06 N dppm 0.06 0.148 0.064 0.03 0.04 0.06 0.05 0.02 0.20 Sm ppm 0.03 0.052 0.031 0.02 0.01 0.03 0.02 0.01 0.05 Eu ppm 0.01 0.021 0.009 0.00 0.00 0.02 0.01 0.00 0.02 O dppm 0.05 0.062 0.037 0.01 0.01 0.04 0.02 0.00 0.04 T bppm 0.01 0.013 0.006 0.00 0.00 0.01 0.00 0.00 0.01 D yppm 0.09 0.093 0.059 0.01 0.02 0.07 0.03 0.02 0.04 Ho ppm 0.02 0.020 0.013 0.00 0.00 0.02 0.01 0.00 0.01 E f ppm 0.09 0.062 0.046 0.01 002 0.05 0.07 0.06 0.02 T m ppm 0.01 0.006 0.006 0.00 0.00 0.01 0.01 0.00 0.00 Y bppm 0.06 0.048 0.048 0.01 0.02 0.04 0.02 0.01 0.03 Lu ppm 0.01 0.006 0.008 0.00 0.00 0.01 0.01 0.00 0.00 NormaHzad vakias Sam pla H94M1B H94NB H942 H841 H942 H848.2 H947 H8412 Z74NS La 0.056 0.391 0.310 0.084 0.147 0.105 0.152 0.080 0.007 Ca 0.048 0.365 0.244 0.066 0.085 0.061 0.112 0.052 0.504 Pr 0.069 0.251 0.166 0.049 0.088 0.093 0.094 0.041 0.433 Nd 0.079 0.209 0.133 0.035 0.052 0.085 0.065 0.024 0.285 Sm 0.124 0.225 0.134 0.088 0.054 0.129 0.080 0.042 0.206 Eu 0.079 0.239 0.105 0.049 0.046 0.191 0.082 0.021 0.186 Od 0.170 0.204 0.122 0.018 0.037 0.147 0.056 0.010 0.133 Tb 0.214 0.225 0.136 0.040 0.046 0.174 0.070 0.016 0.120 Oy 0.240 0.244 0.154 0.031 0.058 0.191 0.084 0.044 0.114 Ho 0.277 0.230 0.156 0.041 0.051 0.193 0.093 0.041 0.088 Er 0.344 0.251 0.185 0.060 0.065 0.211 0.270 0.201 0.090 Tm 0.346 0.235 0.233 0.091 0.093 0.260 0.178 0.124 0.105 Yb 0.259 0.192 0.192 0.059 0.076 0.177 0.088 0.059 0.109 Lu 0.299 0.214 0.211 0.078 0.074 0.173 0.154 0.104 0.074 Table B.4: Whole-rock REE normalized to chondrite from Taylor & McClennan (1985) 299 Sampte Z&P3 Z7-PIS Z7-P3i Z7-P19 Z8#4 Z8-Sc6 Zt-Sbl ZS-ScS ZS-Shi teCteom HLCIirom O.Cteam OCteam O.Cteam NLChram ItC teom D.Chrom O.Cteam UnnonnaliaMt vakMS Lappm 1.715 0.29 0.23 0.32 0.136 0.368 0221 0.110 0.212 C appm 3.717 0.68 0.43 0.62 0.286 0.777 0.482 0233 0.470 P rppm 0.337 0.07 0.04 0.05 0.028 0.072 0.045 0.021 0.041 Ndppm 1.183 0.26 0.13 0.15 0.122 0.256 0.175 0.084 0.153 Sm ppm 0.248 0.07 0.03 0.02 0.031 0.060 0.038 0.018 0.034 Euppm 0.029 0.01 0.01 0.01 0.011 0.009 0.006 0.005 0.006 O dppm 0.196 0.06 0.02 0.01 0.031 0.050 0.032 0.015 0.029 Tbppm 0.036 0.01 0.00 0.00 0.006 0.008 0.006 0.003 0.005 Oyppm 0.214 0.06 0.02 0.01 0.033 0.048 0.037 0.019 0.033 Hoppm 0.045 0.01 0.00 0.00 0.007 0.011 0.007 0.004 0.008 S rppm 0.132 0.04 0.01 0.01 0.020 0.033 0.025 0.015 0.025 Tm ppm 0.021 0.01 0.00 0.00 0.003 0.005 0.004 0.002 0.004 Ybppm 0.134 0.03 0.01 0.01 0.021 0.029 0.026 0.013 0.024 Luppm 0.022 0.00 0.00 0.00 0.004 0.004 0.004 0.002 0.004 NormaHzad valuas Sampte Z9-P3 Z7-P36 Z7-P39 Z7-P18 Z9-P4 Z i-S c i Z9-SM Zt-ScS ZS-Sh8 La 4.674 0.794 0.624 0.877 0.379 1.003 0.601 0.301 0.577 Ca 3.884 0.714 0.453 0.643 0299 0.812 0.503 0.243 0.491 Pr 2.460 0.497 0.286 0.347 0.205 0.525 0.329 0.152 0.302 Nd 1.663 0.373 0.179 0.207 0.171 0.360 0.246 0.119 0.216 Sm 1.073 0.288 0.120 0.092 0.136 0.260 0.171 0.077 0.145 Eu 0.329 0.098 0.079 0.068 0.128 0.103 0.070 0.052 0.066 Od 0.642 0.186 0.056 0.045 0.101 0.163 0.103 0.048 0.085 Tb 0.628 0.172 0.027 0.062 0.100 0.144 0.098 0.054 0.080 Oy 0.563 0.167 0.040 0.037 0.087 0.125 0.097 0.050 0.087 Ho 0.526 0.154 0.027 0.027 0.080 0.124 0.086 0.049 0.090 Er 0.529 0.144 0.036 0.053 0.082 0.131 0.099 0.060 0.089 Tm 0.582 0.146 0.034 0.046 0.096 0.138 0.114 0.062 0.089 Yb 0.539 0.127 0.058 0.051 0.084 0.119 0.104 0.054 0.085 Lu 0.566 0.105 0.021 0.079 0.108 0.117 0.107 0.060 0.112 300 Sam pte H t-vm H84NMA HS4MU Z 7 f1 7 Z7-PS7 Z7-P23 Z7-P14A Z7-P29 Z7-P30 CliiOunIte DunNa DunNa CteDwnNa OunNa DunNa DunNa OunNa DunNa Unnonnalizad valiMt Lappm 0.0B7 0.03 0.150 0.13 0.51 0.23 0.11 0.22 0.12 C appm 0.188 0.03 0.337 0.24 0.98 0.42 0.18 0.40 0.24 P rppm 0.015 0.01 0.031 0.03 0.11 0.05 0.02 0.04 0.03 N dppm 0.064 0.03 0.111 0.10 0.42 0.19 0.08 0.15 0.10 Sm ppm 0.015 0.01 0.026 0.02 0.09 0.04 0.01 0.02 0.02 E uppm 0.004 0.01 0.006 0.00 0.03 0.01 0.01 0.01 0.00 Odppm 0.013 0.01 0.026 0.02 0.08 0.03 0.02 0.01 0.01 T bppm 0.003 0.00 0.006 0.00 0.01 0.00 0.00 0.00 0.00 D yppm 0.023 0.05 0.043 0.01 0.08 0.02 0.01 0.01 0.02 Hoppm 0.005 0.01 0.010 0.00 0.01 0.00 0.00 0.00 0.00 Erppm 0.018 0.04 0.034 0.02 0.04 0.01 0.01 0.01 0.01 T m ppm 0.003 0.01 0.006 0.00 0.01 0.00 0.00 0.00 0.00 Y bppm 0.025 0.07 0.046 0.02 0.04 0.02 0.02 0.01 0.01 Lu ppm 0.005 0.01 0.008 0.00 0.01 0.00 0.00 0.00 0.00 Normalizad valuas Sampte H8-wn H84M1A H94NI4 Z7-P17 Z7-P37 Z7-P23 Z7-P14A Z7-P29 Z7-P30 La 0.238 0.078 0.408 0.359 1.397 0.627 0.296 0.593 0.336 Ca 0.196 0.036 0.352 0.256 1.021 0.441 0.191 0.421 0.247 Pr 0.112 0.059 0.224 0.188 0.771 0.369 0.157 0.296 0.198 Nd 0.090 0.036 0.156 0.146 0.596 0.265 0.108 0.206 0.135 Sm 0.065 0.030 0.111 0.094 0.386 0.175 0.059 0.087 0.071 Eu 0.043 0.076 0.069 0.052 0.361 0.129 0.073 0.086 0.047 Od 0.043 0.020 0.085 0.063 0.258 0.089 0.050 0.024 0.044 Tb 0.054 0.049 0.099 0.051 0.236 0.083 0.079 0.033 0.020 Dy 0.059 0.126 0.113 0.029 0.201 0.059 0.025 0.022 0.043 Ho 0.060 0.150 0.114 0.044 0.174 0.057 0.014 0.035 0.036 Er 0.073 0.167 0.136 0.060 0.148 0.059 0.040 0.038 0.030 Tm 0.094 0.255 0.178 0.081 0.152 0.075 0.038 0.041 0.037 Yb 0.101 0.280 0.184 0.085 0.144 0.073 0.063 0.051 0.059 Lu 0.142 0.360 0.222 0.098 0.132 0.091 0.081 0.049 0.060 301 Sampte 2S-PS ZS-ShS ZS-SM ZS-ShS Zi-SlilO ZS-SM3 Z8-SM4 Z 64M 6 Z6-Shia OunNa CbrOunNa OunNa OunNa OunNa OunNa OunNa OunNa DunNa Unnonnalizad vahMC U p p m 0.632 0.07 0.13 0.007 0.07 0.04 0.06 0.02 0.05 C appm 1.400 0.13 0.24 0.220 0.12 0.09 0.11 0.04 0.10 P rppm 0.124 0.02 0.03 0.020 0.02 0.01 0.01 0.01 0.01 N dppm 0.445 0.07 0.11 0.075 0.05 0.04 0.05 0.02 0.04 Sm ppm 0.084 0.01 0.03 0.017 0.01 0.01 0.00 0.00 0.01 E uppm 0.011 0.01 0.01 0.006 0.01 0.01 0.01 0.00 0.01 O dppm 0.076 0.01 0.03 0.018 0.01 0.01 0.01 0.00 0.01 Tbppm 0.013 0.00 0.01 0.004 0.00 0.00 0.00 0.00 0.00 Oyppm 0.081 0.02 0.03 0.022 0.03 0.03 0.02 0.02 0.02 Hoppm 0.018 0.00 0.01 0.004 0.01 0.00 0.00 0.00 0.00 E rppm 0.048 0.02 0.01 0.013 0.01 0.01 0.01 0.01 0.01 Tm ppm 0.008 0.00 0.00 0.002 0.00 0.00 0.00 0.00 0.00 Ybppm 0.053 0.01 0.02 0.019 0.01 0.01 0.01 0.01 0.01 Lu ppm 0.010 0.00 0.00 0.004 0.00 0.00 0.00 0.00 0.00 Normalizad valua# Sampte Zi-PS ZS-ShS ZS-Sh4 ZS-ShS Z8-SM0 ZI-SM3 Z8-SM4 Z8-SM6 Zi-Sh18 U 1.722 0.179 0.343 0.264 0.189 0.113 0.159 0.059 0.135 Ca 1.463 0.133 0.256 0.230 0.129 0.082 0.113 0.044 0.107 Pr 0.908 0.117 0.207 0.143 0.114 0.087 0.107 0.044 0.090 Nd 0.626 0.094 0.153 0.106 0.075 0.061 0.064 0.023 0.051 Sm 0.406 0.059 0.142 0.074 0.048 0.039 0.013 0.012 0.024 Eu 0.126 0.084 0.131 0.062 0.087 0.079 0.069 0.039 0.065 Od 0.250 0.043 0.083 0.060 0.028 0.019 0.024 0.008 0.016 Tb 0.228 0.052 0.110 0.061 0.038 0.043 0.036 0.018 0.026 Oy 0.212 0.062 0.091 0.057 0.068 0.066 0.060 0.045 0.057 Ho 0.207 0.047 0.085 0.048 0.066 0.036 0.032 0.043 0.045 Er 0.195 0.070 0.058 0.054 0.036 0.036 0.028 0.022 0.024 Tm 0.228 0.071 0.060 0.069 0.040 0.046 0.053 0.052 0.044 Yb 0.213 0.046 0.065 0.078 0.056 0.031 0.055 0.057 0.056 Lu 0.252 0.075 0.072 0.105 0.084 0.075 0.084 0.048 0.070 302 Sampte ZbOhS H84NI8 H8-VM3 Z7-P20 Z7-P31 Z7-P47 ZS-P6 Z8-Sh2 Z9-SC7 DunNi Harzb Harzb Harzb Harzb Harzb Harzb Harzb Harzb Unnonnalizad vahiM Lappm 0.088 0.089 0.03 0.10 0.06 0.32 0.087 0.21 0.085 C appm 0.185 0.141 0.03 0.16 0.12 0.60 0.143 0.42 0.183 Prppm 0.018 0.013 0.01 0.02 0.01 0.07 0.013 0.05 0.015 Ndppm 0.065 0.049 0.02 0.04 0.04 0.27 0.052 0.18 0.057 Smppm 0.016 0.009 0.00 0.00 0.00 0.05 0.010 0.05 0.013 Euppm 0.006 0.003 0.00 0.01 0.00 0.01 0.005 0.02 0.004 Odppm 0.016 0.009 0.01 0.00 0.00 0.05 0.010 0.05 0.012 T bppm 0.003 0.002 0.00 0.00 0.00 0.01 0.002 0.01 0.002 Oyppm 0.018 0.020 0.02 0.01 0.00 0.06 0.015 0.06 0.015 H oppm 0.003 0.005 0.00 0.00 0.00 0.01 0.004 0.01 0.003 E rppm 0.010 0.021 0.01 0.01 0.01 0.04 0.013 0.03 0.008 T m ppm 0.002 0.004 0.00 0.00 0.00 0.01 0.003 0.00 0.001 Ybppm 0.015 0.034 0.02 0.02 0.00 0.05 0.022 0.03 0.011 Lu ppm 0.003 0.007 0.00 0.00 0.00 0.01 0.005 0.01 0.002 Normalizad valu## Sampte Z8-Sh3 H9-VM8 H8-VM3 Z7-P20 Z7-P31 27-PA7 za-ps Z8-Sh2 Z9-Sc7 La 0.242 0.189 0.072 0.277 0.171 0.861 0.238 0.576 0.232 Ca 0.194 0.147 0.027 0.165 0.129 0.631 0.150 0.441 0.191 Pr 0.130 0.097 0.054 0.112 0.090 0.512 0.095 0.355 0.112 Nd 0.092 0.069 0.032 0.057 0.056 0.384 0.074 0.251 0.080 Sm 0.070 0.038 0.012 0.017 0.019 0.228 0.045 0.207 0.055 Eu 0.065 0.031 0.015 0.060 0.006 0.105 0.052 0.186 0.046 Od 0.051 0.029 0.019 0.007 0.006 0.150 0.034 0.164 0.039 Tb 0.053 0.034 0.013 0.010 0.008 0.130 0.033 0.158 0.034 Dy 0.047 0.052 0.044 0.021 0.010 0.152 0.040 0.149 0.038 Ho 0.040 0.064 0.050 0.019 0.015 0.164 0.049 0.141 0.033 Er 0.039 0.083 0.043 0.030 0.020 0.147 0.051 0.114 0.031 Tm 0.054 0.113 0.072 0.033 0.022 0.174 0.079 0.130 0.040 Yb 0.062 0.138 0.089 0.064 0.020 0.187 0.080 0.129 0.043 Lu 0.079 0.173 0.124 0.069 0.038 0.172 0.128 0.158 0.052 303 Sampte Z t-S c l Z7-P44 (Nhars WadS-1 Z7-P6 Z7-P42 Z7-P24 Harzb Harzb DunHa PyrosanMa OranNa G ranite U nnorm aliiad vahMS Lappm 0^ 0.86 0.076 0.26 14.31 42.80 Cappm 0.571 1.63 0.165 0.66 26.36 78.68 P rppm 0.050 0.21 0.015 0.06 3.15 6.08 Ndppm 0.182 0.66 0.058 0.36 13.30 28.40 Sm ppm 0.038 0.18 0.012 0.11 2.81 4.60 Euppm 0.006 0.04 0.003 0.03 1.72 1.56 Odppm 0.032 0.17 0.010 0.08 2.76 3.22 T bppm 0.006 0.03 0.002 0.02 0.41 0.47 Oyppm 0.038 0.16 0.013 0.06 2.33 2.36 Hoppm 0.008 0.04 0.003 0.02 0.46 0.45 E rppm 0.023 0.11 0.006 0.05 1.34 1.12 Tm ppm 0.004 0.02 0.002 0.01 0.18 0.15 Ybppm 0.026 0.12 0.012 0.06 1.26 0.84 L uppm 0.005 0.02 0.002 0.01 0.22 0.16 Normalizad valuas Sampte Z8-SC8 Z7-P44 Wad8-1 Z7-P6 Z7-P42 Z7-P24 La 0.688 2.626 0.212 0.760 36.880 116.664 Ca 0.586 1.811 0.173 0.667 28.628 63.465 Pr 0.367 1.566 0.108 0.584 23.026 58.060 Nd 0.256 1.205 0.063 0.501 16.706 41.353 Sm 0.168 0.613 0.054 0.455 12.561 18.814 Eu 0.066 0.444 0.035 0.400 18.731 17.861 Od 0.104 0.563 0.033 0.281 8.006 10.515 Tb 0.088 0.476 0.036 0.353 7.061 6.044 Oy 0.101 0.466 0.035 0.206 6.126 6.258 Ho 0.080 0.471 0.032 0.211 5.604 5.247 Er 0.081 0.445 0.033 0.187 5.366 4.504 Tm 0.106 0.466 0.046 0.225 5.386 4.231 Yb 0.105 0.482 0.046 0.255 5.072 3.606 Lu 0.125 0.463 0.063 0.264 5.622 4.216 304 Unnormaiizad Valuaa Name M.Chrcmiti M.Chromiti M.Chromiti MChromiti M.Chromiti M.ChromiU Diss.Chron DisaChron Sample H9-WI2 Z9-P3 Z7-P48 Z9-Sh1 Z9-SC4 Z9-Sc8 H9-WI3 H8-I2 POE ppb ppb ppb ppb ppb ppb ppb ppb Oa 5 34 13 200 19 20 14 7 Ir 8.7 33 9.0 120 19 19 5.8 7.3 Ru 11 130 48 530 110 76 10.5 37 Rh 3 11 4 11 9 9 1 3 Pt 8 10 5.5 7 8.5 10 8.5 10 Pd 9 2.5 8 .5 2 5 6 11.5 5.5 8 Au 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Normallzad Valuaa Cl chondrlta Naldrett& Duke M 9601 Sampla DOb H9-W I2 Z9-P3 Z7-P48 Z9-Sh1 Z9-SC4 Z9-Sc6 H9-WI3 H8-I2 Oa 514 0.009728 0.066148 0.025292 0.389105 0.036965 0.038911 0.027237 0.013619 Ir 540 0.016111 0.061111 0.016667 0.222222 0.035185 0.035185 0.010741 0.013519 Ru eoc 0.015942 0.188406 0.069565 0.768116 0.15942 0.110145 0.015217 0.053623 Rh 200 0.014 0.055 0.02 0.055 0.045 0.045 0.005 0.0155 Pt 1020 0.007843 0.009804 0.005392 0.006863 0.006373 0.009804 0.008333 0.009804 Pd 546 0.016514 0.004587 0.011927 0.004587 0.011009 0.021101 0.010092 0.011009 Au 152 0.003289 0.003289 0.003289 0.003289 0.003289 0.003289 0.003289 0.003289 Table B.5: Whole-rock platinum group elements. Note that undetected values are considered 50% of detection limits (as Economou & Naldrett, 1984 suggested) 305 Name Diss.Chror Diss.Chror Diss.Chron Diss.Chror M.Chromiti Dunite Dunite Dunite Dunite Sample H8-I7 Z9-P4 Z8-Sh8 Z9-Sc9 H9-I2 H9-WI4 Z9-P5 Z8-Sh9 Z9-Sc7 ppb ppb ppb ppb ppb ppb ppb ppb ppb Os 12 19 25 18 9 1.5 4 0.5 6 Ir 10 11 16 20 8.7 2.8 4.3 0.2 3.6 Ru 21 37 55 51 31 2.5 4.5 2 9 Rh 6 3 3 7 4 1 2 0.15 1 Pt 10.5 3.5 2 2 11 9 5 8 10 Pd 6.5 2.5 6 4.5 6.5 6.5 5 4.5 5 Au 4.0 0.5 0.5 0.5 3.4 0.5 0.5 0.5 0.5 Sample H8-I7 Z9-P4 Z8-Sh8 Z9-Sc9 H9-I2 H9-WI4 Z9-P5 Z8-Sh9 Z9-Sc7 Os 0.023346 0.036965 0.048638 0.035019 0.01751 0.002918 0.008366 0.000973 0.011673 Ir 0.018519 0.02037 0.02963 0.037037 0.016111 0.005185 0.007963 0.00037 0.006667 Ru 0.030435 0.053623 0.07971 0.073913 0.044928 0.003623 0.006522 0.002899 0.013043 Rh 0.0295 0.015 0.0165 0.035 0.021 0.007 0.01 0.00075 0.0065 Pt 0.010294 0.003431 0.001961 0.001961 0.010784 0.008824 0.004902 0.007843 0.009804 Pd 0.011927 0.004587 0.011009 0.008257 0.011927 0.011927 0.009174 0.008257 0.009174 Au 0.026316 0.003289 0.003289 0.003289 0.022368 0.003289 0.003289 0.003289 0.003289 Not detected value is considered 50% of the detection limit (as Economou & Naldrett, 1984 suggested) 306 Name Dunite Peridotite Peridotite Peridotite Peridotite Talc Sam ple Wad9-1 H9-WI6 Z9-P6 Z9-Sh3 Z9-Sc8 Z8-Sh15 ppb ppb ppb ppb ppb ppb Oa 4 1.5 2 4 6 4 Ir 3.5 3.2 1.0 2.5 12 2.6 Ru 3 7.5 5.5 3.5 5 5 Rh 2 2 2.5 1 2 0.5 Pt 11.5 9.5 6 7.5 9 6.5 Pd 8.5 10 4 7.5 4.5 6.5 Au 5.3 3.9 0.5 0.5 0.5 0.5 Sam ple Wad9-1 H9-WI6 Z9-P6 Z9-Sh3 Z9-Sc8 Z8-Sh15 Oa 0.007782 0.002918 0.003891 0.007782 0.011673 0.007782 Ir 0.006481 0.005926 0.001852 0.00463 0.022222 0.004815 Ru 0.004348 0.01087 0.007971 0.005072 0.007246 0.007246 Rh 0.0095 0.008 0.0125 0.0055 0.008 0.0025 Pt 0.011275 0.009314 0.005882 0.007353 0.008824 0.006373 Pd 0.015596 0.018349 0.007339 0.013761 0.008257 0.011927 Au 0.034868 0.025658 0.003289 0.003289 0.003289 0.003289 307 ABENDDCC MINERAL CHEMISTRY Introduction Analyses of chromite, olivine, pyroxene, and amphibole were obtained using Cameca SX-SO microprobe. Most analyses were done at the Ohio State University (OSU), but some were done at the Washington State University (WSU). The standards used and analytical conditions were similar at both labs. 20 kV acceleration voltage, 15- 16 nanoamps beam current, and 20s counting times for Ka X-ray lines were used for all elements in all minerals. Except for NbzO; and Pt that were analyzed with L|3 and Ma X- ray lines respectively. Thin sections were carbon coated before use in the microprobe. Standards were calibrated every initial work and recalibrated and checked periodically during the work. The standards for chromite and silicate analyses are listed in Tables C.l and C 2 The analyses were used to calculate mineral formula for chromite, olivine, pyroxene, and amphibole. FezOs contents in chromite were calculated from FeO total iron, assuming ideal stoichiometry. 30S Scries Element OSU WSU OSU WSU Standard Standard Crystal Crystal I SiOî Fosterite Diopside TAP TAP 2 AI2O3 Corundum Mg-Al Spinel TAP TAP 3 TiOz Ilmenite Ilmenite LIF PET 4 CrzO] Chromite Chromite PET LIF 5 FeO Magnet Chromite LIF LIF 6 MnO Mn Ilmenite PET LIF 7 MgO Forsterite Mg-Al Spinel TAP TAP 8 NiO Ni NiO LIF LIF 9 CaO Diopside Diopside PET PET 1 0 V2O5 V V LIF PET 11 NbzOs NBC PET 1 2 ZnO Gahnite Gahnite LIF LIF 13 PtzOs Pt PET Figure C 1 : List o f the standards used in analyzing the oxide minerals (chromites). 309 Scries Element OSU WSU OSU WSU Standard Standard Crystal Crystal 1 SiOz Albite Diopside TAP TAP 2 AI2O3 Anorthite Anorthite TAP TAP 3 TiOj Ilmenite Sphene LIF PET 4 CrzO] Chromite Chromite PET PET 5 FeO Fayalite Fayalite LIF LIF 6 MgO Forsterite Olivine TAP TAP 7 MnO Mn Spessartine PET LIF 8 NiO Ni NiO LIF LIF 9 CaO Diopside Diopside PET PET 1 0 NazO Albite Albite TAP TAP Table C 2: List of the standards used in analyzing the silicate minerals. 310 Maurel & Maurel (1982a) equation for calculating the AI2O3 of the melt, using AI2O3 of the chromite composition: (Alz0 3 )sp = 0.035 (Al 2 0 3 )iiq^ ‘‘^ where AI 2O3 is in wt % Calculating temperature of the melt by knowing MgO of the melt: 1) Smith & Erlank’s(l982) equation T°C = 18.79 MgQ t 1042 2) Bickle’s(1982) equation VC = 16.7MgO + 10J7 3) Ramsay et al. s( 1984) equation T*C = 16.307MgO + 1083 311 C alculating C hrom lla Structural Formula; (Mg, Fa|C r204, B ared on 4 O iy g tn a and 3 Cations Sample: Z7-0; Point: CHR4 (A) (B) (C) ID) (E) (F) (G) (H) (1) (J) (K) (L) (M) Oxidos Analvsla Norm.Ana Mol.Wt. Mol.Proo. Ox.Mole OmProo. No.of Ante CatAss. Cations Norm CaL CaLValen Act. Cat W t.% B*100/to1B C/D E'F G*(4/tolG) Cat/Ox HM (J/tolal J)'3 K*L SK)2 0 0 60.0843 0 2 0 0 0-Jan 0 0 4 0 AI203 24.93 25.26739 101.9613 0.247814 3 0.743441 1.35299 0-Jan 0.901993 0.900153 3 270046 TK)2 0.05 0.050677 79.8988 0.000634 2 0.001269 0.002309 0-Jan 0.001154 0.001152 3 0.003456 Cr203 44.482 45.084 151.9902 0.296824 3 0.889873 1.619482 0-Jan 1 079655 1.077453 3 3.232359 FaOtoL 14.63435 14.8324 71.8464 0.206446 1 0.206446 0.375712 1 0.375712 0.374945 2 0.749891 MnO 0.456 0.462171 70.9374 0.006515 1 0.006515 0.011857 1 0.011857 0.011833 2 0023666 MgO 13.701 13.88842 40.3044 0.344539 1 0.344539 0.627027 1 0.827027 0.625748 2 1.251496 NK> 0.014 0.014189 74.6994 0.00019 1 0.00019 0.000346 1 0.000346 0.000345 2 0.00069 CaO 0 0 56.0794 0 1 0 0 1 0 0 2 0 V203 0.115369 0118931 149.881 0.00078 3 0.00234 0.004259 0-Jan 0.00284 0.002834 3 0.008501 Nb2CS 0 0265.8098 0 5 0 0 0-Jan 0 0 5 0 ZnO 0.224 0.227032 81.3794 0.00279 1 0.00279 0.005077 1 0.005077 0.005067 2 0.010134 Pt02 0.058 0 058785 227.0888 0.000259 2 0.000518 0000942 0-Jan 0.000471 0.00047 4 0.001881 Total 9S.S6472 100 2.1S792 3.00S131 3 79S2532 Cations NetCatlon Oxidss Net Anal. SM* 0 SK>2 0 AI3* 0.900153 AI203 25.26739 TI4* 0.001152 TI02 0.050677 Cr3* 1 077453 Cr203 45.084 CrSuCr*100/(Cr*AI) 54.48288 54.48268 54.48268 F#3* 0.017468 Fe203 0.787907 era mCr"100/|Cr*AI*Fe3*| 54.00586 Fs2* 0.357478 FeO 14.1414 MgS«Mg*100/(Mg*Fclot) 8Z53144 82.53144 Mg a «Mg 82.53144 Mn2* 0.011833 MnO 0.462171 Mg"S « Mg'100/(Mg*Fc2*) 63.64235 Mg2* 0.625748 MgO 13.88642 Fs3*RaUoa Fe3*/(AI*Cr*Fe3*) 0.875538 NI2* 0.000345 HtO 0.014189 Cs2* 0 CaO 0 V3* 0.002834 V203 0.116931 NbSe 0 Nb205 0 Zn2* 0.005067 ZnO 0.227032 Actual Total Iron = 14.90931 PM* 0.00047 Pt02 0.058785 The Difference ■ 0.078906 Total 3 100.07SS Figura C.1: SampI* form of (he chromitt formula calculation anti ralatad Abbravlatlona In tha aamolo namaa: H, Al'Hal; I. Icabarg; VI, Viking; Wl, WadM, Z, ZIkt; P, Palace; Sh, B. Sharq; V, Vera; Sc, 8. Scorpion; Wad. Wadi Al'Abadllah Number after the first capital letter Is the collection year; after the site name (second letters) Is sample numtier In th a t site 312 Latwl CR1-A1-C CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C CR4-A2-R O xides W t% W t% W t% Wt% Wt% Wt% Wt% 3102 0.065 0.011 0.040 0.021 0.030 0.046 0.015 A I203 23.432 24.582 24.852 24.010 23.256 23.957 24.666 T I02 0.099 0.063 0.141 0.114 0.116 0.149 0.114 C r203 47.051 45.676 46.252 46.137 46.184 45.786 46.787 F e2 0 3 0.519 0.958 -1.336 1.319 2.367 1.628 -0.989 FeO 14.338 14.169 16.737 13.430 12.719 13.486 15.504 MnO 0.604 0.537 0.539 0.484 0.460 0.542 0.441 MgO 13.524 13.865 12.237 14.297 14.684 14.217 12.964 NIO 0.118 0.040 0.126 0.076 0.071 0.123 0.058 CaO 0.028 0.014 0.004 0.020 0.046 0.000 0.018 V 203 0.179 0.179 0.163 0.140 0.226 0.195 0.199 N b205 0.007 0.000 0.111 0.000 0.000 0.000 0.000 ZnO 0.089 0.000 0.000 0.024 0.051 0.034 0.114 P t0 2 0.000 0.000 0.000 0.059 0.026 0.000 0.008 T otal 100.052 100.096 99.866 100.132 100.237 100.163 99.901 C atio n s 314+ 0.002 0.000 0.001 0.001 0.001 0.001 0.000 AI3+ 0.842 0.878 0.897 0.857 0.830 0.855 0.886 TI4+ 0.002 0.001 0.003 0.003 0.003 0.003 0.003 Cr3+ 1.135 1.094 1.120 1.105 1.106 1.097 1.128 Fe3+ 0.012 0.022 -0.031 0.030 0.054 0.037 -0.023 Fe2+ 0.366 0.359 0.429 0.340 0.322 0.342 0.395 Mn2+ 0.016 0.014 0.014 0.012 0.012 0.014 0.011 Mg2+ 0.615 0.626 0.559 0.645 0.663 0.642 0.589 NI2+ 0.003 0.001 0.003 0.002 0.002 0.003 0.001 Ca2+ 0.001 0.000 0.000 0.001 0.002 0.000 0.001 V3+ 0.004 0.004 0.004 0.003 0.005 0.005 0.005 NbS+ 0.000 0.000 0.002 0.000 0.000 0.000 0.000 Zn2+ 0.002 0.000 0.000 0.001 0.001 0.001 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 T otal 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 57.393 55.487 55.526 56.315 57.123 56.181 55.995 Cr*# 57.050 54.879 56.387 55.465 55.575 55.133 56.633 M g# 61.954 62.182 58.405 63.551 63.805 62.896 61.261 M g'# 62.706 63.561 56.584 65.489 67.299 65.269 59.848 Fe3+ 0.599 1.096 •1.550 1.509 2.711 1.866 •1.140 Table C.3: Sample H8>I1 DIsaemlnated chromltite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 313 CR5-A1-C CR5-A2-R CR6-A2-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R :% Wt% Wt% Wt% Wt% Wt% Wt% W t% 0.046 0.050 0.139 0.037 0.053 0.000 0.036 0.057 24.110 23.816 24.058 24.800 23.673 23.694 24.235 23.305 0.119 0.125 0.079 0.120 0.139 0.104 0.176 0.120 45.358 46.004 45.503 46.320 45.641 45.564 45.326 45.169 2.014 1.963 1.919 -0.595 2.438 2.824 2.074 3.670 13.069 12.588 12.816 14.885 12.785 11.987 12.525 11.691 0.469 0.453 0.441 0.497 0.500 0.451 0.514 0.565 14.534 14.798 14.908 13.348 14.664 15.197 14.969 15.371 0.118 0.143 0.065 0.108 0.168 0.166 0.114 0.108 0.000 0.014 0.000 0.020 0.000 0.001 0.000 0.010 0.172 0.154 0.183 0.165 0.155 0.184 0.151 0.204 0.000 0.000 0.055 0.023 0.000 0.055 0.087 0.055 0.089 0.089 0.000 0.126 0.027 0.056 0.000 0.043 0.102 0.000 0.026 0.086 0.000 0.000 0.000 0.000 100.202 100.197 100.192 99.940 100.244 100.283 100.208 100.368 0.001 0.001 0.004 0.001 0.002 0.000 0.001 0.002 0.859 0.848 0.855 0.889 0.843 0.841 0.860 0.828 0.003 0.003 0.002 0.003 0.003 0.002 0.004 0.003 1.084 1.098 1.084 1.114 1.091 1.085 1.079 1.076 0.046 0.045 0.044 -0.014 0.055 0.064 0.047 0.083 0.330 0.318 0.323 0.378 0.323 0.302 0.315 0.295 0.012 0.012 0.011 0.013 0.013 0.012 0.013 0.014 0.655 0.666 0.670 0.605 0.661 0.683 0.672 0.690 0.003 0.003 0.002 0.003 0.004 0.004 0.003 0.003 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.004 0.004 0.004 0.004 0.004 0.004 0.004 0.005 0.000 0.000 0.001 0.000 0.000 0.001 0.001 0.001 0.002 0.002 0.000 0.003 0.001 0.001 0.000 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.792 56.443 55.924 55.614 56.396 56.333 55.647 56.525 54.507 55.178 54.696 55.994 54.824 54.521 54.330 54.158 63.517 64.759 64.631 62.380 63.572 65.092 64.964 64.633 66.470 67.695 67.465 61.517 67.156 69.325 68.056 70.093 2.303 2.241 2.196 •0.684 2.788 3.217 2.366 4.188 314 R9-A1-C CR9-A1-RWSU-1 WSU-2 WSU-3 WSU-4 Sample H8 Ave Wt% Wt% Wt% Wt% W t% W t% 0.043 0.061 0.159 0.139 0.157 0.168 0.065 23.822 24.254 23.763 23.802 24.372 23.362 23.991 0.114 0.085 0.120 0.112 0.145 0.113 0.118 45.792 46.058 43.921 44.004 43.776 44.399 45.558 1.578 1.228 4.068 3.428 3.413 2.964 1.784 13.424 12.905 13.637 13.384 13.308 12.937 13.444 0.417 0.440 0.175 0.180 0.128 0.173 0.429 14.413 14.666 14.500 14.515 14.784 14.624 14.337 0.117 0.086 0.132 0.126 0.091 0.114 0.108 0.000 0.008 0.030 0.000 0.028 0.000 0.012 0.172 0.207 0.192 0.175 0.207 0.168 0.180 0.182 0.000 0.000 0.000 0.000 0.000 0.027 0.083 0.126 0.042 0.023 0.030 0.029 0.051 0.000 0.000 0.000 0.000 0.000 0.000 0.015 100.158 100.123 100.739 99.889 100.439 99.051 100.118 0.001 0.002 0.005 0.004 0.005 0.005 0.002 0.850 0.863 0.844 0.851 0.864 0.842 0.856 0.003 0.002 0.003 0.003 0.003 0.003 0.003 1.097 1.099 1.047 1.055 1.041 1.073 1.091 0.036 0.028 0.092 0.078 0.077 0.068 0.041 0.340 0.326 0.344 0.340 0.335 0.331 0.341 0.011 0.011 0.004 0.005 0.003 0.004 0.011 0.651 0.660 0.652 0.656 0.663 0.666 0.647 0.003 0.002 0.003 0.003 0.002 0.003 0.003 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.004 0.005 0.005 0.004 0.005 0.004 0.004 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.003 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 56.323 56.023 55.356 55.362 54.648 56.043 56.021 55.301 55.238 52.780 53.179 52.518 54.115 54.879 63.380 65.110 59.908 61.106 61.671 62.554 62.920 65.681 66.952 65.462 65.907 66.446 66.832 65.515 1.814 1.402 4.653 3.943 3.897 3.439 2.041 315 Label CR1 -A1 -C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A2-C CR3-A2-R CR4-A1-C O xides W t% Wt % W t% W t% W t% W t% W t% S i0 2 0.072 0.021 0.019 0.035 0.015 0.044 0.006 AI203 23.804 24.599 24.395 24.446 24.225 24.692 24.081 TI02 0.079 0.076 0.090 0.095 0.112 0.059 0.143 C r203 45.845 46.487 45.367 46.067 45.590 46.017 44.793 F e203 1.665 -0.561 1.978 0.845 1.913 0.055 2.689 FeO 13.504 15.229 12.847 13.477 12.712 14.551 13.107 MnO 0.558 0.551 0.546 0.513 0.453 0.431 0.564 MgO 14.235 13.126 14.656 14.301 14.726 13.751 14.391 NIO 0.105 0.079 0.143 0.068 0.182 0.033 0.115 CaO 0.014 0.040 0.018 0.000 0.007 0.006 0.039 V203 0.167 0.105 0.129 0.188 0.192 0.171 0.168 N b205 0.007 0.096 0.007 0.000 0.000 0.096 0.048 ZnO 0.000 0.079 0.002 0.050 0.064 0.062 0.127 P t0 2 0.111 0.016 0.000 0.000 0.000 0.035 0.000 Total 100.167 99.944 100.198 100.085 100.192 100.006 100.269 C ations SW+ 0.002 0.001 0.001 0.001 0.000 0.001 0.000 AI3+ 0.851 0.883 0.867 0.871 0.861 0.883 0.858 TI4+ 0.002 0.002 0.002 0.002 0.003 0.001 0.003 Cr3+ 1.099 1.120 1.082 1.101 1.087 1.103 1.071 Fe3+ 0.038 -0.013 0.045 0.019 0.043 0.001 0.061 Fe2+ 0.342 0.388 0.324 0.341 0.321 0.369 0.331 Mn2+ 0.014 0.014 0.014 0.013 0.012 0.011 0.014 Mg2+ 0.643 0.596 0.659 0.644 0.662 0.622 0.649 NW+ 0.003 0.002 0.003 0.002 0.004 0.001 0.003 Ca2+ 0.000 0.001 0.001 0.000 0.000 0.000 0.001 V3+ 0.004 0.003 0.003 0.005 0.005 0.004 0.004 Nb5+ 0.000 0.001 0.000 0.000 0.000 0.001 0.001 Zn2+ 0.000 0.002 0.000 0.001 0.001 0.001 0.003 R 4+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 56.371 55.903 55.507 55.634 55.600 55.559 55.513 Cr*# 55.293 56.264 54.257 55.295 54.584 55.524 53.806 M g# 62.846 61.376 64.107 64.165 64.522 62.670 62.296 Mg"# 65.267 60.574 67.036 65.417 67.373 62.750 66.185 Fe3+ 1.911 4 .6 4 6 2.252 0.965 2.161 0.064 3.074 T able C.4: Sam ple H8*I2 O laeem inated ch ro m ltite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte;(Mg, Fe)Cr204. (Fe203 is caiculated by assuming the ideal chromite formula) 316 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R :% W t% Wt % W t% W t% W t% W t% W t% 0.035 0.033 0.002 0.029 0.002 0.063 0.066 0.059 23.433 23.609 23.659 23.674 23.840 23.426 24.110 23.649 0.110 0.138 0.129 0.156 0.103 0.157 0.138 0.068 45.794 45.988 45.598 45.733 45.480 45.796 44.743 45.584 2.324 1.936 2.586 1.745 2.490 2.561 2.519 2.428 13.444 13.010 13.036 14.006 12.936 12.828 13.227 13.382 0.446 0.484 0.522 0.519 0.519 0.427 0.501 0.435 14.311 14.487 14.512 13.907 14.550 14.672 14.489 14.321 0.046 0.086 0.076 0.086 0.148 0.110 0.139 0.154 0.001 0.004 0.007 0.020 0.000 0.006 0.000 0.006 0.165 0.198 0.133 0.216 0.172 0.128 0.174 0.124 0.000 0.032 0.000 0.064 0.000 0.000 0.089 0.000 0.028 0.164 0.000 0.019 0.012 0.074 0.057 0.031 0.095 0.027 0.000 0.000 0.000 0.008 0.000 0.000 100.233 100.194 100.259 100.175 100.249 100.257 100.252 100.243 0.001 0.001 0.000 0.001 0.000 0.002 0.002 0.002 0.838 0.843 0.844 0.848 0.850 0.835 0.859 0.844 0.003 0.003 0.003 0.004 0.002 0.004 0.003 0.002 1.099 1.101 1.091 1.099 1.087 1.096 1.069 1.092 0.053 0.044 0.059 0.040 0.057 0.058 0.057 0.055 0.341 0.330 0.330 0.356 0.327 0.325 0.334 0.339 0.011 0.012 0.013 0.013 0.013 0.011 0.013 0.011 0.647 0.654 0.655 0.630 0.656 0.662 0.653 0.647 0.001 0.002 0.002 0.002 0.004 0.003 0.003 0.004 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.004 0.005 0.003 0.005 0.004 0.003 0.004 0.003 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.001 0.004 0.000 0.000 0.000 0.002 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 56.728 56.646 56.387 56.444 56.136 56.737 55.455 56.391 55.215 55.391 54.722 55.311 54.541 55.073 53.854 54.823 62.151 63.643 82.741 61.413 63.086 63.348 62.505 62.120 65.488 66.499 66.493 63.898 66.723 67.093 66.133 65.608 2.667 2.220 2.953 2.008 2.842 2.932 2.886 2.780 317 CR9-A1-C CR9-A2-R CR10-A1-* CR10-A2-I CR10-A3-IWSU-1 WSU-2 WSU-3 t% w t % Wt% W t% Wt% Wt% W t% Wt% 0.039 0.057 0.061 0.037 0.030 0.157 0.166 0.161 23.875 24.527 24.145 24.829 23.762 23.640 23.434 23.749 0.144 0.138 0.089 0.151 0.170 0.110 0.101 0.107 45.672 46.544 45.525 45.938 45.591 42.387 42.452 42.712 1.763 -0.719 1.989 -0.428 2.026 4.034 3.623 3.776 13.504 15.791 12.590 15.340 13.232 13.605 13.403 13.007 0.438 0.473 0.444 0.480 0.497 0.206 0.191 0.164 14.294 12.783 14.782 13.184 14.434 14.018 14.037 14.483 0.178 0.092 0.181 0.092 0.132 0.125 0.084 0.121 0.000 0.036 0.003 0.015 0.008 0.000 0.007 0.000 0.169 0.155 0.123 0.187 0.114 0.155 0.190 0.209 0.087 0.000 0.000 0.071 0.135 0.000 0.000 0.000 0.012 0.050 0.182 0.002 0.071 0.096 0.041 0.056 0.000 0.000 0.086 0.060 0.000 0.000 0.000 0.000 100.177 99.928 100.199 99.957 100.203 98.532 97.728 98.545 0.001 0.002 0.002 0.001 0.001 0.005 0.005 0.005 0.852 0.883 0.859 0.890 0.848 0.858 0.857 0.859 0.003 0.003 0.002 0.003 0.004 0.003 0.002 0.002 1.094 1.124 1.086 1.105 1.092 1.032 1.041 1.036 0.040 -0.017 0.045 -0.010 0.046 0.093 0.085 0.087 0.342 0.403 0.318 0.390 0.335 0.350 0.348 0.334 0.011 0.012 0.011 0.012 0.013 0.005 0.005 0.004 0.646 0.582 0.665 0.598 0.652 0.644 0.649 0.663 0.004 0.002 0.004 0.002 0.003 0.003 0.002 0.003 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.004 0.003 0.005 0.003 0.004 0.005 0.005 0.001 0.000 0.000 0.001 0.002 0.000 0.000 0.000 0.000 0.001 0.004 0.000 0.002 0.002 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 56.203 56.006 55.847 55.380 56.277 54.604 54.859 54.678 55.066 56.471 54.580 55.654 54.968 52.031 52.518 52.273 62.806 60.074 64.694 61.112 63.087 59.182 60.027 61.147 65.362 59.067 67.668 60.506 66.040 64.747 65.119 66.499 2.023 ■0.830 2.269 •0.493 2.325 4.713 4.266 4.399 318 WSU-4 CrH8-l2 Ave Wt% 0.164 0.057 23.741 23.973 0.108 0.116 42.905 45.192 3.716 1.956 13.124 13.537 0.141 0.438 14.454 14.204 0.100 0.111 0.029 0.011 0.191 0.163 0.000 0.031 0.054 0.056 0.000 0.018 98.726 99.863 0.000 0.000 0.005 0.002 0.857 0.858 0.002 0.003 1.040 1.085 0.086 0.045 0.336 0.344 0.004 0.011 0.660 0.643 0.002 0.003 0.001 0.000 0.005 0.004 0.000 0.000 0.001 0.001 0.000 0.000 3.000 3.000 0.000 54.800 55.836 52.431 54.581 61.009 62.339 66.254 65.158 4.322 2.253 319 Label CR1-A1-IL CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C Section of CHR with Px&Amph O xides Wt% Wt% wt% Wt% Wt% Wt% W t% 8102 0.009 0.078 0.000 0.052 0.149 0.013 0.042 AI203 23.561 24.400 23.053 23.105 23.692 24.107 23.940 TI02 0.459 0.551 0.471 0.293 0.480 0.531 0.498 C r203 43.748 43.237 44.537 45.885 44.058 44.359 44.456 Fe203 1.680 0.007 2.196 0.444 2.128 0.060 2.344 FeO 18.459 20.905 16.181 17.854 16.339 19.584 14.310 MnO 0.566 0.561 0.567 0.512 0.508 0.520 0.470 MgO 10.961 9.424 12.535 11.287 12.428 10.244 13.738 NIO 0.180 0.129 0.074 0.128 0.140 0.209 0.191 CaO 0.000 0.000 0.000 0.014 0.000 0.004 0.000 V203 0.215 0.188 0.179 0.122 0.169 0.213 0.138 N b205 0.240 0.152 0.255 0.118 0.000 0.095 0.081 ZnO 0.090 0.187 0.000 0.145 0.043 0.000 0.026 P t0 2 0.000 0.180 0.171 0.085 0.078 0.069 0.000 Total 100.168 100.001 100.220 100.044 100.213 100.006 100.235 C ations SM+ 0.000 0.002 0.000 0.002 0.005 0.000 0.001 AI3+ 0.861 0.899 0.836 0.845 0.857 0.884 0.858 TI4+ 0.011 0.013 0.011 0.007 0.011 0.012 0.011 Cr3+ 1.073 1.069 1.084 1.125 1.069 1.091 1.068 Fe3+ 0.039 0.000 0.051 0.010 0.049 0.001 0.054 Fe2+ 0.479 0.547 0.417 0.463 0.419 0.510 0.364 Mn2* 0.015 0.015 0.015 0.013 0.013 0.014 0.012 Mg2+ 0.507 0.439 0.575 0.522 0.568 0.475 0.622 NI2+ 0.004 0.003 0.002 0.003 0.003 0.005 0.005 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.005 0.004 0.003 0.004 0.005 0.003 Nb5+ 0.003 0.002 0.004 0.002 0.000 0.001 0.001 Zn2+ 0.002 0.004 0.000 0.003 0.001 0.000 0.001 Pt4+ 0.000 0.001 0.001 0.001 0.001 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 55.469 54.312 56.446 57.123 55.506 55.245 55.471 Cr*# 54.367 54.307 54.989 56.824 54.125 55.206 53.968 M g# 49.453 44.548 55.170 52.432 54.825 48.183 59.863 Mg"# 51.421 44.555 58.000 52.984 57.553 48.251 63.118 Fe3+ 1.987 0.009 2.581 0.523 2.488 0.071 2.709 Table C.5: Sample H8*I5 DIsaemlnated chromltite Intruded by pyroxenltic dike Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 320 CR4-A2-R CR5-A1-C CR5-A2-R WSU-1 WSU-2 CR6-A1-C CR6-A2-R Ave Section of CHR with « Wt% Wt% Wt% Wt% Chr/Amp W t% W t% 0.054 0.048 0.015 0.193 0.153 0.067 0.017 0.013 23.708 23.643 23.358 23.380 22.535 23.540 25.430 0.442 0.446 0.395 0.464 0.500 0.461 0.122 0.167 43.692 45.042 44.979 41.760 41.866 43.968 45.302 45.234 1.579 2.138 1.591 3.619 3.786 1.798 1.739 0.013 18.927 14.177 16.602 17.699 20.051 17.591 12.903 14.356 0.606 0.473 0.609 0.262 0.286 0.495 0.458 0.428 10.589 13.734 12.111 11.464 9.831 11.529 14.684 13.865 0.097 0.160 0.097 0.157 0.143 0.142 0.142 0.101 0.006 0.004 0.000 0.002 0.000 0.003 0.007 0.004 0.142 0.212 0.168 0.204 0.190 0.178 0.171 0.164 0.120 0.032 0.136 0.000 0.000 0.102 0.105 0.113 0.196 0.105 0.099 0.065 0.059 0.085 0.105 0.113 0.000 0.000 0.000 0.000 0.000 0.049 0.000 0.000 100.158 100.214 100.159 99.269 99.398 100.007 100.174 100.001 0.000 0.000 0.002 0.001 0.000 0.006 0.005 0.002 0.001 0.000 0.868 0.848 0.848 0.859 0.839 0.858 0.868 0.906 0.010 0.010 0.009 0.011 0.012 0.011 0.003 0.004 1.073 1.084 1.095 1.029 1.045 1.075 1.080 1.081 0.037 0.049 0.037 0.085 0.090 0.042 0.039 0.000 0.492 0.361 0.428 0.461 0.529 0.456 0.325 0.363 0.016 0.012 0.016 0.007 0.008 0.013 0.012 0.011 0.490 0.623 0.556 0.532 0.463 0.531 0.660 0.625 0.002 0.004 0.002 0.004 0.004 0.004 0.003 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.005 0.004 0.005 0.005 0.004 0.004 0.004 0.002 0.000 0.002 0.000 0.000 0.001 0.001 0.002 0.005 0.002 0.002 0.001 0.001 0.002 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 0.000 55.284 56.102 56.366 54.508 55.482 55.610 55.446 54.406 54.252 54.716 55.316 52.163 52.953 54.432 54.345 54.398 48.122 60.326 54.486 49.373 42.762 51.629 64.403 63.239 49.931 63.328 56.529 53.589 46.638 53.825 66.982 63.257 1.866 2.472 1.863 4.303 4.557 2.119 1.985 0.015 321 CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R WSU-3 WSU-4 01 t% Wt% Wt % Wt% Wt % Wt % Chr/OI 0.034 0.013 0.176 0.042 0.191 0.176 0.083 24.018 23.936 24.066 25.393 23.521 23.237 21.200 0.096 0.108 0.135 0.185 0.321 0.454 0.199 45.751 45.552 45.936 45.983 44.063 42.909 45.091 1.697 1.945 1.140 -1.577 2.607 3.764 1.416 13.679 13.872 13.273 16.490 14.453 14.875 14.237 0.435 0.430 0.428 0.439 0.164 0.198 0.372 14.226 13.976 14.476 12.422 13.735 13.316 13.837 0.011 0.158 0.167 0.134 0.109 0.176 0.125 0.001 0.013 0.020 0.000 0.016 0.000 0.008 0.180 0.151 0.131 0.166 0.213 0.182 0.170 0.000 0.000 0.041 0.000 0.000 0.000 0.032 0.041 0.042 0.124 0.053 0.058 0.091 0.078 0.000 0.000 0.000 0.112 0.000 0.000 0.014 100.170 100.195 100.114 99.842 99.451 99.377 99.916 0.000 0.000 0.001 0.000 0.005 0.001 0.006 0.005 0.003 0.857 0.856 0.857 0.914 0.849 0.843 0.869 0.002 0.002 0.003 0.004 0.007 0.011 0.005 1.095 1.093 1.098 1.110 1.067 1.044 1.083 0.039 0.044 0.026 -0.036 0.060 0.087 0.032 0.346 0.352 0.336 0.421 0.370 0.383 0.362 0.011 0.011 0.011 0.011 0.004 0.005 0.010 0.642 0.632 0.652 0.565 0.627 0.611 0.627 0.000 0.004 0.004 0.003 0.003 0.004 0.003 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.004 0.004 0.003 0.004 0.005 0.004 0.004 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.001 0.003 0.001 0.001 0.002 0.002 0.000 0.000 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 0.000 56.099 56.076 56.149 54.849 55.688 55.333 55.506 55.009 54.827 55.415 55.849 53.995 52.889 54.591 62.514 61.462 64.346 59.503 59.307 56.519 61.412 64.960 64.235 66.034 57.318 62.880 61.477 63.393 1.943 2.228 1.308 •1.823 3.041 4.416 1.639 322 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% W t% Wt% W t% S I02 0.205 0.040 0.032 0.051 0.013 0.065 0.000 AI203 23.814 23.957 23.385 24.029 23.515 23.576 23.835 T I02 0.154 0.208 0.142 0.052 0.073 0.092 0.151 G r203 43.954 44.122 44.739 43.909 44.898 44.177 44.523 F e203 3.447 3.096 2.882 3.467 2.790 3.385 3.473 FeO 13.189 13.457 14.638 14.086 14.800 14.462 13.141 MnO 0.545 0.545 0.491 0.420 0.467 0.496 0.465 MgO 14.588 14.293 13.428 13.935 13.385 13.590 14.510 NIO 0.093 0.086 0.109 0.111 0.095 0.069 0.082 CaO 0.007 0.003 0.017 0.000 0.001 0.003 0.000 V 203 0.292 0.193 0.164 0.156 0.177 0.241 0.142 N b205 0.000 0.130 0.007 0.039 0.031 0.000 0.000 ZnO 0.000 0.130 0.078 0.093 0.034 0.122 0.000 P t0 2 0.058 0.050 0.177 0.000 0.000 0.058 0.026 Total 100.345 100.310 100.288 100.347 100.278 100.337 100.348 C ations SM+ 0.006 0.001 0.001 0.002 0.000 0.002 0.000 AI3+ 0.848 0.855 0.841 0.859 0.845 0.846 0.849 TI4+ 0.004 0.005 0.003 0.001 0.002 0.002 0.003 Cr3+ 1.050 1.056 1.080 1.053 1.083 1.063 1.064 Fe3+ 0.078 0.071 0.066 0.079 0.064 0.078 0.079 Fe2+ 0.333 0.341 0.374 0.357 0.377 0.368 0.332 Mn2+ 0.014 0.014 0.013 0.011 0.012 0.013 0.012 Mg2+ 0.657 0.645 0.611 0.630 0.609 0.617 0.654 NI2+ 0.002 0.002 0.003 0.003 0.002 0.002 0.002 Ca2+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 V3+ 0.007 0.005 0.004 0.004 0.004 0.006 0.003 Nb5+ 0.000 0.002 0.000 0.001 0.000 0.000 0.000 Zn2+ 0.000 0.003 0.002 0.002 0.001 0.003 0.000 Pt4+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 55.321 55.267 56.206 55.073 56.157 55.694 55.616 Cr*# 53.127 53.300 54.334 52.884 54.351 53.520 53.411 M g# 61.484 61.068 58.143 59.079 57.954 58.049 61.393 Mg"# 66.350 65.437 62.052 63.814 61.718 62.620 66.311 Fe3+ 3.965 3.559 3.331 3.975 3.215 3.903 3.965 Table C.6: Sample H8«I6 DIsaemlnated chromltite Microprobe Analysis & Calculated Fonnula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 323 CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR7-A3-R CR8-A1-C W t% Wt% W t% W t% W t% W t% W t% 0.024 0.060 0.015 0.002 0.000 0.048 0.024 0.000 23.978 23.750 23.433 23.393 23.454 23.722 23.633 23.728 0.134 0.125 0.170 0.062 0.063 0.072 0.102 0.122 44.542 44.665 44.915 44.950 45.179 45.358 44.396 44.824 2.682 2.749 2.976 3.218 2.994 1.412 3.504 2.961 14.012 14.397 13.971 13.600 13.654 15.553 13.681 13.609 0.471 0.395 0.412 0.441 0.428 0.476 0.450 0.459 13.908 13.708 13.928 14.059 14.111 12.938 14.183 14.174 0.037 0.092 0.132 0.168 0.131 0.100 0.117 0.080 0.011 0.000 0.003 0.001 0.007 0.033 0.000 0.013 0.283 0.178 0.274 0.178 0.258 0.180 0.183 0.169 0.031 0.031 0.007 0.000 0.000 0.112 0.061 0.070 0.156 0.123 0.021 0.123 0.012 0.059 0.000 0.087 0.000 0.000 0.042 0.127 0.008 0.078 0.017 0.000 100.269 100.274 100.299 100.321 100.300 100.141 100.351 100.297 0.001 0.002 0.000 0.000 0.000 0.001 0.001 0.000 0.857 0.851 0.840 0.838 0.839 0.855 0.845 0.848 0.003 0.003 0.004 0.001 0.001 0.002 0.002 0.003 1.069 1.074 1.080 1.080 1.084 1.097 1.064 1.075 0.061 0.063 0.068 0.074 0.068 0.033 0.080 0.068 0.356 0.366 0.355 0.346 0.347 0.398 0.347 0.345 0.012 0.010 0.011 0.011 0.011 0.012 0.012 0.012 0.629 0.621 0.631 0.637 0.639 0.590 0.641 0.641 0.001 0.002 0.003 0.004 0.003 0.002 0.003 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.007 0.004 0.007 0.004 0.006 0.004 0.004 0.004 0.000 0.000 0.000 0.000 0.000 0.002 0.001 0.001 0.003 0.003 0.000 0.003 0.000 0.001 0.000 0.002 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.480 55.783 56.252 56.313 56.374 56.192 55.757 55.894 53.771 54.018 54.325 54.232 54.439 55.272 53.515 53.996 60.150 59.158 59.861 60.305 60.609 57.821 60.031 60.824 63.890 62.925 63.992 64.823 64.817 59.724 64.888 64.993 3.081 3.165 3.426 3.696 3.434 1.638 4.020 3.395 324 CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-R W t% W t% W t% W t% 0.042 0.058 0.051 0.088 0.013 23.929 23.067 23.254 23.658 23.019 0.099 0.142 0.141 0.115 0.097 46.368 45.176 44.930 44.894 45.194 0.243 3.180 3.194 2.850 3.207 15.859 13.801 13.687 13.686 13.807 0.475 0.488 0.466 0.437 0.482 12.719 14.008 14.121 14.213 13.915 0.082 0.092 0.147 0.088 0.163 0.008 0.015 0.000 0.008 0.006 0.131 0.202 0.242 0.215 0.186 0.023 0.000 0.046 0.000 0.100 0.043 0.015 0.002 0.000 0.133 0.000 0.076 0.042 0.034 0.000 100.021 100.319 100.320 100.285 100.321 0.001 0.002 0.002 0.003 0.000 0.863 0.827 0.833 0.845 0.826 0.002 0.003 0.003 0.003 0.002 1.122 1.087 1.079 1.076 1.088 0.006 0.073 0.073 0.065 0.074 0.406 0.351 0.348 0.347 0.352 0.012 0.013 0.012 0.011 0.012 0.580 0.635 0.640 0.642 0.632 0.002 0.002 0.004 0.002 0.004 0.000 0.000 0.000 0.000 0.000 0.003 0.005 0.006 0.005 0.005 0.000 0.000 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.003 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Average 56.520 58.781 58.449 58.005 58.842 56.361 54.700 54.372 54.172 54.741 54.142 58.509 59.978 80.317 80.924 59.773 59.771 58.840 64.404 64.778 64.927 64.240 0.281 3.885 3.879 3.273 3.897 325 Label CR1-A1-C CR8-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% W t% W t% 8102 0.031 0.033 0.035 0.058 0.035 0.058 0.009 AI203 22.992 23.391 23.142 22.573 23.823 23.571 23.692 T I02 0.485 0.510 0.243 0.362 0.080 0.096 0.180 C r203 44.542 43.899 44.717 44.462 44.730 44.369 44.530 F e203 2.919 2.017 2.979 2.693 2.346 3.030 2.470 FeO 15.706 17.963 15.384 17.488 15.472 15.190 15.331 MnO 0.481 0.506 0.414 0.543 0.526 0.448 0.512 MgO 12.755 11.293 12.950 11.589 12.934 13.094 13.099 NIO 0.098 0.077 0.123 0.080 0.057 0.168 0.044 CaO 0.000 0.018 0.000 0.003 0.000 0.000 0.017 V 203 0.221 0.303 0.204 0.230 0.158 0.148 0.199 N b205 0.040 0.096 0.000 0.144 0.000 0.000 0.096 ZnO 0.022 0.090 0.090 0.046 0.074 0.091 0.009 P t0 2 0.000 0.008 0.016 0.000 0.000 0.043 0.060 T otal 100.292 100.202 100.298 100.270 100.235 100.303 100.247 C ations Si4+ 0.001 0.001 0.001 0.002 0.001 0.002 0.000 AI3+ 0.832 0.853 0.835 0.824 0.858 0.849 0.853 TI4+ 0.011 0.012 0.006 0.008 0.002 0.002 0.004 Cr3+ 1.081 1.074 1.083 1.089 1.080 1.072 1.076 Fe3+ 0.067 0.047 0.069 0.063 0.054 0.070 0.057 Fe2+ 0.403 0.465 0.394 0.453 0.395 0.388 0.392 Mn2+ 0.012 0.013 0.011 0.014 0.014 0.012 0.013 Mg2+ 0.584 0.521 0.591 0.535 0.589 0.596 0.597 NK+ 0.002 0.002 0.003 0.002 0.001 0.004 0.001 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.001 V3+ 0.005 0.008 0.005 0.006 0.004 0.004 0.005 Nb5+ 0.001 0.001 0.000 0.002 0.000 0.000 0.001 Zn2+ 0.000 0.002 0.002 0.001 0.002 0.002 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 T otai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 56.514 55.732 56.451 56.922 55.744 55.606 55.769 c r # 54.589 54.406 54.500 55.113 54.234 53.853 54.174 M g# 55.361 50.441 56.099 50.922 56.733 56.574 57.066 Mg"# 59.145 52.844 60.008 54.156 59.842 60.578 60.366 Fe3+ 3.406 2.360 3.456 3.177 2.706 3.500 2.660 Table C.7: Sample H8-I8 Chromltite MIcroprolM Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideai chromite formula) 326 CR4-A2-R CR5-A1-C CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R :% W t% W t% W t% W t% W t% W t% W t% 0.037 0.054 0.002 0.021 0.050 0.031 0.031 0.027 24.250 23.926 23.768 24.152 23.530 23.725 24.296 23.891 0.093 0.169 0.072 0.100 0.120 0.120 0.119 0.133 44.853 45.124 45.615 45.130 45.604 45.102 44.613 45.020 1.402 2.160 1.963 1.398 1.998 2.556 2.371 2.264 16.071 14.235 14.045 15.148 14.110 13.947 13.606 13.829 0.527 0.485 0.492 0.527 0.550 0.481 0.547 0.487 12.531 13.788 13.846 13.179 13.785 13.871 14.241 14.082 0.102 0.054 0.129 0.073 0.089 0.097 0.165 0.097 0.006 0.013 0.011 0.003 0.000 0.058 0.000 0.000 0.173 0.139 0.174 0.177 0.199 0.155 0.121 0.169 0.000 0.000 0.000 0.104 0.000 0.000 0.129 0.129 0.096 0.069 0.000 0.127 0.056 0.087 0.000 0.084 0.000 0.000 0.078 0.000 0.111 0.027 0.000 0.016 100.140 100.216 100.197 100.140 100.200 100.256 100.237 100.227 0.001 0.002 0.000 0.001 0.002 0.001 0.001 0.001 0.874 0.856 0.852 0.868 0.844 0.849 0.866 0.854 0.002 0.004 0.002 0.002 0.003 0.003 0.003 0.003 1.085 1.084 1.096 1.088 1.098 1.083 1.067 1.080 0.032 0.049 0.045 0.032 0.046 0.058 0.054 0.052 0.411 0.362 0.357 0.386 0.359 0.354 0.344 0.351 0.014 0.012 0.013 0.014 0.014 0.012 0.014 0.013 0.571 0.624 0.627 0.599 0.626 0.628 0.642 0.637 0.003 0.001 0.003 0.002 0.002 0.002 0.004 0.002 0.000 0.000 0.000 0.000 0.000 0.002 0.000 0.000 0.004 0.003 0.004 0.004 0.005 0.004 0.003 0.004 0.000 0.000 0.000 0.001 0.000 0.000 0.002 0.002 0.002 0.002 0.000 0.003 0.001 0.002 0.000 0.002 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.373 55.854 56.283 55.625 56.525 56.050 55.194 55.833 54.475 54.468 55.014 54.728 55.223 54.405 53.694 54.380 56.308 60.305 60.952 58.880 60.702 60.347 61.728 61.273 58.157 63.325 63.733 60.797 63.524 63.936 65.106 64.479 1.621 2.482 2.254 1.613 2.303 2.934 2.717 2.603 327 CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-R :% W t% W t% W t% 0.054 0.052 0.065 0.040 23.701 23.352 23.527 23.451 0.154 0.099 0.089 0.120 45.064 45.602 45.415 45.424 1.996 2.481 1.934 2.406 13.949 13.742 14.301 13.940 0.513 0.465 0.530 0.507 14.043 14.125 13.686 13.990 0.132 0.071 0.201 0.124 0.000 0.000 0.000 0.000 0.159 0.110 0.223 0.121 0.302 0.055 0.071 0.119 0.133 0.035 0.015 0.000 0.000 0.060 0.137 0.000 100.200 100.248 100.194 100.241 0.002 0.002 0.002 0.001 0.849 0.836 0.845 0.840 0.004 0.002 0.002 0.003 1.083 1.096 1.094 1.092 0.046 0.057 0.044 0.055 0.354 0.349 0.364 0.354 0.013 0.012 0.014 0.013 0.636 0.640 0.622 0.634 0.003 0.002 0.005 0.003 0.000 0.000 0.000 0.000 0.004 0.003 0.005 0.003 0.004 0.001 0.001 0.002 0.003 0.001 0.000 0.000 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 Average 56.054 56.711 56.426 56.511 54.760 55.093 55.164 54.945 54.591 61.389 61.184 60.332 60.760 58.283 64.217 64.693 63.045 64.144 2.308 2.852 2.236 2.770 328 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% W t% W t% S i0 2 0.032 0.024 0.000 0.033 0.021 0.002 0.013 AI203 23.168 22.831 22.630 22.792 22.920 23.150 22.394 TI02 0.155 0.068 0.150 0.149 0.101 0.149 0.167 C r203 44.889 44.684 45.229 45.415 45.340 44.528 45.326 F e203 3.079 3.672 3.247 2.273 2.977 3.685 3.680 FeO 14.782 14.579 14.882 16.322 14.961 14.416 14.685 MnO 0.447 0.519 0.482 0.501 0.484 0.491 0.463 MgO 13.328 13.321 13.184 12.360 13.214 13.565 13.245 NIO 0.045 0.084 0.134 0.091 0.102 0.085 0.135 CaO 0.006 0.021 0.010 0.001 0.000 0.000 0.015 V203 0.222 0.316 0.202 0.164 0.178 0.170 0.117 N b205 0.000 0.000 0.078 0.079 0.000 0.000 0.000 ZnO 0.156 0.199 0.097 0.002 0.000 0.051 0.124 P t0 2 0.000 0.051 0.000 0.043 0.000 0.077 0.000 Total 100.309 100.368 100.324 100.227 100.298 100.369 100.367 C ations SI4+ 0.001 0.001 0.000 0.001 0.001 0.000 0.000 AI3+ 0.834 0.823 0.817 0.828 0.827 0.832 0.809 TI4+ 0.004 0.002 0.003 0.003 0.002 0.003 0.004 Cr3+ 1.084 1.081 1.096 1.106 1.097 1.074 1.099 Fe3+ 0.071 0.085 0.075 0.053 0.069 0.085 0.085 Fe2+ 0.378 0.373 0.381 0.421 0.383 0.368 0.376 Mn2+ 0.012 0.013 0.013 0.013 0.013 0.013 0.012 Mg2+ 0.607 0.607 0.602 0.568 0.603 0.617 0.605 NI2+ 0.001 0.002 0.003 0.002 0.003 0.002 0.003 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.008 0.005 0.004 0.004 0.004 0.003 Nb5+ 0.000 0.000 0.001 0.001 0.000 0.000 0.000 Zn2+ 0.004 0.004 0.002 0.000 0.000 0.001 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Totai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 56.518 58.785 57.279 57.204 57.027 56.339 57.587 Cr*# 54.506 54.352 55.121 55.687 55.065 53.945 55.134 M g# 57.512 57.042 56.897 54.536 57.181 57.694 56.747 Mg"# 61.647 61.960 61.228 57.445 61.157 62.650 61.654 Fe3+ 3.559 4.252 3.766 2.653 3.441 4.249 4.261 Table C.8: Sample H8 18.2 Disseminated chromitite Microprobe Analysis & Caiculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 329 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% W t% W t% Wt % Wt % W t% W t% W t% 0.036 0.035 0.035 0.026 0.026 0.026 0.043 0.047 22.383 22.583 21.618 22.290 22.638 22.444 22.962 22.944 0.163 0.168 0.148 0.108 0.108 0.126 0.156 0.093 44.506 45.609 46.691 45.378 45.207 44.940 44.671 44.645 4.192 3.288 2.796 3.595 3.529 3.360 3.447 3.562 14.691 14.267 15.345 14.944 14.587 15.141 14.831 14.591 0.445 0.493 0.448 0.513 0.499 0.509 0.472 0.488 13.402 13.604 12.683 13.188 13.399 13.117 13.336 13.446 0.034 0.091 0.176 0.052 0.048 0.081 0.052 0.118 0.010 0.014 0.092 0.001 0.000 0.001 0.006 0.022 0.186 0.115 0.133 0.195 0.160 0.220 0.231 0.240 0.124 0.000 0.007 0.000 0.000 0.133 0.000 0.070 0.169 0.055 0.110 0.000 0.112 0.051 0.051 0.090 0.077 0.008 0.000 0.069 0.042 0.186 0.085 0.000 100.420 100.329 100.281 100.360 100.354 100.337 100.344 100.356 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.808 0.813 0.786 0.806 0.816 0.812 0.827 0.826 0.004 0.004 0.003 0.003 0.002 0.003 0.004 0.002 1.078 1.102 1.139 1.101 1.094 1.091 1.080 1.078 0.097 0.076 0.065 0.083 0.081 0.078 0.079 0.082 0.376 0.365 0.396 0.383 0.373 0.389 0.379 0.373 0.012 0.013 0.012 0.013 0.013 0.013 0.012 0.013 0.612 0.620 0.584 0.603 0.611 0.601 0.608 0.612 0.001 0.002 0.004 0.001 0.001 0.002 0.001 0.003 0.000 0.000 0.003 0.000 0.000 0.000 0.000 0.001 0.005 0.003 0.003 0.005 0.004 0.005 0.006 0.006 0.002 0.000 0.000 0.000 0.000 0.002 0.000 0.001 0.004 0.001 0.002 0.000 0.003 0.001 0.001 0.002 0.001 0.000 0.000 0.001 0.000 0.002 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 57.153 57.535 59.185 57.729 57.258 57.324 58.817 58.822 54.367 55.350 57.235 55.321 54.922 55.077 54.357 54.287 56.407 58.470 55.888 58.392 57.351 58.279 57.001 57.389 61.922 62.961 59.570 61.137 62.085 60.696 61.581 62.160 4.874 3.798 3.282 4.172 4.080 3.920 3.992 4.123 330 CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-* CR10-A2-R W t% W t% W t% W t% 0.197 0.019 0.009 0.041 0.004 22.590 22.183 22.662 22.748 22.950 0.138 0.088 0.056 0.091 0.077 44.648 45.314 44.924 45.164 44.793 3.648 3.979 3.298 3.231 3.914 14.886 14.717 15.735 14.512 13.697 0.413 0.436 0.464 0.527 0.521 13.430 13.333 12.797 13.515 13.957 0.095 0.096 0.063 0.057 0.062 0.000 0.014 0.014 0.000 0.001 0.270 0.192 0.142 0.192 0.279 0.000 0.000 0.149 0.110 0.000 0.015 0.000 0.000 0.109 0.135 0.034 0.026 0.017 0.026 0.000 100.364 100.399 100.331 100.325 100.391 0.006 0.001 0.000 0.001 0.000 0.814 0.802 0.821 0.820 0.823 0.003 0.002 0.001 0.002 0.002 1.079 1.098 1.091 1.092 1.078 0.084 0.092 0.076 0.074 0.090 0.381 0.377 0.404 0.371 0.349 0.011 0.011 0.012 0.014 0.013 0.612 0.609 0.586 0.616 0.633 0.002 0.002 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.007 0.005 0.004 0.005 0.007 0.000 0.000 0.002 0.002 0.000 0.000 0.000 0.000 0.002 0.003 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Average 57.006 57.812 57.079 57.117 56.697 54.586 55.147 54.889 54.978 54.143 54.924 56.854 56.501 54.948 58.038 59.099 56.910 61.660 61.758 59.179 62.409 64.495 4.245 4.609 3.636 3.744 4.503 331 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-C CR4-A1-C O xides W t% W t% Wt% W t% W t% W t% W t% 8102 0.000 0.000 0.006 0.000 0.034 0.000 0.028 AI203 23.248 23.539 23.420 24.426 23.392 23.619 23.360 TI02 0.220 0.078 0.117 0.094 0.080 0.157 0.127 C r203 44.230 45.282 44.831 45.236 44.306 44.526 43.888 F e203 4.050 2.207 2.918 0.819 3.909 3.327 3.913 FeO 13.936 15.042 14.439 16.106 13.425 13.605 14.291 MnO 0.489 0.437 0.434 0.459 0.437 0.466 0.480 MgO 13.789 13.230 13.674 12.515 14.265 14.200 13.674 NIO 0.116 0.104 0.141 0.102 0.156 0.056 0.132 CaO 0.015 0.000 0.000 0.000 0.022 0.021 0.000 V203 0.153 0.211 0.188 0.190 0.189 0.196 0.292 N b205 0.000 0.046 0.116 0.000 0.084 0.094 0.031 ZnO 0.159 0.045 0.000 0.134 0.091 0.067 0.082 P t0 2 0.000 0.000 0.008 0.000 0.000 0.000 0.094 Total 100.406 100.222 100.291 100.082 100.391 100.334 100.392 C ations SI4+ 0.000 0.000 0.000 0.000 0.001 0.000 0.001 AI3+ 0.834 0.847 0.841 0.880 0.836 0.844 0.839 TI4+ 0.005 0.002 0.003 0.002 0.002 0.004 0.003 Cr3+ 1.064 1.093 1.080 1.094 1.063 1.068 1.057 Fe3+ 0.093 0.051 0.067 0.019 0.089 0.076 0.090 Fe2+ 0.355 0.384 0.368 0.412 0.341 0.345 0.364 Mn2+ 0.013 0.011 0.011 0.012 0.011 0.012 0.012 Mg2+ 0.626 0.602 0.621 0.571 0.645 0.642 0.621 NK+ 0.003 0.003 0.003 0.003 0.004 0.001 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.001 0.001 0.000 V3+ 0.004 0.005 0.005 0.005 0.005 0.005 0.007 Nb5+ 0.000 0.001 0.002 0.000 0.001 0.001 0.000 Zn2+ 0.004 0.001 0.000 0.003 0.002 0.001 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 56.069 56.342 56.220 55.404 55.960 55.844 55.759 Cr*# 53.456 54.907 54.327 54.880 53.448 53.710 53.240 M g# 56.302 56.071 56.619 56.961 60.013 60.396 57.778 Mg'*# 63.819 61.056 62.799 58.074 65.447 65.042 63.040 Fe3+ 4.659 2.547 3.366 0.946 4.469 3.620 4.516 Table C.9; Sample H8410 Disseminated chromltite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 332 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% W t% W t% W t% W t% W t% W t% W t% 0.044 0.046 0.072 0.031 0.000 0.031 0.002 0.017 24.008 23.395 24.192 23.605 23.683 23.735 23.933 22.937 0.085 0.059 0.082 0.074 0.111 0.265 0.161 0.126 44.867 44.694 44.544 44.328 45.229 43.897 44.113 44.961 2.008 3.257 2.222 3.783 2.709 3.953 3.810 3.639 15.224 13.434 14.496 13.225 13.470 13.076 13.104 13.766 0.404 0.488 0.469 0.461 0.364 0.412 0.362 0.424 13.173 14.280 13.656 14.392 14.249 14.568 14.613 14.083 0.077 0.146 0.123 0.143 0.094 0.154 0.093 0.075 0.017 0.014 0.004 0.000 0.000 0.000 0.000 0.007 0.143 0.241 0.246 0.155 0.214 0.206 0.184 0.224 0.000 0.164 0.040 0.063 0.007 0.055 0.007 0.078 0.083 0.109 0.076 0.119 0.140 0.043 0.000 0.027 0.069 0.000 0.000 0.000 0.000 0.000 0.000 0.000 100.202 100.327 100.224 100.379 100.270 100.394 100.382 100.363 0.001 0.001 0.002 0.001 0.000 0.001 0.000 0.001 0.863 0.837 0.866 0.843 0.846 0.846 0.852 0.823 0.002 0.001 0.002 0.002 0.003 0.006 0.004 0.003 1.082 1.072 1.069 1.061 1.084 1.049 1.053 1.082 0.046 0.074 0.051 0.086 0.062 0.090 0.087 0.083 0.388 0.341 0.368 0.335 0.341 0.331 0.331 0.350 0.010 0.013 0.012 0.012 0.009 0.011 0.009 0.011 0.599 0.646 0.618 0.650 0.644 0.657 0.658 0.639 0.002 0.004 0.003 0.003 0.002 0.004 0.002 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.006 0.006 0.004 0.005 0.005 0.004 0.005 0.000 0.002 0.001 0.001 0.000 0.001 0.000 0.001 0.002 0.002 0.002 0.003 0.003 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.629 56.171 55.261 55.748 56.162 55.371 55.287 56.803 54.341 54.065 53.848 53.333 54.420 52.862 52.883 54.421 57.962 60.869 59.609 60.674 61.490 60.958 61.175 59.565 60.668 65.455 62.678 65.986 65.345 66.511 66.531 64.583 2.315 3.749 2.557 4.332 3.102 4.531 4.347 4.193 333 R8-A2-R WSU-1 WSU-2 WSU-3 WSU-4 CrH8-l10 Ave W t% W t% W t% W t% 0.009 0.204 0.201 0.198 0.174 0.055 23.370 24.348 24.130 24.213 24.130 23.734 0.142 0.096 0.117 0.135 0.133 0.123 44.658 43.622 43.603 43.260 43.521 44.380 2.870 3.360 3.160 3.801 3.684 3.170 14.379 13.102 13.269 13.722 13.894 13.950 0.448 0.195 0.156 0.207 0.161 0.388 13.774 14.803 14.608 14.479 14.357 14.019 0.103 0.153 0.153 0.094 0.109 0.116 0.006 0.005 0.005 0.001 0.024 0.007 0.218 0.166 0.224 0.195 0.184 0.201 0.231 0.000 0.000 0.000 0.000 0.051 0.036 0.067 0.062 0.016 0.013 0.068 0.042 0.000 0.000 0.000 0.000 0.011 100.286 100.121 99.689 100.322 100.383 100.273 0.000 0.000 0.000 0.006 0.006 0.006 0.005 0.002 0.839 0.865 0.862 0.861 0.859 0.849 0.003 0.002 0.003 0.003 0.003 0.003 1.076 1.040 1.045 1.032 1.039 1.065 0.066 0.076 0.072 0.086 0.084 0.072 0.366 0.330 0.336 0.346 0.351 0.354 0.012 0.005 0.004 0.005 0.004 0.010 0.626 0.665 0.660 0.652 0.646 0.634 0.003 0.004 0.004 0.002 0.003 0.003 0.000 0.000 0.000 0.000 0.001 0.000 0.005 0.004 0.005 0.005 0.004 0.005 0.003 0.000 0.000 0.000 0.000 0.001 0.001 0.002 0.001 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 0.000 56.177 54.584 54.796 54.516 54.750 55.643 54.311 52.484 52.800 52.139 52.437 53.616 59.142 62.069 61.776 60.089 59.794 59.777 63.066 66.822 66.245 65.289 64.814 64.164 3.322 3.848 3.642 4.361 4.225 3.643 334 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% W t% W t% W t% W t% W t% W t% S i0 2 0.030 0.011 0.000 0.011 0.011 0.019 0.028 AI203 23.273 24.413 23.329 23.793 23.117 23.720 23.091 T i02 0.155 0.079 0.102 0.153 0.133 0.182 0.139 C r203 45.438 43.772 45.070 44.849 44.972 44.178 44.939 F e203 2.797 3.330 3.182 2.710 3.510 3.478 3.441 FeO 13.688 13.686 13.746 13.623 13.514 13.708 13.847 MnO 0.449 0.428 0.421 0.429 0.476 0.443 0.561 MgO 14.006 14.229 14.013 14.145 14.179 14.135 13.911 NIO 0.151 0.102 0.103 0.155 0.183 0.086 0.089 CaO 0.008 0.000 0.000 0.000 0.000 0.000 0.010 V 203 0.175 0.168 0.251 0.237 0.180 0.265 0.195 N b205 0.000 0.054 0.000 0.063 0.078 0.007 0.039 ZnO 0.108 0.060 0.102 0.103 0.000 0.050 0.055 P t0 2 0.000 0.000 0.000 0.000 0.000 0.077 0.000 Total 100.278 100.333 100.320 100.272 100.353 100.348 100.346 C ations SI4+ 0.001 0.000 0.000 0.000 0.000 0.001 0.001 AI3+ 0.834 0.870 0.836 0.850 0.828 0.848 0.828 TI4+ 0.004 0.002 0.002 0.003 0.003 0.004 0.003 Cr3+ 1.092 1.046 1.083 1.075 1.080 1.059 1.082 Fe3+ 0.064 0.076 0.073 0.062 0.080 0.079 0.079 Fe2+ 0.348 0.346 0.349 0.345 0.343 0.348 0.352 Mn2+ 0.012 0.011 0.011 0.011 0.012 0.011 0.014 Mg2+ 0.635 0.641 0.635 0.639 0.642 0.639 0.631 NI2+ 0.004 0.002 0.003 0.004 0.004 0.002 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.004 0.006 0.006 0.004 0.006 0.005 Nb5+ 0.000 0.001 0.000 0.001 0.001 0.000 0.001 Zn2+ 0.002 0.001 0.002 0.002 0.000 0.001 0.001 P t4 f 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 56.705 54.603 56.446 55.840 56.617 55.544 56.627 cr# 54.882 52.526 54.383 54.103 54.332 53.324 54.383 M g# 60.641 60.326 60.062 61.088 60.255 59.942 59.409 Mg"# 64.589 64.954 64.503 64.925 65.161 64.765 64.169 Fe3+ 3.215 3.803 3.655 3.112 4.036 3.996 3.963 Table C IO: Sample H8 111 Diaseminated chromltite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Pe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 335 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C :% W t% W t% W t% W t% W t% W t% W t% 0.026 0.000 0.002 0.011 0.002 0.015 0.015 0.018 23.580 23.014 23.539 23.372 23.638 23.508 24.288 24.148 0.145 0.150 0.071 0.117 0.161 0.137 0.153 0.190 44.415 45.454 44.867 45.076 44.364 44.472 43.681 42.990 3.372 3.258 2.797 3.035 3.552 3.370 3.229 4.831 13.955 13.580 14.252 13.849 13.724 13.723 14.190 12.537 0.513 0.496 0.495 0.522 0.436 0.521 0.402 0.374 13.899 14.108 13.803 13.876 14.064 14.106 13.969 14.948 0.067 0.075 0.095 0.161 0.080 0.052 0.056 0.162 0.013 0.000 0.000 0.000 0.004 0.010 0.000 0.015 0.191 0.172 0.191 0.171 0.158 0.191 0.262 0.248 0.000 0.000 0.149 0.023 0.000 0.101 0.063 0.000 0.078 0.017 0.017 0.091 0.111 0.071 0.015 0.025 0.085 0.000 0.000 0.000 0.060 0.060 0.000 0.000 100.339 100.324 100.279 100.304 100.354 100.338 100.323 100.485 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.845 0.825 0.844 0.838 0.846 0.841 0.867 0.856 0.003 0.003 0.002 0.003 0.004 0.003 0.003 0.004 1.067 1.093 1.079 1.084 1.065 1.068 1.046 1.023 0.077 0.075 0.064 0.069 0.081 0.077 0.074 0.109 0.355 0.345 0.363 0.352 0.348 0.349 0.359 0.315 0.013 0.013 0.013 0.013 0.011 0.013 0.010 0.010 0.630 0.640 0.626 0.629 0.636 0.639 0.631 0.671 0.002 0.002 0.002 0.004 0.002 0.001 0.001 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.004 0.005 0.004 0.004 0.005 0.006 0.006 0.000 0.000 0.002 0.000 0.000 0.001 0.001 0.000 0.002 0.000 0.000 0.002 0.002 0.002 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.822 56.988 56.115 56.404 55.733 55.929 54.676 54.426 53.657 54.855 54.306 54.436 53.462 53.760 52.653 51.433 59.323 60.365 59.469 59.670 59.704 60.011 59.294 61.213 63.971 64.935 63.321 64.107 64.623 64.694 63.701 68.005 3.878 3.742 3.223 3.466 4.075 3.676 3.704 5.501 336 CR8-A1-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-I CR11-A1-* CR11-A2-I CR12-A1- W t% W t% W t% Wt% W t% W t% W t% W t% 0.025 0.006 0.015 0.031 0.000 0.000 0.000 0.066 23.661 23.251 23.198 23.547 22.133 23.614 23.351 23.398 0.093 0.183 0.144 0.114 0.069 0.139 0.007 0.127 44.188 44.539 44.980 44.578 47.600 44.168 44.855 43.709 3.517 3.974 3.349 3.515 1.118 3.869 3.375 4.506 13.951 13.398 13.743 13.568 16.021 13.430 14.156 13.805 0.440 0.426 0.427 0.417 0.474 0.377 0.474 0.372 13.973 14.187 13.932 14.278 12.411 14.227 13.802 14.081 0.130 0.127 0.179 0.028 0.097 0.075 0.011 0.111 0.008 0.000 0.001 0.001 0.000 0.010 0.001 0.000 0.226 0.140 0.215 0.252 0.186 0.199 0.251 0.179 0.000 0.000 0.000 0.000 0.000 0.032 0.000 0.000 0.000 0.168 0.153 0.024 0.002 0.247 0.055 0.100 0.139 0.000 0.000 0.000 0.000 0.000 0.000 0.000 100.352 100.399 100.336 100.353 100.110 100.387 100.339 100.452 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.847 0.832 0.832 0.841 0.806 0.844 0.837 0.837 0.002 0.004 0.003 0.003 0.002 0.003 0.000 0.003 1.061 1.069 1.082 1.068 1.162 1.059 1.079 1.049 0.080 0.091 0.077 0.080 0.026 0.088 0.077 0.103 0.354 0.340 0.350 0.344 0.414 0.341 0.360 0.350 0.011 0.011 0.011 0.011 0.012 0.010 0.012 0.010 0.633 0.642 0.632 0.645 0.571 0.643 0.626 0.637 0.003 0.003 0.004 0.001 0.002 0.002 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.003 0.005 0.006 0.005 0.005 0.006 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.003 0.001 0.000 0.006 0.001 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.611 56.237 56.535 55.947 59.062 55.649 56.306 55.618 53.363 53.673 54.357 53.693 58.292 53.182 54.123 52.740 59.272 59.838 59.712 60.338 56.510 59.994 58.864 58.429 64.099 65.369 64.377 65.229 58.000 65.378 63.477 64.518 4.043 4.559 3.852 4.029 1.303 4.434 3.876 5.175 337 CR12-A2-I CR12-A3-R2 W t % W t % 0.040 0.006 23.200 23.234 0.139 0.114 44.557 44.221 3.622 3.770 14.289 14.118 0.511 0.447 13.675 13.800 0.110 0.141 0.000 0.010 0.191 0.198 0.000 0.168 0.012 0.150 0.018 0.000 100.364 100.378 0.001 0.000 0.833 0.834 0.003 0.003 1.073 1.065 0.083 0.086 0.364 0.360 0.013 0.012 0.621 0.627 0.003 0.003 0.000 0.000 0.005 0.005 0.000 0.002 0.000 0.003 0.000 0.000 3.000 3.000 56.301 56.079 53.951 53.638 53.900 56.144 56.416 59.620 63.045 63.536 4.174 4.352 338 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR4-A1-C CR4-A2-R O xidea W t% W t% W t% W t% W t% W t% W t% S I02 0.000 0.045 0.000 0.017 0.004 0.017 0.000 AI203 23.782 24.023 23.796 24.444 23.545 23.752 23.750 TI02 0.125 0.080 0.098 0.073 0.125 0.094 0.129 C r203 43.928 43.916 44.237 44.473 44.459 44.092 44.655 F e203 3.766 3.250 2.774 1.109 3.236 3.434 2.733 FeO 14.146 14.580 15.231 16.765 14.469 14.632 14.991 MnO 0.478 0.480 0.401 0.500 0.412 0.385 0.456 MgO 13.814 13.695 13.228 12.252 13.615 13.616 13.232 NIO 0.097 0.037 0.078 0.124 0.108 0.070 0.104 GaO 0.004 0.000 0.000 0.000 0.000 0.000 0.000 V203 0.149 0.132 0.186 0.183 0.182 0.230 0.150 N b205 0.031 0.084 0.163 0.171 0.070 0.023 0.000 ZnO 0.057 0.000 0.085 0.000 0.100 0.000 0.073 P t0 2 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 100.376 100.324 100.279 100.110 100.323 100.344 100.274 C ationa SI4+ 0.000 0.001 0.000 0.001 0.000 0.001 0.000 AI3+ 0.851 0.860 0.856 0.883 0.845 0.851 0.854 TI4+ 0.003 0.002 0.002 0.002 0.003 0.002 0.003 Cr3+ 1.055 1.055 1.067 1.077 1.070 1.060 1.077 Fe3+ 0.086 0.074 0.064 0.026 0.074 0.079 0.063 Fe2+ 0.359 0.370 0.389 0.430 0.368 0.372 0.382 Mn2+ 0.012 0.012 0.010 0.013 0.011 0.010 0.012 Mg2+ 0.625 0.620 0.602 0.560 0.618 0.617 0.602 NK+ 0.002 0.001 0.002 0.003 0.003 0.002 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.003 0.005 0.004 0.004 0.006 0.004 Nb5+ 0.000 0.001 0.002 0.002 0.001 0.000 0.000 Zn2+ 0.001 0.000 0.002 0.000 0.002 0.000 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Or# 55.340 55.083 55.498 54.966 55.884 55.463 55.778 Or*# 52.949 53.025 53.719 54.258 53.801 53.272 54.022 M g# 58.408 58.240 57.084 55.147 58.271 57.799 57.477 Mg"# 63.514 62.609 60.755 56.573 62.651 62.390 61.142 Fe3* 4.321 3.735 3.208 1.288 3.727 3.949 3.147 Table C.11: Sample H8 112 Diaseminated chromitite Microprobe Analyaie & Calculated Formula (baaed on 4 oxygéna) of chromlte:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the Ideal chromite formula) 339 CR5-A1-C CR5-A2-R CH6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R :% W t% W t% W t% W t% W t% W t% W t% 0.000 3.660 0.013 0.000 0.011 0.046 0.050 0.025 22.969 20.569 23.438 23.328 23.717 23.407 23.533 23.285 0.063 0.170 0.126 0.074 0.128 0.075 0.102 0.013 45.191 41.354 44.829 45.595 44.146 44.779 44.766 45.093 3.451 1.255 3.160 2.034 3.748 2.878 2.810 2.427 14.399 18.032 13.935 15.409 13.628 15.129 14.025 14.633 0.474 0.533 0.477 0.521 0.464 0.472 0.512 0.472 13.598 13.814 13.992 12.872 14.154 13.067 13.931 13.453 0.027 0.342 0.089 0.125 0.118 0.164 0.110 0.174 0.007 0.011 0.003 0.014 0.000 0.014 0.004 0.011 0.129 0.219 0.179 0.186 0.171 0.148 0.179 0.226 0.000 0.000 0.077 0.007 0.032 0.000 0.118 0.239 0.040 0.071 0.000 0.031 0.059 0.108 0.055 0.191 0.000 0.096 0.000 0.008 0.000 0.000 0.087 0.000 100.348 100.127 100.317 100.204 100.375 100.288 100.282 100.242 0.000 0.112 0.000 0.000 0.000 0.001 0.002 0.001 0.826 0.740 0.839 0.842 0.847 0.843 0.843 0.838 0.001 0.004 0.003 0.002 0.003 0.002 0.002 0.000 1.090 0.997 1.077 1.104 1.058 1.082 1.076 1.089 0.079 0.029 0.072 0.047 0.086 0.066 0.064 0.056 0.367 0.460 0.354 0.395 0.345 0.387 0.357 0.374 0.012 0.014 0.012 0.014 0.012 0.012 0.013 0.012 0.619 0.628 0.634 0.588 0.640 0.595 0.632 0.612 0.001 0.008 0.002 0.003 0.003 0.004 0.003 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.005 0.004 0.005 0.004 0.004 0.004 0.006 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.003 0.001 0.002 0.000 0.001 0.001 0.002 0.001 0.004 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 56.894 57.424 56.199 56.732 55.529 56.205 56.066 56.505 54.635 56.487 54.157 55.397 53.144 54.336 54.249 54.915 58.067 56.240 59.783 57.100 59.744 56.796 60.003 58.780 62.734 57.728 64.156 59.824 64.930 60.624 63.907 62.104 3.971 1.631 3.633 2.352 4.295 3.324 3.241 2.813 340 CR9-A1 -C CR9-A2-R CR10-A1 CR10-A2-F CR11 -A1-CCR11-A2-FCR12-A1 -( CR12-A2-R Wt% Wt% Wt% Wt% W t% Wt % Wt % 0.000 0.083 0.000 0.015 0.011 0.035 0.000 0.027 23.852 24.065 23.217 23.400 23.573 25.055 23.767 24.117 0.124 0.113 0.081 0.098 0.080 0.148 0.109 0.082 43.985 45.085 44.896 45.719 44.410 44.124 44.595 44.437 3.364 0.900 3.454 1.614 3.349 1.671 2.798 1.961 14.250 16.768 13.958 15.739 14.068 15.017 14.406 15.372 0.405 0.484 0.433 0.512 0.493 0.498 0.452 0.494 13.814 12.126 13.899 12.645 13.868 13.355 13.705 13.146 0.109 0.107 0.075 0.109 0.051 0.149 0.129 0.039 0.000 0.000 0.000 0.000 0.027 0.000 0.006 0.000 0.202 0.212 0.174 0.190 0.178 0.108 0.127 0.220 0.016 0.000 0.000 0.000 0.100 0.000 0.142 0.142 0.027 0.093 0.073 0.113 0.102 0.000 0.046 0.077 0.189 0.053 0.086 0.008 0.026 0.008 0.000 0.087 100.337 100.090 100.346 100.162 100.335 100.167 100.281 100.198 0.000 0.003 0.000 0.000 0.000 0.001 0.000 0.001 0.854 0.871 0.833 0.846 0.845 0.896 0.852 0.867 0.003 0.003 0.002 0.002 0.002 0.003 0.002 0.002 1.057 1.094 1.080 1.109 1.067 1.058 1.072 1.072 0.077 0.021 0.079 0.037 0.077 0.038 0.064 0.045 0.362 0.431 0.355 0.404 0.358 0.381 0.366 0.392 0.010 0.013 0.011 0.013 0.013 0.013 0.012 0.013 0.626 0.555 0.631 0.578 0.629 0.604 0.621 0.598 0.003 0.003 0.002 0.003 0.001 0.004 0.003 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.005 0.005 0.004 0.005 0.004 0.003 0.003 0.005 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.002 0.001 0.002 0.002 0.003 0.002 0.000 0.001 0.002 0.002 0.000 0.001 0.000 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.300 55.689 58.469 56.723 55.827 54.158 55.727 55.279 53.160 55.106 54.227 55.662 53.676 53.121 53.932 54.025 58.767 55.152 59.214 56.733 59.137 59.034 59.078 57.762 63.343 56.316 63.964 58.885 63.732 61.320 62.906 60.388 3.869 1.047 3.970 1.870 3.853 1.915 3.221 2.269 341 Label CR1-A1-C CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C CR4-A2-R O xidea W t% W t% Wt% W t% Wt% W t% W t% S I02 0.000 0.443 1.209 0.000 0.000 0.026 0.106 AI203 24.358 23.479 23.560 23.359 23.596 23.458 23.023 TI02 0.126 0.072 0.219 0.045 0.073 0.148 0.149 C r203 43.444 43.413 43.832 44.968 44.790 45.277 46.820 F e203 4.097 4.129 0.914 3.196 3.121 2.453 0.904 FeO 12.471 12.925 15.550 13.598 13.667 13.589 14.733 MnO 0.564 0.516 0.518 0.446 0.446 0.507 0.442 MgO 14.793 14.925 13.821 14.125 14.121 14.170 13.541 NIO 0.100 0.194 0.110 0.164 0.196 0.134 0.032 CaO 0.000 0.019 0.013 0.000 0.000 0.008 0.004 V203 0.190 0.112 0.191 0.205 0.222 0.207 0.258 N b205 0.000 0.105 0.056 0.062 0.070 0.170 0.079 ZnO 0.233 0.037 0.096 0.066 0.000 0.096 0.000 P t0 2 0.035 0.043 0.000 0.086 0.008 0.000 0.000 Total 100.411 100.414 100.089 100.320 100.312 100.245 100.091 C ationa SI4+ 0.000 0.013 0.037 0.000 0.000 0.001 0.003 AI3+ 0.865 0.835 0.842 0.837 0.844 0.840 0.829 TI4+ 0.003 0.002 0.005 0.001 0.002 0.003 0.003 Cr3+ 1.035 1.035 1.051 1.080 1.075 1.087 1.131 Fe3+ 0.093 0.094 0.021 0.073 0.071 0.056 0.021 Fe2+ 0.314 0.326 0.395 0.346 0.347 0.345 0.376 Mn2+ 0.014 0.013 0.013 0.011 0.011 0.013 0.011 Mg2+ 0.664 0.671 0.625 0.640 0.639 0.642 0.617 NI2+ 0.002 0.005 0.003 0.004 0.005 0.003 0.001 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.003 0.005 0.005 0.005 0.005 0.006 Nb5+ 0.000 0.001 0.001 0.001 0.001 0.002 0.001 Zn2+ 0.005 0.001 0.002 0.001 0.000 0.002 0.000 Pt4+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 54.472 55.366 55.517 56.359 56.012 56.424 57.702 Cr*# 51.933 52.723 54.912 54.290 54.006 54.828 57.097 M g# 62.008 61.521 60.078 60.450 60.440 61.524 60.826 Mg"# 67.893 67.303 61.307 64.933 64.811 65.020 62.099 Fe3+ 4.661 4.773 1.090 3.672 3.582 2.627 1.050 Table C.12: Sample H8 113 Chromitite Microprobe Analyaie & Calculated Formula (baaed on 4 oxygéna) of chromite:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the Ideal chromite formula) 342 CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R :% W t% W t% W t% W t% W t% W t% W t% 0.011 0.000 0.000 0.811 0.000 0.021 0.000 1.165 23.315 23.248 23.647 24.389 23.180 23.184 23.479 23.243 0.082 0.186 0.101 0.144 0.138 0.157 0.101 0.036 44.622 46.269 44.707 43.963 45.181 45.305 46.372 45.054 4.065 1.272 3.565 0.481 3.660 2.484 1.275 0.389 12.712 15.293 12.807 15.698 12.673 14.548 14.367 15.187 0.490 0.438 0.382 0.525 0.475 0.463 0.470 0.474 14.730 12.984 14.714 13.488 14.645 13.523 13.495 14.029 0.078 0.082 0.131 0.209 0.209 0.057 0.138 0.140 0.017 0.000 0.000 0.001 0.000 0.008 0.000 0.006 0.205 0.260 0.186 0.165 0.178 0.228 0.240 0.248 0.000 0.000 0.000 0.078 0.000 0.094 0.000 0.000 0.000 0.088 0.039 0.000 0.027 0.134 0.189 0.000 0.079 0.008 0.078 0.095 0.000 0.043 0.000 0.070 100.407 100.128 100.357 100.047 100.366 100.248 100.128 100.040 0.000 0.000 0.000 0.025 0.000 0.001 0.000 0.035 0.831 0.839 0.842 0.873 0.827 0.834 0.844 0.831 0.002 0.004 0.002 0.003 0.003 0.004 0.002 0.001 1.067 1.121 1.068 1.055 1.082 1.094 1.118 1.081 0.093 0.029 0.081 0.011 0.083 0.057 0.029 0.009 0.322 0.392 0.324 0.399 0.321 0.371 0.367 0.385 0.013 0.011 0.010 0.013 0.012 0.012 0.012 0.012 0.664 0.593 0.663 0.610 0.661 0.615 0.614 0.635 0.002 0.002 0.003 0.005 0.005 0.001 0.003 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.006 0.005 0.004 0.004 0.006 0.006 0.006 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.002 0.001 0.000 0.001 0.003 0.004 0.000 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 56.215 57.176 55.914 54.736 56.665 56.728 56.988 56.528 53.602 56.333 53.638 54.426 54.292 55.097 56.150 56.266 61.598 58.473 62.090 59.849 62.049 58.953 60.793 61.679 67.380 60.215 67.192 60.501 67.320 62.363 62.609 62.217 4.647 1.474 4.071 0.567 4.187 2.876 1.470 0.463 343 CR9-A1-C CR9-A2-R CR10-A1-* CR10-A2-R .% W t% Wt% W t% 0.021 0.054 0.000 0.029 23.537 23.241 23.415 23.770 0.020 0.135 0.099 0.162 44.553 46.123 44.293 45.194 3.820 1.594 3.912 2.345 12.725 14.500 13.461 14.052 0.529 0.442 0.485 0.452 14.757 13.636 14.205 13.890 0.135 0.046 0.150 0.087 0.000 0.008 0.000 0.001 0.189 0.189 0.143 0.187 0.095 0.071 0.088 0.000 0.000 0.052 0.098 0.056 0.000 0.069 0.043 0.008 100.382 100.160 100.393 100.234 0.001 0.002 0.000 0.001 0.838 0.836 0.838 0.851 0.000 0.003 0.002 0.004 1.065 1.113 1.063 1.085 0.087 0.037 0.089 0.054 0.322 0.370 0.342 0.357 0.014 0.011 0.012 0.012 0.665 0.620 0.643 0.629 0.003 0.001 0.004 0.002 0.000 0.000 0.000 0.000 0.005 0.005 0.003 0.005 0.001 0.001 0.001 0.000 0.000 0.001 0.002 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 Average 55.944 57.106 55.927 56.053 53.501 56.053 53.416 54.543 54.585 61.942 60.405 59.856 60.506 60.792 67.398 62.637 65.290 63.795 4.366 1.843 4.491 2.694 344 Label WSU-1 WSU-2 WSU-3 WSU-4 CrH9-l2 WSU-5 Chromitite Section Ave Gabbro Section O xides W t% W t% Wt% W t% W t% 5102 0.154 0.167 0.152 0.167 0.160 0.237 AI203 22.769 22.832 24.103 23.412 23.279 20.411 TI02 0.330 0.393 0.508 0.121 0.338 0.707 C r203 42.806 42.340 40.679 42.050 41.969 39.450 F e203 5.239 5.056 5.205 3.835 4.834 8.244 FeO 15.843 15.355 15.627 14.802 15.407 17.651 MnO 0.237 0.224 0.235 0.224 0.230 0.305 MgO 12.910 13.062 13.013 13.176 13.040 10.619 NIO 0.107 0.128 0.131 0.093 0.115 0.164 CaO 0.010 0.000 0.008 0.016 0.008 0.529 V203 0.233 0.219 0.224 0.230 0.227 0.341 N b205 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.060 0.078 0.065 0.043 0.061 0.070 P t0 2 0.000 0.000 0.000 0.000 0.000 0.000 Total 100.698 99.854 99.951 98.168 99.668 98.727 C ations 514+ 0.005 0.005 0.005 0.005 0.005 0.008 AI3+ 0.821 0.828 0.869 0.858 0.844 0.767 TI4+ 0.008 0.009 0.012 0.003 0.008 0.017 Cr3+ 1.036 1.030 0.984 1.034 1.021 0.994 Fe3+ 0.121 0.117 0.120 0.090 0.112 0.198 Fe2+ 0.405 0.395 0.400 0.385 0.396 0.471 Mn2+ 0.006 0.006 0.006 0.006 0.006 0.008 Mg2+ 0.589 0.599 0.594 0.611 0.598 0.505 NI2+ 0.003 0.003 0.003 0.002 0.003 0.004 Ca2+ 0.000 0.000 0.000 0.001 0.000 0.018 V3+ 0.006 0.005 0.006 0.006 0.006 0.009 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.001 0.002 0.001 0.001 0.001 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 Cr* 55.776 55.436 53.100 54.646 54.740 56.456 Cr*# 52.373 52.152 49.875 52.172 51.643 50.758 M g# 52.817 53.911 53.317 56.271 54.079 43.023 Mg”# 59.225 60.259 59.749 61.342 60.144 51.747 Fe3+ 6.101 5.928 6.074 4.529 5.658 10.095 Table C I 3: Sample H9-I2 Chromitite & Gabbro Microprobe Analyaie & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 345 Label CR1-A1-C CR1-A2-C CR1-A3-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R O xides W t% W t% W t% W t% W t% W t% W t% S i0 2 0.000 0.019 0.028 0.000 0.000 0.011 0.000 AI203 24.657 24.960 25.295 24.732 25.355 24.963 24.727 T i02 0.195 0.169 0.132 0.107 0.118 0.175 0.176 C r203 42.997 42.847 43.268 42.832 43.147 43.203 43.272 F e203 4.088 3.992 2.754 4.295 2.854 3.664 3.869 FeO 12.301 12.529 13.377 12.501 13.623 12.255 12.658 MnO 0.478 0.503 0.514 0.502 0.505 0.484 0.445 MgO 15.075 14.965 14.304 14.950 14.166 15.088 14.886 NiO 0.188 0.159 0.141 0.167 0.179 0.152 0.152 CaO 0.000 0.000 0.007 0.000 0.004 0.000 0.008 V203 0.213 0.199 0.188 0.200 0.125 0.258 0.186 N b205 0.109 0.023 0.016 0.071 0.031 0.000 0.007 ZnO 0.108 0.034 0.252 0.073 0.174 0.115 0.000 P t0 2 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 100.408 100.400 100.275 100.430 100.283 100.369 100.387 C ations SI4+ 0.000 0.001 0.001 0.000 0.000 0.000 0.000 AI3+ 0.873 0.883 0.898 0.876 0.900 0.882 0.876 TI4+ 0.004 0.004 0.003 0.002 0.003 0.004 0.004 Cr3+ 1.021 1.016 1.030 1.017 1.028 1.024 1.028 Fe3+ 0.092 0.090 0.062 0.097 0.065 0.083 0.087 Fe2+ 0.309 0.314 0.337 0.314 0.343 0.307 0.318 Mn2+ 0.012 0.013 0.013 0.013 0.013 0.012 0.011 Mg2+ 0.675 0.669 0.642 0.669 0.636 0.674 0.667 NI2+ 0.005 0.004 0.003 0.004 0.004 0.004 0.004 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.005 0.005 0.005 0.003 0.006 0.004 Nb5+ 0.001 0.000 0.000 0.001 0.000 0.000 0.000 Zn2+ 0.002 0.001 0.006 0.002 0.004 0.003 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 53.914 53.522 53.434 53.742 53.306 53.725 54.001 Cr*# 51.406 51.097 51.759 51.120 51.575 51.492 51.628 M g# 62.710 62.332 61.660 61.954 60.931 63.362 62.161 Mg"# 68.599 68.043 65.591 68.071 64.957 68.698 67.704 Fe3+ 4.652 4.531 3.136 4.679 3.246 4.157 4.394 Table C I 4: Sample H8>VI1 DIsaemInated chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 346 CR4-A1-C CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R .% W t% W t% W t% W t% W t% W t% W t% 0.004 0.000 0.066 0.000 0.043 0.002 0.011 0.476 24.857 24.692 24.658 24.527 25.491 25.558 25.285 25.739 0.119 0.130 0.103 0.132 0.231 0.160 0.131 0.155 42.995 43.846 43.095 44.150 42.540 41.971 42.084 43.249 4.334 2.476 4.232 2.764 3.690 4.445 3.919 0.527 11.771 13.511 12.075 13.631 12.537 12.133 12.822 15.448 0.462 0.379 0.463 0.473 0.414 0.414 0.462 0.446 15.359 14.413 15.330 14.150 15.103 15.312 14.875 13.470 0.238 0.165 0.151 0.193 0.059 0.159 0.215 0.233 0.007 0.008 0.006 0.000 0.028 0.007 0.000 0.020 0.123 0.198 0.153 0.213 0.176 0.128 0.203 0.221 0.031 0.268 0.054 0.000 0.000 0.007 0.169 0.031 0.130 0.162 0.021 0.043 0.057 0.055 0.066 0.037 0.000 0.000 0.017 0.000 0.000 0.093 0.151 0.000 100.432 100.248 100.424 100.276 100.370 100.445 100.392 100.053 0.000 0.000 0.002 0.000 0.001 0.000 0.000 0.014 0.877 0.879 0.871 0.874 0.899 0.900 0.895 0.916 0.003 0.003 0.002 0.003 0.005 0.004 0.003 0.004 1.018 1.047 1.021 1.055 1.006 0.992 0.999 1.033 0.098 0.056 0.095 0.063 0.083 0.100 0.089 0.012 0.295 0.341 0.303 0.345 0.314 0.303 0.322 0.390 0.012 0.010 0.012 0.012 0.010 0.010 0.012 0.011 0.686 0.649 0.685 0.638 0.674 0.682 0.666 0.607 0.006 0.004 0.004 0.005 0.001 0.004 0.005 0.006 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.003 0.005 0.004 0.005 0.004 0.003 0.005 0.005 0.000 0.004 0.001 0.000 0.000 0.000 0.002 0.000 0.003 0.004 0.000 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 53.711 54.364 53.969 54.701 52.819 52.418 52.754 52.990 51.078 52.820 51.377 52.974 50.612 49.788 50.397 52.667 63.599 62.012 63.242 61.013 62.934 62.852 61.860 60.128 69.934 65.537 69.354 64.919 68.229 69.228 67.406 60.851 4.901 2.839 4.802 3.157 4.178 5.018 4.467 0.611 347 CR8-A1-C CR8-A2-R W t% W t% 0.024 0.000 24.735 25.054 0.163 0.180 41.749 41.240 5.105 5.269 13.715 13.392 0.515 0.499 14.189 14.352 0.122 0.047 0.021 0.017 0.173 0.157 0.000 0.047 0.000 0.257 0.000 0.017 100.511 100.528 0.001 0.000 0.879 0.889 0.004 0.004 0.996 0.982 0.116 0.119 0.346 0.337 0.013 0.013 0.638 0.644 0.003 0.001 0.001 0.001 0.004 0.004 0.000 0.001 0.000 0.006 0.000 0.000 3.000 3.000 Average 53.102 52.478 50.011 49.329 51.243 58.010 58.523 61.724 64.841 65.642 5.820 5.998 348 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CHR3-A2-R Chromite-rich dunite Section O xidea W t% W t% Wt% W t% W t% W t% 3102 0.017 0.013 0.000 0.021 0.000 0.002 AI203 28.687 28.682 28.738 28.728 28.932 29.227 T i02 0.070 0.161 0.227 0.201 0.116 0.132 C r203 38.935 38.727 38.726 38.885 38.485 38.766 F e203 3.653 3.720 3.416 3.431 3.797 3.532 FeO 13.011 13.492 13.476 13.409 12.926 12.758 MnO 0.360 0.323 0.442 0.402 0.395 0.375 MgO 15.072 14.858 14.833 14.880 15.300 15.316 NiO 0.169 0.023 0.155 0.152 0.133 0.161 CaO 0.014 0.025 0.004 0.000 0.000 0.001 V 203 0.156 0.119 0.082 0.124 0.105 0.069 N b205 0.047 0.062 0.180 0.079 0.182 0.000 ZnO 0.123 0.142 0.063 0.034 0.006 0.012 P t0 2 0.051 0.026 0.000 0.000 0.000 0.000 Total 100.364 100.373 100.341 100.346 100.378 100.352 C ations Si4+ 0.001 0.000 0.000 0.001 0.000 0.000 AI3+ 1.000 1.001 1.003 1.002 1.006 1.014 Ti4* 0.002 0.004 0.005 0.004 0.003 0.003 Cr3+ 0.910 0.906 0.907 0.910 0.898 0.903 Fe3+ 0.081 0.083 0.076 0.076 0.084 0.078 Fe2+ 0.322 0.334 0.334 0.332 0.319 0.314 Mn2+ 0.009 0.008 0.011 0.010 0.010 0.009 Mg2+ 0.664 0.656 0.655 0.656 0.673 0.672 NI2+ 0.004 0.001 0.004 0.004 0.003 0.004 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 V3+ 0.004 0.003 0.002 0.003 0.002 0.002 NbS+ 0.001 0.001 0.002 0.001 0.002 0.000 Zn2+ 0.003 0.003 0.001 0.001 0.000 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 T otal 3.000 3.000 3.000 3.000 3.000 3.000 C r# 47.658 47.528 47.479 47.589 47.156 47.084 Cr*# 45.712 45.549 45.659 45.761 45.156 45.237 M g# 62.242 61.133 61.503 61.656 62.531 63.142 Mg"# 67.373 66.251 66.239 66.422 67.846 68.152 Fe3+ 4.083 4.164 3.833 3.843 4.241 3.923 Table CIS: Sample H8WI1 Chromite-rich dunite & Maasive chromitite Microprobe Analyaie & Calculated Formula (baaed on 4 oxygéna) of chromite:(Mg. Fe)Cr204. (Fe203 la calculated by aaauming the ideal chromite formula) 349 R4-A1-C CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C t% W t% W t% W t% W t% W t% W t% 0.015 0.002 0.000 0.000 0.009 0.000 0.002 28.514 29.311 28.606 27.420 28.550 27.620 28.620 0.220 0.179 0.172 0.199 0.154 0.174 0.175 39.120 38.211 39.120 40.442 38.907 39.676 38.560 3.463 3.312 3.706 3.179 3.324 3.337 3.397 13.727 13.902 12.972 14.051 13.998 14.849 14.371 0.441 0.453 0.428 0.339 0.398 0.409 0.375 14.600 14.499 15.039 14.272 14.505 13.869 14.230 0.135 0.127 0.118 0.143 0.133 0.129 0.122 0.000 0.014 0.013 0.000 0.017 0.000 0.000 0.111 0.176 0.091 0.120 0.128 0.134 0.128 0.000 0.016 0.000 0.000 0.134 0.129 0.117 0.000 0.092 0.106 0.093 0.034 0.000 0.136 0.000 0.035 0.000 0.062 0.043 0.008 0.104 100.347 100.332 100.372 100.320 100.334 100.333 100.340 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.997 1.023 0.997 0.965 0.999 0.974 1.003 0.005 0.004 0.004 0.004 0.003 0.004 0.004 0.917 0.894 0.915 0.955 0.913 0.938 0.907 0.077 0.074 0.082 0.071 0.074 0.075 0.076 0.341 0.344 0.321 0.351 0.348 0.372 0.358 0.011 0.011 0.011 0.009 0.010 0.010 0.009 0.646 0.640 0.663 0.635 0.642 0.619 0.631 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.003 0.004 0.002 0.003 0.003 0.003 0.003 0.000 0.000 0.000 0.000 0.002 0.002 0.002 0.000 0.002 0.002 0.002 0.001 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 47.927 48.853 47.848 49.735 47.759 49.074 47.474 46.067 44.924 45.867 47.950 45.973 47.219 45.657 60.710 80.490 82.179 80.070 80.347 58.070 59.278 65.469 65.025 67.391 64.421 64.876 62.477 63.836 3.881 3.708 4.138 3.587 3.738 3.780 3.829 350 CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-C Massive Chrotr Wt% Wt% Wt% Wt% Wt% Wt% 0.000 0.011 0.002 0.006 0.006 0.021 28.353 28.800 28.593 29.046 29.117 29.212 0.221 0.214 0.223 0.153 0.147 0.183 38.541 39.104 39.248 38.763 38.486 39.234 4.177 3.079 3.039 3.458 3.510 3.155 13.756 13.237 13.929 13.018 13.064 12.026 0.453 0.424 0.416 0.438 0.402 0.400 14.520 14.943 14.490 15.064 15.033 15.815 0.152 0.174 0.132 0.143 0.188 0.122 0.000 0.000 0.022 0.004 0.028 0.006 0.119 0.151 0.125 0.104 0.144 0.140 0.016 0.087 0.039 0.040 0.000 0.000 0.058 0.069 0.000 0.110 0.063 0.002 0.051 0.017 0.043 0.000 0.163 0.000 100.418 100.309 100.302 100.346 100.352 100.316 0.000 0.000 0.000 0.000 0.000 0.001 0.992 1.004 1.000 1.011 1.014 1.011 0.005 0.005 0.005 0.003 0.003 0.004 0.905 0.915 0.921 0.905 0.899 0.911 0.093 0.069 0.068 0.077 0.078 0.070 0.342 0.327 0.346 0.321 0.323 0.295 0.011 0.011 0.010 0.011 0.010 0.010 0.643 0.659 0.641 0.663 0.662 0.692 0.004 0.004 0.003 0.003 0.004 0.003 0.000 0.000 0.001 0.000 0.001 0.000 0.003 0.004 0.003 0.002 0.003 0.003 0.000 0.001 0.001 0.001 0.000 0.000 0.001 0.002 0.000 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 Ave 47.696 47.668 47.939 47.236 46.997 47.395 45.459 46.024 46.303 45.415 45.155 45.838 45.736 59.642 62.465 60.785 62.473 62.291 61.167 65.475 65.298 66.805 64.966 67.349 67.227 70.097 4.690 3.449 3.413 3.856 3.920 3.501 351 CR10-A2-I CR11 -A1 -( CR11-A2-R CR12-A1 -< CR12-A2-ICR13-A1 -C CR13-A2-R litite Section t% Wt % Wt % W t% W t% Wt % Wt % 0.024 0.120 0.002 0.093 0.000 0.000 0.060 29.490 28.714 29.266 29.166 29.193 29.255 29.703 0.132 0.143 0.084 0.211 0.115 0.167 0.113 38.545 39.459 40.689 39.212 39.683 39.404 39.339 3.244 3.285 0.546 2.966 2.246 3.033 1.819 12.151 11.764 14.021 11.654 12.534 11.775 13.355 0.412 0.390 0.368 0.383 0.330 0.382 0.420 15.721 15.900 14.528 16.009 15.532 15.896 14.913 0.126 0.209 0.184 0.254 0.182 0.165 0.264 0.000 0.055 0.001 0.004 0.015 0.015 0.007 0.175 0.168 0.069 0.133 0.153 0.134 0.186 0.079 0.031 0.191 0.039 0.157 0.000 0.000 0.159 0.091 0.088 0.103 0.042 0.078 0.002 0.069 0.000 0.017 0.070 0.043 0.000 0.000 100.325 100.328 100.053 100.298 100.224 100.304 100.181 0.001 0.004 0.000 0.003 0.000 0.000 0.002 1.021 0.995 1.023 1.009 1.013 1.012 1.032 0.003 0.003 0.002 0.005 0.003 0.004 0.003 0.895 0.917 0.954 0.910 0.924 0.914 0.917 0.072 0.073 0.012 0.066 0.050 0.067 0.040 0.298 0.289 0.348 0.286 0.309 0.289 0.329 0.010 0.010 0.009 0.010 0.008 0.009 0.010 0.688 0.697 0.642 0.700 0.682 0.695 0.655 0.003 0.005 0.004 0.006 0.004 0.004 0.006 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.004 0.004 0.002 0.003 0.004 0.003 0.004 0.001 0.000 0.003 0.001 0.002 0.000 0.000 0.003 0.002 0.002 0.002 0.001 0.002 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 46.718 47.968 48.258 47.421 47.696 47.467 47.047 45.033 46.211 47.963 45.855 46.501 45.872 46.093 65.030 65.817 64.088 66.583 65.544 66.143 63.941 69.754 70.668 64.876 71.005 68.837 70.644 66.561 3.607 3.662 0.612 3.302 2.505 3.361 2.028 352 Bio inCR13 CR14-A1 -C CR14-A2-F CR15-A1 -C CR15-A2-R W t% Wt% Wt % Wt % W t% 0.002 0.009 0.000 0.000 0.000 27.338 28.954 29.117 29.097 29.239 0.185 0.139 0.220 0.195 0.150 40.937 39.711 39.794 39.379 40.038 3.449 3.179 2.284 2.956 1.649 12.205 11.455 12.144 11.696 12.816 0.522 0.434 0.408 0.376 0.353 15.385 16.053 15.764 16.017 15.319 0.114 0.196 0.159 0.201 0.144 0.029 0.000 0.000 0.000 0.017 0.154 0.130 0.162 0.146 0.169 0.000 0.000 0.133 0.149 0.133 0.027 0.057 0.000 0.078 0.076 0.000 0.000 0.043 0.008 0.061 100.344 100.317 100.229 100.296 100.166 0.000 0.000 0.000 0.000 0.000 0.955 1.002 1.009 1.007 1.016 0.004 0.003 0.005 0.004 0.003 0.960 0.922 0.925 0.914 0.934 0.077 0.070 0.051 0.065 0.037 0.303 0.281 0.299 0.287 0.316 0.013 0.011 0.010 0.009 0.009 0.680 0.702 0.691 0.701 0.673 0.003 0.005 0.004 0.005 0.003 0.001 0.000 0.000 0.000 0.001 0.004 0.003 0.004 0.003 0.004 0.000 0.000 0.002 0.002 0.002 0.001 0.001 0.000 0.002 0.002 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Ave 50.113 47.919 47.831 47.586 47.879 48.177 46.231 46.613 46.022 46.997 46.261 64.178 66.654 66.432 66.542 65.632 65.657 69.203 71.413 69.824 70.939 68.058 3.663 3.523 2.546 3.288 1.842 353 Label CR1-A1 -C CR1-A2-RCR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% W t% W t% W t% W t% W t% W t% 8102 0.000 0.004 0.000 0.000 0.000 0.000 0.013 AI203 20.944 21.398 20.477 21.732 20.363 19.396 20.220 TI02 0.067 0.040 0.047 0.095 0.043 0.063 0.098 C r203 46.917 45.895 47.182 44.641 47.088 48.274 46.768 F e203 2.539 3.005 3.296 4.438 2.934 2.857 3.645 FeO 17.409 17.338 16.454 16.398 17.247 17.527 16.903 MnO 0.539 0.482 0.455 0.453 0.556 0.549 0.576 MgO 11.288 11.448 11.908 12.035 11.454 11.007 11.453 NiO 0.075 0.060 0.131 0.066 0.041 0.144 0.029 CaO 0.000 0.003 0.010 0.008 0.000 0.015 0.062 V203 0.339 0.306 0.273 0.264 0.286 0.330 0.310 N b205 0.000 0.100 0.000 0.000 0.092 0.000 0.016 ZnO 0.138 0.221 0.098 0.261 0.075 0.117 0.271 P t0 2 0.000 0.000 0.000 0.052 0.118 0.008 0.000 Total 100.255 100.301 100.331 100.442 100.296 100.286 100.365 C ations SI4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.771 0.786 0.752 0.793 0.751 0.720 0.746 TI4+ 0.002 0.001 0.001 0.002 0.001 0.002 0.002 Cr3+ 1.159 1.131 1.163 1.093 1.166 1.202 1.157 Fe3+ 0.060 0.070 0.077 0.103 0.069 0.068 0.086 Fe2+ 0.455 0.452 0.429 0.425 0.452 0.462 0.442 Mn2+ 0.014 0.013 0.012 0.012 0.015 0.015 0.015 Mg2+ 0.526 0.532 0.553 0.556 0.535 0.517 0.534 NI2+ 0.002 0.002 0.003 0.002 0.001 0.004 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.001 0.002 V3+ 0.008 0.008 0.007 0.007 0.007 0.008 0.008 Nb5+ 0.000 0.001 0.000 0.000 0.001 0.000 0.000 Zn2+ 0.003 0.005 0.002 0.006 0.002 0.003 0.006 Pt4+ 0.000 0.000 0.000 0.000 0.001 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 60.045 58.996 60.718 57.948 60.804 62.542 60.809 Cr*# 58.244 56.904 58.362 54.936 58.688 60.414 58.184 M g# 50.537 50.450 52.223 51.269 50.659 49.399 50.287 Mg'*# 53.613 54.065 56.333 56.679 54.210 52.818 54.707 Fe3+ 3.000 3.547 3.881 5.199 3.480 3.404 4.317 T abled6: SampleH8>WI3 Harzburglte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 354 CR4-A2-R CR5-A1-C CR5-A2-I CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R Wt% Wt% Wt% Wt% W t% W t% 0.066 0.047 0.707 0.034 0.000 0.000 0.024 21.440 21.060 29.458 20.343 20.606 20.755 20.974 0.075 0.095 0.046 0.050 0.079 0.030 0.068 45.204 46.057 36.363 47.483 47.589 46.754 46.512 3.600 2.965 2.600 2.754 2.263 2.939 2.948 17.226 17.498 16.518 16.518 16.855 17.611 17.363 0.535 0.486 0.431 0.491 0.466 0.523 0.564 11.518 11.363 13.437 11.895 11.733 11.231 11.395 0.088 0.064 0.103 0.101 0.089 0.067 0.045 0.038 0.000 0.010 0.003 0.000 0.000 0.001 0.233 0.331 0.275 0.239 0.348 0.370 0.236 0.084 0.100 0.120 0.146 0.055 0.000 0.016 0.187 0.188 0.190 0.218 0.067 0.015 0.085 0.068 0.042 0.000 0.000 0.077 0.000 0.068 100.361 100.296 100.259 100.275 100.227 100.295 100.297 0.002 0.001 0.021 0.001 0.000 0.000 0.001 0.787 0.775 1.032 0.748 0.758 0.765 0.772 0.002 0.002 0.001 0.001 0.002 0.001 0.002 1.113 1.137 0.855 1.172 1.175 1.156 1.148 0.084 0.070 0.058 0.065 0.053 0.069 0.069 0.449 0.457 0.411 0.431 0.440 0.461 0.453 0.014 0.013 0.011 0.013 0.012 0.014 0.015 0.535 0.529 0.596 0.553 0.546 0.524 0.530 0.002 0.002 0.002 0.003 0.002 0.002 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.008 0.007 0.006 0.009 0.009 0.006 0.001 0.001 0.002 0.002 0.001 0.000 0.000 0.004 0.004 0.004 0.005 0.002 0.000 0.002 0.001 0.000 0.000 0.000 0.001 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 58.582 59.467 45.298 61.028 60.774 80.178 59.802 56.091 57.376 43.944 59.037 59.147 58.087 57.719 56.938 50.081 50.111 55.951 52.747 52.542 49.709 50.367 51.167 54.378 53.652 59.185 56.212 55.376 53.202 53.914 4.252 3.515 2.991 3.259 2.878 3.475 3.482 355 Label WSU-1 WSU-2 WSU-3 WSU-4 WSU-5 CrH9-WI2. Ave O xidea wt% W t% W t% W t% Wt% 3102 0.164 0.190 0.209 0.170 0.189 0.184 AI203 28.701 28.935 28.980 29.018 28.681 28.863 1102 0.170 0.125 0.186 0.136 0.142 0.152 C r203 38.153 39.341 38.845 37.890 38.159 38.478 F e203 4.072 3.564 3.534 4.140 3.885 3.839 FeO 12.665 12.104 12.321 13.172 13.253 12.703 MnO 0.173 0.158 0.169 0.178 0.182 0.172 MgO 15.468 16.095 15.888 15.242 15.088 15.556 NIO 0.138 0.163 0.182 0.148 0.169 0.160 CaO 0.012 0.000 0.000 0.011 0.013 0.007 V 203 0.178 0.143 0.157 0.152 0.115 0.149 N b205 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.093 0.065 0.046 0.093 0.061 0.072 P t0 2 0.000 0.000 0.000 0.000 0.000 0.000 Total 99.988 100.883 100.519 100.349 99.936 100.335 C ationa SI4+ 0.005 0.006 0.006 0.005 0.006 0.005 AI3+ 1.000 0.996 1.001 1.008 1.002 1.002 TI4+ 0.004 0.003 0.004 0.003 0.003 0.003 Cr3+ 0.892 0.908 0.901 0.883 0.894 0.896 Fe3+ 0.091 0.078 0.078 0.092 0.087 0.085 Fe2+ 0.313 0.296 0.302 0.325 0.329 0.313 Mn2+ 0.004 0.004 0.004 0.004 0.005 0.004 Mg2+ 0.682 0.701 0.694 0.670 0.667 0.683 NI2+ 0.003 0.004 0.004 0.004 0.004 0.004 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.003 0.004 0.004 0.003 0.004 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.002 0.001 0.001 0.002 0.001 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 C r# 47.140 47.702 47.346 46.693 47.161 47.208 Cr*# 44.985 45.817 45.481 44.531 45.100 45.183 M g# 62.806 65.203 64.628 61.656 61.624 63.183 Mg**# 68.526 70.330 69.685 67.350 66.990 68.576 Fe3+ 4.570 3.951 3.938 4.631 4.370 4.292 T able C.17: Sam ple H9*WI2.1 B anded C hrom itite MIcroprolM Analyala & Calculated Formula (baaed on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the Ideal chromite formula) 356 Label WSU-1 WSU-2 WSU-3 WSU-4 AVç Oxidea w t % W t% W t% Wt% 3102 0.180 0.190 0.155 0.16/ 0.173 AI203 28.814 28.835 28.509 29.57^ 28.932 TI02 0.191 0.236 0.255 0.10/ 0.220 C r203 37.751 38.047 37.941 36.56^ 37.573 F e203 4.429 3.943 4.470 4.60/ 4.362 FeO 14.679 14.519 13.845 14.400 14.378 MnO 0.225 0.189 0.187 0.103 0.199 MgO 14.384 14.464 14.767 14.500 14.530 NIO 0.117 0.110 0.140 0.140 0.128 CaO 0.007 0.025 0.037 0.000 0.018 V203 0.147 0.102 0.154 0.1 0.129 N b205 0.000 0.000 0.000 0.000 0.000 ZnO 0.066 0.064 0.061 0.o 7 ^ 0.066 P t02 0.000 0.000 0.000 0.000 0.000 Total 100.990 100.724 100.521 100.500 100.708 C ationa 314+ 0.005 0.006 0.005 0.000 0.005 AI3+ 1.002 1.004 0.994 1.0^0 1.007 TI4+ 0.004 0.005 0.006 O.oO^ 0.005 Cr3+ 0.881 0.889 0.888 0.800 0.878 Fe3+ 0.098 0.088 0.100 0.100 0.097 Fe2+ 0.362 0.359 0.343 0.30/ 0.355 Mn2+ 0.006 0.005 0.005 0.000 0.005 Mg2+ 0.633 0.637 0.651 0.600 0.640 NI2+ 0.003 0.003 0.003 0.000 0.003 Ca2+ 0.000 0.001 0.001 0.000 0.001 V3+ 0.003 0.002 0.004 0.000 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.001 0.001 0.001 0.000 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 C r# 46.778 48.954 47.188 45.301 46.558 Cr*# 44.456 44.876 44.799 42.900 44.281 M g# 57.873 58.798 59.587 58.140 88.598 Mg"# 63.594 63.974 65.532 64.1 64.306 Fe3+ 4.985 4.427 5.023 5.100 4.893 Table G.18: Sam ple H9*WI3 D Iaaem Inated Microprobe Analyaie & Calculated Formel* (^oeed on 4 oxygéna) of chromlte:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the id#** ^hromlte formula) 357 Label WSU-1 WSU-2 WSU-3 WSU-4 CrH9-WI4 Ave O xides wt% W t% W t% W t% 3102 0.111 0.131 0.110 0.120 0.118 AI203 21.007 21.326 21.075 21.247 21.164 T I02 0.535 0.555 0.448 0.494 0.508 C r203 40.133 40.767 39.794 39.869 40.141 F e203 9.156 9.053 9.539 9.767 9.379 FeO 17.658 16.923 17.568 17.481 17.407 MnO 0.276 0.206 0.280 0.303 0.266 MgO 11.362 12.095 11.448 11.628 11.633 NIO 0.138 0.182 0.122 0.182 0.156 CaO 0.010 0.004 0.011 0.035 0.015 V203 0.189 0.173 0.154 0.187 0.176 N b205 0.000 0.000 0.000 0.000 0.000 ZnO 0.172 0.164 0.116 0.086 0.134 P t0 2 0.000 0.000 0.000 0.000 0.000 Total 100.747 101.579 100.665 101.398 101.097 0.000 C ations 0.000 SI4+ 0.003 0.004 0.003 0.004 0.004 AI3+ 0.772 0.773 0.774 0.774 0.773 TI4+ 0.013 0.013 0.010 0.011 0.012 Cr3+ 0.989 0.992 0.981 0.975 0.984 Fe3+ 0.215 0.210 0.224 0.227 0.219 Fe2+ 0.460 0.435 0.458 0.452 0.451 Mn2+ 0.007 0.005 0.007 0.008 0.007 Mg2+ 0.528 0.555 0.532 0.536 0.538 NI2+ 0.003 0.004 0.003 0.005 0.004 Ca2+ 0.000 0.000 0.000 0.001 0.000 V3+ 0.005 0.004 0.004 0.005 0.004 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.004 0.004 0.003 0.002 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 0.000 C r# 56.172 58.188 55.883 55.729 55.992 Cr*# 50.065 50.222 49.563 49.320 49.792 M g# 43.886 48.239 43.831 44.103 44.515 Mg**# 53.423 56.027 53.739 54.248 54.359 Fe3+ 10.872 10.815 11.308 11.500 11.074 Table C.19: Sample H9-WM Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 358 Label WSU-1 WSU-2 WSU-3 WSU-4 CrH9-WI5 Ave O xides wt% W t% W t% W t% 3102 0.112 0.132 0.166 0.108 0.129 AI203 18.202 19.179 18.828 18.859 18.767 TI02 0.054 0.043 0.052 0.046 0.049 C r203 48.997 47.704 47.780 48.651 48.283 F e203 3.875 4.199 3.868 4.048 3.998 FeO 16.558 18.060 17.298 16.578 17.123 MnO 0.218 0.235 0.179 0.217 0.212 MgO 11.853 11.154 11.445 12.061 11.628 NIO 0.087 0.088 0.071 0.095 0.086 CaO 0.000 0.026 0.038 0.018 0.020 V203 0.294 0.339 0.343 0.319 0.324 N b205 0.000 0.000 0.000 0.000 0.000 ZnO 0.196 0.171 0.203 0.145 0.179 P t0 2 0.000 0.000 0.000 0.000 0.000 Total 100.445 101.330 100.271 101.146 100.798 C ations SI4+ 0.004 0.004 0.005 0.003 0.004 AI3+ 0.675 0.706 0.699 0.692 0.693 TI4+ 0.001 0.001 0.001 0.001 0.001 Cr3+ 1.218 1.178 1.189 1.197 1.196 Fe3+ 0.092 0.099 0.092 0.095 0.094 Fe2+ 0.435 0.472 0.455 0.432 0.449 Mn2+ 0.006 0.006 0.005 0.006 0.006 Mg2+ 0.556 0.519 0.537 0.560 0.543 NI2+ 0.002 0.002 0.002 0.002 0.002 Ca2+ 0.000 0.001 0.001 0.001 0.001 V3+ 0.007 0.008 0.009 0.008 0.008 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.005 0.004 0.005 0.003 0.004 R 4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 0.000 C r# 64.359 62.526 62.996 63.377 63.315 cr# 61.385 59.414 60.079 60.349 60.307 M g# 51.317 47.656 49.541 51.533 50.012 Mg"# 56.065 52.402 54.115 56.463 54.761 Fe3+ 4.621 4.978 4.630 4.779 4.752 Table C.20: Sample H9-WI5 Perldotite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 359 Label WSU-1 WSU-2 WSU-3 WSU-4 CrH9-WI6 Ave O xides wt% W t% W t% W t% S i0 2 0.133 0.162 0.139 0.122 0.139 A1203 20.842 20.099 21.315 19.385 20.410 T i02 0.023 0.062 0.052 0.017 0.038 C r203 46.576 47.122 44.944 46.521 46.291 F e203 3.689 3.096 4.002 3.828 3.654 FeO 17.162 16.430 17.092 18.315 17.250 MnO 0.241 0.196 0.252 0.239 0.232 MgO 11.894 12.020 11.764 10.686 11.591 NiO 0.128 0.118 0.082 0.058 0.097 CaO 0.016 0.034 0.006 0.000 0.014 V203 0.290 0.275 0.298 0.300 0.291 N b205 0.000 0.000 0.000 0.000 0.000 ZnO 0.092 0.188 0.181 0.174 0.159 P t0 2 0.000 0.000 0.000 0.000 0.000 Total 101.084 99.803 100.126 99.644 100.164 0.000 C ations 0.000 SI4+ 0.004 0.005 0.004 0.004 0.004 AI3+ 0.760 0.742 0.782 0.725 0.752 Ti4+ 0.001 0.001 0.001 0.000 0.001 Cr3+ 1.139 1.167 1.107 1.168 1.145 Fe3+ 0.086 0.073 0.094 0.091 0.086 Fe2+ 0.444 0.430 0.445 0.486 0.451 Mn2+ 0.006 0.005 0.007 0.006 0.006 Mg2+ 0.548 0.561 0.546 0.506 0.540 NI2+ 0.003 0.003 0.002 0.001 0.002 Ca2+ 0.001 0.001 0.000 0.000 0.000 V3+ 0.007 0.007 0.007 0.008 0.007 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.002 0.004 0.004 0.004 0.004 R 4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 Cr# 59.986 61.131 58.584 61.885 60.347 Cr*# 57.391 58.880 55.813 58.842 57.732 M g# 50.864 52.719 50.331 46.678 50.148 Mg'*# 55.265 56.599 55.094 50.982 54.485 Fe3+ 4.326 3.682 4.731 4.808 4.337 Table C.21: Sample H9-WI6 Peridotlte Microprob* Analyste & Calculated Formula (baaed on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fs203 Is calculated by assuming the ideal chromite formula) 360 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% Wt% Wt% Wt% Wt% Wt% W t% S i0 2 0.006 0.000 0.002 0.017 0.000 0.031 0.000 AI203 22.538 23.535 23.250 23.275 23.020 23.124 23.234 T i02 0.356 0.332 0.341 0.294 0.378 0.275 0.261 C r203 44.300 43.827 44.441 45.339 44.253 45.277 44.324 F e203 5.076 4.049 3.731 2.074 4.172 1.995 4.229 FeO 12.833 13.597 13.672 15.283 13.655 15.407 12.849 MnO 0.536 0.504 0.430 0.495 0.483 0.502 0.427 MgO 14.390 14.099 14.099 13.053 13.998 12.911 14.579 NiO 0.200 0.203 0.084 0.129 0.198 0.224 0.169 CaO 0.000 0.025 0.000 0.000 0.000 0.001 0.000 V 203 0.090 0.091 0.088 0.129 0.117 0.089 0.150 N b205 0.007 0.101 0.094 0.102 0.062 0.149 0.062 ZnO 0.153 0.042 0.143 0.017 0.084 0.069 0.127 P t0 2 0.026 0.000 0.000 0.000 0.000 0.146 0.017 T otal 100.510 100.404 100.375 100.208 100.418 100.200 100.427 C atio n s Si4+ 0.000 0.000 0.000 0.001 0.000 0.001 0.000 AI3+ 0.808 0.842 0.833 0.840 0.826 0.836 0.830 Ti4+ 0.008 0.008 0.008 0.007 0.009 0.006 0.006 Cr3+ 1.065 1.052 1.068 1.097 1.065 1.099 1.062 Fe3+ 0.116 0.092 0.085 0.048 0.096 0.046 0.096 Fe2+ 0.326 0.345 0.348 0.391 0.348 0.395 0.326 Mn2+ 0.014 0.013 0.011 0.013 0.012 0.013 0.011 Mg2+ 0.652 0.638 0.639 0.596 0.635 0.591 0.658 Ni2+ 0.005 0.005 0.002 0.003 0.005 0.006 0.004 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.002 0.002 0.002 0.003 0.003 0.002 0.004 Nb5+ 0.000 0.001 0.001 0.001 0.001 0.002 0.001 Zn2+ 0.003 0.001 0.003 0.000 0.002 0.002 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 T otal 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 56.870 55.541 56.184 56.650 56.324 56.776 56.136 Cr*# 53.548 52.955 53.770 55.286 53.615 55.456 53.413 M g# 59.582 59.313 59.610 57.569 58.905 57.228 60.944 Mg’*# 66.654 64.892 64.767 60.356 64.632 59.902 66.916 Fe3+ 5.840 4.656 4.296 2.407 4.811 2.326 4.851 Table C.22: Sample S8*Lm2 Masalve Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 361 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C W t% W t% W t% W t% W t% Wt% W t% 0.000 0.000 0.029 0.000 0.032 0.000 0.000 0.002 23.685 22.658 23.609 23.317 22.971 23.039 22.831 23.238 0.394 0.377 0.296 0.290 0.320 0.278 0.209 0.335 44.598 44.907 45.754 44.022 44.048 44.378 44.390 44.122 2.949 3.815 0.755 4.451 4.124 4.257 4.768 4.255 13.864 13.435 16.246 12.927 13.442 13.149 12.977 13.125 0.405 0.524 0.531 0.491 0.523 0.446 0.433 0.446 13.962 14.106 12.302 14.421 14.282 14.329 14.473 14.398 0.131 0.203 0.177 0.249 0.221 0.169 0.172 0.132 0.000 0.000 0.025 0.001 0.004 0.021 0.000 0.000 0.153 0.094 0.132 0.180 0.144 0.087 0.151 0.206 0.000 0.094 0.086 0.000 0.241 0.054 0.023 0.000 0.103 0.066 0.131 0.099 0.000 0.135 0.051 0.090 0.051 0.102 0.000 0.000 0.060 0.085 0.000 0.076 100.295 100.381 100.075 100.446 100.412 100.426 100.479 100.426 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.848 0.814 0.855 0.833 0.823 0.825 0.817 0.831 0.009 0.009 0.007 0.007 0.007 0.006 0.005 0.008 1.071 1.082 1.112 1.055 1.059 1.066 1.065 1.058 0.067 0.087 0.017 0.102 0.094 0.097 0.109 0.097 0.352 0.342 0.418 0.328 0.342 0.334 0.329 0.333 0.010 0.014 0.014 0.013 0.013 0.011 0.011 0.011 0.632 0.641 0.564 0.651 0.647 0.649 0.655 0.651 0.003 0.005 0.004 0.006 0.005 0.004 0.004 0.003 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.004 0.002 0.003 0.004 0.004 0.002 0.004 0.005 0.000 0.001 0.001 0.000 0.003 0.001 0.000 0.000 0.002 0.001 0.003 0.002 0.000 0.003 0.001 0.002 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 55.814 57.074 56.524 55.880 56.263 56.374 56.603 56.019 53.920 54.556 56.026 53.029 53.576 53.614 53.507 53.280 60.110 59.851 56.440 60.289 59.745 60.069 59.905 60.219 64.226 65.176 57.445 66.540 65.445 66.016 66.533 66.163 3.393 4.411 0.880 5.103 4.774 4.895 5.470 4.891 362 CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-R t% W t% Wt % Wt % W t% W t% W t% 0.017 0.000 0.000 0.000 0.006 0.000 0.000 22.968 23.222 23.688 23.863 23.945 23.515 23.799 0.370 0.337 0.269 0.312 0.317 0.336 0.344 45.007 44.498 44.902 43.233 43.191 44.097 44.423 3.044 3.927 2.626 4.514 4.557 3.931 2.943 14.231 13.078 14.020 12.917 13.205 13.330 14.267 0.402 0.497 0.423 0.449 0.479 0.490 0.440 13.656 14.302 13.893 14.755 14.435 14.217 13.685 0.248 0.206 0.159 0.138 0.127 0.180 0.126 0.000 0.003 0.001 0.000 0.000 0.000 0.024 0.117 0.086 0.112 0.089 0.129 0.122 0.167 0.124 0.046 0.055 0.181 0.016 0.000 0.000 0.120 0.190 0.052 0.000 0.052 0.107 0.076 0.000 0.000 0.061 0.000 0.000 0.068 0.000 100.304 100.393 100.262 100.451 100.458 100.394 100.295 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.826 0.831 0.849 0.849 0.853 0.841 0.853 0.008 0.008 0.006 0.007 0.007 0.008 0.008 1.086 1.068 1.079 1.032 1.032 1.058 1.068 0.070 0.090 0.060 0.103 0.104 0.090 0.067 0.363 0.332 0.356 0.326 0.334 0.338 0.363 0.010 0.013 0.011 0.011 0.012 0.013 0.011 0.621 0.647 0.630 0.664 0.650 0.643 0.620 0.006 0.005 0.004 0.003 0.003 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.002 0.003 0.002 0.003 0.003 0.004 0.002 0.001 0.001 0.002 0.000 0.000 0.000 0.003 0.004 0.001 0.000 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 56.795 56.245 55.979 54.862 54.752 55.713 55.599 54.792 53.708 54.287 52.025 51.898 53.198 53.716 53.781 58.924 60.547 60.186 60.770 59.788 60.040 59.052 59.504 63.108 66.094 63.853 67.064 66.084 65.532 63.098 3.527 4.511 3.022 5.170 5.212 4.514 3.387 363 Label CHR1-A1-( CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR5-A1-C CR5-A2-R Chromite bands (w/o CR4) section O xides Wt % Wt % Wt % W t% W t% Wt% W t% Si02 0.000 0.021 0.000 0.017 0.002 0.024 0.000 Ai203 22.736 22.948 22.847 23.535 22.293 23.047 23.412 Ti02 0.337 0.265 0.263 0.362 0.287 0.325 0.322 C r203 45.743 45.389 45.787 45.264 45.646 45.177 45.319 Fe203 2.888 3.155 2.748 2.171 3.432 3.223 2.291 FeO 13.994 13.683 14.277 14.318 13.804 13.599 13.840 MnO 0.515 0.467 0.487 0.460 0.470 0.460 0.529 MgO 13.675 14.028 13.671 13.694 13.935 14.067 14.056 NIC 0.121 0.156 0.000 0.108 0.175 0.161 0.105 CaO 0.001 0.006 0.000 0.000 0.000 0.004 0.000 V203 0.086 0.139 0.142 0.114 0.133 0.094 0.085 N b205 0.016 0.000 0.007 0.085 0.124 0.047 0.178 ZnO 0.177 0.000 0.046 0.088 0.000 0.093 0.000 P t0 2 0.000 0.060 0.000 0.000 0.042 0.000 0.093 Total 100.288 100.316 100.275 100.216 100.343 100.323 100.229 C ations SI4+ 0.000 0.001 0.000 0.001 0.000 0.001 0.000 AI3+ 0.818 0.823 0.822 0.845 0.803 0.826 0.839 TI4+ 0.008 0.006 0.006 0.008 0.007 0.007 0.007 Cr3+ 1.105 1.093 1.105 1.090 1.103 1.087 1.090 Fe3+ 0.066 0.072 0.063 0.050 0.079 0.074 0.052 Fe2+ 0.357 0.348 0.364 0.365 0.353 0.346 0.352 Mn2+ 0.013 0.012 0.013 0.012 0.012 0.012 0.014 Mg2+ 0.623 0.637 0.622 0.622 0.635 0.638 0.637 NB+ 0.003 0.004 0.000 0.003 0.004 0.004 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.002 0.003 0.003 0.003 0.003 0.002 0.002 Nb5+ 0.000 0.000 0.000 0.001 0.002 0.001 0.002 Zn2+ 0.004 0.000 0.001 0.002 0.000 0.002 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 57.441 57.024 57.345 56.335 57.869 56.803 56.495 Cr*# 55.525 54.950 55.526 54.923 55.567 54.693 55.000 M g* 59.500 60.214 59.265 60.004 59.522 60.314 61.175 Mg"* 63.530 64.633 63.058 63.030 64.279 64.838 64.417 Fe3+ 3.337 3.636 3.172 2.507 3.977 3.714 2.646 Table C.23: Sample 58 Lm3 Banded Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fs203 is calculated by assuming the ideal chromite formula) 364 CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CH8-A1-C CR8-A2-R CR9-A1-C Dunitic section wt% W t% Wt% Wt% Wt% Wt% Wt% 0.000 0.013 0.000 0.021 0.000 0.000 0.000 23.084 23.249 23.097 23.982 22.960 23.472 22.434 0.337 0.265 0.313 0.312 0.181 0.263 0.352 44.829 45.121 44.449 44.618 44.948 44.682 45.269 4.058 3.604 4.290 3.022 3.856 3.403 3.864 12.617 12.603 12.587 13.063 13.739 13.971 13.778 0.489 0.511 0.456 0.370 0.474 0.413 0.464 14.633 14.723 14.766 14.593 13.974 13.884 13.817 0.180 0.122 0.167 0.196 0.163 0.169 0.227 0.000 0.018 0.017 0.000 0.000 0.000 0.000 0.070 0.037 0.123 0.040 0.091 0.047 0.111 0.000 0.000 0.078 0.023 0.000 0.000 0.000 0.109 0.036 0.042 0.000 0.000 0.036 0.068 0.000 0.059 0.042 0.059 0.000 0.000 0.000 100.406 100.362 100.429 100.302 100.386 100.340 100.385 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.824 0.829 0.824 0.854 0.824 0.841 0.807 0.008 0.006 0.007 0.007 0.004 0.006 0.008 1.074 1.080 1.064 1.066 1.082 1.074 1.093 0.093 0.082 0.098 0.069 0.088 0.078 0.089 0.320 0.319 0.319 0.330 0.350 0.355 0.352 0.013 0.013 0.012 0.009 0.012 0.011 0.012 0.661 0.664 0.666 0.657 0.634 0.629 0.629 0.004 0.003 0.004 0.005 0.004 0.004 0.006 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.002 0.001 0.003 0.001 0.002 0.001 0.003 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.001 0.001 0.000 0.000 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 1stAvew/oCR4 56.574 56.556 56.350 55.518 56.772 56.083 57.514 53.945 54.227 53.577 53.599 54.685 54.257 53.892 54.946 61.589 62.354 61.543 62.240 60.702 59.142 59.233 58.804 67.400 67.559 67.649 66.571 64.453 63.917 64.128 4.648 4.123 4.922 3.455 4.431 3.907 4.464 365 CR9-A2-R CR10-A1-* CR10-A2-I CR11-A1-* CR11-A2-R CR4-A1-C CR4-A2-R Wt % Wt % Wt % Wt % Wt % Wt % Wt % 0.011 0.000 0.022 0.006 0.006 0.004 0.021 22.316 23.565 23.215 23.287 23.087 23.235 23.425 0.264 0.237 0.229 0.273 0.223 0.268 0.296 45.377 43.907 44.625 43.904 44.037 44.111 43.949 3.423 3.936 3.171 4.456 4.565 3.504 3.785 14.977 13.798 15.222 13.598 13.646 15.151 14.575 0.464 0.511 0.449 0.454 0.458 0.446 0.407 13.072 13.950 13.084 14.050 14.070 13.161 13.543 0.154 0.183 0.112 0.181 0.159 0.152 0.136 0.000 0.003 0.007 0.007 0.014 0.000 0.008 0.182 0.146 0.065 0.134 0.110 0.129 0.180 0.000 0.047 0.056 0.000 0.046 0.125 0.023 0.076 0.069 0.062 0.093 0.036 0.040 0.030 0.027 0.043 0.000 0.000 0.000 0.026 0.000 100.343 100.394 100.318 100.444 100.457 100.352 100.378 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.808 0.844 0.837 0.834 0.827 0.838 0.841 0.006 0.005 0.005 0.006 0.005 0.006 0.007 1.102 1.055 1.079 1.055 1.058 1.067 1.059 0.079 0.090 0.073 0.102 0.104 0.081 0.087 0.385 0.351 0.389 0.345 0.347 0.388 0.371 0.012 0.013 0.012 0.012 0.012 0.012 0.011 0.598 0.632 0.597 0.636 0.638 0.600 0.615 0.004 0.004 0.003 0.004 0.004 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.004 0.002 0.003 0.003 0.003 0.004 0.000 0.001 0.001 0.000 0.001 0.002 0.000 0.002 0.002 0.001 0.002 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 2nd Average 57.700 55.555 56.323 55.845 56.133 56.016 55.725 55.405 53.040 54.256 52.986 53.187 53.996 53.740 53.291 56.340 58.916 56.338 58.717 56.553 58.255 56.174 57.313 60.873 64.314 60.509 64.811 64.764 60.761 62.354 3.978 4.526 3.670 5.119 5.248 4.063 4.368 366 Label CR1-A1-C CR1-A2-RICR2-A1-C CR2-A2-RICR3-A1-C CR3-A2-Rf CR4-A1-0 O xides W t% W t% W t% W t% W t% W t% W t% 3102 0.013 0.029 0.017 0.042 0.006 0.000 0.014 AI203 18.729 18.078 19.126 18.531 18.381 18.238 18.324 TI02 0.233 0.116 0.201 0.192 0.198 0.138 0.127 C r203 50.160 48.809 49.483 48.664 50.326 48.741 48.408 F e203 1.568 4.523 1.885 3.673 2.611 4.532 4.589 FeO 17.283 15.667 17.385 16.717 15.753 15.901 16.161 MnO 0.631 0.666 0.583 0.630 0.533 0.553 0.553 MgO 11.074 12.113 11.059 11.410 12.115 12.004 11.853 NiO 0.096 0.018 0.080 0.140 0.116 0.082 0.069 CaO 0.004 0.004 0.006 0.011 0.013 0.011 0.015 V203 0.129 0.142 0.155 0.124 0.134 0.135 0.133 N b205 0.007 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.139 0.171 0.183 0.176 0.076 0.119 0.140 P t0 2 0.091 0.117 0.024 0.059 0.000 0.000 0.073 Total 100.157 100.453 100.189 100.368 100.262 100.454 100.460 C ations SM+ 0.000 0.001 0.001 0.001 0.000 0.000 0.000 AI3+ 0.698 0.670 0.711 0.689 0.680 0.675 0.679 TI4+ 0.006 0.003 0.005 0.005 0.005 0.003 0.003 Cr3+ 1.254 1.213 1.234 1.213 1.250 1.211 1.204 Fe3+ 0.037 0.107 0.045 0.087 0.062 0.107 0.109 Fe2+ 0.457 0.412 0.459 0.441 0.414 0.418 0.425 Mn2+ 0.017 0.018 0.016 0.017 0.014 0.015 0.015 Mg2+ 0.522 0.568 0.520 0.536 0.567 0.562 0.556 NK+ 0.002 0.000 0.002 0.004 0.003 0.002 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.004 0.004 0.003 0.003 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.003 0.004 0.004 0.004 0.002 0.003 0.003 R 4+ 0.001 0.001 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 64.243 64.428 63.444 63.790 64.748 64.195 63.928 C r # 63.038 60.963 62.018 60.995 62.742 60.744 60.442 M g# 51.362 52.244 50.815 50.393 54.399 51.715 51.011 Mg"# 53.320 57.951 53.139 54.888 57.822 57.369 56.661 Fe3+ 1.876 5.378 2.249 4.382 3.099 5.376 5.454 Table C.24: Sample Z7-14A Chromite bearing dunite MIcroprotw Analysia & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 367 CR4-A2-RICR5-A1-C CR5-A2-RICR6-A1-C CR6-A2-RF CR7-A1-I CR7-A2-LF CR7-A3-LF t% W t% W t% W t% W t% W t% W t% W t% 0.045 0.002 0.022 0.023 0.020 0.002 0.056 0.008 11.207 17.816 15.277 17.799 18.294 18.589 18.573 18.918 0.122 0.140 0.182 0.160 0.125 0.115 0.156 0.191 48.570 49.394 50.545 49.145 48.886 48.246 48.500 47.504 13.141 4.135 6.289 4.772 4.610 4.674 4.133 4.968 16.011 15.421 14.641 14.955 15.032 15.098 15.903 15.746 0.631 0.533 0.531 0.594 0.534 0.582 0.526 0.591 11.330 12.421 12.616 12.575 12.613 12.545 12.199 12.205 0.045 0.048 0.052 0.044 0.052 0.042 0.075 0.065 0.000 0.000 0.022 0.010 0.030 0.000 0.003 0.000 0.110 0.130 0.177 0.139 0.102 0.177 0.066 0.162 0.000 0.198 0.103 0.000 0.023 0.066 0.089 0.030 0.105 0.151 0.174 0.166 0.141 0.259 0.069 0.109 0.000 0.024 0.000 0.096 0.000 0.072 0.065 0.000 101.316 100.414 100.630 100.478 100.462 100.468 100.414 100.498 0.001 0.000 0.001 0.001 0.001 0.000 0.002 0.000 0.428 0.660 0.570 0.658 0.675 0.685 0.686 0.698 0.003 0.003 0.004 0.004 0.003 0.003 0.004 0.004 1.243 1.227 1.265 1.219 1.209 1.193 1.202 1.175 0.320 0.098 0.150 0.113 0.109 0.110 0.098 0.117 0.434 0.405 0.388 0.392 0.393 0.395 0.417 0.412 0.017 0.014 0.014 0.016 0.014 0.015 0.014 0.016 0.547 0.582 0.596 0.588 0.588 0.585 0.570 0.569 0.001 0.001 0.001 0.001 0.001 0.001 0.002 0.002 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.003 0.003 0.004 0.003 0.003 0.004 0.002 0.004 0.000 0.003 0.001 0.000 0.000 0.001 0.001 0.000 0.003 0.004 0.004 0.004 0.003 0.006 0.002 0.003 0.000 0.000 0.000 0.001 0.000 0.001 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 74.407 65.034 68.940 64.941 64.192 63.518 63.660 62.749 62.442 61.830 63.736 61.264 60.694 60.004 60.534 59.060 42.048 53.634 52.557 53.802 53.964 53.671 52.568 51.834 55.781 58.946 60.568 59.983 59.932 59.696 57.760 58.013 16.081 4.926 7.549 5.662 5.448 5.532 4.909 5.879 368 CR8-A1 -C CR8-A2-RICR8-A3-RICR9-A1 -I CR9-A2-LF CR10/M63 CR10/M63 CR10-A1 -I t% W t% W t% W t% W t% W t% W t% W t% 0.023 1.775 0.170 0.057 0.017 0.004 0.023 0.063 18.076 15.204 16.845 17.718 17.971 17.588 17.860 17.733 0.214 0.090 0.187 0.071 0.148 0.151 0.215 0.167 48.799 43.642 50.521 49.153 49.405 49.168 49.334 49.691 4.410 11.814 3.313 4.796 4.053 5.028 4.240 4.162 15.904 10.340 17.579 14.840 15.764 14.911 15.224 15.327 0.485 0.601 0.479 0.589 0.578 0.579 0.572 0.598 12.062 16.994 11.002 12.572 12.077 12.771 12.584 12.376 0.072 0.093 0.026 0.189 0.027 0.030 0.006 0.008 0.000 0.015 0.012 0.004 0.000 0.000 0.000 0.000 0.239 0.205 0.116 0.110 0.142 0.141 0.183 0.129 0.000 0.219 0.000 0.067 0.000 0.133 0.125 0.000 0.125 0.149 0.081 0.258 0.167 0.000 0.057 0.162 0.032 0.042 0.000 0.057 0.057 0.000 0.000 0.000 100.442 101.183 100.332 100.480 100.406 100.504 100.425 100.417 0.001 0.054 0.005 0.002 0.001 0.000 0.001 0.002 0.670 0.548 0.632 0.655 0.666 0.650 0.660 0.656 0.005 0.002 0.004 0.002 0.004 0.004 0.005 0.004 1.213 1.055 1.271 1.220 1.229 1.219 1.223 1.234 0.104 0.272 0.079 0.113 0.096 0.119 0.100 0.098 0.418 0.264 0.468 0.389 0.415 0.391 0.399 0.403 0.013 0.016 0.013 0.016 0.015 0.015 0.015 0.016 0.565 0.775 0.522 0.588 0.566 0.597 0.588 0.580 0.002 0.002 0.001 0.005 0.001 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.005 0.003 0.003 0.004 0.004 0.005 0.003 0.000 0.003 0.000 0.001 0.000 0.002 0.002 0.000 0.003 0.003 0.002 0.006 0.004 0.000 0.001 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 64.427 65.819 66.799 65.048 64.842 65.221 64.949 65.276 61.044 56.276 64.125 61.342 61.717 61.328 61.672 62.047 51.969 59.094 48.819 53.915 52.587 53.946 54.091 53.635 57.482 74.554 52.733 60.161 57.729 60.424 59.572 59.007 5.251 14.499 4.003 5.696 4.819 5.969 5.046 4.947 369 CR11-A1-I CR11-A2-LCR12-A1-CCR12-A2-F CR14-A2-I CR15-A1- CR15-A1-' CR15-A2- % W t% W t% W t% w t% W t% w t% w t% 0.028 0.009 0.017 0.041 0.013 0.021 0.004 0.013 17.739 18.653 17.896 18.785 18.906 19.167 18.416 19.674 0.178 0.158 0.137 0.108 0.147 0.155 0.178 0.098 49.586 47.782 49.517 48.193 49.717 49.440 49.631 48.294 4.369 5.345 3.814 3.724 2.910 3.095 3.486 3.598 14.979 14.887 15.963 16.985 15.142 14.292 14.797 14.792 0.580 0.627 0.566 0.599 0.564 0.582 0.570 0.608 12.588 12.692 12.017 11.511 12.603 13.148 12.757 12.890 0.075 0.074 0.076 0.052 0.053 0.015 0.075 0.079 0.000 0.000 0.002 0.006 0.000 0.003 0.014 0.001 0.116 0.147 0.185 0.084 0.153 0.113 0.141 0.136 0.044 0.023 0.082 0.191 0.000 0.000 0.060 0.060 0.140 0.140 0.076 0.086 0.083 0.186 0.138 0.117 0.016 0.000 0.033 0.008 0.000 0.092 0.081 0.000 100.438 100.535 100.382 100.373 100.291 100.310 100.349 100.360 0.001 0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.656 0.686 0.664 0.697 0.696 0.703 0.679 0.720 0.004 0.004 0.003 0.003 0.003 0.004 0.004 0.002 1.230 1.179 1.233 1.199 1.228 1.216 1.227 1.186 0.103 0.126 0.090 0.088 0.068 0.072 0.082 0.084 0.393 0.389 0.420 0.447 0.395 0.372 0.387 0.384 0.015 0.017 0.015 0.016 0.015 0.015 0.015 0.016 0.589 0.591 0.564 0.540 0.587 0.610 0.595 0.597 0.002 0.002 0.002 0.001 0.001 0.000 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.004 0.005 0.002 0.004 0.003 0.004 0.003 0.001 0.000 0.001 0.003 0.000 0.000 0.001 0.001 0.003 0.003 0.002 0.002 0.002 0.004 0.003 0.003 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 65.221 63.215 64.988 63.249 63.822 63.375 64.386 62.218 61.839 59.228 62.033 60.438 61.630 61.069 61.729 59.589 54.267 53.459 52.482 50.226 55.848 57.849 55.909 56.033 59.968 60.314 57.300 54.713 59.737 62.120 60.581 60.836 5.186 6.306 4.548 4.445 3.434 3.639 4.127 4.225 370 R16-A1-' CR16-A2-I CR17-A1-' CR17-A2-I CR18-A1-I CR19-A1-' CR19-A2-I CR20-A1 t% W t% Wt % Wt % W t% W t% W t% W t% 0.000 0.017 0.011 0.000 0.024 0.021 0.011 0.017 18.009 18.973 17.855 19.219 18.268 18.312 18.808 18.180 0.128 0.139 0.157 0.160 0.159 0.216 0.156 0.147 49.989 49.330 50.139 49.088 49.796 49.510 49.049 49.578 3.582 2.265 3.649 2.535 3.835 3.468 3.704 3.875 15.432 16.370 15.090 16.152 14.232 15.241 14.875 15.216 0.609 0.635 0.654 0.614 0.704 0.566 0.566 0.630 12.235 11.834 12.535 11.985 12.988 12.511 12.851 12.403 0.079 0.121 0.053 0.065 0.046 0.110 0.043 0.025 0.015 0.000 0.015 0.000 0.003 0.010 0.000 0.000 0.157 0.179 0.089 0.056 0.111 0.099 0.126 0.126 0.000 0.158 0.066 0.106 0.007 0.148 0.076 0.000 0.124 0.068 0.037 0.105 0.212 0.127 0.050 0.192 0.000 0.138 0.016 0.170 0.000 0.008 0.057 0.000 100.359 100.227 100.365 100.254 100.384 100.347 100.371 100.388 0.000 0.001 0.000 0.000 0.001 0.001 0.000 0.001 0.667 0.703 0.660 0.710 0.672 0.676 0.692 0.672 0.003 0.003 0.004 0.004 0.004 0.005 0.004 0.003 1.242 1.226 1.244 1.217 1.229 1.227 1.210 1.229 0.085 0.054 0.086 0.060 0.090 0.082 0.087 0.091 0.405 0.430 0.396 0.424 0.372 0.399 0.388 0.399 0.016 0.017 0.017 0.016 0.019 0.015 0.015 0.017 0.573 0.554 0.586 0.560 0.605 0.584 0.598 0.580 0.002 0.003 0.001 0.002 0.001 0.003 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.005 0.002 0.001 0.003 0.002 0.003 0.003 0.000 0.002 0.001 0.001 0.000 0.002 0.001 0.000 0.003 0.002 0.001 0.002 0.005 0.003 0.001 0.004 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 65.061 63.560 65.323 63.146 64.648 64.461 63.630 64.657 62.297 61.842 62.495 61.245 61.722 61.805 60.847 61.690 53.898 53.401 54.877 53.683 56.696 54.846 55.715 54.174 58.563 56.306 59.691 56.948 61.930 59.405 60.630 59.234 4.249 2.702 4.329 3.011 4.525 4.121 4.374 4.589 371 R20-A2-I CR21-A1-' CR21-A2-I CR22-A1- CR23-A1- CR23-A2-I CR24-A1-' CR24-A2-I t% W t% W t% Wt% Wt% Wt% Wt% W t% 0.019 0.039 0.064 0.034 0.002 0.013 0.017 0.000 18.941 17.854 17.789 13.263 17.741 19.369 18.224 17.942 0.110 0.166 0.183 0.113 0.128 0.098 0.164 0.130 49.061 50.726 49.776 51.110 50.653 49.084 50.300 49.961 3.163 2.719 3.841 7.486 2.869 2.201 3.138 4.154 16.080 15.814 15.080 16.365 15.356 16.673 14.809 14.395 0.582 0.674 0.568 0.687 0.641 0.635 0.604 0.584 11.888 11.978 12.621 11.168 12.468 11.677 12.679 12.926 0.069 0.064 0.127 0.076 0.018 0.083 0.064 0.046 0.003 0.000 0.000 0.000 0.000 0.025 0.024 0.003 0.140 0.090 0.134 0.147 0.118 0.082 0.084 0.098 0.000 0.016 0.130 0.074 0.173 0.113 0.023 0.000 0.236 0.130 0.071 0.210 0.006 0.021 0.151 0.178 0.024 0.000 0.000 0.016 0.114 0.147 0.033 0.000 100.317 100.272 100.385 100.750 100.287 100.220 100.314 100.416 0.001 0.001 0.002 0.001 0.000 0.000 0.001 0.000 0.700 0.663 0.658 0.504 0.657 0.717 0.672 0.661 0.003 0.004 0.004 0.003 0.003 0.002 0.004 0.003 1.217 1.263 1.234 1.302 1.259 1.219 1.245 1.235 0.075 0.064 0.091 0.182 0.068 0.052 0.074 0.098 0.422 0.417 0.396 0.441 0.404 0.438 0.388 0.377 0.015 0.018 0.015 0.019 0.017 0.017 0.016 0.015 0.556 0.562 0.590 0.537 0.584 0.547 0.592 0.603 0.002 0.002 0.003 0.002 0.000 0.002 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.004 0.002 0.003 0.004 0.003 0.002 0.002 0.002 0.000 0.000 0.002 0.001 0.002 0.002 0.000 0.000 0.005 0.003 0.002 0.005 0.000 0.000 0.003 0.004 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 63.472 65.588 65.243 72.108 65.698 62.963 64.931 65.133 61.092 63.464 62.260 65.521 63.451 61.315 62.521 61.940 52.823 53.901 54.828 46.288 55.339 52.739 56.175 55.960 56.857 57.450 59.871 54.885 59.140 55.525 60.415 61.548 3.749 3.238 4.573 9.135 3.421 2.616 3.712 4.902 372 R25-A1-' CR26-A1-' CR26-A2-I CR28-A1-* CR29-A1-* CR30-A1-' CR31-A1-* CR31-A2-R :% W t% W t% W t% W t% W t% W t% W t% 0.048 0.004 0.000 0.000 0.000 0.015 0.041 0.015 18.075 17.652 19.824 18.954 19.658 19.597 19.911 19.596 0.176 0.043 0.142 0.012 0.103 0.110 0.226 0.107 50.084 50.914 47.843 50.001 48.984 49.121 48.255 48.049 3.062 2.944 3.815 2.294 2.179 2.351 3.024 3.383 15.442 15.272 15.261 16.029 16.380 15.989 14.997 15.360 0.616 0.648 0.585 0.620 0.642 0.597 0.656 0.607 12.347 12.370 12.475 11.883 11.809 12.145 12.702 12.530 0.063 0.090 0.102 0.121 0.064 0.047 0.074 0.133 0.014 0.008 0.007 0.000 0.003 0.000 0.000 0.000 0.157 0.105 0.091 0.105 0.177 0.139 0.093 0.133 0.052 0.120 0.000 0.000 0.000 0.000 0.077 0.172 0.074 0.092 0.236 0.170 0.073 0.019 0.247 0.156 0.097 0.033 0.000 0.041 0.146 0.106 0.000 0.097 100.307 100.295 100.382 100.230 100.218 100.235 100.303 100.339 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.669 0.654 0.727 0.701 0.726 0.722 0.730 0.720 0.004 0.001 0.003 0.000 0.002 0.003 0.005 0.003 1.244 1.266 1.178 1.241 1.213 1.214 1.186 1.185 0.072 0.070 0.089 0.054 0.051 0.055 0.071 0.079 0.406 0.402 0.397 0.421 0.429 0.418 0.390 0.401 0.016 0.017 0.015 0.016 0.017 0.016 0.017 0.016 0.578 0.580 0.579 0.556 0.552 0.566 0.589 0.583 0.002 0.002 0.003 0.003 0.002 0.001 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.003 0.002 0.003 0.004 0.003 0.002 0.003 0.001 0.002 0.000 0.000 0.000 0.000 0.001 0.002 0.002 0.002 0.005 0.004 0.002 0.000 0.006 0.004 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 65.020 65.928 61.817 63.895 62.569 62.708 61.917 62.191 62.650 63.620 59.047 62.160 60.954 60.966 59.711 59.702 54.742 55.165 54.330 53.933 53.440 54.459 56.101 54.825 58.768 59.080 59.303 56.925 56.239 57.520 60.157 59.253 3.645 3.502 4.481 2.715 2.581 2.777 3.561 4.001 373 Label CR7-A1-C CR8-A1-C CR8-A2-R CR9-F1-A1 CR9-A1-C CR9-A1-R CR10-A1-C Chromitite Section O xides W t% W t% W t% W t% W t% W t% W t% 8102 0.009 0.021 0.004 0.021 0.026 0.013 0.006 AI203 17.785 17.756 14.333 16.758 17.129 17.441 17.315 TI02 0.254 0.225 0.234 0.222 0.161 0.135 0.130 C r203 52.225 52.483 56.168 54.441 54.061 54.258 53.022 F e203 1.997 2.089 1.382 0.706 1.083 -0.050 1.600 FeO 12.884 12.795 14.944 13.421 12.952 14.460 13.248 MnO 0.506 0.512 0.610 0.550 0.470 0.587 0.568 MgO 14.115 14.132 12.267 13.582 13.932 12.898 13.784 NIO 0.000 0.000 0.008 0.032 0.100 0.065 0.092 CaO 0.003 0.027 0.000 0.000 0.000 0.022 0.003 V203 0.117 0.106 0.074 0.093 0.080 0.128 0.049 N b205 0.188 0.030 0.023 0.129 0.000 0.037 0.220 ZnO 0.117 0.000 0.057 0.101 0.000 0.000 0.057 P t0 2 0.000 0.033 0.033 0.016 0.116 0.000 0.066 Total 100.200 100.209 100.138 100.071 100.108 99.995 100.160 C ations SI4+ 0.000 0.001 0.000 0.001 0.001 0.000 0.000 AI3+ 0.652 0.650 0.539 0.619 0.630 0.645 0.638 TI4+ 0.006 0.005 0.006 0.005 0.004 0.003 0.003 Cr3+ 1.284 1.290 1.418 1.350 1.335 1.347 1.310 Fe3+ 0.047 0.049 0.033 0.017 0.025 -0.001 0.038 Fe2+ 0.335 0.333 0.399 0.352 0.338 0.380 0.346 Mn2+ 0.013 0.013 0.016 0.015 0.012 0.016 0.015 Mg2+ 0.654 0.655 0.584 0.635 0.649 0.604 0.642 NI2+ 0.000 0.000 0.000 0.001 0.003 0.002 0.002 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.001 0.000 V3+ 0.003 0.003 0.002 0.002 0.002 0.003 0.001 Nb5+ 0.003 0.000 0.000 0.002 0.000 0.001 0.003 Zn2+ 0.003 0.000 0.001 0.002 0.000 0.000 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.001 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 66.329 66.476 72.443 68.547 67.920 67.605 67.259 cr# 64.766 64.842 71.235 67.973 67.052 67.645 65.985 M g# 63.152 63.169 57.461 63.269 64.071 61.465 62.589 Mg"# 66.135 66.317 59.403 64.337 65.723 61.391 64.971 Fe3+ 2.357 2.457 1.669 0.839 1.278 •0.059 1.895 Table C.25: Sample Z7»15.1 Chromitite & Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 374 CR10-A1-C CR10-A1-R CR11-A1-C CR11-A2-C CR12-A1-C CR12-A2-R CR13-A1-C t% W t% W t% W t% Wt% W t% Wt% 0.032 0.017 0.026 0.032 0.068 0.000 0.000 17.300 17.252 17.319 17.992 17.440 15.224 17.750 0.139 0.182 0.229 0.197 0.169 0.147 0.236 52.429 52.736 52.473 52.484 52.547 55.618 52.380 2.162 2.550 2.757 2.028 2.007 1.882 1.999 12.903 12.669 12.540 12.375 13.237 12.514 12.925 0.560 0.496 0.509 0.549 0.466 0.572 0.473 14.095 14.073 14.190 14.322 13.869 13.968 14.023 0.045 0.143 0.069 0.094 0.000 0.036 0.062 0.014 0.014 0.000 0.000 0.020 0.000 0.010 0.101 0.123 0.076 0.074 0.155 0.062 0.101 0.206 0.000 0.016 0.000 0.112 0.046 0.100 0.009 0.000 0.073 0.055 0.111 0.063 0.083 0.223 0.000 0.000 0.000 0.000 0.057 0.058 100.216 100.255 100.276 100.203 100.201 100.188 100.200 0.001 0.001 0.001 0.001 0.002 0.000 0.000 0.636 0.633 0.635 0.658 0.641 0.564 0.651 0.003 0.004 0.005 0.005 0.004 0.003 0.006 1.293 1.299 1.291 1.287 1.295 1.383 1.289 0.051 0.060 0.065 0.047 0.047 0.045 0.047 0.337 0.330 0.326 0.321 0.345 0.329 0.336 0.015 0.013 0.013 0.014 0.012 0.015 0.012 0.655 0.653 0.658 0.662 0.645 0.655 0.651 0.001 0.004 0.002 0.002 0.000 0.001 0.002 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.003 0.003 0.002 0.002 0.004 0.002 0.003 0.003 0.000 0.000 0.000 0.002 0.001 0.001 0.000 0.000 0.002 0.001 0.003 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 1st Ave w/c 67.030 67.220 67.023 66.180 66.901 71.022 66.438 65.312 65.203 64.850 64.607 65.313 69.433 64.873 65.989 62.856 62.638 62.742 64.259 62.171 63.670 62.932 63.000 66.071 66.444 66.856 67.353 65.129 66.551 65.917 2.563 3.001 3.243 2.377 2.374 2.236 2.357 375 CR15-A1-C CR15-A2-R CR16-A1-C CR16-A2-R CR17-A1-I CR17-A2-R CR20-A1-C CR21-A1-C □unite Section Wt% wt% wt% Wt% Wt% Wt% wt% wt% 0.019 0.000 0.000 0.000 0.028 0.019 0.000 0.034 16.139 16.033 17.884 18.141 15.741 15.312 15.680 16.282 0.241 0.142 0.190 0.202 0.241 0.146 0.229 0.226 53.674 53.856 51.700 50.970 53.568 52.857 52.764 51.561 1.155 1.755 1.623 2.037 1.862 3.216 3.239 3.659 16.210 15.271 15.735 16.164 16.557 16.072 15.548 15.970 0.602 0.576 0.551 0.587 0.584 0.556 0.584 0.646 11.516 12.248 11.985 11.762 11.375 11.786 11.974 11.802 0.099 0.065 0.087 0.125 0.022 0.000 0.043 0.000 0.001 0.006 0.000 0.007 0.011 0.000 0.000 0.000 0.149 0.126 0.165 0.087 0.057 0.155 0.089 0.102 0.083 0.023 0.007 0.000 0.047 0.085 0.031 0.000 0.227 0.000 0.236 0.097 0.092 0.000 0.143 0.077 0.000 0.074 0.000 0.024 0.000 0.118 0.000 0.009 100.116 100.176 100.163 100.204 100.186 100.322 100.324 100.366 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.001 0.606 0.599 0.664 0.674 0.592 0.576 0.587 0.609 0.006 0.003 0.005 0.005 0.006 0.003 0.005 0.005 1.352 1.350 1.288 1.270 1.352 1.333 1.326 1.293 0.028 0.042 0.038 0.048 0.045 0.077 0.077 0.087 0.432 0.405 0.415 0.426 0.442 0.429 0.413 0.424 0.016 0.015 0.015 0.016 0.016 0.015 0.016 0.017 0.547 0.579 0.563 0.553 0.541 0.560 0.567 0.558 0.003 0.002 0.002 0.003 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.003 0.004 0.002 0.001 0.004 0.002 0.003 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.005 0.000 0.005 0.002 0.002 0.000 0.003 0.002 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 ) CR8-A2 69.050 69.263 65.978 65.336 69.539 69.840 69.301 67.994 68.087 67.807 64.702 63.752 67.975 67.125 66.604 65.008 54.340 56.441 55.406 53.812 52.654 52.557 53.621 52.202 55.877 58.843 57.587 56.468 55.049 56.659 57.856 56.847 1.394 2.103 1.934 2.424 2.249 3.887 3.891 4.391 376 CR22-A1-C CR22-A1-C CR23-A1-C CR23-A2-R CR24-A1-I CR24-A2-R CR25-A1-I CR26-A1-C Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 0.027 0.019 0.000 0.042 0.011 0.019 0.000 0.011 14.852 16.205 15.672 15.772 15.274 15.702 16.572 16.308 0.214 0.202 0.244 0.197 0.176 0.226 0.245 0.181 53.696 53.034 53.198 53.633 53.887 52.934 52.578 52.466 3.306 1.404 2.515 0.963 2.006 2.132 2.173 2.171 15.147 16.772 15.931 18.512 16.894 17.469 15.813 16.151 0.745 0.596 0.590 0.555 0.632 0.603 0.614 0.556 12.029 11.191 11.632 10.046 10.999 10.703 11.811 11.783 0.123 0.192 0.132 0.063 0.137 0.077 0.028 0.080 0.000 0.000 0.007 0.000 0.007 0.003 0.011 0.000 0.055 0.111 0.097 0.170 0.144 0.103 0.047 0.127 0.017 0.068 0.037 0.000 0.000 0.007 0.000 0.220 0.112 0.098 0.181 0.144 0.034 0.111 0.209 0.106 0.008 0.249 0.016 0.000 0.000 0.124 0.115 0.057 100.331 100.141 100.252 100.096 100.201 100.214 100.218 100.217 0.001 0.001 0.000 0.001 0.000 0.001 0.000 0.000 0.558 0.610 0.589 0.599 0.577 0.594 0.620 0.611 0.005 0.005 0.006 0.005 0.004 0.005 0.006 0.004 1.353 1.340 1.341 1.366 1.366 1.343 1.319 1.318 0.079 0.034 0.060 0.023 0.048 0.051 0.052 0.052 0.404 0.448 0.425 0.499 0.453 0.469 0.420 0.429 0.020 0.016 0.016 0.015 0.017 0.016 0.016 0.015 0.572 0.533 0.553 0.482 0.526 0.512 0.559 0.558 0.003 0.005 0.003 0.002 0.004 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.002 0.004 0.004 0.003 0.001 0.003 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.003 0.003 0.002 0.004 0.003 0.001 0.003 0.005 0.002 0.000 0.002 0.000 0.000 0.000 0.001 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 70.805 68.705 69.486 69.524 70.298 69.339 68.034 68.337 67.984 67.536 67.379 68.707 68.590 67.544 66.261 66.546 54.196 52.518 53.264 48.027 51.188 49.599 54.231 53.707 58.603 54.325 56.551 49.170 53.718 52.203 57.107 56.530 3.985 1.701 3.032 1.174 2.431 2.589 2.606 2.621 377 CR26-A1-R CR27-A1-C CR28-A1-C CR29-A1-C CR16-A3-1 Z' CR18-A1-C CR18-A2-R W t% W t% W t% W t% W t% W t% W t% 0.172 0.053 0.017 0.000 0.054 0.004 0.017 17.747 15.993 16.315 15.780 11.707 16.081 16.234 0.182 0.237 0.246 0.248 0.273 0.242 0.235 50.910 52.598 51.907 52.730 52.331 52.146 51.979 0.984 2.378 2.818 3.029 6.404 2.985 3.079 19.354 16.475 16.570 15.633 20.050 15.713 16.454 0.584 0.614 0.587 0.602 0.705 0.661 0.631 9.724 11.578 11.486 11.915 8.612 11.928 11.415 0.082 0.000 0.069 0.028 0.111 0.000 0.060 0.006 0.004 0.000 0.000 0.032 0.020 0.018 0.127 0.114 0.094 0.148 0.123 0.158 0.068 0.000 0.151 0.130 0.000 0.106 0.170 0.000 0.228 0.042 0.042 0.133 0.132 0.189 0.084 0.000 0.000 0.000 0.058 0.000 0.000 0.034 100.099 100.238 100.282 100.303 100.641 100.299 100.308 0.005 0.002 0.001 0.000 0.002 0.000 0.001 0.669 0.600 0.612 0.591 0.456 0.602 0.609 0.004 0.006 0.006 0.006 0.007 0.006 0.006 1.288 1.324 1.306 1.326 1.367 1.309 1.308 0.024 0.057 0.067 0.072 0.159 0.071 0.074 0.518 0.439 0.441 0.416 0.554 0.417 0.438 0.016 0.017 0.016 0.016 0.020 0.018 0.017 0.464 0.550 0.545 0.565 0.424 0.565 0.542 0.002 0.000 0.002 0.001 0.003 0.000 0.002 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.003 0.003 0.002 0.004 0.003 0.004 0.002 0.000 0.002 0.002 0.000 0.002 0.002 0.000 0.005 0.001 0.001 0.003 0.003 0.004 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 2nd Ave w/ 3.000 3.000 3.000 65.805 68.811 68.094 69.151 74.991 68.507 68.234 65.019 66.831 65.779 66.632 66.793 68.967 66.042 65.706 46.133 52.579 51.728 53.637 52.592 37.293 53.610 51.420 47.246 55.611 55.269 57.602 43.363 57.505 55.291 1.196 2.876 3.400 3.643 8.033 3.599 3.704 378 CR18-A3-I ZCR18-A4-0. CR19-A1-C CR19-A2-IZ CR19-A3-R CR19-A4-IZ CR20-A2-IZ CR28-A2-R t% Wt% W t% Wt% Wt% Wt% Wt% W t% 3.909 0.047 0.013 0.016 0.069 0.059 0.027 0.006 8.233 13.313 16.248 9.241 9.860 10.342 9.494 16.610 0.198 0.214 0.264 0.245 0.144 0.236 0.199 0.180 48.779 55.164 52.975 51.402 53.559 50.927 58.874 51.884 7.527 1.713 1.996 11.036 7.640 10.240 2.316 1.569 18.491 19.545 16.152 18.822 20.046 18.475 18.963 19.502 0.927 0.718 0.721 0.770 0.715 0.699 0.625 0.659 12.449 9.066 11.498 9.118 8.442 9.547 9.200 9.397 0.063 0.058 0.072 0.112 0.135 0.226 0.101 0.069 0.006 0.004 0.011 0.003 0.034 0.000 0.010 0.024 0.081 0.075 0.105 0.073 0.121 0.110 0.131 0.156 0.016 0.085 0.000 0.046 0.000 0.093 0.167 0.000 0.074 0.162 0.143 0.145 0.000 0.047 0.043 0.101 0.000 0.008 0.000 0.076 0.000 0.025 0.082 0.000 100.754 100.172 100.200 101.105 100.765 101.026 100.232 100.157 0.126 0.002 0.000 0.001 0.002 0.002 0.001 0.000 0.313 0.514 0.609 0.362 0.387 0.402 0.373 0.631 0.005 0.005 0.006 0.006 0.004 0.006 0.005 0.004 1.244 1.429 1.333 1.350 1.410 1.327 1.550 1.322 0.183 0.042 0.048 0.276 0.191 0.254 0.058 0.038 0.499 0.536 0.430 0.523 0.558 0.509 0.528 0.526 0.025 0.020 0.019 0.022 0.020 0.020 0.018 0.018 0.599 0.443 0.546 0.451 0.419 0.469 0.457 0.452 0.002 0.002 0.002 0.003 0.004 0.006 0.003 0.002 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.002 0.002 0.003 0.002 0.003 0.003 0.004 0.004 0.000 0.001 0.000 0.001 0.000 0.001 0.003 0.000 0.002 0.004 0.003 0.004 0.000 0.001 0.001 0.002 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.899 73.543 68.625 78.865 78.466 76.763 80.620 67.695 71.507 71.978 66.977 67.919 70.911 66.930 78.258 66.401 46.762 43.367 53.315 36.113 35.855 38.065 43.794 44.473 54.548 45.260 55.928 46.338 42.880 47.947 46.375 46.206 10.503 2.128 2.402 13.679 9.628 12.809 2.930 1.912 379 Label CR1-A1-I CR1-A2-R CR1-A4-R CR2-A1-C CR2-A2-R CR4-A1-I CR5-A1-C Oxidea W t% W t% W t% W t% W t% W t% W t% 3102 0.000 0.000 0.000 0.000 0.046 0.006 0.013 AI203 17.043 16.842 18.598 17.234 17.935 16.668 16.531 TI02 0.171 0.233 0.218 0.213 0.242 0.221 0.219 C r203 51.755 52.769 51.385 53.128 51.649 51.272 51.232 Fe203 3.316 2.084 1.792 0.298 1.475 3.205 3.892 FeO 13.287 14.874 13.843 16.606 16.308 16.075 15.216 MnO 0.655 0.646 0.615 0.649 0.619 0.684 0.778 MgO 13.628 12.525 13.423 11.483 11.739 11.768 12.069 NiO 0.105 0.080 0.091 0.137 0.096 0.058 0.097 CaO 0.003 0.001 0.006 0.000 0.000 0.007 0.003 V203 0.124 0.121 0.146 0.068 0.037 0.140 0.123 Nb205 0.166 0.000 0.063 0.164 0.000 0.143 0.000 ZnO 0.078 0.000 0.000 0.000 0.000 0.074 0.216 P t0 2 0.000 0.034 0.000 0.051 0.000 0.000 0.000 Total 100.332 100.209 100.179 100.030 100.148 100.321 100.390 C ationa 514+ 0.000 0.000 0.000 0.000 0.001 0.000 0.000 AI3+ 0.628 0.626 0.682 0.645 0.667 0.623 0.616 TI4+ 0.004 0.006 0.005 0.005 0.006 0.005 0.005 Cr3+ 1.280 1.316 1.264 1.333 1.288 1.285 1.282 Fe3+ 0.078 0.049 0.042 0.007 0.035 0.076 0.093 Fe2+ 0.347 0.392 0.360 0.441 0.430 0.426 0.403 Mn2+ 0.017 0.017 0.016 0.017 0.017 0.018 0.021 Mg2+ 0.635 0.589 0.623 0.543 0.552 0.556 0.569 NI2+ 0.003 0.002 0.002 0.003 0.002 0.001 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.003 0.004 0.002 0.001 0.004 0.003 Nb5+ 0.002 0.000 0.001 0.002 0.000 0.002 0.000 Zn2+ 0.002 0.000 0.000 0.000 0.000 0.002 0.005 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 67.074 87.782 84.958 87.405 85.892 87.358 87.522 Cr*# 64.438 66.079 63.584 67.164 64.732 64.763 64.379 M g# 59.889 57.138 80.758 54.814 54.288 52.527 53.475 Mg"# 64.645 60.016 63.350 55.210 56.201 56.616 58.574 Fe3+ 3.930 2.484 2.111 0.358 1.780 3.853 4.855 Table C.26: Sample Z717 Dunite Microprobe Analyaia & Calculated Formula (baaed on 4 oxygéna) of chromite:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the Ideal chromite formula) 380 CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR8-A1-C CR8-A2-R CR10-A1-' CR11-A1-* W t% Wt% Wt% Wt% Wt% W t% W t% 0.009 0.037 0.000 0.000 0.006 0.019 0.027 0.589 16.099 17.151 16.367 16.996 17.078 18.293 16.869 16.404 0.200 0.268 0.163 0.208 0.257 0.248 0.172 0.266 51.764 50.954 51.939 50.889 51.153 50.950 51.974 51.507 3.525 3.331 3.738 4.141 4.074 2.280 2.448 2.470 15.870 15.093 14.577 13.928 13.508 14.614 16.198 15.719 0.676 0.703 0.699 0.668 0.721 0.657 0.663 0.564 11.844 12.447 12.604 13.098 13.383 12.853 11.666 12.503 0.000 0.032 0.078 0.024 0.070 0.065 0.030 0.024 0.000 0.000 0.064 0.000 0.007 0.004 0.006 0.008 0.082 0.121 0.146 0.159 0.092 0.089 0.128 0.087 0.133 0.047 0.000 0.065 0.000 0.071 0.000 0.024 0.152 0.064 0.000 0.238 0.058 0.086 0.065 0.047 0.000 0.085 0.000 0.000 0.000 0.000 0.000 0.035 100.353 100.334 100.374 100.415 100.408 100.228 100.245 100.247 0.000 0.001 0.000 0.000 0.000 0.001 0.001 0.019 0.603 0.637 0.608 0.628 0.630 0.674 0.630 0.610 0.005 0.006 0.004 0.005 0.006 0.006 0.004 0.006 1.300 1.269 1.295 1.262 1.265 1.260 1.302 1.284 0.084 0.079 0.089 0.098 0.096 0.054 0.058 0.059 0.422 0.398 0.385 0.365 0.353 0.382 0.429 0.415 0.018 0.019 0.019 0.018 0.019 0.017 0.018 0.015 0.561 0.585 0.593 0.613 0.624 0.599 0.551 0.588 0.000 0.001 0.002 0.001 0.002 0.002 0.001 0.001 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.002 0.003 0.004 0.004 0.002 0.002 0.003 0.002 0.002 0.001 0.000 0.001 0.000 0.001 0.000 0.000 0.004 0.001 0.000 0.006 0.001 0.002 0.002 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 68.325 66.588 68.040 66.762 66.770 65.138 67.394 67.809 65.427 63.939 65.010 63.479 63.379 65.418 65.773 65.523 52.580 55.086 55.602 56.943 57.890 53.054 55.402 53.036 57.089 59.515 60.650 62.635 63.848 61.055 56.213 58.642 4.241 3.979 4.453 4.917 4.817 2.700 2.932 3.002 381 :r i i -A2- i CR12-A1-I CR12-A2-I CR13-A1-* CR13-A2-R CR3-A1-C 't% W t% W t% W t% W t% W t% 0.000 0.000 0.013 0.011 0.037 0.043 16.998 16.894 16.854 16.722 17.061 4.494 0.164 0.188 0.178 0.189 0.157 0.427 51.775 51.036 51.905 51.994 51.714 50.962 2.002 3.726 2.429 3.014 2.805 16.103 16.531 15.504 16.216 15.124 15.547 20.204 0.589 0.636 0.598 0.555 0.629 0.868 11.614 12.060 11.685 12.358 12.147 7.838 0.070 0.086 0.103 0.108 0.042 0.216 0.008 0.004 0.013 0.000 0.001 0.000 0.117 0.114 0.163 0.077 0.085 0.155 0.219 0.000 0.040 0.032 0.000 0.238 0.041 0.126 0.021 0.118 0.056 0.065 0.075 0.000 0.025 0.000 0.000 0.000 100.200 100.373 100.243 100.302 100.281 101.613 0.000 0.000 0.000 0.000 0.001 0.001 0.636 0.629 0.630 0.622 0.635 0.181 0.004 0.004 0.004 0.004 0.004 0.011 1.299 1.275 1.301 1.298 1.291 1.376 0.048 0.089 0.058 0.072 0.067 0.414 0.439 0.410 0.430 0.399 0.410 0.577 0.016 0.017 0.016 0.015 0.017 0.025 0.549 0.568 0.552 0.582 0.572 0.399 0.002 0.002 0.003 0.003 0.001 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.003 0.004 0.002 0.002 0.004 0.003 0.000 0.001 0.000 0.000 0.004 0.001 0.003 0.001 0.003 0.001 0.002 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 67.142 66.959 67.384 67.593 67.034 78.313 63.982 65.420 65.164 64.792 66.087 64.927 69.823 53.272 53.094 55.260 54.508 54.508 55.155 28.710 55.601 58.098 56.227 59.293 58.207 40.883 2.411 4.446 2.914 3.595 3.345 20.999 382 CR3-A2-R CR4-A2-R CR7-A2-R CR9-A2-R CR13-A3-R % W t% W t% W t% W t% 0.018 0.136 0.000 0.046 0.042 8.031 11.016 10.076 9.513 5.170 0.171 0.250 0.277 0.189 0.165 52.780 54.726 54.236 54.882 49.176 10.540 6.254 6.964 6.926 16.569 20.164 15.052 18.200 19.006 22.946 0.819 0.809 0.785 0.751 0.875 7.965 11.904 9.712 9.090 6.053 0.112 0.059 0.102 0.047 0.192 0.003 0.018 0.004 0.000 0.009 0.162 0.116 0.112 0.124 0.149 0.000 0.175 0.172 0.024 0.139 0.282 0.113 0.000 0.070 0.097 0.008 0.000 0.059 0.025 0.079 101.056 100.626 100.697 100.694 101.659 0.001 0.004 0.000 0.002 0.001 0.319 0.421 0.392 0.373 0.210 0.004 0.006 0.007 0.005 0.004 1.404 1.401 1.416 1.442 1.341 0.267 0.152 0.173 0.173 0.430 0.568 0.408 0.503 0.528 0.662 0.023 0.022 0.022 0.021 0.026 0.400 0.575 0.478 0.450 0.311 0.003 0.002 0.003 0.001 0.005 0.000 0.001 0.000 0.000 0.000 0.004 0.003 0.003 0.003 0.004 0.000 0.003 0.003 0.000 0.002 0.007 0.003 0.000 0.002 0.002 0.000 0.000 0.001 0.000 0.001 3.000 3.000 3.000 3.000 3.000 79.466 70.577 70.981 71.472 72.542 67.686 32.382 50.645 41.438 39.100 22.181 41.319 58.503 48.750 46.021 31.984 13.414 7.721 8.735 8.713 21.707 383 Label CR1-A1-I CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-I CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% W t% W t% 3102 0.000 0.002 0.000 0.006 0.015 0.021 0.000 AI203 18.121 17.160 18.304 16.063 17.268 17.185 15.810 T102 0.188 0.227 0.194 0.167 0.196 0.232 0.118 C r203 52.972 54.800 52.920 55.663 52.820 52.570 54.608 F e203 0.615 -0.153 0.955 -0.107 2.555 3.019 2.127 FeO 14.286 14.113 12.698 14.316 11.796 11.307 12.687 MnO 0.660 0.653 0.526 0.664 0.615 0.630 0.595 MgO 12.985 13.027 14.121 12.862 14.575 14.864 13.889 NiO 0.126 0.058 0.169 0.074 0.123 0.113 0.103 CaO 0.000 0.000 0.003 0.003 0.014 0.008 0.000 V203 0.109 0.077 0.108 0.092 0.128 0.115 0.107 N b205 0.000 0.000 0.063 0.131 0.063 0.055 0.101 ZnO 0.000 0.021 0.034 0.006 0.071 0.123 0.067 P t0 2 0.000 0.000 0.000 0.050 0.016 0.059 0.000 Total 100.062 99.985 100.096 99.989 100.256 100.302 100.213 C ations SM+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 AI3+ 0.668 0.635 0.669 0.598 0.632 0.628 0.585 TI4+ 0.004 0.005 0.005 0.004 0.005 0.005 0.003 Cr3+ 1.310 1.361 1.298 1.391 1.297 1.289 1.355 Fe3+ 0.014 -0.004 0.022 -0.003 0.060 0.070 0.050 Fe2+ 0.374 0.371 0.330 0.378 0.306 0.293 0.333 Mn2+ 0.017 0.017 0.014 0.018 0.016 0.017 0.016 Mg2+ 0.606 0.610 0.653 0.606 0.675 0.687 0.650 NK+ 0.003 0.001 0.004 0.002 0.003 0.003 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.002 0.003 0.002 0.003 0.003 0.003 Nb5+ 0.000 0.000 0.001 0.002 0.001 0.001 0.001 Zn2+ 0.000 0.000 0.001 0.000 0.002 0.003 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 66.227 68.177 65.960 69.921 67.235 67.237 69.854 Cr*# 65.746 68.301 65.241 70.011 65.215 64.853 68.090 Mg# 60.934 62.429 64.996 61.720 64.829 65.391 62.904 Mg"# 61.835 62.199 66.470 61.560 68.776 70.089 66.119 Fe3+ 0.727 -0.182 1.120 •0.128 3.003 3.545 2.525 Table C.27: Sample Z7 19 Diaaeminated chromitite MIcroprolie Analyiis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 384 CR5-A1-I CR5-A2-R CR6-A1-I CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-I CR8-A2-R % W t% W t% W t% W t% Wt% W t% W t% 0.013 0.044 0.000 0.013 0.061 0.000 0.000 0.000 16.941 17.038 17.416 16.839 17.347 17.714 17.004 17.124 0.196 0.177 0.224 0.287 0.182 0.207 0.234 0.252 52.956 52.906 53.122 53.705 52.442 52.116 52.719 53.415 3.051 2.918 1.357 0.434 2.251 1.968 2.763 2.014 11.819 11.795 13.127 14.959 13.760 13.728 12.369 12.246 0.543 0.608 0.554 0.602 0.612 0.618 0.595 0.630 14.615 14.602 13.793 12.531 13.327 13.433 14.170 14.295 0.081 0.119 0.097 0.136 0.053 0.077 0.159 0.057 0.003 0.000 0.008 0.011 0.000 0.003 0.011 0.000 0.087 0.087 0.141 0.137 0.075 0.122 0.086 0.126 0.000 0.000 0.109 0.157 0.000 0.148 0.000 0.000 0.000 0.000 0.071 0.043 0.117 0.064 0.000 0.000 0.000 0.000 0.117 0.187 0.000 0.000 0.167 0.042 100.306 100.292 100.136 100.043 100.225 100.197 100.277 100.202 0.000 0.001 0.000 0.000 0.002 0.000 0.000 0.000 0.620 0.624 0.641 0.627 0.640 0.652 0.625 0.628 0.005 0.004 0.005 0.007 0.004 0.005 0.005 0.006 1.301 1.299 1.312 1.342 1.297 1.287 1.300 1.315 0.071 0.068 0.032 0.010 0.053 0.046 0.065 0.047 0.307 0.306 0.343 0.395 0.360 0.359 0.323 0.319 0.014 0.016 0.015 0.016 0.016 0.016 0.016 0.017 0.677 0.676 0.642 0.590 0.622 0.626 0.659 0.663 0.002 0.003 0.002 0.003 0.001 0.002 0.004 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.002 0.004 0.003 0.002 0.003 0.002 0.003 0.000 0.000 0.002 0.002 0.000 0.002 0.000 0.000 0.000 0.000 0.002 0.001 0.003 0.001 0.000 0.000 0.000 0.000 0.001 0.002 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 67.711 67.565 67.172 68.148 66.975 66.372 67.532 67.664 65.286 65.251 66.092 67.793 65.191 64.826 65.331 66.061 64.141 64.350 63.146 59.271 60.080 60.708 62.968 64.446 68.791 68.817 65.192 59.892 63.323 63.561 67.129 67.541 3.580 3.425 1.607 0.522 2.663 2.329 3.259 2.370 385 R9-A1-C CR10-A1-' CR10-A2-I CR11-A1-' CR12-A1-* CR12-A2-I CR13-A1-' CR13-A2-I t% W t% W t% W t% Wt% Wt% Wt% Wt% 0.000 0.000 0.004 0.025 0.013 0.000 0.017 0.020 17.402 17.495 17.818 17.270 17.280 15.961 16.903 17.684 0.235 0.238 0.250 0.196 0.214 0.218 0.203 0.275 53.649 52.882 52.516 53.952 52.843 54.183 52.846 52.823 1.162 2.169 1.396 0.311 2.596 2.868 3.085 1.382 13.014 12.128 12.924 13.884 11.823 11.762 11.852 13.058 0.565 0.551 0.580 0.604 0.551 0.625 0.601 0.577 13.825 14.345 14.035 13.200 14.538 14.459 14.464 13.844 0.121 0.223 0.173 0.120 0.242 0.076 0.076 0.160 0.011 0.018 0.003 0.025 0.000 0.007 0.001 0.000 0.087 0.125 0.081 0.171 0.161 0.087 0.102 0.133 0.040 0.023 0.242 0.071 0.000 0.000 0.000 0.056 0.006 0.019 0.000 0.087 0.000 0.041 0.160 0.000 0.000 0.000 0.117 0.118 0.000 0.000 0.000 0.129 100.116 100.217 100.140 100.031 100.260 100.287 100.309 100.138 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.001 0.640 0.641 0.654 0.639 0.632 0.587 0.620 0.650 0.006 0.006 0.006 0.005 0.005 0.005 0.005 0.006 1.323 1.299 1.293 1.339 1.297 1.338 1.300 1.302 0.027 0.051 0.033 0.007 0.061 0.067 0.072 0.032 0.340 0.315 0.337 0.364 0.307 0.307 0.308 0.341 0.015 0.015 0.015 0.016 0.014 0.017 0.016 0.015 0.643 0.664 0.652 0.617 0.673 0.673 0.671 0.644 0.003 0.006 0.004 0.003 0.006 0.002 0.002 0.004 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.003 0.002 0.004 0.004 0.002 0.003 0.003 0.001 0.000 0.003 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.000 0.001 0.004 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 67.407 66.972 66.412 67.698 67.228 69.487 67.715 66.709 66.484 65.265 65.315 67.447 65.180 67.137 65.259 65.619 63.674 64.490 63.827 62.425 64.669 64.248 63.802 63.309 65.442 67.829 65.939 62.891 68.671 68.666 68.508 65.396 1.370 2.548 1.652 0.370 3.047 3.383 3.626 1.634 386 R14-A1- CR14-A2-I CR15-A1-* CR16-A1-' CR16-A2-I CR17-A1-' CR17-A2-I CR18-A1-' t% W t% Wt% W t% W t% W t% W t% Wt% 0.035 0.022 0.011 0.004 0.032 0.000 0.013 0.021 17.844 15.959 17.137 16.719 17.063 16.899 17.025 17.068 0.238 0.225 0.177 0.147 0.155 0.190 0.145 0.203 53.122 55.072 52.586 52.736 53.321 52.563 53.432 53.339 0.327 1.767 2.940 3.413 1.715 2.996 2.310 2.190 14.273 11.783 12.208 11.808 13.226 12.498 11.742 12.560 0.513 0.595 0.552 0.587 0.693 0.516 0.603 0.522 13.226 14.523 14.332 14.362 13.572 14.094 14.501 14.150 0.051 0.000 0.091 0.145 0.081 0.062 0.066 0.086 0.008 0.000 0.000 0.025 0.000 0.000 0.000 0.006 0.053 0.152 0.133 0.086 0.104 0.167 0.163 0.073 0.165 0.016 0.000 0.031 0.007 0.031 0.000 0.000 0.027 0.063 0.068 0.277 0.092 0.200 0.230 0.000 0.151 0.000 0.059 0.000 0.110 0.084 0.000 0.000 100.033 100.177 100.294 100.342 100.172 100.300 100.231 100.219 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.001 0.659 0.587 0.628 0.614 0.630 0.621 0.624 0.627 0.006 0.005 0.004 0.003 0.004 0.004 0.003 0.005 1.315 1.360 1.294 1.299 1.320 1.297 1.314 1.314 0.008 0.042 0.069 0.080 0.040 0.070 0.054 0.051 0.374 0.308 0.318 0.308 0.346 0.326 0.305 0.327 0.014 0.016 0.015 0.015 0.018 0.014 0.016 0.014 0.617 0.676 0.665 0.667 0.633 0.656 0.672 0.657 0.001 0.000 0.002 0.004 0.002 0.002 0.002 0.002 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.004 0.003 0.002 0.003 0.004 0.004 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.002 0.006 0.002 0.005 0.005 0.000 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 66.635 69.834 67.305 67.908 67.704 67.602 67.798 67.705 66.375 68.376 64.977 65.182 66.329 65.210 65.958 65.959 61.810 65.939 63.235 63.244 62.094 62.315 65.160 63.448 62.291 68.723 67.666 68.435 64.655 66.780 68.763 66.758 0.389 2.088 3.458 4.015 2.030 3.537 2.714 2.578 387 Î18-A2-! CR19-A1-' CR19-A2-I CR20-A1-' CR20-A2-I % W t% W t% W t% W t% 0.000 0.052 0.044 0.000 0.013 17.262 17.724 17.867 17.211 17.758 0.210 0.209 0.203 0.202 0.189 54.276 53.270 53.727 53.366 52.901 -0.011 0.760 -0.758 1.366 0.705 14.378 13.644 15.735 13.389 14.173 0.660 0.686 0.658 0.528 0.558 12.862 13.422 12.082 13.575 13.291 0.089 0.075 0.110 0.125 0.105 0.013 0.010 0.000 0.000 0.004 0.112 0.040 0.124 0.089 0.087 0.047 0.095 0.047 0.141 0.286 0.025 0.090 0.000 0.145 0.000 0.076 0.000 0.085 0.000 0.000 99.999 100.076 99.924 100.137 100.071 0.000 0.002 0.001 0.000 0.000 0.640 0.653 0.664 0.635 0.655 0.005 0.005 0.005 0.005 0.004 1.349 1.316 1.340 1.320 1.309 0.000 0.018 -0.018 0.032 0.017 0.378 0.357 0.415 0.350 0.371 0.018 0.018 0.018 0.014 0.015 0.603 0.625 0.568 0.633 0.620 0.002 0.002 0.003 0.003 0.003 0.000 0.000 0.000 0.000 0.000 0.003 0.001 0.003 0.002 0.002 0.001 0.001 0.001 0.002 0.004 0.001 0.002 0.000 0.003 0.000 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 67.839 66.845 66.857 67.534 66.650 67.847 66.244 67.463 66.440 66.091 66.207 61.475 62.547 58.862 62.340 61.540 62.966 61.459 63.685 57.784 64.379 62.571 •0.013 0.899 •0.906 1.619 0.838 388 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% W t% Wt% Wt% Wt% Wt% Wt% S i0 2 0.033 0.000 0.013 0.000 0.006 0.002 0.002 AI203 16.436 16.781 15.899 16.662 16.371 18.529 15.995 TI02 0.107 0.012 0.029 0.039 0.059 0.070 0.078 Cr203 53.546 51.141 53.568 51.980 53.751 50.856 53.230 Fe203 0.820 2.560 1.299 2.708 1.029 1.371 2.147 FeO 17.095 18.632 17.468 16.249 16.305 16.456 16.175 MnO 0.715 0.835 0.714 0.704 0.672 0.699 0.644 MgO 10.886 9.759 10.429 11.451 11.483 11.533 11.476 NiO 0.010 0.105 0.095 0.067 0.000 0.018 0.082 CaO 0.004 0.000 0.003 0.000 0.000 0.000 0.001 V203 0.169 0.146 0.194 0.169 0.224 0.237 0.195 N b205 0.000 0.000 0.000 0.000 0.000 0.040 0.000 ZnO 0.261 0.284 0.418 0.227 0.151 0.266 0.189 P t0 2 0.000 0.000 0.000 0.016 0.052 0.059 0.000 Total 100.082 100.256 100.130 100.271 100.103 100.137 100.215 C ations SM+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.619 0.635 0.602 0.624 0.614 0.689 0.601 TI4+ 0.003 0.000 0.001 0.001 0.001 0.002 0.002 Cr3+ 1.352 1.299 1.360 1.306 1.353 1.268 1.341 Fe3+ 0.020 0.062 0.031 0.065 0.025 0.033 0.051 Fe2+ 0.457 0.501 0.469 0.432 0.434 0.434 0.431 Mn2+ 0.019 0.023 0.019 0.019 0.018 0.019 0.017 Mg2+ 0.518 0.467 0.499 0.542 0.545 0.542 0.545 NK+ 0.000 0.003 0.002 0.002 0.000 0.000 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.004 0.005 0.004 0.006 0.006 0.005 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Zn2+ 0.006 0.007 0.010 0.005 0.004 0.006 0.004 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 68.607 67.153 69.327 67.667 68.776 84.805 69.065 Cr*# 67.928 65.070 68.235 65.470 67.924 63.744 67.281 M g# 52.113 45.383 49.939 52.207 54.296 53.751 53.048 Mg"# 53.166 48.285 51.557 55.677 55.663 55.543 55.846 Fe3+ 0.990 3.101 1.575 3.247 1.238 1.636 2.583 Table C.28: Sample Z7-20 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 389 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR8-A1-C CR8-A2-R t% W t% W t% W t% W t% W t% W t% W t% 0.020 0.000 0.000 0.011 0.000 0.020 0.025 0.000 16.916 17.160 18.828 16.916 17.162 16.917 17.056 18.301 0.028 0.067 0.083 0.055 0.054 0.062 0.055 0.078 52.307 52.237 50.202 52.713 52.186 53.128 50.718 47.788 1.686 1.423 1.562 1.183 1.252 0.735 1.831 3.523 17.026 16.995 17.019 17.401 17.860 17.140 20.637 20.414 0.731 0.702 0.643 0.656 0.673 0.686 0.816 0.837 11.065 11.071 11.217 10.757 10.409 10.983 8.569 8.691 0.026 0.020 0.043 0.059 0.038 0.034 0.095 0.000 0.000 0.000 0.000 0.000 0.000 0.014 0.018 0.086 0.157 0.174 0.110 0.148 0.159 0.165 0.183 0.148 0.000 0.000 0.113 0.000 0.000 0.040 0.000 0.000 0.102 0.174 0.336 0.219 0.330 0.148 0.166 0.410 0.105 0.120 0.000 0.000 0.000 0.000 0.016 0.077 100.169 100.143 100.156 100.118 100.125 100.074 100.183 100.353 0.001 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.635 0.644 0.700 0.636 0.646 0.635 0.650 0.693 0.001 0.002 0.002 0.001 0.001 0.001 0.001 0.002 1.317 1.314 1.253 1.330 1.318 1.338 1.297 1.214 0.040 0.034 0.037 0.028 0.030 0.018 0.045 0.085 0.453 0.452 0.449 0.464 0.477 0.457 0.558 0.549 0.020 0.019 0.017 0.018 0.018 0.019 0.022 0.023 0.525 0.525 0.528 0.512 0.496 0.522 0.413 0.416 0.001 0.001 0.001 0.002 0.001 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.004 0.004 0.003 0.004 0.004 0.004 0.005 0.004 0.000 0.000 0.002 0.000 0.000 0.001 0.000 0.000 0.002 0.004 0.008 0.005 0.008 0.003 0.004 0.010 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 67.473 67.128 64.141 67.642 67.104 67.812 66.609 63.659 66.105 65.979 62.945 66.679 66.091 67.212 65.119 60.937 51.544 51.921 52.045 50.944 49.425 52.378 40.668 39.645 53.672 53.731 54.021 52.426 50.955 53.321 42.533 43.146 2.028 1.711 1.864 1.424 1.510 0.885 2.237 4.276 390 'RI 0-A1 *• CR10-A2-I CR11-Al-' CR11-A2-I CR12-A1-' CR12-A2-I CR13-A1- CR13-A2-I t% W t% Wt % Wt % W t% W t% W t% W t% 0.006 0.006 0.000 0.006 0.002 0.020 0.000 0.000 16.480 16.337 15.676 16.375 15.492 17.893 16.656 18.719 0.045 0.044 0.060 0.021 0.106 0.078 0.076 0.086 53.141 53.041 52.385 52.114 54.358 50.705 51.939 50.760 1.611 1.866 1.608 0.927 1.052 1.270 2.336 1.063 16.328 16.439 20.799 21.330 17.139 19.393 16.531 16.941 0.640 0.696 0.891 0.832 0.807 0.789 0.783 0.618 11.437 11.388 8.176 7.998 10.688 9.471 11.299 11.390 0.059 0.031 0.003 0.000 0.077 0.000 0.031 0.023 0.010 0.014 0.032 0.015 0.001 0.006 0.008 0.015 0.218 0.235 0.168 0.187 0.134 0.132 0.182 0.184 0.000 0.000 0.000 0.000 0.000 0.000 0.088 0.138 0.186 0.089 0.362 0.289 0.181 0.293 0.208 0.163 0.000 0.000 0.000 0.000 0.068 0.077 0.097 0.008 100.161 100.187 100.161 100.093 100.105 100.127 100.234 100.106 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.618 0.613 0.603 0.629 0.587 0.676 0.625 0.696 0.001 0.001 0.001 0.001 0.003 0.002 0.002 0.002 1.337 1.335 1.352 1.343 1.381 1.285 1.307 1.266 0.039 0.045 0.039 0.023 0.025 0.031 0.056 0.025 0.434 0.438 0.568 0.581 0.460 0.520 0.440 0.447 0.017 0.019 0.025 0.023 0.022 0.021 0.021 0.017 0.542 0.540 0.398 0.389 0.512 0.453 0.536 0.536 0.002 0.001 0.000 0.000 0.002 0.000 0.001 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.006 0.006 0.004 0.005 0.003 0.003 0.005 0.005 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.002 0.004 0.002 0.009 0.007 0.004 0.007 0.005 0.004 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 68.386 68.534 69.152 68.102 70.184 65.529 67.658 64.528 67.063 66.996 67.783 67.326 69.288 64.521 65.754 63.709 63.420 52.838 39.583 39.146 51.301 45.120 51.945 53.150 55.529 55.254 41.202 40.064 52.643 46.542 54.922 54.514 1.935 2.244 1.980 1.140 1.277 1.538 2.814 1.269 391 R14-A1-i CR14-A2-I CR15-A1-* CR15-A2-I t% Wt% W t% W t% 0.022 0.006 0.000 0.025 17.346 17.805 15.995 16.536 0.088 0.060 0.041 0.072 50.949 50.256 53.591 52.001 2.178 2.019 0.837 1.432 18.165 18.902 18.168 19.487 0.692 0.708 0.792 0.700 10.314 9.922 10.072 9.273 0.060 0.028 0.006 0.000 0.016 0.000 0.000 0.014 0.165 0.187 0.156 0.226 0.000 0.095 0.000 0.000 0.178 0.214 0.271 0.377 0.045 0.000 0.153 0.000 100.218 100.202 100.084 100.143 0.001 0.000 0.000 0.001 0.653 0.671 0.607 0.629 0.002 0.001 0.001 0.002 1.286 1.270 1.365 1.327 0.052 0.049 0.020 0.035 0.485 0.505 0.489 0.526 0.019 0.019 0.022 0.019 0.491 0.473 0.484 0.446 0.002 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.004 0.005 0.004 0.006 0.000 0.001 0.000 0.000 0.004 0.005 0.006 0.009 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 Ave w/o separated strangers 66.334 65.440 69.208 67.842 64.591 63.842 68.504 66.656 71.310 47.743 46.052 48.689 44.308 52.904 50.303 48.338 49.704 45.893 2.628 2.442 1.018 1.747 392 Label CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C CR5-A1-C CR5-A2-R O xides W t% W t% W t% W t% W t% W t% W t% S i02 0.006 0.017 0.006 0.000 0.000 0.000 0.000 AI203 21.579 23.351 20.039 19.877 20.610 20.362 19.986 TI02 0.105 0.035 0.032 0.000 0.002 0.000 0.020 C r203 49.064 46.972 50.958 50.566 50.239 50.755 50.676 Fe203 0.314 0.627 0.109 1.074 0.465 -0.055 0.335 FeO 15.167 15.053 15.386 14.701 14.700 15.325 15.904 MnO 0.523 0.544 0.587 0.604 0.555 0.593 0.537 MgO 12.733 13.030 12.407 12.881 12.904 12.376 12.157 NiO 0.088 0.000 0.048 0.170 0.164 0.144 0.041 CaO 0.015 0.000 0.000 0.000 0.000 0.014 0.007 V203 0.161 0.158 0.151 0.131 0.195 0.147 0.217 N b205 0.000 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.235 0.274 0.263 0.055 0.190 0.299 0.153 P t02 0.042 0.000 0.024 0.050 0.024 0.033 0.000 Total 100.031 100.063 100.011 100.108 100.047 99.995 100.034 C ations Si4+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Ai3+ 0.786 0.843 0.736 0.728 0.753 0.747 0.735 Ti4+ 0.002 0.001 0.001 0.000 0.000 0.000 0.000 Cr3+ 1.199 1.137 1.256 1.243 1.231 1.250 1.251 Fe3+ 0.007 0.014 0.003 0.025 0.011 -0.001 0.008 Fe2+ 0.392 0.385 0.401 0.382 0.381 0.399 0.415 Mn2+ 0.014 0.014 0.015 0.016 0.015 0.016 0.014 Mg2+ 0.587 0.595 0.577 0.597 0.596 0.575 0.566 NK+ 0.002 0.000 0.001 0.004 0.004 0.004 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.004 0.004 0.003 0.005 0.004 0.005 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.005 0.006 0.006 0.001 0.004 0.007 0.004 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 60.400 57.436 63.043 63.053 62.053 62.577 62.976 Cr*# 60.179 57.020 62.962 62.260 61.716 62.617 62.728 M g# 59.500 59.794 58.819 59.442 60.340 59.087 57.215 Mg"# 59.944 60.676 58.973 60.966 61.010 59.009 57.674 Fe3+ 0.367 0.725 0.129 1.258 0.544 •0.064 0.395 Tabla C.29: Sample Z7>P21 Hanburgita MIcroproba Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 393 CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R t% W t% W t% W t% W t% W t% W t% Wt% 0.002 0.013 0.000 0.000 0.009 0.002 0.009 0.024 19.803 20.049 21.205 22.150 21.747 22.577 20.322 23.315 0.039 0.039 0.038 0.079 0.087 0.013 0.043 0.048 50.944 50.770 49.019 47.456 48.198 47.870 50.422 47.610 1.114 0.606 0.695 1.655 1.075 0.285 0.564 0.210 13.730 14.236 15.884 14.701 15.057 15.544 14.848 14.239 0.602 0.514 0.532 0.526 0.546 0.552 0.632 0.532 13.544 13.228 12.299 13.121 12.876 12.636 12.807 13.564 0.076 0.099 0.000 0.038 0.059 0.033 0.000 0.082 0.000 0.008 0.007 0.000 0.004 0.006 0.000 0.000 0.165 0.188 0.181 0.165 0.162 0.213 0.169 0.189 0.000 0.000 0.000 0.000 0.054 0.054 0.000 0.007 0.093 0.194 0.202 0.274 0.233 0.243 0.241 0.201 0.000 0.117 0.008 0.000 0.000 0.000 0.000 0.000 100.112 100.061 100.070 100.166 100.108 100.029 100.056 100.021 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.722 0.733 0.776 0.802 0.791 0.820 0.744 0.839 0.001 0.001 0.001 0.002 0.002 0.000 0.001 0.001 1.247 1.245 1.203 1.153 1.176 1.166 1.238 1.149 0.026 0.014 0.016 0.038 0.025 0.007 0.013 0.005 0.355 0.369 0.412 0.378 0.388 0.400 0.385 0.363 0.016 0.014 0.014 0.014 0.014 0.014 0.017 0.014 0.625 0.612 0.569 0.601 0.592 0.580 0.593 0.617 0.002 0.002 0.000 0.001 0.001 0.001 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.005 0.004 0.004 0.004 0.005 0.004 0.005 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.002 0.004 0.005 0.006 0.005 0.006 0.006 0.005 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 63.313 62.947 60.796 58.970 59.788 58.718 62.469 57.804 62.490 62.500 60.301 57.838 59.039 58.523 62.057 57.664 62.106 61.468 57.044 59.093 58.890 58.772 59.786 62.628 63.749 62.355 57.988 61.403 60.388 59.168 60.592 62.936 1.300 0.710 0.814 1.920 1.253 0.332 0.661 0.242 394 CR10-A1-' CR10-A2-I CR11-A1-' CR11-A2-R Wt% Wt% Wt% Wt% 0.000 0.032 0.000 0.021 20.957 23.719 20.049 21.767 0.044 0.012 0.027 0.053 49.670 46.487 50.580 48.927 0.573 0.369 0.500 0.382 15.033 15.469 14.847 14.510 0.542 0.508 0.516 0.526 12.789 12.763 12.882 13.315 0.095 0.102 0.079 0.107 0.004 0.014 0.008 0.000 0.191 0.181 0.158 0.179 0.000 0.023 0.063 0.110 0.158 0.293 0.175 0.142 0.000 0.066 0.167 0.000 100.057 100.037 100.050 100.038 0.000 0.001 0.000 0.001 0.765 0.857 0.735 0.789 0.001 0.000 0.001 0.001 1.216 1.126 1.244 1.190 0.013 0.008 0.012 0.009 0.389 0.396 0.386 0.373 0.014 0.013 0.014 0.014 0.590 0.583 0.597 0.611 0.002 0.003 0.002 0.003 0.000 0.000 0.000 0.000 0.005 0.004 0.004 0.004 0.000 0.000 0.001 0.002 0.004 0.007 0.004 0.003 0.000 0.001 0.001 0.000 3.000 3.000 3.000 3.000 Average 61.390 56.600 62.858 60.126 60.978 56.558 62.489 59.858 60.514 59.451 59.014 60.019 61.508 59.683 60.262 59.526 60.733 62.062 0.670 0.427 0.568 0.445 395 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C Massive chromitite Section O xides W t% W t% W t% W t% W t% W t% W t% S i0 2 0.000 0.000 0.004 0.000 0.002 0.000 0.000 AI203 13.934 14.086 13.553 15.824 13.881 14.537 14.228 T i02 0.098 0.237 0.141 0.207 0.122 0.160 0.179 C r203 56.507 56.893 56.707 55.889 57.037 56.499 56.523 F e203 2.178 1.575 1.921 0.201 1.537 1.209 1.971 FeO 13.491 13.007 14.179 14.290 13.329 13.570 12.877 MnO 0.672 0.609 0.717 0.554 0.569 0.616 0.638 MgO 13.082 13.331 12.633 12.812 13.249 13.149 13.571 NiO 0.078 0.109 0.065 0.124 0.134 0.000 0.011 CaO 0.000 0.000 0.000 0.000 0.018 0.003 0.000 V 203 0.053 0.097 0.145 0.119 0.086 0.106 0.073 N b205 0.016 0.000 0.086 0.000 0.078 0.094 0.000 ZnO 0.074 0.213 0.041 0.000 0.050 0.178 0.067 P t0 2 0.034 0.000 0.000 0.000 0.059 0.000 0.059 Total 100.218 100.158 100.192 100.020 100.154 100.121 100.197 C ations SM+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.522 0.527 0.510 0.590 0.520 0.544 0.531 TI4+ 0.002 0.006 0.003 0.005 0.003 0.004 0.004 Cr3+ 1.421 1.427 1.432 1.397 1.434 1.417 1.415 Fe3+ 0.052 0.038 0.046 0.005 0.037 0.029 0.047 Fe2+ 0.359 0.345 0.379 0.378 0.354 0.360 0.341 Mn2+ 0.018 0.016 0.019 0.015 0.015 0.017 0.017 Mg2+ 0.620 0.631 0.602 0.604 0.628 0.622 0.641 Ni2+ 0.002 0.003 0.002 0.003 0.003 0.000 0.000 Ca2+ 0.000 0.000 0.000 0.000 0.001 0.000 0.000 V3+ 0.001 0.002 0.004 0.003 0.002 0.003 0.002 Nb5+ 0.000 0.000 0.001 0.000 0.001 0.001 0.000 Zn2+ 0.002 0.005 0.001 0.000 0.001 0.004 0.002 R 4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Totai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 73.121 73.042 73.732 70.321 73.379 72.278 72.715 Cr*# 71.211 71.663 72.019 70.152 72.023 71.230 71.001 M g# 60.149 62.229 58.602 61.215 61.617 61.524 62.281 Mg"# 63.352 64.627 61.363 61.514 63.924 63.333 65.262 Fe3+ 2.612 1.888 2.323 0.240 1.848 1.451 2.357 TabI* C.30: Sample Z7>P23 Masaive chromltita & Dunita Microprobe Anaiyala & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 396 CR5-A1-C CR5-A2-R CR6-A1-C CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2LF CR9-A1-C :% W t% Wt% W t% W t% W t% W t% W t% 0.028 0.002 0.013 0.002 0.000 0.000 0.035 0.000 13.686 14.488 13.676 13.703 14.129 13.554 14.446 13.707 0.120 0.171 0.140 0.125 0.208 0.136 0.111 0.142 56.857 56.247 57.316 56.418 56.288 56.850 56.963 56.871 2.104 1.381 1.542 2.856 2.354 2.527 0.450 2.177 13.328 13.646 13.590 12.673 12.837 12.677 13.891 13.161 0.716 0.643 0.528 0.642 0.602 0.668 0.707 0.581 13.134 13.092 13.119 13.640 13.624 13.605 13.014 13.350 0.068 0.089 0.023 0.087 0.061 0.117 0.102 0.085 0.000 0.007 0.010 0.010 0.000 0.006 0.000 0.000 0.068 0.137 0.147 0.132 0.057 0.049 0.067 0.098 0.000 0.023 0.000 0.000 0.000 0.031 0.214 0.000 0.102 0.009 0.050 0.000 0.000 0.000 0.002 0.022 0.000 0.202 0.000 0.000 0.076 0.034 0.042 0.025 100.211 100.138 100.154 100.286 100.236 100.253 100.045 100.218 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.513 0.542 0.513 0.512 0.527 0.507 0.541 0.513 0.003 0.004 0.003 0.003 0.005 0.003 0.003 0.003 1.430 1.413 1.442 1.414 1.409 1.426 1.432 1.428 0.050 0.033 0.037 0.068 0.056 0.060 0.011 0.052 0.355 0.362 0.362 0.336 0.340 0.336 0.369 0.350 0.019 0.017 0.014 0.017 0.016 0.018 0.019 0.016 0.623 0.620 0.622 0.644 0.643 0.644 0.617 0.632 0.002 0.002 0.001 0.002 0.002 0.003 0.003 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.003 0.004 0.003 0.001 0.001 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.000 0.002 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.000 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 73.594 72.256 73.764 73.418 72.771 73.779 72.567 73.569 71.735 71.056 72.396 70.910 70.722 71.546 72.173 71.648 60.603 61.052 60.958 61.467 61.868 61.862 61.872 61.149 63.725 63.103 63.246 65.737 65.420 65.671 62.548 64.389 2.526 1.661 1.854 3.416 2.615 3.026 0.543 2.610 397 CR9-A2-R CR12-A1-. CR12-A2-I CR13-A1-' CR13-A2-I CR14-A1-' CR14-A2-I Dunite Section W t% W t% Wt% W t% Wt% W t% W t% 0.000 0.000 0.017 0.000 0.027 0.015 0.035 14.092 11.687 13.165 11.544 12.802 11.581 14.798 0.115 0.133 0.135 0.123 0.118 0.156 0.189 56.761 56.699 54.858 56.764 55.383 56.471 53.188 1.956 3.177 3.010 3.136 2.644 3.614 3.369 12.936 17.257 17.169 16.836 17.930 16.608 16.598 0.621 0.631 0.707 0.737 0.728 0.735 0.679 13.476 10.533 10.668 10.525 10.131 10.743 11.093 0.039 0.035 0.026 0.089 0.000 0.008 0.098 0.003 0.001 0.000 0.013 0.000 0.000 0.030 0.081 0.093 0.156 0.140 0.112 0.109 0.124 0.000 0.072 0.109 0.110 0.157 0.000 0.000 0.117 0.000 0.130 0.298 0.183 0.219 0.137 0.000 0.000 0.151 0.000 0.050 0.101 0.000 100.196 100.318 100.301 100.314 100.265 100.362 100.337 0.000 0.000 0.001 0.000 0.001 0.001 0.001 0.526 0.450 0.503 0.445 0.492 0.445 0.560 0.003 0.003 0.003 0.003 0.003 0.004 0.005 1.422 1.463 1.407 1.467 1.428 1.457 1.349 0.047 0.078 0.073 0.077 0.065 0.089 0.081 0.343 0.471 0.466 0.460 0.489 0.453 0.445 0.017 0.017 0.019 0.020 0.020 0.020 0.018 0.637 0.513 0.516 0.513 0.492 0.522 0.531 0.001 0.001 0.001 0.002 0.000 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.002 0.002 0.004 0.004 0.003 0.003 0.003 0.000 0.001 0.002 0.002 0.002 0.000 0.000 0.003 0.000 0.003 0.007 0.004 0.005 0.003 0.000 0.000 0.001 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 1st Average 72.988 76.495 73.853 76.736 74.373 76.586 70.685 71.282 71.423 73.497 70.925 73.760 71.942 73.173 67.796 82.043 81.282 48.277 48.894 48.834 47.070 49.090 50.184 64.998 52.107 52.553 52.705 50.181 53.554 54.366 2.338 3.920 3.704 3.878 3.269 4.457 4.087 398 CR15-A1-' CR15-A2-R W t% W t% 0.022 0.000 12.192 13.164 0.220 0.195 56.099 55.066 3.200 3.273 16.492 16.188 0.678 0.704 11.008 11.285 0.071 0.085 0.000 0.000 0.088 0.088 0.125 0.150 0.124 0.115 0.000 0.016 100.321 100.328 0.001 0.000 0.467 0.501 0.005 0.005 1.441 1.406 0.078 0.080 0.448 0.437 0.019 0.019 0.533 0.543 0.002 0.002 0.000 0.000 0.002 0.002 0.002 0.002 0.003 0.003 0.000 0.000 3.000 3.000 2nd Average 75.531 73.727 72.555 70.776 71.803 50.322 51.254 49.240 54.335 55.411 3.940 4.003 399 Label CR1-A1-C CR1-A2-R CR2-A1-C CR3-A1-I CR3-A2-R CR4-A1-C CR4-A2-R O xides W t% Wt% W t% W t% W t% W t% Wt% S i0 2 0.037 0.011 0.006 0.000 0.013 0.000 0.000 A i203 12.754 13.372 13.522 13.428 14.258 13.250 14.288 T i02 0.056 0.041 0.059 0.088 0.046 0.038 0.063 C r203 56.459 55.431 55.753 55.871 54.527 56.016 54.615 F e203 2.179 2.157 2.028 1.469 2.194 1.602 2.366 FeO 16.815 17.972 16.987 17.752 17.659 17.200 16.756 MnO 0.919 0.731 0.712 0.734 0.700 0.761 0.766 MgO 10.627 10.040 10.627 10.245 10.285 10.616 10.934 NiO 0.025 0.072 0.005 0.004 0.033 0.039 0.086 CaO 0.006 0.000 0.000 0.027 0.000 0.000 0.000 V 203 0.175 0.161 0.186 0.219 0.233 0.207 0.188 N b205 0.000 0.031 0.000 0.101 0.000 0.238 0.047 ZnO 0.157 0.147 0.310 0.134 0.271 0.193 0.086 P t0 2 0.008 0.050 0.008 0.074 0.000 0.000 0.042 Totai 100.218 100.216 100.203 100.147 100.220 100.160 100.237 C ations SM+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Ai3+ 0.488 0.513 0.516 0.514 0.544 0.507 0.542 TM+ 0.001 0.001 0.001 0.002 0.001 0.001 0.002 Cr3+ 1.450 1.426 1.428 1.436 1.395 1.437 1.391 Fe3+ 0.053 0.053 0.049 0.036 0.053 0.039 0.057 Fe2+ 0.457 0.489 0.460 0.483 0.478 0.467 0.451 Mn2+ 0.025 0.020 0.020 0.020 0.019 0.021 0.021 Mg2+ 0.515 0.487 0.513 0.496 0.496 0.514 0.525 Ni2+ 0.001 0.002 0.000 0.000 0.001 0.001 0.002 Ca2+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 V3+ 0.005 0.004 0.005 0.006 0.006 0.005 0.005 Nb5+ 0.000 0.000 0.000 0.001 0.000 0.003 0.001 Zn2+ 0.004 0.004 0.007 0.003 0.006 0.005 0.002 Pt4+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 T otai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 75.024 73.550 73.447 73.623 71.954 73.932 71.944 Cr*# 72.807 71.599 71.625 72.291 70.024 72.473 69.872 M g# 50.221 47.334 50.174 48.913 48.289 50.376 50.790 Mg"# 52.975 49.896 52.722 50.708 50.937 52.387 53.773 Fe3+ 2.675 2.652 2.480 1.809 2.682 1.973 2.881 Table C.31: Sample CrZ7*P26 Harzburglte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg. Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 400 CR5-A1-C CR6-A1-I CR7-A1-C CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-C CR10-A2-R W t% W t% W t% W t% Wt% Wt% Wt% Wt% W t% 0.000 0.000 0.000 0.000 0.035 0.000 0.000 0.000 0.009 12.969 14.154 13.169 13.950 13.879 13.024 12.840 13.280 13.771 0.034 0.018 0.097 0.096 0.000 0.053 0.022 0.069 0.035 55.634 55.148 54.984 54.731 53.442 56.314 53.178 56.060 54.850 2.317 2.000 2.701 2.147 4.078 2.105 6.275 1.737 2.206 17.922 16.852 17.838 17.944 16.680 16.850 14.868 17.371 17.432 0.833 0.836 0.860 0.731 0.789 0.723 0.862 0.795 0.826 9.888 10.740 10.132 10.231 10.954 10.716 11.634 10.467 10.392 0.079 0.036 0.043 0.000 0.072 0.004 0.091 0.066 0.096 0.000 0.000 0.000 0.025 0.025 0.000 0.282 0.003 0.006 0.206 0.190 0.229 0.159 0.234 0.216 0.203 0.168 0.178 0.040 0.000 0.132 0.084 0.024 0.000 0.000 0.101 0.155 0.262 0.202 0.087 0.043 0.089 0.206 0.280 0.050 0.207 0.050 0.024 0.000 0.074 0.109 0.000 0.093 0.008 0.058 100.232 100.200 100.271 100.215 100.408 100.211 100.628 100.174 100.221 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.499 0.538 0.505 0.533 0.527 0.498 0.487 0.508 0.526 0.001 0.000 0.002 0.002 0.000 0.001 0.001 0.002 0.001 1.435 1.407 1.415 1.403 1.362 1.444 1.353 1.439 1.406 0.057 0.049 0.066 0.052 0.099 0.051 0.152 0.042 0.054 0.489 0.455 0.485 0.487 0.450 0.457 0.400 0.472 0.473 0.023 0.023 0.024 0.020 0.022 0.020 0.024 0.022 0.023 0.481 0.517 0.492 0.495 0.527 0.518 0.558 0.507 0.502 0.002 0.001 0.001 0.000 0.002 0.000 0.002 0.002 0.003 0.000 0.000 0.000 0.001 0.001 0.000 0.010 0.000 0.000 0.005 0.005 0.006 0.004 0.006 0.006 0.005 0.004 0.005 0.001 0.000 0.002 0.001 0.000 0.000 0.000 0.001 0.002 0.006 0.005 0.002 0.001 0.002 0.005 0.007 0.001 0.005 0.000 0.000 0.000 0.001 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 74.212 72.328 73.690 72.466 72.092 74.364 73.533 73.903 72.766 72.092 70.566 71.236 70.557 68.505 72.447 67.923 72.326 70.795 46.838 50.653 47.122 47.851 48.966 50.475 50.271 49.633 48.826 49.585 53.185 50.312 50.406 53.931 53.134 58.244 51.786 51.521 2.857 2.435 3.331 2.635 4.975 2.577 7.629 2.133 2.709 401 Label CR1-A1-C CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1 -C CR5-A1-C O xides W t% W t% Wt% Wt% Wt% Wt% W t% S i0 2 0.009 0.000 0.009 0.006 0.000 0.036 0.000 AI203 9.095 9.385 9.306 9.401 9.578 9.058 9.174 T i02 0.058 0.033 0.158 0.101 0.123 0.069 0.108 C r203 60.762 60.509 59.156 60.578 59.308 60.770 60.147 Fe203 2.004 2.019 3.353 1.654 2.559 1.885 2.084 FeO 16.838 16.937 16.726 17.098 17.356 17.092 17.561 MnO 0.773 0.790 0.813 0.805 0.880 0.773 0.928 MgO 10.324 10.314 10.450 10.266 10.011 10.211 9.763 NiO 0.114 0.075 0.037 0.039 0.105 0.009 0.102 CaO 0.000 0.006 0.000 0.003 0.000 0.013 0.004 V203 0.122 0.133 0.200 0.080 0.151 0.197 0.112 N b205 0.030 0.000 0.016 0.098 0.084 0.000 0.023 ZnO 0.072 0.000 0.069 0.036 0.060 0.076 0.066 P t0 2 0.000 0.000 0.042 0.000 0.041 0.000 0.138 Totai 100.201 100.202 100.336 100.166 100.256 100.189 100.209 C ations Si4+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Ai3+ 0.355 0.365 0.362 0.366 0.373 0.353 0.359 Ti4+ 0.001 0.001 0.004 0.003 0.003 0.002 0.003 Cr3+ 1.589 1.580 1.544 1.583 1.551 1.590 1.580 Fe3+ 0.050 0.050 0.083 0.041 0.064 0.047 0.052 Fe2+ 0.466 0.468 0.462 0.473 0.480 0.473 0.488 Mn2+ 0.022 0.022 0.023 0.023 0.025 0.022 0.026 Mg2+ 0.509 0.508 0.514 0.506 0.494 0.504 0.483 NK+ 0.003 0.002 0.001 0.001 0.003 0.000 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.004 0.005 0.002 0.004 0.005 0.003 Nb5+ 0.000 0.000 0.000 0.001 0.001 0.000 0.000 Zn2+ 0.002 0.000 0.002 0.001 0.001 0.002 0.002 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Totai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 81.758 81.222 81.004 81.212 80.598 81.820 81.476 Cr*# 79.712 79.179 77.613 79.534 78.015 79.890 79.344 M g# 49.878 49.505 48.547 49.812 47.581 49.208 47.243 Mg"# 52.220 52.051 52.690 51.698 50.694 51.573 49.776 Fe3+ 2.502 2.515 4.187 2.087 3.204 2.359 2.816 Table C.32: Sample Z7-P29A Chromite bearing dunite iMicroprobe Anaiysie & Caiculated Formula (baaed on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is caiculated by assuming the ideal chromite formula) 402 IR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C1 t% Wt% Wt% Wt% W t% W t% W t% W t% 0.011 0.000 0.006 0.004 0.000 0.000 0.000 0.000 9.605 8.971 8.954 8.920 9.138 9.065 9.462 8.981 0.106 0.121 0.128 0.098 0.058 0.086 0.080 0.114 59.594 60.938 59.540 60.578 59.939 60.604 59.769 60.712 2.028 1.740 3.322 1.934 2.546 1.675 1.536 1.932 18.381 17.305 17.117 17.531 17.828 17.953 18.562 17.405 0.900 0.802 0.894 0.837 0.904 0.830 0.921 0.940 9.307 10.044 10.011 9.882 9.657 9.702 9.230 9.816 0.063 0.046 0.051 0.000 0.040 0.028 0.057 0.037 0.017 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.077 0.195 0.124 0.115 0.104 0.096 0.129 0.125 0.037 0.007 0.000 0.128 0.000 0.128 0.227 0.000 0.078 0.000 0.184 0.168 0.017 0.000 0.165 0.133 0.000 0.000 0.000 0.000 0.024 0.000 0.016 0.000 100.203 100.174 100.333 100.194 100.255 100.168 100.154 100.193 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.376 0.351 0.350 0.349 0.358 0.355 0.371 0.351 0.003 0.003 0.003 0.002 0.001 0.002 0.002 0.003 1.566 1.597 1.560 1.591 1.574 1.593 1.574 1.594 0.051 0.043 0.083 0.048 0.064 0.042 0.038 0.048 0.511 0.480 0.475 0.487 0.495 0.499 0.517 0.483 0.025 0.023 0.025 0.024 0.025 0.023 0.026 0.026 0.461 0.496 0.495 0.489 0.478 0.481 0.458 0.486 0.002 0.001 0.001 0.000 0.001 0.001 0.002 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.005 0.003 0.003 0.003 0.003 0.003 0.003 0.001 0.000 0.000 0.002 0.000 0.002 0.003 0.000 0.002 0.000 0.004 0.004 0.000 0.000 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.629 82.004 81.688 82.001 81.482 81.767 80.907 81.934 78.577 80.216 78.291 80.007 78.883 80.045 79.337 79.950 45.088 48 685 47.021 47.755 46.109 47.055 45.204 47.755 47.440 50.849 51.041 50.119 49.124 49.067 46.988 50.134 2.545 2.180 4.158 2.431 3.190 2.106 1.940 2.422 403 CR9-A2-C2 CR9-A2-R CR10-A1-C CR10-A2-R CR11-A1-C CR11-A2-R CR12-A1-C CR12-A2-R t% W t% W t% W t% W t% W t% W t% W t% 0.004 0.000 0.000 0.000 0.000 0.000 0.046 0.011 9.114 9.666 8.691 9.310 9.513 9.717 8.758 9.372 0.110 0.166 0.174 0.107 0.041 0.158 0.106 0.086 60.569 60.430 60.959 60.579 59.780 59.649 60.379 59.368 1.558 1.009 1.922 1.504 2.344 2.225 2.625 3.226 17.817 18.199 17.240 17.931 17.412 17.143 16.737 16.664 0.963 0.783 0.913 0.819 0.950 0.905 0.922 0.827 9.693 9.472 9.873 9.532 9.867 10.051 10.327 10.447 0.043 0.035 0.094 0.094 0.066 0.037 0.056 0.085 0.000 0.000 0.000 0.008 0.000 0.003 0.007 0.022 0.121 0.197 0.164 0.123 0.164 0.143 0.128 0.144 0.139 0.000 0.000 0.000 0.000 0.000 0.038 0.016 0.024 0.119 0.138 0.143 0.097 0.191 0.083 0.055 0.000 0.025 0.024 0.000 0.000 0.000 0.050 0.000 100.156 100.101 100.193 100.151 100.235 100.223 100.263 100.323 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.000 0.357 0.378 0.341 0.365 0.371 0.378 0.342 0.364 0.003 0.004 0.004 0.003 0.001 0.004 0.003 0.002 1.592 1.587 1.602 1.592 1.565 1.558 1.581 1.548 0.039 0.025 0.048 0.038 0.058 0.055 0.065 0.080 0.495 0.505 0.479 0.498 0.482 0.474 0.464 0.460 0.027 0.022 0.026 0.023 0.027 0.025 0.026 0.023 0.480 0.469 0.489 0.472 0.487 0.495 0.510 0.514 0.001 0.001 0.003 0.003 0.002 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.005 0.004 0.003 0.004 0.004 0.003 0.004 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.001 0.003 0.003 0.004 0.002 0.005 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 81.679 80.747 82.472 81.361 80.827 80.481 82.221 80.951 80.077 79.724 80.480 79.826 78.460 78.225 79.516 77.698 47.342 46.914 48.126 46.839 47.397 48.342 49.080 48.764 49.233 48.128 50.516 48.655 50.254 51.104 52.378 52.776 1.961 1.267 2.415 1.887 2.929 2.778 3.290 4.019 404 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CH3-A2-R CR4-A1-C O xidea Wt% Wt% Wt% Wt% Wt% Wt% Wt% S I02 0.017 0.000 0.000 0.013 0.000 0.000 0.006 AI203 11.711 11.972 12.578 13.397 12.330 13.097 11.572 TI02 0.139 0.065 0.126 0.155 0.124 0.187 0.121 C r203 57.201 57.300 55.912 54.730 56.546 55.385 57.288 F e203 1.731 1.164 2.476 2.429 1.968 1.771 1.775 FeO 18.594 19.264 18.166 18.944 18.257 18.598 18.435 MnO 0.780 0.769 0.770 0.821 0.752 0.821 0.935 MgO 9.403 8.939 9.775 9.343 9.798 9.700 9.368 NIO 0.073 0.081 0.000 0.127 0.000 0.000 0.022 CaO 0.000 0.000 0.000 0.008 0.008 0.001 0.010 V203 0.117 0.164 0.144 0.221 0.137 0.172 0.179 N b205 0.076 0.060 0.037 0.000 0.114 0.222 0.091 ZnO 0.242 0.280 0.264 0.056 0.164 0.140 0.318 P t0 2 0.088 0.057 0.000 0.000 0.000 0.082 0.057 Total 100.173 100.117 100.248 100.243 100.197 100.177 100.178 C ationa SI4+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.455 0.466 0.485 0.516 0.476 0.505 0.450 TI4+ 0.003 0.002 0.003 0.004 0.003 0.005 0.003 Cr3+ 1.490 1.496 1.446 1.414 1.464 1.431 1.493 Fe3+ 0.043 0.029 0.061 0.060 0.048 0.044 0.044 Fe2+ 0.512 0.532 0.497 0.518 0.500 0.508 0.508 Mn2+ 0.022 0.022 0.021 0.023 0.021 0.023 0.026 Mg2+ 0.462 0.440 0.477 0.455 0.478 0.473 0.460 NK+ 0.002 0.002 0.000 0.003 0.000 0.000 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.004 0.004 0.006 0.004 0.005 0.005 Nb5+ 0.001 0.001 0.001 0.000 0.002 0.003 0.001 Zn2+ 0.006 0.007 0.006 0.001 0.004 0.003 0.008 Pt4+ 0.001 0.000 0.000 0.000 0.000 0.001 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 76.617 76.252 74.886 73.265 75.469 73.937 76.857 Cr"# 74.963 75.144 72.595 71.066 73.628 72.310 75.153 M g# 45.409 43.961 46.073 44.077 46.584 46.130 45.462 Mg"# 47.409 45.270 48.958 46.783 48.893 48.179 47.529 Fe3+ 2.159 1.453 3.060 3.002 2.439 2.201 2.217 Table C.33; Sample Z7-P30 Dunite Mlcroprolie Analyeia & Calculated Formula (baaed on 4 oxygéna) of chromite:(Mg, Fe)Cr204. (Fe203 la calculated by aaauming the Ideal chromite formula) 405 R6-A2-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R t% W t% W t% Wt% W t% W t% W t% W t% 0.000 0.019 0.015 0.000 0.000 0.019 0.000 0.019 12.234 12.569 12.472 14.270 11.754 12.334 11.862 11.875 0.086 0.111 0.111 0.098 0.109 0.159 0.084 0.095 56.746 56.348 56.845 53.335 57.537 55.939 58.156 55.928 1.713 2.230 1.603 3.317 1.701 2.662 1.082 3.348 18.047 17.690 17.838 17.629 17.966 17.661 17.808 17.506 0.751 0.741 0.737 0.794 0.742 0.754 0.754 0.756 9.832 10.045 9.963 10.265 9.879 10.102 9.874 10.172 0.028 0.074 0.161 0.173 0.019 0.100 0.028 0.061 0.011 0.004 0.001 0.000 0.003 0.000 0.003 0.000 0.205 0.131 0.175 0.158 0.168 0.148 0.173 0.155 0.169 0.000 0.040 0.100 0.016 0.060 0.000 0.129 0.340 0.263 0.165 0.192 0.152 0.206 0.285 0.291 0.008 0.000 0.033 0.000 0.123 0.123 0.000 0.000 100.172 100.223 100.161 100.332 100.170 100.267 100.108 100.335 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.001 0.472 0.484 0.481 0.544 0.455 0.475 0.459 0.458 0.002 0.003 0.003 0.002 0.003 0.004 0.002 0.002 1.470 1.454 1.469 1.364 1.493 1.446 1.508 1.446 0.042 0.055 0.039 0.081 0.042 0.065 0.027 0.082 0.495 0.483 0.488 0.477 0.493 0.483 0.488 0.479 0.021 0.020 0.020 0.022 0.021 0.021 0.021 0.021 0.480 0.489 0.486 0.495 0.483 0.492 0.483 0.496 0.001 0.002 0.004 0.005 0.001 0.003 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.003 0.005 0.004 0.004 0.004 0.005 0.004 0.003 0.000 0.001 0.001 0.000 0.001 0.000 0.002 0.008 0.006 0.004 0.005 0.004 0.005 0.007 0.007 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 75.678 75.047 75.355 71.488 76.656 75.263 76.684 75.959 74.068 72.984 73.861 68.586 75.037 72.782 75.657 72.808 47.223 47.618 47.948 47.028 47.458 47.310 48.379 46.914 49.269 50.302 49.890 50.933 49.500 50.487 49.708 50.880 2.128 2.749 1.982 4.060 2.112 3.296 1.339 4.149 406 CR10-A1-C CR10-A2-R CR11-A1-C CR11-A2-R CR12-A1-C CR12-A2-R CR13-A1-C CR13-A2-R W t% W t% W t% Wt% Wt% Wt% Wt% 0.000 0.015 0.006 0.000 0.024 0.043 0.017 0.009 11.997 11.895 12.383 12.799 12.616 12.901 11.856 12.627 0.103 0.095 0.074 0.128 0.104 0.118 0.111 0.093 57.389 56.729 57.417 56.599 56.818 55.850 57.631 56.157 1.654 2.548 0.962 0.977 1.345 1.542 0.947 1.796 17.853 18.183 18.666 19.480 18.667 19.051 18.968 18.283 0.800 0.775 0.765 0.721 0.730 0.807 0.796 0.821 9.823 9.770 9.356 8.966 9.495 9.283 9.173 9.610 0.118 0.039 0.089 0.000 0.048 0.085 0.053 0.081 0.013 0.003 0.004 0.006 0.006 0.000 0.000 0.015 0.164 0.133 0.142 0.159 0.083 0.129 0.148 0.246 0.000 0.000 0.000 0.000 0.023 0.023 0.123 0.107 0.201 0.070 0.232 0.207 0.176 0.101 0.271 0.333 0.049 0.000 0.000 0.057 0.000 0.221 0.000 0.000 100.166 100.255 100.096 100.098 100.135 100.154 100.095 100.180 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.000 0.464 0.460 0.479 0.496 0.487 0.499 0.461 0.487 0.003 0.002 0.002 0.003 0.003 0.003 0.003 0.002 1.488 1.471 1.491 1.471 1.472 1.449 1.502 1.454 0.041 0.063 0.024 0.024 0.033 0.038 0.023 0.044 0.490 0.499 0.513 0.536 0.512 0.523 0.523 0.501 0.022 0.022 0.021 0.020 0.020 0.022 0.022 0.023 0.480 0.478 0.458 0.439 0.464 0.454 0.451 0.469 0.003 0.001 0.002 0.000 0.001 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.004 0.003 0.004 0.004 0.002 0.003 0.004 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.002 0.005 0.002 0.006 0.005 0.004 0.002 0.007 0.008 0.000 0.000 0.000 0.001 0.000 0.002 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 76.241 76.186 75.673 74.769 75.133 74.386 76.532 74.896 74.679 73.783 74.771 73.882 73.882 72.959 75.627 73.226 47.514 45.962 46.060 43.978 45.989 44.741 45.205 46.261 49.515 48.923 47.189 45.068 47.552 46.485 46.296 48.373 2.049 3.154 1.192 1.214 1.664 1.917 1.182 2.230 407 Label CR1-A1-C CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C CR4-A2-R O xides W t% W t% W t% W t% W t% W t% Wt% 3102 0.000 0.000 0.015 0.009 0.013 0.000 0.000 A I203 11.536 11.841 12.264 11.859 13.741 11.638 12.472 T I02 0.039 0.094 0.090 0.059 0.100 0.041 0.036 C r203 56.987 56.879 55.777 57.417 54.504 57.362 54.901 F e203 2.659 1.283 2.349 1.782 2.578 1.549 3.396 FeO 17.603 19.677 19.443 18.057 17.670 18.960 18.892 MnO 0.980 0.841 0.728 0.813 0.812 0.900 0.805 MgO 9.836 8.727 8.972 9.733 10.099 9.110 9.246 NIO 0.067 0.029 0.066 0.061 0.058 0.049 0.057 CaO 0.032 0.017 0.000 0.021 0.023 0.007 0.007 V 203 0.279 0.280 0.209 0.206 0.245 0.254 0.287 N b205 0.000 0.101 0.101 0.000 0.047 0.023 0.016 ZnO 0.222 0.175 0.221 0.153 0.358 0.129 0.225 P t0 2 0.025 0.183 0.000 0.008 0.008 0.132 0.000 T otal 100.266 100.129 100.235 100.179 100.258 100.155 100.340 C ations 514+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 AI3+ 0.446 0.462 0.476 0.459 0.526 0.453 0.482 TI4+ 0.001 0.002 0.002 0.001 0.002 0.001 0.001 Cr3+ 1.479 1.489 1.452 1.490 1.399 1.498 1.425 Fe3+ 0.066 0.032 0.058 0.044 0.063 0.038 0.084 Fe2+ 0.483 0.545 0.536 0.496 0.480 0.524 0.519 Mn2+ 0.027 0.024 0.020 0.023 0.022 0.025 0.022 Mg2+ 0.481 0.431 0.441 0.476 0.489 0.448 0.452 NI2+ 0.002 0.001 0.002 0.002 0.002 0.001 0.002 Ca2+ 0.001 0.001 0.000 0.001 0.001 0.000 0.000 V3+ 0.007 0.007 0.006 0.005 0.006 0.007 0.008 Nb5+ 0.000 0.002 0.002 0.000 0.001 0.000 0.000 Zn2+ 0.005 0.004 0.005 0.004 0.009 0.003 0.005 Pt4+ 0.000 0.002 0.000 0.000 0.000 0.001 0.000 T otal 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 76.819 76.316 75.315 76.459 72.684 76.779 74.703 Cr*# 74.284 75.086 73.108 74.770 70.381 75.294 71.556 M g # 46.720 42.752 42.592 46.879 47.385 44.376 42.888 M g"# 49.902 44.153 45.132 49.002 50.466 46.135 46.593 Fe3+ 3.300 1.612 2.930 2.209 3.168 1.935 4.212 Table C.34: Sample Z7-P31 Harzburglte Mlcroprobe Anaiyala & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 408 CR5-A1-C CR5-A2-R CR7-A2-R CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-I W t% W t% W t% W t% Wt% W t% W t% 0.000 0.006 0.013 0.000 0.002 0.020 0.000 0.000 11.388 12.466 12.377 11.281 11.912 13.057 12.186 12.827 0.082 0.054 0.053 0.085 0.054 0.091 0.067 0.028 56.975 56.193 56.651 57.329 56.491 55.065 57.031 56.530 2.773 2.286 1.676 2.020 2.421 2.215 1.536 1.706 17.846 18.061 18.499 19.232 18.556 19.282 18.373 17.764 0.931 0.735 0.731 0.871 0.793 0.821 0.784 0.779 9.762 9.887 9.470 8.833 9.466 9.023 9.641 10.042 0.062 0.043 0.108 0.119 0.083 0.129 0.024 0.008 0.000 0.000 0.003 0.000 0.001 0.000 0.007 0.015 0.304 0.221 0.208 0.226 0.195 0.261 0.195 0.224 0.000 0.070 0.024 0.000 0.087 0.040 0.094 0.000 0.155 0.206 0.296 0.172 0.181 0.219 0.191 0.213 0.000 0.000 0.058 0.034 0.000 0.000 0.025 0.034 100.278 100.229 100.168 100.202 100.242 100.222 100.154 100.171 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.441 0.480 0.479 0.440 0.461 0.505 0.471 0.493 0.002 0.001 0.001 0.002 0.001 0.002 0.002 0.001 1.480 1.453 1.470 1.501 1.468 1.428 1.479 1.458 0.069 0.056 0.041 0.050 0.060 0.055 0.038 0.042 0.490 0.494 0.508 0.533 0.510 0.529 0.504 0.485 0.026 0.020 0.020 0.024 0.022 0.023 0.022 0.022 0.478 0.482 0.463 0.436 0.464 0.441 0.472 0.488 0.002 0.001 0.003 0.003 0.002 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.008 0.006 0.005 0.006 0.005 0.007 0.005 0.006 0.000 0.001 0.000 0.000 0.001 0.001 0.001 0.000 0.004 0.005 0.007 0.004 0.004 0.005 0.005 0.005 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 77.045 75.148 75.434 77.319 76.085 73.884 75.843 74.725 74.389 73.023 73.865 75.365 73.795 71.852 74.397 73.155 46.106 46.697 45.763 42.792 44.868 43.053 46.521 48.120 49.370 49.389 47.713 45.015 47.627 45.479 48.329 50.191 3.446 2.828 2.080 2.527 3.010 2.751 1.907 2.101 409 R11-A1-I CR11-A2-I CR12-A1-i CR13-A1-* CR13-A2-I t% W t% W t% W t% W t% 0.015 0.000 0.000 0.000 0.000 11.766 11.415 12.833 12.769 13.413 0.065 0.071 0.041 0.069 0.057 57.456 57.229 55.569 54.077 54.908 0.770 1.542 2.311 3.771 1.697 19.938 19.717 18.530 19.141 20.216 1.067 0.922 0.951 1.020 0.882 8.350 8.545 9.351 8.992 8.457 0.019 0.026 0.032 0.055 0.067 0.000 0.000 0.000 0.000 0.004 0.257 0.284 0.268 0.289 0.292 0.055 0.065 0.000 0.000 0.000 0.245 0.256 0.346 0.193 0.127 0.075 0.084 0.000 0.000 0.051 100.077 100.154 100.231 100.378 100.170 0.001 0.000 0.000 0.000 0.000 0.460 0.446 0.496 0.494 0.520 0.002 0.002 0.001 0.002 0.001 1.507 1.501 1.439 1.403 1.428 0.019 0.039 0.057 0.093 0.042 0.553 0.547 0.508 0.525 0.556 0.030 0.026 0.026 0.028 0.025 0.413 0.423 0.457 0.440 0.415 0.000 0.001 0.001 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.007 0.008 0.007 0.008 0.008 0.001 0.001 0.000 0.000 0.000 0.006 0.006 0.008 0.005 0.003 0.001 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Average 76.612 77.061 74.391 73.965 73.306 75.871 75.587 72.262 70.504 71.759 73.515 41.910 41.919 44.713 41.567 40.946 44.428 42.744 43.584 47.355 45.577 42.718 0.967 1.939 2.661 4.679 2.110 410 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR5-A1-C O xides W t% W t% W t% W t% W t% W t% W t% S i0 2 0.000 0.000 0.027 0.015 0.002 0.015 0.015 A i203 11.331 10.909 11.937 11.761 11.815 11.385 12.112 T i02 0.034 0.089 0.142 0.051 0.130 0.069 0.146 C r203 58.201 58.722 58.647 57.569 57.922 57.898 58.167 F e203 2.212 2.992 1.378 1.867 2.461 2.811 1.864 FeO 16.434 14.324 14.618 17.717 14.776 15.608 14.800 MnO 0.777 0.627 0.818 0.770 0.761 0.683 0.796 MgO 10.879 12.268 12.046 10.038 11.877 11.369 11.838 NiO 0.083 0.031 0.074 0.076 0.134 0.000 0.139 CaO 0.000 0.000 0.010 0.006 0.000 0.011 0.008 V203 0.180 0.133 0.151 0.161 0.156 0.161 0.107 N b205 0.038 0.047 0.110 0.047 0.030 0.007 0.000 ZnO 0.002 0.149 0.180 0.108 0.183 0.263 0.194 P t0 2 0.050 0.008 0.000 0.000 0.000 0.000 0.000 Total 100.222 100.300 100.138 100.187 100.246 100.282 100.187 C ations Si4+ 0.000 0.000 0.001 0.001 0.000 0.000 0.000 AI3+ 0.436 0.416 0.455 0.454 0.450 0.436 0.461 Ti4+ 0.001 0.002 0.003 0.001 0.003 0.002 0.004 Cr3+ 1.502 1.503 1.498 1.491 1.481 1.488 1.486 Fe3+ 0.054 0.073 0.034 0.046 0.060 0.069 0.045 Fe2+ 0.449 0.388 0.395 0.485 0.400 0.424 0.400 Mn2+ 0.021 0.017 0.022 0.021 0.021 0.019 0.022 Mg2+ 0.529 0.592 0.580 0.490 0.573 0.551 0.570 Ni2+ 0.002 0.001 0.002 0.002 0.003 0.000 0.004 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.003 0.004 0.004 0.004 0.004 0.003 Nb5+ 0.001 0.001 0.002 0.001 0.000 0.000 0.000 Zn2+ 0.000 0.004 0.004 0.003 0.004 0.006 0.005 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 77.506 78.312 76.722 76.656 76.684 77.332 76.312 Cr*# 75.393 75.447 75.427 74.884 74.377 74.663 74.576 M g# 51.282 56.239 57.520 47.984 55.478 52.771 56.155 Mg"# 54.130 60.423 59.497 50.248 58.895 56.492 58.779 Fe3+ 2.727 3.659 1.687 2.311 3.008 3.451 2.275 Table C 35: Sample Z7>P32 Masaive chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 411 CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR9-A1-C CR9-A2-R t% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 0.000 0.000 0.000 0.000 0.019 0.000 0.059 0.000 11.616 11.753 11.254 12.163 10.375 11.747 12.227 12.058 0.068 0.098 0.074 0.094 0.124 0.081 0.099 0.082 58.192 58.098 58.268 57.394 59.165 58.041 57.695 57.782 2.112 2.606 2.284 2.520 2.765 1.942 2.271 2.274 15.471 14.650 15.983 15.112 15.086 15.777 14.904 15.579 0.816 0.865 0.857 0.788 0.750 0.859 0.850 0.792 11.470 12.053 11.043 11.820 11.726 11.314 11.974 11.503 0.142 0.000 0.058 0.000 0.004 0.023 0.034 0.035 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.018 0.128 0.127 0.117 0.151 0.094 0.154 0.110 0.088 0.115 0.000 0.030 0.078 0.070 0.132 0.000 0.016 0.082 0.012 0.146 0.132 0.073 0.123 0.000 0.000 0.000 0.000 0.115 0.000 0.024 0.000 0.000 0.000 100.212 100.261 100.229 100.252 100.277 100.195 100.227 100.228 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.000 0.444 0.447 0.433 0.463 0.398 0.450 0.465 0.460 0.002 0.002 0.002 0.002 0.003 0.002 0.002 0.002 1.494 1.484 1.503 1.466 1.524 1.491 1.471 1.479 0.052 0.063 0.056 0.061 0.068 0.047 0.055 0.055 0.420 0.396 0.436 0.408 0.411 0.429 0.402 0.422 0.022 0.024 0.024 0.022 0.021 0.024 0.023 0.022 0.555 0.580 0.537 0.569 0.569 0.548 0.576 0.555 0.004 0.000 0.002 0.000 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.003 0.003 0.004 0.002 0.004 0.003 0.002 0.002 0.000 0.000 0.001 0.001 0.002 0.000 0.000 0.002 0.000 0.004 0.003 0.002 0.003 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 77.068 76.831 77.646 75.993 79.277 76.822 75.992 76.273 75.069 74.392 75.460 73.654 76.576 74.988 73.889 74.155 54.065 55.835 52.183 54.800 54.325 53.508 55.740 53.776 56.926 59.457 55.190 58.235 58.082 56.109 58.883 56.825 2.594 3.176 2.815 3.078 3.407 2.388 2.768 2.777 412 R10-A1-' CR10-A2-I CR11-Al-' CR11-A2-I CR12-A1-' CR12-A2-I t% W t% W t% W t% W t% W t% 0.016 0.000 0.000 0.002 0.000 0.000 12.248 11.764 11.447 11.396 11.374 11.176 0.084 0.041 0.106 0.139 0.056 0.066 57.225 58.038 58.073 57.974 58.308 58.319 2.897 2.208 2.833 1.991 2.937 2.199 14.294 15.460 15.002 17.273 14.081 15.763 0.917 0.812 0.811 0.840 1.001 1.003 12.189 11.540 11.798 10.263 12.221 11.124 0.070 0.053 0.062 0.000 0.067 0.043 0.001 0.000 0.000 0.001 0.015 0.008 0.170 0.138 0.152 0.150 0.180 0.162 0.000 0.054 0.000 0.000 0.000 0.116 0.155 0.046 0.000 0.104 0.052 0.166 0.025 0.066 0.000 0.066 0.000 0.074 100.290 100.221 100.284 100.199 100.294 100.220 0.001 0.000 0.000 0.000 0.000 0.000 0.465 0.450 0.437 0.440 0.433 0.430 0.002 0.001 0.003 0.003 0.001 0.002 1.457 1.488 1.487 1.502 1.489 1.504 0.070 0.054 0.069 0.049 0.071 0.054 0.385 0.419 0.406 0.473 0.380 0.430 0.025 0.022 0.022 0.023 0.027 0.028 0.585 0.558 0.570 0.501 0.589 0.541 0.002 0.001 0.002 0.000 0.002 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.004 0.004 0.004 0.004 0.005 0.004 0.000 0.001 0.000 0.000 0.000 0.002 0.004 0.001 0.000 0.003 0.001 0.004 0.000 0.001 0.000 0.001 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 Average 75.812 76.796 77.289 77.339 77.472 77.781 73.141 74.718 74.612 75.432 74.697 75.669 74.820 56.249 54.109 54.509 48.970 56.572 52.777 54.040 60.319 57.093 58.366 51.437 60.741 55.711 3.524 2.705 3.465 2.466 3.582 2.716 413 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR6-A1-C O xides W t% W t% W t% W t% W t% W t% W t% 3102 0.015 0.000 0.000 0.000 0.009 0.000 0.002 AI203 12.686 13.427 12.156 13.006 12.864 12.334 11.534 TI02 0.128 0.051 0.136 0.094 0.139 0.059 0.083 C r203 56.341 55.476 56.914 54.982 56.246 56.316 56.817 Fe203 2.314 2.183 2.710 3.718 2.443 3.648 2.666 FeO 17.209 17.577 16.346 16.355 16.245 14.989 18.252 MnO 0.797 0.723 0.755 0.817 0.745 0.762 0.872 MgO 10.509 10.420 10.961 10.987 11.254 11.944 9.690 NIO 0.000 0.091 0.083 0.050 0.066 0.051 0.000 CaO 0.000 0.000 0.001 0.018 0.013 0.000 0.000 V203 0.163 0.128 0.122 0.200 0.079 0.112 0.183 N b205 0.000 0.102 0.000 0.000 0.141 0.063 0.023 ZnO 0.052 0.000 0.087 0.145 0.000 0.071 0.027 P t0 2 0.016 0.042 0.000 0.000 0.000 0.016 0.117 Total 100.232 100.219 100.271 100.372 100.245 100.365 100.267 C ations 314+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.486 0.514 0.465 0.496 0.490 0.469 0.447 TI4+ 0.003 0.001 0.003 0.002 0.003 0.001 0.002 Cr3+ 1.449 1.423 1.462 1.406 1.438 1.435 1.477 Fe3+ 0.057 0.053 0.066 0.091 0.059 0.088 0.066 Fe2+ 0.468 0.477 0.444 0.442 0.439 0.404 0.502 Mn2+ 0.022 0.020 0.021 0.022 0.020 0.021 0.024 Mg2+ 0.509 0.504 0.531 0.530 0.543 0.574 0.475 NI2+ 0.000 0.002 0.002 0.001 0.002 0.001 0.000 Ca2+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 V3+ 0.004 0.003 0.003 0.005 0.002 0.003 0.005 NbS+ 0.000 0.001 0.000 0.000 0.002 0.001 0.000 Zn2+ 0.001 0.000 0.002 0.003 0.000 0.002 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 74.870 73.486 75.650 73.930 74.575 75.367 76.769 Cr*# 72.740 71.518 73.329 70.572 72.345 72.039 74.224 M g# 49.266 46.731 50.964 49.653 52.100 53.616 45.546 Mg"# 52.120 51.379 54.449 54.494 55.255 58.685 48.622 Fe3+ 2.644 2.679 3.324 4.542 2.991 4.441 3.315 Table C.36; Sample Z7*P37 Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 414 CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' t% Wt% Wt% Wt% W t% W t% W t% W t% 0.000 0.013 0.000 0.000 0.000 0.000 0.000 0.017 12.351 12.139 12.533 12.021 13.659 12.325 13.521 12.302 0.094 0.079 0.107 0.073 0.113 0.122 0.054 0.067 55.971 56.726 56.124 56.523 54.003 55.499 54.421 56.436 2.434 2.308 2.559 3.088 3.904 3.919 3.700 3.138 18.559 17.584 17.617 16.847 16.819 16.521 16.611 15.955 0.831 0.884 0.782 0.918 0.843 0.806 0.665 0.672 9.577 10.129 10.211 10.582 10.854 10.871 10.982 11.355 0.091 0.049 0.006 0.061 0.000 0.113 0.123 0.000 0.000 0.015 0.000 0.000 0.008 0.000 0.000 0.003 0.141 0.123 0.129 0.158 0.157 0.176 0.218 0.181 0.086 0.000 0.030 0.016 0.000 0.000 0.000 0.047 0.024 0.031 0.108 0.021 0.015 0.016 0.074 0.140 0.085 0.151 0.051 0.000 0.016 0.025 0.000 0.000 100.244 100.231 100.256 100.309 100.391 100.393 100.371 100.314 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.477 0.468 0.482 0.462 0.520 0.472 0.514 0.469 0.002 0.002 0.003 0.002 0.003 0.003 0.001 0.002 1.451 1.467 1.447 1.456 1.378 1.425 1.389 1.445 0.060 0.057 0.063 0.076 0.095 0.096 0.090 0.076 0.509 0.481 0.481 0.459 0.454 0.449 0.448 0.432 0.023 0.024 0.022 0.025 0.023 0.022 0.018 0.018 0.468 0.494 0.496 0.514 0.522 0.526 0.528 0.548 0.002 0.001 0.000 0.002 0.000 0.003 0.003 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.003 0.003 0.004 0.004 0.005 0.006 0.005 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.003 0.001 0.000 0.000 0.002 0.003 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 75.247 75.816 75.026 75.929 72.620 75.130 72.973 75.476 72.975 73.653 72.660 73.045 69.165 71.518 69.682 72.576 45.140 47.871 47.746 49.009 48.761 49.152 49.539 51.873 47.914 50.661 50.816 52.822 53.496 53.980 54.098 55.920 3.020 2.853 3.153 3.798 4.759 4.807 4.510 3.841 415 R10-A2-I CR10-A3-I CR11-AI-' CR11-A2-I CR12-A2-I CR12-A2-I CR13-A1-' CR13-A2-I t% W t% W t% W t% W t% W t% W t% W t% 0.006 0.013 0.000 0.000 0.000 0.000 0.054 0.032 14.535 14.437 12.457 13.032 11.916 12.092 11.957 12.196 0.094 0.207 0.145 0.150 0.049 0.064 0.061 0.073 53.512 53.722 56.189 54.325 56.035 55.291 56.570 56.295 3.075 3.014 3.157 4.175 3.124 3.570 2.971 3.217 17.340 17.215 15.827 16.322 18.173 18.547 16.393 16.495 0.605 0.636 0.749 0.711 0.768 0.862 0.723 0.842 10.686 10.738 11.336 11.146 9.794 9.310 11.091 10.813 0.092 0.063 0.096 0.166 0.057 0.142 0.000 0.103 0.003 0.000 0.000 0.000 0.001 0.020 0.000 0.021 0.108 0.161 0.166 0.165 0.166 0.168 0.198 0.143 0.071 0.007 0.055 0.102 0.086 0.000 0.140 0.000 0.121 0.088 0.140 0.058 0.118 0.249 0.140 0.092 0.060 0.000 0.000 0.067 0.025 0.042 0.000 0.000 100.308 100.302 100.316 100.418 100.313 100.358 100.298 100.322 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.001 0.552 0.548 0.475 0.496 0.460 0.468 0.458 0.467 0.002 0.005 0.004 0.004 0.001 0.002 0.001 0.002 1.364 1.368 1.438 1.388 1.453 1.437 1.453 1.447 0.075 0.073 0.077 0.102 0.077 0.088 0.073 0.079 0.467 0.464 0.428 0.441 0.498 0.510 0.445 0.448 0.017 0.017 0.021 0.019 0.021 0.024 0.020 0.023 0.513 0.516 0.547 0.537 0.479 0.456 0.537 0.524 0.002 0.002 0.002 0.004 0.002 0.004 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.001 0.003 0.004 0.004 0.004 0.004 0.004 0.005 0.004 0.001 0.000 0.001 0.001 0.001 0.000 0.002 0.000 0.003 0.002 0.003 0.001 0.003 0.006 0.003 0.002 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 71.180 71.399 75.161 73.680 75.930 75.415 76.041 75.569 68.513 68.776 72.256 69.894 72.989 72.074 73.256 72.605 48.649 48.995 51.979 49.736 45.414 43.269 50.906 49.652 52.347 52.650 56.077 54.899 48.997 47.224 54.670 53.886 3.747 3.673 3.884 5.112 3.873 4.429 3.662 3.949 416 WSU-1 WSU-2 WSU-3 WSU-4 % w t % w t % Wt % 0.135 0.179 0.168 0.149 12.820 13.550 13.448 13.098 0.081 0.094 0.112 0.108 55.025 53.974 53.674 54.164 3.382 3.140 3.370 3.050 18.710 17.262 18.070 18.691 0.273 0.248 0.230 0.286 10.060 10.901 10.345 9.873 0.021 0.015 0.044 0.024 0.009 0.003 0.000 0.001 0.166 0.173 0.194 0.141 0.000 0.000 0.000 0.000 0.062 0.074 0.141 0.083 0.000 0.000 0.000 0.000 100.745 99.612 99.796 99.667 0.004 0.006 0.005 0.005 0.490 0.519 0.516 0.506 0.002 0.002 0.003 0.003 1.412 1.386 1.382 1.403 0.083 0.077 0.083 0.075 0.508 0.469 0.492 0.512 0.007 0.007 0.006 0.008 0.487 0.528 0.502 0.482 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.004 0.005 0.005 0.004 0.000 0.000 0.000 0.000 0.001 0.002 0.003 0.002 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 74.223 72.769 72.807 73.504 71.134 69.950 69.771 70.718 71.629 45.187 49.170 46.634 45.086 48.676 48.940 52.957 50.508 48.496 4.162 3.874 4.170 3.790 417 Latiel CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% W t% W t% W t% 3102 0.000 0.000 0.000 0.000 0.000 0.000 0.030 AI203 13.503 13.445 13.471 13.578 13.105 13.634 12.669 TI02 0.116 0.056 0.090 0.018 0.106 0.041 0.048 C r203 56.565 57.436 56.291 56.061 56.499 57.347 58.262 F e203 2.118 1.453 2.728 3.142 3.040 1.790 2.053 FeO 13.865 14.141 13.250 13.110 13.143 13.161 12.476 MnO 0.851 0.716 0.798 0.855 0.925 0.784 0.895 MgO 12.808 12.640 13.166 13.169 13.109 13.234 13.562 NIO 0.038 0.074 0.124 0.124 0.126 0.058 0.004 CaO 0.000 0.018 0.004 0.000 0.000 0.000 0.004 V 203 0.088 0.087 0.178 0.169 0.144 0.130 0.098 N b205 0.134 0.078 0.127 0.000 0.086 0.000 0.000 ZnO 0.025 0.000 0.047 0.037 0.022 0.000 0.021 P t0 2 0.102 0.000 0.000 0.051 0.000 0.000 0.084 Total 100.212 100.146 100.273 100.315 100.304 100.179 100.206 C ations 314+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 AI3+ 0.508 0.507 0.505 0.509 0.493 0.511 0.476 TI4+ 0.003 0.001 0.002 0.000 0.003 0.001 0.001 Cr3+ 1.428 1.452 1.417 1.410 1.425 1.442 1.468 Fe3+ 0.051 0.035 0.065 0.075 0.073 0.043 0.049 Fe2+ 0.370 0.378 0.353 0.349 0.351 0.350 0.332 Mn2+ 0.023 0.019 0.022 0.023 0.025 0.021 0.024 Mg2+ 0.610 0.602 0.625 0.625 0.623 0.627 0.644 NI2+ 0.001 0.002 0.003 0.003 0.003 0.001 0.000 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.002 0.002 0.005 0.004 0.004 0.003 0.003 Nb5+ 0.002 0.001 0.002 0.000 0.001 0.000 0.000 Zn2+ 0.001 0.000 0.001 0.001 0.001 0.000 0.000 Pt4+ 0.001 0.000 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 73.755 74.132 73.707 73.473 74.307 73.834 75.521 Cr*# 71.866 72.832 71.283 70.702 71.583 72.249 73.656 M g# 59.147 59.326 59.910 59.563 59.543 61.493 62.796 Mg'*# 62.218 61.441 63.916 64.165 64.003 64.189 65.960 Fe3+ 2.561 1.754 3.288 3.771 3.666 2.147 2.470 Table C.37: Sample Z7*P39 DIseemInated chromltlte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 418 :R4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% W t% W t% W t% Wt% Wt% Wt% Wt% 0.011 0.000 0.000 0.000 0.000 0.000 0.013 0.000 13.390 13.551 13.418 13.797 12.927 13.667 14.022 13.412 0.150 0.090 0.041 0.092 0.078 0.101 0.081 0.062 57.064 56.698 56.922 56.594 57.627 56.539 57.420 56.849 2.142 2.404 2.587 2.299 2.227 2.288 0.908 2.578 13.285 13.426 12.735 13.443 12.590 13.298 13.534 12.998 0.882 0.824 0.867 0.911 0.852 0.917 0.831 0.851 13.053 13.009 13.460 12.996 13.555 13.050 12.822 13.206 0.058 0.058 0.067 0.047 0.042 0.085 0.072 0.100 0.006 0.000 0.003 0.000 0.001 0.000 0.013 0.007 0.078 0.085 0.118 0.036 0.096 0.091 0.110 0.122 0.000 0.000 0.040 0.000 0.154 0.064 0.000 0.000 0.036 0.043 0.000 0.000 0.074 0.069 0.265 0.072 0.059 0.052 0.000 0.016 0.000 0.060 0.000 0.000 100.215 100.241 100.259 100.230 100.223 100.229 100.091 100.258 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.503 0.509 0.502 0.517 0.485 0.513 0.526 0.503 0.004 0.002 0.001 0.002 0.002 0.002 0.002 0.001 1.438 1.428 1.430 1.424 1.451 1.424 1.446 1.431 0.051 0.058 0.062 0.055 0.053 0.055 0.022 0.062 0.354 0.358 0.338 0.358 0.335 0.354 0.361 0.346 0.024 0.022 0.023 0.025 0.023 0.025 0.022 0.023 0.620 0.618 0.638 0.617 0.643 0.620 0.609 0.627 0.001 0.001 0.002 0.001 0.001 0.002 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.002 0.003 0.001 0.002 0.002 0.003 0.003 0.000 0.000 0.001 0.000 0.002 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.002 0.002 0.006 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 74.087 73.732 73.997 73.346 74.941 73.512 73.313 73.961 72.176 71.601 71.702 71.324 72.930 71.488 72.513 71.692 60.467 59.600 61.433 59.695 62.345 60.237 61.430 60.581 63.655 63.333 65.327 63.279 65.745 63.629 62.810 64.427 2.579 2.690 3.102 2.757 2.663 2.753 1.092 3.095 419 CR9-A1-C CR9-A2-R CR10-A1-C CR10-A2-R CR11-A1-C CR11-A2-R CR12-A1-C CR12-A2-R t% W t% W t% W t% W t% W t% W t% W t% 0.000 0.011 0.000 0.015 0.011 0.031 0.000 0.000 13.715 12.058 13.480 12.497 13.475 13.053 13.543 13.459 0.126 0.078 0.100 0.051 0.096 0.086 0.056 0.039 56.230 58.899 56.328 58.942 55.496 57.069 55.416 57.348 2.918 1.919 2.837 1.650 3.837 3.249 4.348 1.901 12.788 13.091 13.357 12.668 12.826 11.697 12.246 13.309 0.817 0.702 0.727 0.676 0.725 0.662 0.829 0.705 13.408 13.137 13.098 13.532 13.447 14.282 13.791 13.086 0.080 0.022 0.103 0.032 0.088 0.000 0.015 0.093 0.008 0.000 0.008 0.008 0.011 0.007 0.021 0.000 0.085 0.163 0.107 0.095 0.211 0.121 0.105 0.144 0.000 0.000 0.063 0.000 0.048 0.032 0.000 0.000 0.082 0.112 0.075 0.000 0.105 0.037 0.066 0.106 0.035 0.000 0.000 0.000 0.008 0.000 0.000 0.000 100.292 100.192 100.284 100.165 100.384 100.325 100.435 100.190 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.513 0.455 0.506 0.470 0.504 0.487 0.505 0.505 0.003 0.002 0.002 0.001 0.002 0.002 0.001 0.001 1.411 1.492 1.418 1.486 1.393 1.427 1.387 1.444 0.070 0.046 0.068 0.040 0.092 0.077 0.104 0.046 0.340 0.351 0.356 0.338 0.341 0.309 0.324 0.355 0.022 0.019 0.020 0.018 0.019 0.018 0.022 0.019 0.635 0.627 0.622 0.643 0.637 0.674 0.651 0.621 0.002 0.001 0.003 0.001 0.002 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.004 0.003 0.002 0.005 0.003 0.003 0.004 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.002 0.003 0.002 0.000 0.002 0.001 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 73.336 76.619 73.707 75.985 73.425 74.574 73.298 74.083 70.773 74.841 71.191 74.477 70.040 71.678 69.494 72.391 60.794 61.247 59.473 63.022 59.555 63.521 60.341 60.831 65.145 64.144 63.610 65.566 65.144 68.519 66.750 63.672 3.496 2.321 3.413 1.985 4.609 3.884 5.190 2.284 420 Label CR1-A1-C CR1-A1-R CR2-A1-C CR3-A1-C CR3-A2-R CR4-A2-R CR5-A1-C O xides Wt% Wt% Wt% Wt% Wt% W t% W t% S i0 2 0.000 0.000 0.000 0.006 0.006 0.000 0.000 AI203 17.323 16.784 17.162 17.243 17.314 17.758 17.059 T i02 0.211 0.167 0.235 0.242 0.180 0.146 0.196 C r203 53.802 54.233 53.813 54.010 54.283 54.029 53.966 F e203 1.265 1.688 1.498 1.043 0.328 -0.040 1.878 FeO 12.339 11.944 12.219 12.613 13.114 13.583 11.810 MnO 0.472 0.440 0.426 0.583 0.548 0.477 0.487 MgO 14.331 14.495 14.376 14.067 13.856 13.651 14.664 NIO 0.156 0.140 0.131 0.109 0.112 0.081 0.056 CaO 0.000 0.017 0.000 0.004 0.000 0.000 0.000 V203 0.124 0.124 0.094 0.116 0.105 0.147 0.072 N b205 0.069 0.000 0.030 0.039 0.163 0.163 0.000 ZnO 0.002 0.039 0.075 0.021 0.000 0.000 0.000 P t0 2 0.033 0.099 0.091 0.008 0.024 0.000 0.000 Total 100.127 100.169 100.150 100.104 100.033 99.996 100.188 C ations Si4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.635 0.616 0.630 0.634 0.637 0.653 0.624 TI4+ 0.005 0.004 0.006 0.006 0.004 0.003 0.005 Cr3+ 1.324 1.336 1.325 1.331 1.340 1.334 1.325 Fe3+ 0.030 0.040 0.035 0.024 0.008 -0.001 0.044 Fe2+ 0.321 0.311 0.318 0.329 0.343 0.355 0.307 Mn2+ 0.012 0.012 0.011 0.015 0.014 0.013 0.013 Mg2+ 0.665 0.673 0.667 0.654 0.645 0.635 0.679 NK+ 0.004 0.004 0.003 0.003 0.003 0.002 0.001 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.003 0.002 0.003 0.003 0.004 0.002 Nb5+ 0.001 0.000 0.000 0.001 0.002 0.002 0.000 Zn2+ 0.000 0.001 0.002 0.000 0.000 0.000 0.000 Pt4+ 0.000 0.001 0.001 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 67.570 68.431 67.779 67.756 67.775 67.116 67.972 Cr*# 66.563 67.071 66.583 66.922 67.512 67.148 66.476 Mg# 65.465 65.744 65.384 64.917 64.813 64.238 65.944 Mg"# 67.431 68.387 67.713 66.533 65.319 64.177 68.879 Fe3+ 1.489 1.987 1.764 1.230 0.388 •0.047 2.201 Table C.38: Sample Z7-P41 Massive chromltlte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite;(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromito formula) 421 CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' [% Wt% W t% W t% W t% W t% W t% W t% 0.034 0.017 0.000 0.017 0.019 0.000 0.000 0.000 17.026 17.619 16.816 16.546 17.160 17.075 16.934 16.840 0.177 0.169 0.174 0.194 0.146 0.160 0.187 0.173 54.544 53.952 54.044 54.321 54.159 54.107 54.730 54.118 0.766 0.649 1.741 1.340 1.154 1.510 0.996 1.350 12.421 13.059 12.068 12.479 12.505 11.979 11.793 12.152 0.463 0.497 0.493 0.521 0.524 0.542 0.599 0.524 14.320 13.787 14.416 14.195 14.141 14.375 14.536 14.445 0.107 0.147 0.065 0.122 0.187 0.194 0.170 0.119 0.001 0.021 0.001 0.000 0.001 0.010 0.001 0.000 0.072 0.063 0.075 0.089 0.089 0.115 0.106 0.059 0.114 0.000 0.007 0.194 0.030 0.000 0.047 0.225 0.024 0.069 0.099 0.081 0.000 0.076 0.000 0.081 0.008 0.016 0.174 0.033 0.000 0.008 0.000 0.049 100.077 100.065 100.174 100.134 100.116 100.151 100.100 100.135 0.001 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.625 0.648 0.618 0.609 0.630 0.626 0.621 0.619 0.004 0.004 0.004 0.005 0.003 0.004 0.004 0.004 1.344 1.330 1.332 1.342 1.335 1.332 1.347 1.334 0.018 0.015 0.041 0.032 0.027 0.035 0.023 0.032 0.324 0.341 0.315 0.326 0.326 0.312 0.307 0.317 0.012 0.013 0.013 0.014 0.014 0.014 0.016 0.014 0.665 0.641 0.670 0.661 0.657 0.667 0.674 0.671 0.003 0.004 0.002 0.003 0.005 0.005 0.004 0.003 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.002 0.002 0.002 0.002 0.003 0.003 0.001 0.002 0.000 0.000 0.003 0.000 0.000 0.001 0.003 0.001 0.002 0.002 0.002 0.000 0.002 0.000 0.002 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 68.245 67.259 68.314 68.773 67.920 68.008 68.435 68.314 67.629 66.745 66.912 67.680 66.998 66.801 67.633 67.223 66.069 64.304 65.335 64.900 65.051 65.769 67.126 65.828 67.268 65.302 68.045 66.972 66.842 68.145 68.722 67.938 0.904 0.764 2.052 1.589 1.359 1.774 1.172 1.596 422 CR11-A1-' CR11-A2-R Wt % Wt % 0.164 0.015 17.127 17.432 0.164 0.201 54.041 54.033 1.031 0.495 12.295 12.861 0.481 0.562 14.471 13.994 0.090 0.138 0.008 0.000 0.099 0.082 0.000 0.181 0.000 0.056 0.133 0.000 100.103 100.050 0.005 0.000 0.628 0.641 0.004 0.005 1.329 1.332 0.024 0.012 0.320 0.335 0.013 0.015 0.671 0.651 0.002 0.003 0.000 0.000 0.002 0.002 0.000 0.003 0.000 0.001 0.001 0.000 3.000 3.000 Average 67.916 67.526 67.088 67.131 67.066 66.111 65.214 65.424 67.722 65.982 1.218 0.585 423 Label CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C CR4-A2-R CR5-A1-C O xides W t% W t% W t% W t% W t% W t% W t% 8102 0.013 0.044 0.000 0.000 0.015 0.035 0.002 AI203 19.855 23.682 18.935 21.385 14.586 15.921 15.623 TI02 0.038 0.063 0.058 0.018 0.007 0.005 0.000 C r203 49.104 42.825 49.780 46.123 54.849 52.496 53.045 F e203 1.345 3.584 1.836 2.044 1.405 2.630 2.336 FeO 17.574 17.621 17.771 19.222 18.021 16.990 17.698 MnO 0.750 0.663 0.611 0.661 0.719 0.674 0.710 MgO 10.840 11.400 10.781 10.117 10.090 10.895 10.456 NIO 0.080 0.043 0.062 0.068 0.056 0.063 0.064 CaO 0.003 0.000 0.003 0.004 0.000 0.030 0.000 V203 0.177 0.168 0.152 0.224 0.176 0.213 0.179 N b205 0.040 0.048 0.016 0.117 0.007 0.000 0.000 ZnO 0.315 0.218 0.179 0.179 0.210 0.269 0.120 P t0 2 0.000 0.000 0.000 0.043 0.000 0.042 0.000 Total 100.135 100.359 100.184 100.205 100.141 100.263 100.234 C ations SM+ 0.000 0.001 0.000 0.000 0.000 0.001 0.000 AI3+ 0.737 0.861 0.706 0.793 0.556 0.600 0.592 Ti4+ 0.001 0.001 0.001 0.000 0.000 0.000 0.000 Cr3+ 1.223 1.045 1.245 1.147 1.403 1.328 1.347 Fe3+ 0.032 0.083 0.044 0.048 0.034 0.063 0.056 Fe2+ 0.463 0.455 0.470 0.506 0.488 0.455 0.475 Mn2+ 0.020 0.017 0.016 0.018 0.020 0.018 0.019 Mg2+ 0.509 0.525 0.508 0.474 0.487 0.520 0.501 NK+ 0.002 0.001 0.002 0.002 0.001 0.002 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 V3+ 0.004 0.004 0.004 0.006 0.005 0.005 0.005 Nb5+ 0.001 0.001 0.000 0.002 0.000 0.000 0.000 Zn2+ 0.007 0.005 0.004 0.004 0.005 0.006 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 62.393 54.815 63.815 59.131 71.612 68.866 69.491 Cr*# 61.394 52.522 62.417 57.692 70.383 66.676 67.524 M g# 50.708 49.363 49.733 46.130 48.257 50.084 48.490 Mg"# 52.371 53.558 51.955 48.408 49.952 53.340 51.295 Fe3+ 1.601 4.184 2.191 2.434 1.717 3.180 2.830 Table C.39: Sample Z7-P45 High altered peridotite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 424 CR5-A2-R CR7-A1-C CR8-A1-C CR9-A2-R CR11-A1-' CR11-A2-R [% Wt% W t% Wt% W t% W t% 0.002 0.000 0.006 0.002 0.000 0.000 16.228 14.435 13.289 12.911 11.632 13.347 0.038 0.047 0.034 0.025 0.002 0.013 51.562 53.609 54.941 56.041 57.445 55.474 2.976 2.587 2.087 1.509 1.868 1.697 17.809 18.468 19.985 18.764 18.102 18.595 0.673 0.745 0.822 0.722 0.691 0.677 10.478 9.770 8.727 9.553 9.847 9.720 0.047 0.114 0.056 0.059 0.052 0.075 0.011 0.008 0.000 0.007 0.000 0.008 0.248 0.251 0.262 0.292 0.230 0.248 0.023 0.023 0.000 0.145 0.138 0.123 0.154 0.153 0.000 0.122 0.180 0.119 0.050 0.049 0.000 0.000 0.000 0.073 100.298 100.259 100.209 100.151 100.187 100.170 0.000 0.000 0.000 0.000 0.000 0.000 0.613 0.552 0.514 0.498 0.450 0.513 0.001 0.001 0.001 0.001 0.000 0.000 1.306 1.375 1.426 1.450 1.491 1.431 0.072 0.063 0.052 0.037 0.046 0.042 0.477 0.501 0.549 0.514 0.497 0.508 0.018 0.020 0.023 0.020 0.019 0.019 0.500 0.473 0.427 0.466 0.482 0.473 0.001 0.003 0.001 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.007 0.007 0.008 0.006 0.006 0.000 0.000 0.000 0.002 0.002 0.002 0.004 0.004 0.000 0.003 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 Ave 68.067 71.358 73.498 74.436 76.813 73.602 65.614 69.094 71.596 73.043 75.029 72.057 66.542 47.690 45.578 41.575 45.837 47.013 46.269 47.441 51.190 48.535 43.771 47.576 49.230 48.236 3.604 3.173 2.588 1.872 2.323 2.098 425 Label CR1-A1-C CR2-A1-C CR3-A2-R CR4-A1-C CR5-A1-C CR6-A1-C CR7-A1-C O xides W t% Wt% W t% W t% Wt% W t% W t% 3102 0.000 0.015 0.074 0.021 0.000 0.000 0.000 AI203 14.570 14.251 12.623 15.060 13.954 13.357 12.867 TI02 0.054 0.059 0.025 0.038 0.000 0.073 0.061 C r203 53.455 54.417 55.472 54.170 55.580 54.732 56.596 Fe203 1.602 0.961 3.408 1.287 1.457 2.068 1.476 FeO 21.405 20.714 16.434 17.703 17.762 19.982 17.744 MnO 0.721 0.758 0.634 0.607 0.646 0.682 0.768 MgO 7.890 8.165 11.092 10.576 10.261 8.708 10.073 NIO 0.000 0.068 0.019 0.000 0.057 0.000 0.015 CaO 0.000 0.014 0.157 0.000 0.000 0.013 0.000 V203 0.241 0.193 0.239 0.280 0.233 0.276 0.196 N b205 0.000 0.070 0.070 0.153 0.000 0.000 0.000 ZnO 0.222 0.412 0.051 0.175 0.154 0.242 0.221 P t0 2 0.000 0.000 0.042 0.057 0.041 0.074 0.131 Total 100.160 100.096 100.341 100.129 100.146 100.207 100.148 C ations Si4+ 0.000 0.000 0.002 0.001 0.000 0.000 0.000 AI3+ 0.564 0.552 0.482 0.572 0.533 0.517 0.495 Ti4+ 0.001 0.001 0.001 0.001 0.000 0.002 0.001 Cr3+ 1.389 1.414 1.420 1.380 1.425 1.421 1.460 Fe3+ 0.040 0.024 0.083 0.031 0.036 0.051 0.036 Fe2+ 0.588 0.569 0.445 0.477 0.482 0.549 0.484 Mn2+ 0.020 0.021 0.017 0.017 0.018 0.019 0.021 Mg2+ 0.386 0.400 0.535 0.508 0.496 0.426 0.490 NK+ 0.000 0.002 0.001 0.000 0.001 0.000 0.000 Ca2+ 0.000 0.000 0.005 0.000 0.000 0.000 0.000 V3+ 0.006 0.005 0.006 0.007 0.006 0.007 0.005 Nb5+ 0.000 0.001 0.001 0.002 0.000 0.000 0.000 Zn2+ 0.005 0.010 0.001 0.004 0.004 0.006 0.005 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.001 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 71.108 71.923 74.671 70.700 72.767 73.326 74.689 Cr*# 69.694 71.063 71.547 69.588 71.469 71.442 73.329 M g# 38.103 40.281 50.346 49.989 48.954 41.543 48.492 Mg"# 39.652 41.269 54.610 51.572 50.734 43.721 50.296 Fe3+ 1.988 1.195 4.184 1.573 1.783 2.570 1.820 Table C.40: Sample Z7 P47 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 426 CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-RCR10-A1-CCR10-A2-R t% W t% W t% W t% W t% W t% W t% 0.015 0.013 0.004 0.000 0.026 0.052 0.000 13.212 13.860 14.757 13.592 15.099 13.098 14.633 0.022 0.000 0.033 0.013 0.086 0.080 0.027 55.957 54.089 53.469 55.171 52.580 55.594 52.517 1.877 2.763 2.220 2.143 2.414 2.164 2.878 17.420 18.717 18.712 18.159 18.913 17.706 19.991 0.797 0.790 0.723 0.713 0.613 0.659 0.763 10.306 9.541 9.595 9.943 9.757 10.221 8.886 0.038 0.065 0.000 0.000 0.046 0.066 0.103 0.018 0.000 0.000 0.000 0.004 0.006 0.007 0.243 0.269 0.234 0.296 0.218 0.222 0.275 0.000 0.000 0.030 0.000 0.223 0.071 0.116 0.191 0.170 0.395 0.185 0.262 0.259 0.093 0.091 0.000 0.050 0.000 0.000 0.016 0.000 100.188 100.277 100.222 100.215 100.242 100.217 100.288 0.000 0.000 0.000 0.000 0.001 0.002 0.000 0.506 0.532 0.564 0.521 0.576 0.502 0.562 0.001 0.000 0.001 0.000 0.002 0.002 0.001 1.438 1.393 1.372 1.419 1.346 1.430 1.354 0.046 0.068 0.054 0.052 0.059 0.053 0.071 0.474 0.510 0.508 0.494 0.512 0.482 0.545 0.022 0.022 0.020 0.020 0.017 0.018 0.021 0.499 0.463 0.464 0.482 0.471 0.496 0.432 0.001 0.002 0.000 0.000 0.001 0.002 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.007 0.006 0.008 0.006 0.006 0.007 0.000 0.000 0.000 0.000 0.003 0.001 0.002 0.005 0.004 0.009 0.004 0.006 0.006 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 73.966 72.360 70.851 73.139 70.024 74.008 70.654 72.259 69.901 68.922 71.214 67.946 72.033 68.143 70.611 49.014 44.511 45.232 46.876 45.203 48.109 41.228 45.563 51.328 47.609 47.754 49.395 47.907 50.716 44.208 2.308 3.399 2.723 2.632 2.969 2.669 3.555 427 Label CHR1 CHR2 CHR3 CHR4 CHR5 CHR6 CHR7 O xides W t% W t% W t% W t% W t% W t% W t% 8102 0.000 0.004 0.000 0.004 0.000 0.013 0.000 AI203 16.433 15.989 15.016 15.197 14.896 15.116 15.105 TI02 0.102 0.127 0.094 0.124 0.124 0.101 0.154 C r203 55.027 54.882 56.349 56.483 57.128 56.131 56.477 F e203 1.536 2.152 1.649 1.608 0.979 1.713 1.802 FeO 11.164 11.452 11.176 10.833 11.346 11.376 11.050 MnO 0.463 0.440 0.462 0.457 0.458 0.508 0.437 MgO 14.939 14.758 14.882 15.116 14.685 14.726 14.929 NIO 0.145 0.225 0.160 0.110 0.208 0.217 0.113 CaO 0.001 0.000 0.000 0.003 0.000 0.000 0.000 V203 0.104 0.108 0.117 0.119 0.159 0.117 0.068 N b205 0.085 0.070 0.102 0.023 0.078 0.131 0.000 ZnO 0.154 0.009 0.015 0.000 0.036 0.000 0.046 P t0 2 0.000 0.000 0.142 0.084 0.000 0.024 0.000 Total 100.154 100.216 100.165 100.161 100.098 100.172 100.181 C ations 314+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.602 0.588 0.554 0.559 0.550 0.558 0.556 TI4+ 0.002 0.003 0.002 0.003 0.003 0.002 0.004 Cr3+ 1.353 1.353 1.395 1.394 1.416 1.390 1.396 Fe3+ 0.036 0.050 0.039 0.038 0.023 0.040 0.042 Fe2+ 0.290 0.299 0.293 0.283 0.298 0.298 0.289 Mn2+ 0.012 0.012 0.012 0.012 0.012 0.013 0.012 Mg2+ 0.693 0.686 0.695 0.704 0.686 0.687 0.696 NI2+ 0.004 0.006 0.004 0.003 0.005 0.005 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.003 0.003 0.003 0.004 0.003 0.002 Nb5+ 0.001 0.001 0.001 0.000 0.001 0.002 0.000 Zn2+ 0.004 0.000 0.000 0.000 0.001 0.000 0.001 Pt4+ 0.000 0.000 0.001 0.001 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 69.196 69.721 71.570 71.375 72.011 71.356 71.496 Cr"# 67.946 67.953 70.171 70.020 71.175 69.907 69.977 M g# 67.974 66.272 67.695 68.693 68.163 67.022 67.744 Mg"# 70.461 69.670 70.359 71.325 69.762 69.767 70.661 Fe3+ 1.806 2.536 1.955 1.898 1.161 2.031 2.125 Table C.41: Sample Z7>P48 Masalve chromltlte Mlcroprotie Analyais & Calculated Formula (baaed on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 la calculated by assuming the Ideal chromite formula) 428 HR8 CHR9 CHR10 CHR11 CHR12 CHR13 CHR14 CHR15 t% W t% W t% W t% W t% W t% W t% W t% 0.000 0.000 0.000 0.009 0.019 0.000 0.066 0.000 15.040 14.943 15.072 14.906 14.509 13.642 15.242 15.066 0.182 0.135 0.096 0.091 0.092 0.127 0.103 0.154 56.001 55.989 56.425 57.235 57.773 57.984 56.283 56.423 2.028 2.218 1.725 1.227 0.717 1.907 1.396 1.674 10.922 11.145 11.165 11.164 11.218 10.990 11.254 11.319 0.500 0.494 0.429 0.465 0.535 0.453 0.512 0.486 14.944 14.849 14.768 14.806 14.713 14.796 14.842 14.733 0.206 0.148 0.119 0.175 0.129 0.138 0.149 0.151 0.001 0.004 0.004 0.000 0.011 0.000 0.000 0.000 0.125 0.092 0.139 0.047 0.099 0.114 0.033 0.091 0.115 0.070 0.007 0.000 0.116 0.000 0.147 0.046 0.108 0.036 0.191 0.000 0.115 0.039 0.114 0.024 0.033 0.100 0.033 0.000 0.024 0.000 0.000 0.000 100.203 100.222 100.173 100.123 100.072 100.191 100.140 100.168 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.000 0.554 0.551 0.556 0.550 0.537 0.506 0.562 0.556 0.004 0.003 0.002 0.002 0.002 0.003 0.002 0.004 1.385 1.386 1.397 1.417 1.435 1.443 1.392 1.397 0.048 0.052 0.041 0.029 0.017 0.045 0.033 0.039 0.286 0.292 0.292 0.292 0.295 0.289 0.294 0.296 0.013 0.013 0.011 0.012 0.014 0.012 0.014 0.013 0.697 0.693 0.689 0.691 0.689 0.694 0.692 0.688 0.005 0.004 0.003 0.004 0.003 0.003 0.004 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.002 0.003 0.001 0.002 0.003 0.001 0.002 0.002 0.001 0.000 0.000 0.002 0.000 0.002 0.001 0.002 0.001 0.004 0.000 0.003 0.001 0.003 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 71.412 71.539 71.522 72.035 72.761 74.035 71.241 71.529 69.696 69.660 70.064 70.992 72.140 72.358 70.063 70.113 67.636 66.825 67.427 68.269 68.856 67.487 67.896 67.189 70.922 70.371 70.219 70.275 70.043 70.587 70.158 69.882 2.402 2.626 2.039 1.448 0.852 2.266 1.654 1.980 429 HR16 CHR17 CHR18 CHR19 CHR20 CHR21 t% W t% W t% Wt% W t% W t% 0.000 0.000 0.000 0.002 0.000 0.000 14.839 14.421 14.620 14.519 14.418 15.098 0.189 0.145 0.086 0.103 0.053 0.112 56.768 56.928 56.991 56.874 57.222 56.962 1.488 2.005 1.831 1.856 1.684 1.167 11.345 11.254 10.981 10.941 11.301 10.922 0.503 0.556 0.530 0.648 0.583 0.566 14.631 14.643 14.832 14.840 14.616 14.975 0.147 0.166 0.120 0.134 0.133 0.119 0.013 0.000 0.000 0.004 0.000 0.007 0.047 0.084 0.101 0.086 0.109 0.108 0.007 0.000 0.000 0.108 0.000 0.070 0.063 0.000 0.091 0.072 0.000 0.012 0.108 0.000 0.000 0.000 0.050 0.000 100.149 100.201 100.183 100.186 100.169 100.117 0.000 0.000 0.000 0.000 0.000 0.000 0.549 0.534 0.540 0.537 0.534 0.556 0.004 0.003 0.002 0.002 0.001 0.003 1.408 1.413 1.412 1.410 1.421 1.408 0.035 0.047 0.043 0.044 0.040 0.027 0.298 0.296 0.288 0.287 0.297 0.286 0.013 0.015 0.014 0.017 0.016 0.015 0.684 0.685 0.693 0.694 0.685 0.698 0.004 0.004 0.003 0.003 0.003 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.002 0.003 0.002 0.003 0.003 0.000 0.000 0.000 0.002 0.000 0.001 0.001 0.000 0.002 0.002 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 71.960 72.590 72.337 72.436 72.695 71.679 70.691 70.865 70.771 70.842 71.245 70.691 70.350 67.281 66.656 67.674 67.719 67.028 69.038 67.645 69.688 69.875 70.655 70.742 69.746 70.965 1.763 2.376 2.165 2.200 1.995 1.378 430 Label WSU-1 WSU-2 WSU-3 WSU-4 O xides wt% W t% W t% W t% 8102 0.217 0.193 0.213 0.195 AI203 16.128 16.633 16.525 16.494 T i02 0.228 0.207 0.176 0.218 C r203 52.926 53.519 52.681 52.769 F e203 3.072 0.938 2.843 3.119 FeO 11.424 12.858 11.567 11.566 MnO 0.171 0.166 0.184 0.158 MgO 14.947 13.909 14.887 14.958 NiO 0.160 0.138 0.120 0.155 CaO 0.000 0.006 0.012 0.021 V 203 0.094 0.071 0.111 0.102 N b205 0.000 0.000 0.000 0.000 ZnO 0.040 0.081 0.050 0.017 P t0 2 0.000 0.000 0.000 0.000 Total 99.406 98.718 99.368 99.771 C ations SI4+ 0.007 0.006 0.007 0.006 AI3+ 0.595 0.620 0.609 0.606 TI4+ 0.005 0.005 0.004 0.005 Cr3+ 1.311 1.339 1.303 1.301 Fe3+ 0.072 0.022 0.067 0.073 Fe2+ 0.299 0.340 0.303 0.302 Mn2+ 0.005 0.004 0.005 0.004 Mg2+ 0.698 0.656 0.694 0.695 NI2+ 0.004 0.004 0.003 0.004 Ca2+ 0.000 0.000 0.000 0.001 V3+ 0.002 0.002 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.000 Zn2+ 0.001 0.002 0.001 0.000 Pt4+ 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 C r# 68.764 68.339 68.139 68.216 cr# 66.248 67.569 65.835 65.695 66.337 M g# 65.252 64.407 65.264 64.977 64.975 Mg"# 69.990 65.851 69.645 69.746 Fe3+ 3.660 1.127 3.381 3.696 Tabla C.42: Sample Z7 P52 Massive Chromltlte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 431 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% Wt% S I02 0.000 0.000 0.009 0.009 0.000 0.000 0.009 AI203 8.525 9.042 8.384 7.278 10.127 9.235 8.686 T I02 0.068 0.000 0.051 0.080 0.046 0.071 0.031 C r203 60.753 58.310 61.175 61.966 59.126 58.784 60.763 F e203 0.814 2.800 0.258 -0.349 0.796 1.507 0.483 FeO 21.661 21.834 22.154 24.069 21.012 23.126 21.583 MnO 0.693 0.773 0.715 0.874 0.790 0.777 0.788 MgO 7.039 6.953 6.685 5.195 7.592 6.103 7.075 NIO 0.071 0.060 0.063 0.075 0.056 0.027 0.060 CaO 0.007 0.032 0.000 0.006 0.006 0.046 0.000 V 203 0.194 0.229 0.248 0.209 0.223 0.215 0.227 N b205 0.000 0.000 0.000 0.091 0.038 0.000 0.054 ZnO 0.258 0.231 0.283 0.388 0.267 0.261 0.290 P t0 2 0.000 0.016 0.000 0.072 0.000 0.000 0.000 T otal 100.081 100.280 100.026 99.965 100.080 100.151 100.048 C atio n s 314+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.341 0.361 0.337 0.297 0.401 0.371 0.347 TI4+ 0.002 0.000 0.001 0.002 0.001 0.002 0.001 Cr3+ 1.631 1.561 1.648 1.698 1.570 1.583 1.630 Fe3+ 0.021 0.071 0.007 -0.009 0.020 0.039 0.012 Fe2+ 0.615 0.618 0.631 0.698 0.590 0.659 0.613 Mn2+ 0.020 0.022 0.021 0.026 0.022 0.022 0.023 Mg2+ 0.356 0.351 0.340 0.268 0.380 0.310 0.358 NI2+ 0.002 0.002 0.002 0.002 0.002 0.001 0.002 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.002 0.000 V3+ 0.005 0.006 0.007 0.006 0.006 0.006 0.006 NbS+ 0.000 0.000 0.000 0.001 0.001 0.000 0.001 Zn2+ 0.006 0.006 0.007 0.010 0.007 0.007 0.007 Pt4+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 82.700 81.225 83.036 85.100 79.661 81.026 82.435 cr# 81.838 78.318 82.760 85.489 78.855 79.455 81.924 M g# 35.911 33.729 34.741 28.048 38.379 30.765 36.420 M g'# 36.679 36.212 34.977 27.784 39.175 31.992 36.883 Fe3+ 1.043 3.579 0.332 •0.458 1.011 1.939 0.619 Table C.43: Sample Z7-6.2 Altered pyroxenite dike Microprobe Analysla & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 432 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R WSU-1 WSU-2 WSU-3 WSU-4 Vt% W t% W t% Wt% Wt% W t% W t% W t% W t% 0.000 0.000 0.026 0.013 0.000 0.075 0.061 0.043 0.066 8.798 8.291 8.467 9.869 9.150 9.106 8.238 7.820 9.036 0.051 0.066 0.008 0.049 0.000 0.023 0.051 0.041 0.024 60.270 60.307 60.502 58.988 58.645 58.554 58.448 59.268 58.466 0.084 0.501 0.229 0.426 1.265 1.682 2.391 2.313 1.718 23.599 23.756 24.006 23.673 24.666 22.453 23.794 24.048 22.667 0.729 0.751 0.740 0.795 0.723 0.386 0.391 0.403 0.361 5.732 5.623 5.520 5.829 5.028 6.799 5.794 5.695 6.582 0.000 0.105 0.053 0.048 0.034 0.016 0.026 0.029 0.037 0.000 0.000 0.008 0.000 0.036 0.006 0.008 0.008 0.011 0.278 0.250 0.242 0.078 0.156 0.255 0.335 0.366 0.283 0.030 0.084 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.437 0.292 0.221 0.250 0.422 0.202 0.323 0.249 0.301 0.000 0.024 0.000 0.024 0.000 0.000 0.000 0.000 0.000 100.008 100.050 100.023 100.043 100.127 99.556 99.861 100.284 99.553 0.000 0.000 0.001 0.000 0.000 0.003 0.002 0.001 0.002 0.355 0.336 0.343 0.396 0.370 0.366 0.334 0.317 0.364 0.001 0.002 0.000 0.001 0.000 0.001 0.001 0.001 0.001 1.632 1.638 1.643 1.588 1.593 1.578 1.589 1.610 1.579 0.002 0.013 0.006 0.011 0.033 0.043 0.062 0.060 0.044 0.676 0.683 0.689 0.674 0.709 0.640 0.684 0.691 0.648 0.021 0.022 0.022 0.023 0.021 0.011 0.011 0.012 0.010 0.293 0.288 0.283 0.296 0.257 0.346 0.297 0.292 0.335 0.000 0.003 0.001 0.001 0.001 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.008 0.007 0.007 0.002 0.004 0.007 0.009 0.010 0.008 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.011 0.007 0.006 0.006 0.011 0.005 0.008 0.006 0.008 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 82.128 82.993 82.740 80.038 81.130 81.180 82.638 83.564 81.275 82.039 82.452 82.493 79.600 79.801 79.418 80.062 81.049 79.469 30.148 29.282 28.894 30.168 25.779 33.586 28.473 27.980 32.641 30.215 29.673 29.071 30.506 26.652 35.056 30.269 29.683 34.108 0.109 0.652 0.298 0.548 1.639 2.171 3.117 3.011 2.223 433 Label CR1-A1-C- CR-A2-C2 CR1-A3-R CR2-A1-! CR3-A1-C CR3-A2-R CR4 O xides W t% W t% W t% W t% Wt % Wt % W t% SIG2 0.030 0.000 0.021 0.000 0.028 0.000 0.000 AI203 27.392 28.180 27.288 26.478 24.693 25.519 25.267 TI02 0.076 0.012 0.018 0.074 0.020 0.017 0.051 C r203 43.343 42.250 43.187 43.089 45.992 45.109 45.084 Fe203 -1.155 -0.381 -0.357 0.503 -0.059 0.099 0.768 FeO 16.868 16.145 15.834 15.658 15.133 14.865 14.141 MnO 0.672 0.538 0.687 0.610 0.441 0.513 0.462 MgO 12.144 12.774 12.774 12.783 13.266 13.448 13.886 NiO 0.037 0.057 0.029 0.117 0.032 0.029 0.014 CaO 0.010 0.000 0.032 0.013 0.007 0.000 0.000 V203 0.205 0.142 0.167 0.176 0.169 0.121 0.117 N b205 0.000 0.000 0.000 0.069 0.039 0.062 0.000 ZnO 0.261 0.244 0.285 0.404 0.148 0.194 0.227 P t0 2 0.000 0.000 0.000 0.075 0.084 0.034 0.059 Total 99.884 99.962 99.964 100.050 99.994 100.010 100.077 C ations Si4+ 0.001 0.000 0.001 0.000 0.001 0.000 0.000 AI3+ 0.979 1.000 0.971 0.946 0.886 0.911 0.900 Ti4+ 0.002 0.000 0.000 0.002 0.000 0.000 0.001 Cr3+ 1.039 1.005 1.031 1.033 1.107 1.080 1.077 Fe3+ -0.026 -0.009 -0.008 0.011 -0.001 0.002 0.017 Fe2+ 0.428 0.406 0.400 0.397 0.385 0.377 0.357 Mn2+ 0.017 0.014 0.018 0.016 0.011 0.013 0.012 Mg2+ 0.549 0.573 0.575 0.578 0.602 0.607 0.626 Ni2+ 0.001 0.001 0.001 0.003 0.001 0.001 0.000 Ca2+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 V3+ 0.005 0.003 0.004 0.004 0.004 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.001 0.001 0.001 0.000 Zn2+ 0.006 0.005 0.006 0.009 0.003 0.004 0.005 R 4+ 0.000 0.000 0.000 0.001 0.001 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 51.491 50.144 51.496 52.192 55.546 54.250 54.483 cr# 52.173 50.360 51.705 51.891 55.583 54.189 54.006 M g# 57.764 59.033 59.479 56.581 61.061 61.584 62.531 Mg"# 56.205 58.514 58.984 59.271 60.978 61.725 63.642 Fe3+ -1.323 ■0.432 •0.406 0.577 ■0.067 0.114 0.876 Table C.44: Sample Z7>P9 Harzburgite Microprobe Analytie & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 434 Label WSU-1 WSU-2 WSU-3 CrZ9-P3 Ave O xides wt% W t% W t% SI02 0.097 0.075 0.098 0.090 AI203 16.795 15.533 15.035 15.788 TI02 0.163 0.119 0.149 0.144 Cr203 54.322 55.390 55.917 55.210 Fe203 1.306 1.813 2.125 1.748 FeO 12.695 13.068 12.897 12.887 MnO 0.160 0.164 0.198 0.174 MgO 14.299 13.912 14.004 14.071 NIO 0.107 0.123 0.163 0.131 CaO 0.004 0.000 0.026 0.010 V203 0.116 0.131 0.081 0.109 Nb205 0.000 0.000 0.000 0.000 ZnO 0.009 0.101 0.082 0.064 P t02 0.000 0.000 0.000 0.000 Total 100.076 100.430 100.776 100.427 0.000 C ations 0.000 SI4+ 0.003 0.002 0.003 0.003 AI3+ 0.617 0.574 0.555 0.582 TI4+ 0.004 0.003 0.004 0.003 Cr3+ 1.339 1.373 1.384 1.365 Fe3+ 0.031 0.043 0.050 0.041 Fe2+ 0.331 0.343 0.338 0.337 Mn2+ 0.004 0.004 0.005 0.005 Mg2+ 0.665 0.650 0.653 0.656 NI2+ 0.003 0.003 0.004 0.003 Ca2+ 0.000 0.000 0.001 0.000 V3+ 0.003 0.003 0.002 0.003 Nb5+ 0.000 0.000 0.000 0.000 Zn2+ 0.000 0.002 0.002 0.001 Pt4+ 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 C r# 68.452 70.520 71.387 70.120 Cr*# 67.396 69.004 69.590 68.663 M g# 64.758 62.785 62.765 63.436 Mg'*# 66.752 65.489 65.935 66.059 Fe3+ 1.542 2.149 2.517 2.070 Table C.45: Sample Z9-P3 Massive Chromltlte MIcroprotM Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 435 Label WSU-C1 WSU-C2 WSU-C3 WSU-C4 WSU-D1 WSU-D2 WSU-D3 Chromltlte Section Dunite Section O xides W t% W t% Wt% W t% W t% W t% W t% 3102 0.105 0.145 0.117 0.120 0.095 0.089 0.003 AI203 17.647 17.835 17.883 17.831 14.816 14.427 2.988 T I02 0.098 0.060 0.116 0.084 0.080 0.097 0.130 C r203 51.295 52.190 51.229 51.443 54.673 52.395 53.776 F e203 2.929 2.213 2.701 2.171 1.963 3.831 14.803 FeO 13.847 14.353 13.891 14.355 18.719 17.709 21.656 MnO 0.188 0.186 0.186 0.190 0.276 0.337 0.534 MgO 13.580 13.467 13.569 13.236 10.305 10.524 6.708 NiO 0.087 0.066 0.089 0.106 0.053 0.071 0.093 CaO 0.005 0.016 0.007 0.000 0.028 0.021 0.000 V203 0.137 0.159 0.169 0.163 0.219 0.178 0.180 N b205 0.000 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.031 0.061 0.095 0.021 0.090 0.107 0.105 P t0 2 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 99.949 100.750 100.052 99.719 101.318 99.785 100.975 C ations Si4+ 0.003 0.004 0.004 0.004 0.003 0.003 0.000 AI3+ 0.650 0.653 0.658 0.659 0.558 0.551 0.123 TI4+ 0.002 0.001 0.003 0.002 0.002 0.002 0.003 Cr3+ 1.268 1.281 1.264 1.276 1.381 1.343 1.481 Fe3+ 0.069 0.052 0.063 0.051 0.047 0.093 0.388 Fe2+ 0.362 0.373 0.363 0.377 0.500 0.480 0.631 Mn2+ 0.005 0.005 0.005 0.005 0.007 0.009 0.016 Mg2+ 0.633 0.623 0.631 0.619 0.491 0.508 0.348 NK+ 0.002 0.002 0.002 0.003 0.001 0.002 0.003 Ca2+ 0.000 0.001 0.000 0.000 0.001 0.001 0.000 V3+ 0.003 0.004 0.004 0.004 0.006 0.005 0.005 NbS-c 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.001 0.001 0.002 0.000 0.002 0.003 0.003 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 66.101 66.251 65.774 65.934 71.226 70.899 92.352 Or*# 63.808 64.525 63.673 64.233 69.534 67.564 74.359 Mg# 59.491 59.494 59.711 59.129 47.277 46.997 25.478 Mg"# 63.612 62.583 63.522 62.173 49.529 51.440 35.574 Fe3+ 3.468 2.605 3.195 2.580 2.377 4.703 19.483 Table C.46: Sample Z9-P4 Oise. Chromltlte & Dunite Microprobe Analysla & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 436 Label WSU-1 WSU-2 WSU-4 CrZ9-P5 WSU-3 Ave O xides wt% W t% W t% W t% 5102 0.059 0.069 0.081 0.069 0.014 A1203 13.220 13.620 13.927 13.589 5.576 T I02 0.097 0.134 0.148 0.126 0.137 C r203 53.851 52.997 53.316 53.388 54.461 F e2 0 3 3.923 3.961 3.821 3.902 10.779 FeO 17.710 18.203 18.884 18.265 21.581 MnO 0.266 0.300 0.318 0.295 0.361 MgO 10.453 10.105 9.886 10.148 7.021 NIC 0.079 0.045 0.089 0.071 0.089 CaO 0.000 0.029 0.000 0.010 0.018 V 203 0.162 0.166 0.184 0.171 0.191 N b205 0.000 0.000 0.000 0.000 0.000 ZnO 0.122 0.154 0.193 0.156 0.157 P t0 2 0.000 0.000 0.000 0.000 0.000 T otal 99.941 99.783 100.847 100.190 100.385 C atio n s 514+ 0.002 0.002 0.003 0.002 0.000 AI3+ 0.507 0.524 0.531 0.521 0.227 TI4+ 0.002 0.003 0.004 0.003 0.004 Cr3+ 1.386 1.367 1.363 1.372 1.484 Fe3+ 0.096 0.097 0.093 0.095 0.280 Fe2+ 0.482 0.497 0.511 0.496 0.622 Mn2+ 0.007 0.008 0.009 0.008 0.011 Mg2+ 0.507 0.491 0.476 0.492 0.361 NI2+ 0.002 0.001 0.002 0.002 0.002 Ca2+ 0.000 0.001 0.000 0.000 0.001 V3+ 0.004 0.004 0.005 0.004 0.005 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.003 0.004 0.005 0.004 0.004 Pt4+ 0.000 0.000 0.000 0.000 0.000 T otal 3.000 3.000 3.000 3.000 3.000 C r# 73.210 72.302 71.975 72.495 86.758 Cr"# 69.673 68.765 68.606 69.014 74.571 Mg# 46.732 45.282 44.116 45.377 28.578 M g"# 51.271 49.739 48.272 49.761 36.707 Fe3+ 4.831 4.892 4.680 4.801 14.047 Table C.47: Sample Z9*P5 Dunite Microprobe Analyeis & Calculated Formula (based on 4 oxygens) of chromite;(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 437 Label WSU-1 WSU-2 WSU-3 CRZ9-P6 Ave O xides w t% W t% W t% S i0 2 0.121 0.096 0.077 0.098 A I203 16.665 16.028 16.496 16.397 T I02 0.054 0.066 0.054 0.058 C r203 52.811 53.397 53.085 53.098 F e203 1.443 1.567 1.370 1.460 FeO 16.834 17.102 17.223 17.053 MnO 0.240 0.236 0.245 0.240 MgO 11.521 11.247 11.205 11.324 NiO 0.063 0.042 0.045 0.050 CaO 0.000 0.014 0.001 0.005 V 203 0.243 0.216 0.199 0.219 N b205 0.000 0.000 0.000 0.000 ZnO 0.126 0.177 0.166 0.156 P t0 2 0.000 0.000 0.000 0.000 T otal 100.121 100.187 100.166 100.158 0.000 C ations 0.000 Si4+ 0.004 0.003 0.002 0.003 AI3+ 0.624 0.603 0.619 0.615 TI4+ 0.001 0.002 0.001 0.001 Cr3+ 1.326 1.347 1.337 1.337 Fe3+ 0.035 0.038 0.033 0.035 Fe2+ 0.447 0.456 0.459 0.454 Mn2+ 0.006 0.006 0.007 0.006 Mg2+ 0.546 0.535 0.532 0.537 Ni2+ 0.002 0.001 0.001 0.001 Ca2+ 0.000 0.000 0.000 0.000 V3+ 0.006 0.006 0.005 0.006 Nb5+ 0.000 0.000 0.000 0.000 Zn2+ 0.003 0.004 0.004 0.004 Pt4+ 0.000 0.000 0.000 0.000 T otal 3.000 3.000 3.000 3.000 C r# 68.009 69.087 68.342 68.479 Cr"# 66.826 67.779 67.214 67.273 Mg# 53.109 51.992 51.975 52.359 Mg"# 54.955 53.965 53.697 54.206 Fe3+ 1.738 1.893 1.651 1.761 Table C.48: Sample Z9-P6 Harzburgite Microprobe Analysia & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 438 Label CR1-A1-C CR2-A1-C CR3-A1-C CR3-A2-R CR4-A1-C CR5-A1-C CR5-A2-R O xides Wt% Wt% Wt% Wt% W t% W t% W t% S I02 0.000 0.000 0.009 0.000 0.002 0.000 0.015 AI203 10.240 10.371 10.097 10.100 10.147 10.333 10.439 TI02 0.013 0.000 0.043 0.023 0.000 0.003 0.020 C r203 58.601 58.390 57.102 56.869 58.787 58.681 57.930 F e203 1.140 1.182 2.985 3.166 1.786 1.426 2.061 FeO 20.366 19.993 20.648 20.732 19.708 19.925 19.898 MnO 0.650 0.692 0.723 0.716 0.732 0.643 0.659 MgO 8.227 8.593 7.942 7.835 8.514 8.369 8.466 NIO 0.055 0.020 0.032 0.129 0.084 0.036 0.080 CaO 0.000 0.007 0.000 0.003 0.000 0.024 0.022 V 203 0.337 0.319 0.384 0.387 0.242 0.336 0.269 N b205 0.207 0.336 0.068 0.037 0.000 0.000 0.073 ZnO 0.279 0.214 0.266 0.225 0.177 0.327 0.259 P t0 2 0.000 0.000 0.000 0.098 0.000 0.041 0.016 Total 100.114 100.116 100.300 100.319 100.179 100.144 100.206 C ations SI4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.403 0.408 0.398 0.399 0.399 0.406 0.410 TI4+ 0.000 0.000 0.001 0.001 0.000 0.000 0.000 Cr3+ 1.549 1.539 1.511 1.507 1.550 1.548 1.526 Fe3+ 0.029 0.030 0.075 0.080 0.045 0.036 0.052 Fe2+ 0.569 0.557 0.578 0.581 0.550 0.556 0.554 Mn2+ 0.018 0.020 0.021 0.020 0.021 0.018 0.019 Mg2+ 0.410 0.427 0.396 0.391 0.423 0.416 0.421 NI2+ 0.001 0.001 0.001 0.003 0.002 0.001 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.001 0.001 V3+ 0.009 0.009 0.010 0.010 0.006 0.009 0.007 NbS-t- 0.003 0.005 0.001 0.001 0.000 0.000 0.001 Zn2+ 0.007 0.005 0.007 0.006 0.004 0.008 0.006 R 4+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 79.335 79.065 79.140 79.067 79.535 79.208 78.826 Cr"# 78.187 77.879 76.142 75.888 77.747 77.783 76.776 Mg# 40.672 42.110 37.762 37.199 41.589 41.296 40.959 Mg"# 41.863 43.379 40.677 40.253 43.505 42.816 43.131 Fe3+ 1.448 1.501 3.789 4.021 2.248 1.799 2.600 Table C.49: Sample Z8-Sh1 Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 439 CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R [% W t% Wt% W t% W t% W t% W t% W t% 0.000 0.000 0.000 0.109 0.006 0.000 0.000 0.000 9.610 9.702 10.071 10.575 10.494 10.145 10.942 11.082 0.000 0.030 0.000 0.017 0.087 0.095 0.027 0.017 58.053 58.142 59.717 57.768 58.621 58.475 58.264 57.584 2.422 2.444 0.947 2.023 0.941 1.610 1.346 1.966 21.222 21.046 19.187 19.317 20.121 20.619 19.675 19.732 0.665 0.730 0.617 0.666 0.714 0.695 0.643 0.634 7.519 7.661 9.106 8.998 8.398 7.950 8.720 8.677 0.051 0.000 0.000 0.077 0.032 0.039 0.000 0.057 0.000 0.000 0.024 0.050 0.000 0.007 0.013 0.014 0.295 0.324 0.329 0.312 0.300 0.328 0.296 0.276 0.090 0.000 0.083 0.122 0.164 0.000 0.000 0.000 0.308 0.167 0.000 0.167 0.216 0.198 0.170 0.157 0.008 0.000 0.016 0.000 0.000 0.000 0.041 0.000 100.243 100.245 100.096 100.202 100.094 100.161 100.137 100.196 0.000 0.000 0.000 0.004 0.000 0.000 0.000 0.000 0.381 0.384 0.394 0.413 0.413 0.400 0.428 0.433 0.000 0.001 0.000 0.000 0.002 0.002 0.001 0.000 1.545 1.545 1.569 1.515 1.546 1.548 1.529 1.510 0.061 0.062 0.024 0.050 0.024 0.041 0.034 0.049 0.597 0.591 0.533 0.536 0.561 0.577 0.546 0.547 0.019 0.021 0.017 0.019 0.020 0.020 0.018 0.018 0.377 0.384 0.451 0.445 0.418 0.397 0.431 0.429 0.001 0.000 0.000 0.002 0.001 0.001 0.000 0.002 0.000 0.000 0.001 0.002 0.000 0.000 0.000 0.000 0.008 0.009 0.009 0.008 0.008 0.009 0.008 0.007 0.001 0.000 0.001 0.002 0.002 0.000 0.000 0.000 0.008 0.004 0.000 0.004 0.005 0.005 0.004 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.207 80.080 79.911 78.562 78.935 79.452 78.129 77.707 77.731 77.594 78.959 76.557 77.995 77.831 76.809 75.793 36.416 37.006 44.752 43.146 41.656 39.104 42.667 41.841 38.709 39.351 45.829 45.367 42.662 40.733 44.134 43.944 3.087 3.104 1.192 2.552 1.192 2.040 1.689 2.463 440 CR10-A1-' CR10-A2-R W t % W t % 0.000 0.000 9.895 9.973 0.023 0.030 58.378 57.655 1.733 2.222 21.386 21.689 0.820 0.748 7.314 7.348 0.043 0.000 0.020 0.000 0.336 0.303 0.000 0.119 0.224 0.136 0.000 0.000 100.172 100.223 0.000 0.000 0.393 0.396 0.001 0.001 1.554 1.534 0.044 0.056 0.602 0.610 0.023 0.021 0.367 0.369 0.001 0.000 0.001 0.000 0.009 0.008 0.000 0.002 0.006 0.003 0.000 0.000 3.000 3.000 Average 79.830 79.500 78.069 77.247 77.352 36.234 35.606 40.001 37.876 37.653 2.206 2.834 441 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% Wt% 3102 0.004 0.000 0.026 0.000 0.000 0.024 0.000 AI203 5.064 5.271 4.644 4.629 4.472 4.551 5.496 TI02 0.000 0.093 0.045 0.035 0.087 0.022 0.013 C r203 64.771 63.545 63.838 63.667 63.874 63.349 63.379 F e203 1.315 2.302 2.242 2.558 2.206 3.039 1.852 FeO 20.070 19.996 21.244 20.895 21.353 20.997 20.306 MnO 0.803 0.694 0.746 0.697 0.815 0.730 0.728 MgO 7.782 7.836 7.124 7.242 6.908 7.113 7.620 NiO 0.017 0.063 0.020 0.098 0.000 0.052 0.059 CaO 0.006 0.013 0.000 0.018 0.017 0.003 0.010 V203 0.190 0.199 0.172 0.227 0.267 0.192 0.228 N b205 0.000 0.000 0.074 0.059 0.073 0.000 0.066 ZnO 0.111 0.209 0.050 0.133 0.147 0.236 0.317 P t0 2 0.000 0.008 0.000 0.000 0.000 0.000 0.111 Total 100.133 100.231 100.225 100.257 100.220 100.307 100.186 C ations 314+ 0.000 0.000 0.001 0.000 0.000 0.001 0.000 AI3+ 0.205 0.213 0.189 0.188 0.182 0.185 0.222 TI4+ 0.000 0.002 0.001 0.001 0.002 0.001 0.000 Cr3+ 1.756 1.720 1.742 1.736 1.747 1.728 1.718 Fe3+ 0.034 0.059 0.058 0.066 0.057 0.079 0.048 Fe2+ 0.576 0.572 0.613 0.602 0.618 0.606 0.582 Mn2+ 0.023 0.020 0.022 0.020 0.024 0.021 0.021 Mg2+ 0.398 0.400 0.366 0.372 0.356 0.366 0.390 NI2+ 0.000 0.002 0.001 0.003 0.000 0.001 0.002 Ca2+ 0.000 0.000 0.000 0.001 0.001 0.000 0.000 V3+ 0.005 0.005 0.005 0.006 0.007 0.005 0.006 Nb5+ 0.000 0.000 0.001 0.001 0.001 0.000 0.001 Zn2+ 0.003 0.005 0.001 0.003 0.004 0.006 0.008 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 89.563 88.995 90.218 90.221 90.549 90.326 68.552 Cr’ # 88.039 86.345 87.576 87.213 87.932 86.749 86.423 Mg# 39.493 38.764 35.314 35.754 34.540 34.823 38.204 Mg”# 40.870 41.128 37.413 38.188 36.577 37.651 40.083 Fe3+ 1.701 2.977 2.928 3.335 2.890 3.961 2.404 Table C.5C Sample Z8*Sh3 Dunite Microprobe Analysis & Calculated Formule (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 442 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R t% Wt% Wt% Wt% Wt% 0.000 0.000 0.000 0.000 0.000 5.350 4.999 5.014 4.983 4.972 0.018 0.086 0.018 0.051 0.106 62.456 64.427 64.095 63.688 63.069 3.097 1.258 1.760 1.812 2.392 20.781 20.970 20.812 21.149 21.531 0.796 0.724 0.784 0.725 0.759 7.337 7.234 7.328 7.078 6.807 0.000 0.043 0.009 0.074 0.019 0.015 0.010 0.001 0.013 0.025 0.215 0.173 0.205 0.252 0.127 0.037 0.021 0.030 0.118 0.131 0.206 0.110 0.121 0.238 0.300 0.000 0.071 0.000 0.000 0.000 100.309 100.126 100.176 100.181 100.239 0.000 0.000 0.000 0.000 0.000 0.216 0.203 0.203 0.203 0.202 0.000 0.002 0.000 0.001 0.003 1.695 1.755 1.744 1.737 1.723 0.080 0.033 0.046 0.047 0.062 0.597 0.604 0.599 0.610 0.622 0.023 0.021 0.023 0.021 0.022 0.376 0.372 0.376 0.364 0.351 0.000 0.001 0.000 0.002 0.001 0.001 0.000 0.000 0.000 0.001 0.006 0.005 0.006 0.007 0.004 0.001 0.000 0.000 0.002 0.002 0.005 0.003 0.003 0.006 0.008 0.000 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Average 88.676 89.632 89.557 89.555 89.485 85.114 88.164 87.509 87.435 86.685 87.099 35.690 36.846 36.839 35.645 33.876 36.316 38.627 38.078 38.561 37.367 36.042 4.017 1.638 2.287 2.368 3.129 443 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides w t% W t% Wt% Wt% W t% Wt% W t% 3102 0.009 0.000 0.009 0.000 0.021 0.027 0.032 AI203 10.024 9.988 10.228 8.915 10.423 8.314 9.688 TI02 0.111 0.107 0.063 0.068 0.087 0.107 0.112 C r203 58.510 58.885 59.156 58.958 58.653 59.573 59.099 F e203 2.399 2.553 1.978 3.236 2.528 2.888 2.197 FeO 19.716 17.917 17.922 19.645 17.498 19.873 19.182 MnO 0.709 0.646 0.673 0.777 0.659 0.717 0.691 MgO 8.604 9.797 9.834 8.458 10.099 8.281 9.031 NIO 0.000 0.064 0.017 0.032 0.084 0.063 0.031 CaO 0.017 0.014 0.006 0.000 0.004 0.008 0.000 V203 0.035 0.102 0.119 0.065 0.082 0.113 0.076 N b205 0.000 0.052 0.030 0.007 0.007 0.084 0.060 ZnO 0.107 0.122 0.112 0.162 0.108 0.239 0.020 P t0 2 0.000 0.008 0.049 0.000 0.000 0.000 0.000 Total 100.240 100.256 100.198 100.324 100.252 100.288 100.220 C ations 314+ 0.000 0.000 0.000 0.000 0.001 0.001 0.001 AI3+ 0.394 0.389 0.398 0.352 0.404 0.330 0.380 TI4+ 0.003 0.003 0.002 0.002 0.002 0.003 0.003 Cr3+ 1.542 1.539 1.545 1.562 1.527 1.586 1.555 Fe3+ 0.060 0.064 0.049 0.082 0.063 0.073 0.055 Fe2+ 0.550 0.495 0.495 0.551 0.482 0.559 0.534 Mn2+ 0.020 0.018 0.019 0.022 0.018 0.020 0.019 Mg2+ 0.428 0.483 0.484 0.423 0.496 0.416 0.448 NI2+ 0.000 0.002 0.000 0.001 0.002 0.002 0.001 Ca2+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.001 0.003 0.003 0.002 0.002 0.003 0.002 NbS+ 0.000 0.001 0.000 0.000 0.000 0.001 0.001 Zn2+ 0.003 0.003 0.003 0.004 0.003 0.006 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 79.658 79.819 79.507 81.607 79.058 82.778 80.363 Cr*# 77.256 77.273 77.545 78.270 76.575 79.733 78.141 M g# 41.218 46.349 47.083 40.061 47.658 39.645 43.210 Mg"# 43.756 49.359 49.447 43.421 50.712 42.620 45.631 Fe3+ 3.014 3.189 2.468 4.089 3.141 3.679 2.765 Table C.51; Sample Z8-Sh5 Chromite bearing dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 444 CR4-A2-R CR5-A1-C CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR9-A1-C t% Wt% Wt% Wt% W t% Wt% Wt% W t% 0.004 0.009 0.000 0.017 0.013 0.024 0.000 0.013 9.126 9.885 9.829 9.155 10.124 9.989 9.534 10.003 0.030 0.161 0.114 0.113 0.124 0.104 0.102 0.085 58.414 59.189 59.506 58.222 59.362 59.309 58.738 59.242 3.665 1.918 2.216 4.125 1.965 2.118 2.800 2.170 19.379 18.131 17.371 18.256 17.911 17.908 18.952 18.152 0.724 0.604 0.699 0.757 0.662 0.740 0.781 0.707 8.669 9.778 10.112 9.382 9.861 9.742 8.953 9.680 0.000 0.009 0.094 0.114 0.088 0.126 0.046 0.038 0.010 0.000 0.006 0.000 0.003 0.000 0.000 0.000 0.124 0.096 0.102 0.129 0.054 0.072 0.137 0.128 0.000 0.216 0.073 0.000 0.030 0.000 0.014 0.000 0.223 0.196 0.099 0.142 0.000 0.047 0.184 0.000 0.000 0.000 0.000 0.000 0.000 0.033 0.041 0.000 100.369 100.193 100.221 100.413 100.197 100.212 100.280 100.217 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.360 0.386 0.383 0.359 0.394 0.389 0.374 0.390 0.001 0.004 0.003 0.003 0.003 0.003 0.003 0.002 1.544 1.550 1.554 1.531 1.550 1.551 1.548 1.550 0.092 0.048 0.055 0.103 0.049 0.053 0.070 0.054 0.542 0.502 0.480 0.508 0.495 0.495 0.528 0.502 0.020 0.017 0.020 0.021 0.019 0.021 0.022 0.020 0.432 0.483 0.498 0.465 0.486 0.480 0.445 0.477 0.000 0.000 0.002 0.003 0.002 0.003 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.003 0.003 0.003 0.001 0.002 0.004 0.003 0.000 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.006 0.005 0.002 0.003 0.000 0.001 0.005 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 81.110 80.067 80.242 81.011 79.731 79.932 80.518 79.892 77.363 78.137 78.023 76.815 77.777 77.818 77.680 77.726 40.526 46.748 48.211 43.225 47.180 46.708 42.837 46.185 44.363 49.015 50.926 47.812 49.531 49.231 45.713 48.733 4.620 2.410 2.765 5.179 2.451 2.645 3.524 2.710 445 CR9-A2-RCR10-A1-CCR10-A2-FCR11-A1-CCR11-A2-F WSU-1 WSU-2 WSU-3 t% Wt% Wt% W t% Wt% W t% Wt% Wt% 0.000 0.021 0.019 0.000 0.006 0.091 0.074 0.065 9.825 9.627 9.721 9.838 9.994 10.278 10.557 10.178 0.050 0.111 0.083 0.092 0.141 0.101 0.114 0.122 59.674 59.332 58.923 59.256 58.596 58.465 58.985 57.740 1.780 2.454 2.870 1.933 2.589 2.871 2.594 3.057 18.090 18.253 17.963 18.933 18.428 18.355 17.604 18.107 0.703 0.700 0.637 0.671 0.724 0.326 0.274 0.293 9.794 9.572 9.787 9.078 9.398 9.886 10.488 9.833 0.000 0.028 0.081 0.104 0.043 0.021 0.061 0.075 0.013 0.008 0.000 0.000 0.000 0.004 0.000 0.008 0.096 0.081 0.153 0.118 0.128 0.071 0.096 0.087 0.149 0.014 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.044 0.032 0.082 0.148 0.153 0.141 0.089 0.000 0.000 0.016 0.090 0.064 0.000 0.000 0.000 100.179 100.245 100.285 100.195 100.259 100.621 100.988 99.653 0.000 0.001 0.001 0.000 0.000 0.003 0.002 0.002 0.383 0.376 0.379 0.386 0.391 0.398 0.406 0.398 0.001 0.003 0.002 0.002 0.004 0.002 0.003 0.003 1.562 1.556 1.542 1.559 1.536 1.520 1.521 1.516 0.044 0.061 0.071 0.048 0.065 0.071 0.064 0.076 0.501 0.506 0.497 0.527 0.511 0.505 0.480 0.503 0.020 0.020 0.018 0.019 0.020 0.009 0.008 0.008 0.483 0.473 0.483 0.450 0.465 0.485 0.510 0.487 0.000 0.001 0.002 0.003 0.001 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.002 0.004 0.003 0.003 0.002 0.003 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.002 0.004 0.004 0.003 0.002 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.294 80.523 80.261 80.162 79.730 79.235 78.939 79.192 78.504 78.049 77.382 78.215 77.143 76.405 76.414 76.153 46.995 45.471 45.920 43.907 44.660 45.700 48.394 45.663 49.112 48.315 49.269 46.082 47.618 48.982 51.505 49.188 2.229 3.073 3.588 2.428 3.245 3.572 3.198 3.837 446 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% Wt% Wt% Wt% Wt% Wt% Wt% 5102 0.000 0.000 0.000 0.017 0.000 0.019 0.009 AI203 9.364 9.355 9.558 9.148 8.864 9.068 9.739 T I02 0.033 0.103 0.082 0.105 0.129 0.154 0.169 C r203 59.693 59.614 60.179 59.912 60.907 60.656 60.341 F e203 2.834 2.956 2.211 2.764 1.782 1.701 1.796 FeO 17.250 16.861 16.662 16.859 17.107 17.167 16.380 MnO 0.698 0.758 0.786 0.755 0.720 0.775 0.738 MgO 10.168 10.323 10.496 10.325 10.241 10.193 10.655 NiO 0.084 0.073 0.094 0.130 0.053 0.084 0.038 CaO 0.001 0.000 0.006 0.000 0.000 0.011 0.003 V 203 0.110 0.065 0.069 0.121 0.141 0.076 0.107 N b205 0.000 0.000 0.000 0.044 0.098 0.144 0.000 ZnO 0.015 0.130 0.020 0.097 0.062 0.074 0.204 P t0 2 0.033 0.057 0.057 0.000 0.074 0.050 0.000 Total 100.285 100.296 100.220 100.278 100.176 100.170 100.180 C ations SI4+ 0.000 0.000 0.000 0.001 0.000 0.001 0.000 AI3+ 0.365 0.364 0.371 0.356 0.346 0.354 0.378 TI4+ 0.001 0.003 0.002 0.003 0.003 0.004 0.004 Cr3+ 1.560 1.557 1.569 1.566 1.597 1.589 1.570 Fe3+ 0.071 0.073 0.055 0.069 0.044 0.042 0.044 Fe2+ 0.477 0.466 0.459 0.466 0.474 0.476 0.451 Mn2+ 0.020 0.021 0.022 0.021 0.020 0.022 0.021 Mg2+ 0.501 0.508 0.516 0.509 0.506 0.503 0.523 NI2+ 0.002 0.002 0.002 0.003 0.001 0.002 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.002 0.002 0.003 0.004 0.002 0.003 Nb5+ 0.000 0.000 0.000 0.001 0.001 0.002 0.000 Zn2+ 0.000 0.003 0.000 0.002 0.002 0.002 0.005 Pt4+ 0.000 0.001 0.000 0.000 0.001 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 81.047 81.043 80.856 61.460 82.174 81.777 80.607 Cr*# 78.183 78.057 78.633 78.646 80.336 80.030 78.808 M g# 47.792 48.523 50.077 48.754 49.385 49.284 51.350 Mg'*# 51.237 52.184 52.894 52.193 51.625 51.418 53.696 Fe3* 3.533 3.685 2.750 3.454 2.237 2.136 2.232 Tabla C.S2: Sample Z8-Sh7 Chromite bearing dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 447 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% Wt% Wt% W t% Wt% Wt% Wt% Wt% 0.028 0.000 0.011 0.002 0.000 0.011 0.021 0.000 9.481 9.712 9.229 9.597 9.277 9.635 9.715 9.104 0.115 0.154 0.129 0.089 0.044 0.136 0.137 0.113 59.679 60.883 60.910 62.298 62.984 61.237 61.210 61.113 2.922 1.498 1.724 0.249 -0.179 1.535 1.461 2.283 16.276 16.112 16.317 15.389 15.400 15.035 14.983 14.799 0.707 0.670 0.702 0.691 0.740 0.637 0.727 0.728 10.834 10.935 10.875 11.402 11.431 11.779 11.709 11.680 0.103 0.100 0.054 0.000 0.030 0.000 0.057 0.076 0.000 0.000 0.000 0.027 0.000 0.000 0.011 0.000 0.031 0.066 0.079 0.113 0.073 0.057 0.052 0.100 0.060 0.000 0.144 0.000 0.124 0.060 0.037 0.030 0.056 0.021 0.000 0.053 0.000 0.000 0.000 0.122 0.000 0.000 0.000 0.115 0.059 0.033 0.024 0.082 100.293 100.151 100.174 100.025 99.982 100.155 100.144 100.230 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.368 0.376 0.358 0.371 0.359 0.371 0.374 0.352 0.003 0.004 0.003 0.002 0.001 0.003 0.003 0.003 1.552 1.581 1.587 1.616 1.636 1.582 1.582 1.584 0.072 0.037 0.043 0.006 -0.004 0.038 0.036 0.056 0.448 0.443 0.450 0.422 0.423 0.411 0.410 0.406 0.020 0.019 0.020 0.019 0.021 0.018 0.020 0.020 0.531 0.536 0.534 0.558 0.560 0.574 0.570 0.571 0.003 0.003 0.001 0.000 0.001 0.000 0.001 0.002 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.002 0.002 0.003 0.002 0.002 0.001 0.003 0.001 0.000 0.002 0.000 0.002 0.001 0.001 0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.000 0.003 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.852 80.789 81.576 81.325 81.997 81.002 80.867 81.829 77.917 79.289 79.821 81.075 82.180 79.467 79.408 79.516 50.533 52.752 52.037 56.556 57.212 56.122 56.154 55.266 54.266 54.749 54.298 56.910 56.954 58.273 58.213 58.453 3.631 1.856 2.151 0.308 •0.223 1.896 1.804 2.827 448 CR8-A2-R CR9-A1-C CR9-A2-R Wt % Wt % Wt % 0.000 0.024 0.000 9.448 8.679 8.456 0.109 0.027 0.098 61.135 60.103 59.442 1.987 2.930 3.502 15.183 17.637 17.663 0.615 0.797 0.665 11.615 9.839 9.846 0.027 0.103 0.126 0.000 0.007 0.000 0.079 0.073 0.107 0.000 0.075 0.203 0.000 0.000 0.170 0.000 0.000 0.073 100.199 100.293 100.351 0.000 0.001 0.000 0.364 0.340 0.332 0.003 0.001 0.002 1.582 1.579 1.565 0.049 0.073 0.088 0.416 0.490 0.492 0.017 0.022 0.019 0.567 0.487 0.489 0.001 0.003 0.003 0.000 0.000 0.000 0.002 0.002 0.003 0.000 0.001 0.003 0.000 0.000 0.004 0.000 0.000 0.001 3.000 3.000 3.000 Average 81.276 62.287 82.504 79.282 79.261 78.856 79.376 54.955 46.384 45.749 51.605 57.693 49.861 49.842 2.453 3.678 4.421 449 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides w t% Wt% Wt% Wt% Wt% Wt% W t% SI02 0.015 0.015 0.030 0.033 0.034 0.025 0.039 AI203 9.434 9.754 9.351 9.786 10.082 9.816 9.800 TIG2 0.150 0.144 0.149 0.135 0.108 0.038 0.210 C r203 60.026 59.805 59.641 60.313 59.673 60.746 59.493 F e203 2.957 3.014 3.332 1.456 2.747 1.591 2.770 FeO 15.143 15.162 15.331 17.372 14.946 15.709 16.006 MnO 0.744 0.632 0.622 0.664 0.623 0.554 0.620 MgO 11.595 11.661 11.399 10.210 11.842 11.311 11.087 NIO 0.070 0.000 0.095 0.008 0.052 0.015 0.023 CaO 0.007 0.010 0.015 0.003 0.000 0.001 0.000 V203 0.018 0.070 0.082 0.112 0.096 0.108 0.089 N b205 0.075 0.000 0.000 0.000 0.000 0.000 0.014 ZnO 0.002 0.035 0.163 0.020 0.021 0.120 0.127 P t0 2 0.058 0.000 0.122 0.034 0.049 0.125 0.000 Total 100.295 100.302 100.333 100.147 100.275 100.159 100.278 C ations SW+ 0.000 0.000 0.001 0.001 0.001 0.001 0.001 AI3+ 0.364 0.375 0.361 0.381 0.387 0.379 0.379 TI4+ 0.004 0.004 0.004 0.003 0.003 0.001 0.005 Cr3+ 1.554 1.544 1.546 1.574 1.537 1.574 1.542 Fe3+ 0.073 0.074 0.082 0.036 0.067 0.039 0.068 Fe2+ 0.415 0.414 0.420 0.480 0.407 0.431 0.439 Mn2+ 0.021 0.017 0.017 0.019 0.017 0.015 0.017 Mg2+ 0.566 0.568 0.557 0.502 0.575 0.553 0.542 NI2+ 0.002 0.000 0.003 0.000 0.001 0.000 0.001 Ca2+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 V3+ 0.000 0.002 0.002 0.003 0.003 0.003 0.002 Nb5+ 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.000 0.001 0.004 0.000 0.001 0.003 0.003 R 4+ 0.001 0.000 0.001 0.000 0.000 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 81.018 80.443 81.056 80.523 79.881 80.588 80.286 Cr*# 78.053 77.454 77.707 79.060 77.180 79.001 77.528 M g# 53.725 53.767 52.576 49.346 54.791 54.050 51.653 Mg"# 57.717 57.824 56.997 51.164 58.547 56.207 55.253 Fe3+ 3.660 3.716 4.132 1.817 3.382 1.970 3.436 Table C.53: Sample Z8-Sh8 Chromite rich dunite Microprobe Analytfs & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 450 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C :% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 0.015 0.017 0.000 0.002 0.000 0.015 0.000 0.009 9.524 9.367 9.658 9.963 9.680 9.823 9.942 9.782 0.109 0.167 0.080 0.139 0.130 0.129 0.136 0.081 59.506 60.080 60.135 59.791 60.457 59.894 60.363 60.388 3.193 2.746 2.785 2.528 1.821 2.940 2.387 2.360 15.863 15.103 15.254 15.520 16.206 14.078 14.368 14.180 0.601 0.641 0.535 0.651 0.576 0.600 0.608 0.606 11.211 11.618 11.582 11.425 11.002 12.417 12.146 12.368 0.081 0.076 0.011 0.038 0.019 0.095 0.062 0.062 0.000 0.000 0.000 0.006 0.010 0.000 0.000 0.000 0.110 0.091 0.104 0.114 0.124 0.100 0.092 0.089 0.068 0.105 0.000 0.000 0.084 0.114 0.016 0.206 0.021 0.149 0.133 0.000 0.072 0.039 0.087 0.105 0.016 0.115 0.000 0.074 0.000 0.049 0.033 0.000 100.320 100.275 100.277 100.252 100.182 100.294 100.240 100.236 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.368 0.362 0.372 0.384 0.375 0.376 0.381 0.375 0.003 0.004 0.002 0.003 0.003 0.003 0.003 0.002 1.543 1.556 1.555 1.546 1.570 1.539 1.553 1.553 0.079 0.068 0.069 0.062 0.045 0.072 0.058 0.058 0.435 0.414 0.417 0.424 0.445 0.383 0.391 0.386 0.017 0.018 0.015 0.018 0.016 0.017 0.017 0.017 0.548 0.567 0.565 0.557 0.539 0.602 0.589 0.600 0.002 0.002 0.000 0.001 0.001 0.002 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.002 0.003 0.003 0.003 0.003 0.002 0.002 0.001 0.002 0.000 0.000 0.001 0.002 0.000 0.003 0.001 0.004 0.003 0.000 0.002 0.001 0.002 0.003 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.737 81.143 80.684 80.102 80.731 80.355 80.287 80.549 77.539 78.376 77.913 77.600 78.904 77.447 77.932 78.206 51.612 54.096 53.758 53.370 52.359 56.963 56.727 57.487 55.749 57.829 57.510 56.753 54.755 61.125 60.110 60.857 3.960 3.410 3.434 3.123 2.263 3.619 2.933 2.909 451 CR8-A2-R CR9-A1-C CR9-A2-F CR10-A1-C CR10-A2 WSU-1 WSU-2 WSU-3 WSU-4 t% Wt% Wt % Wt % Wt% W t% Wt% W t% Wt% 0.006 0.006 0.000 0.000 0.000 0.095 0.068 0.091 0.076 9.324 9.836 9.322 10.072 9.903 10.518 10.479 10.476 10.948 0.131 0.103 0.043 0.129 0.047 0.139 0.099 0.142 0.136 61.084 60.209 60.403 60.211 60.623 59.725 58.469 59.771 59.347 2.261 2.554 2.710 2.670 2.320 2.723 3.675 2.605 2.887 14.533 14.014 14.191 13.853 13.758 14.714 15.054 14.453 13.906 0.682 0.626 0.586 0.668 0.617 0.242 0.283 0.242 0.233 12.012 12.502 12.352 12.444 12.680 12.434 12.024 12.536 12.951 0.018 0.077 0.067 0.138 0.031 0.020 0.086 0.056 0.060 0.000 0.008 0.001 0.008 0.000 0.015 0.018 0.011 0.014 0.108 0.104 0.051 0.076 0.102 0.093 0.077 0.111 0.106 0.045 0.183 0.280 0.000 0.136 0.000 0.000 0.000 0.000 0.021 0.000 0.139 0.000 0.000 0.046 0.045 0.033 0.063 0.000 0.033 0.124 0.000 0.016 0.000 0.000 0.000 0.000 100.225 100.256 100.269 100.268 100.233 100.763 100.377 100.527 100.729 0.000 0.000 0.000 0.000 0.000 0.003 0.002 0.003 0.002 0.359 0.377 0.358 0.385 0.379 0.400 0.401 0.399 0.414 0.003 0.003 0.001 0.003 0.001 0.003 0.002 0.003 0.003 1.577 1.547 1.558 1.545 1.555 1.522 1.501 1.526 1.505 0.056 0.062 0.067 0.065 0.057 0.066 0.090 0.063 0.070 0.397 0.381 0.387 0.376 0.373 0.397 0.409 0.390 0.373 0.019 0.017 0.016 0.018 0.017 0.007 0.008 0.007 0.006 0.585 0.606 0.601 0.602 0.613 0.598 0.582 0.603 0.619 0.000 0.002 0.002 0.004 0.001 0.001 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.003 0.003 0.001 0.002 0.003 0.002 0.002 0.003 0.003 0.001 0.003 0.004 0.000 0.002 0.000 0.000 0.000 0.000 0.001 0.000 0.003 0.000 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 81.464 80.417 81.298 80.042 80.418 79.207 78.917 79.285 78.433 79.191 77.888 78.570 77.426 78.130 76.575 75.359 76.760 75.684 56.378 57.739 56.973 57.710 58.789 56.357 53.860 57.086 58.314 59.569 61.394 60.809 61.558 62.164 60.102 58.742 60.724 62.409 2.790 3.145 3.355 3.268 2.846 3.323 4.508 3.185 3.505 452 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% W t% Wt% Wt% W t% Wt% W t% 3102 0.000 0.024 0.000 0.000 0.002 0.004 0.000 AI203 10.005 11.033 10.948 11.123 11.179 11.432 11.091 TI02 0.131 0.125 0.062 0.212 0.144 0.137 0.102 C r203 58.517 56.642 57.570 57.022 57.317 56.549 57.502 F e203 3.403 4.698 3.141 3.170 3.242 3.701 3.348 FeO 16.209 15.635 16.975 17.969 16.743 16.388 16.134 MnO 0.710 0.675 0.729 0.596 0.603 0.676 0.613 MgO 10.808 11.379 10.510 10.021 10.745 11.013 10.981 NIO 0.050 0.088 0.027 0.048 0.105 0.051 0.115 CaO 0.000 0.000 0.000 0.001 0.000 0.008 0.003 V203 0.138 0.047 0.124 0.086 0.100 0.139 0.075 N b205 0.000 0.000 0.030 0.068 0.068 0.149 0.000 ZnO 0.237 0.127 0.091 0.000 0.077 0.122 0.249 P t0 2 0.133 0.000 0.107 0.000 0.000 0.000 0.123 Total 100.342 100.471 100.316 100.316 100.325 100.370 100.336 C ations 314+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 AI3+ 0.387 0.423 0.423 0.431 0.430 0.439 0.427 TI4+ 0.003 0.003 0.002 0.005 0.004 0.003 0.003 Cr3+ 1.519 1.456 1.492 1.481 1.481 1.456 1.484 Fe3+ 0.084 0.115 0.077 0.078 0.080 0.091 0.082 Fe2+ 0.445 0.425 0.465 0.494 0.457 0.446 0.441 Mn2+ 0.020 0.019 0.020 0.017 0.017 0.019 0.017 Mg2+ 0.529 0.552 0.513 0.491 0.523 0.535 0.534 NI2+ 0.001 0.002 0.001 0.001 0.003 0.001 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.004 0.001 0.003 0.002 0.003 0.004 0.002 Nb5+ 0.000 0.000 0.000 0.001 0.001 0.002 0.000 Zn2+ 0.006 0.003 0.002 0.000 0.002 0.003 0.006 Pt4+ 0.001 0.000 0.001 0.000 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 79.689 77.498 77.913 77.472 77.474 76.843 77.669 Cr*# 76.323 73.030 74.883 74.421 74.372 73.333 74.464 M g# 49.993 50.527 48.617 46.176 49.347 49.890 50.552 Mg"# 54.308 56.473 52.464 49.852 53.358 54.503 54.817 Fe3+ 4.224 5.765 3.888 3.938 4.005 4.568 4.127 Table C.54: Sample Z8*Sh9 Chromite bearing Dunite Microprobe Analysia & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 453 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% Wt% W t% Wt% W t% Wt% W t% W t% 0.013 0.047 0.000 0.000 0.000 0.000 0.013 0.000 12.905 11.343 11.491 11.144 10.696 11.526 11.627 11.022 0.162 0.187 0.193 0.152 0.138 0.170 0.150 0.159 54.484 57.504 56.872 57.597 57.940 57.615 57.801 57.823 4.751 3.151 3.574 2.613 3.078 2.857 2.261 3.248 15.621 15.709 16.005 16.582 16.457 15.897 16.862 16.007 0.539 0.560 0.588 0.595 0.576 0.604 0.621 0.583 11.740 11.454 11.209 10.953 10.887 11.345 10.714 11.249 0.051 0.111 0.042 0.059 0.069 0.099 0.059 0.065 0.000 0.000 0.000 0.007 0.015 0.004 0.006 0.001 0.162 0.000 0.085 0.116 0.125 0.099 0.091 0.075 0.007 0.083 0.016 0.239 0.118 0.046 0.000 0.023 0.041 0.166 0.199 0.123 0.169 0.024 0.024 0.030 0.000 0.000 0.083 0.083 0.040 0.000 0.000 0.041 100.476 100.317 100.358 100.262 100.309 100.286 100.228 100.325 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.489 0.434 0.441 0.429 0.413 0.441 0.447 0.423 0.004 0.005 0.005 0.004 0.003 0.004 0.004 0.004 1.386 1.477 1.463 1.488 1.499 1.480 1.491 1.490 0.115 0.077 0.088 0.064 0.076 0.070 0.055 0.080 0.420 0.427 0.435 0.453 0.450 0.432 0.460 0.436 0.015 0.015 0.016 0.016 0.016 0.017 0.017 0.016 0.563 0.555 0.544 0.533 0.531 0.549 0.521 0.546 0.001 0.003 0.001 0.002 0.002 0.003 0.002 0.002 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.004 0.000 0.002 0.003 0.003 0.003 0.002 0.002 0.000 0.001 0.000 0.004 0.002 0.001 0.000 0.000 0.001 0.004 0.005 0.003 0.004 0.001 0.001 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 73.906 77.276 76.853 77.614 78.421 77.029 76.932 77.872 69.634 74.282 73.475 75.097 75.429 74.327 74.790 74.759 51.264 52.403 50.969 50.769 50.233 52.268 50.265 51.439 57.260 56.516 55.525 54.075 54.113 55.988 53.109 55.609 5.779 3.875 4.395 3.242 3.814 3.508 2.785 3.997 454 CR8-A1-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-R t% Wt% Wt% Wt% Wt% 0.000 0.000 0.000 0.000 0.000 11.494 11.170 11.492 10.914 12.357 0.148 0.217 0.144 0.115 0.274 56.789 56.366 55.484 56.811 53.545 3.343 3.689 4.529 4.368 5.488 16.646 17.470 17.502 16.377 17.430 0.666 0.623 0.644 0.605 0.640 10.815 10.323 10.301 10.974 10.391 0.129 0.046 0.039 0.038 0.118 0.001 0.006 0.007 0.003 0.003 0.061 0.119 0.146 0.146 0.170 0.089 0.189 0.000 0.000 0.047 0.055 0.151 0.026 0.062 0.078 0.098 0.000 0.139 0.024 0.008 100.335 100.369 100.452 100.437 100.549 0.000 0.000 0.000 0.000 0.000 0.442 0.431 0.443 0.420 0.474 0.004 0.005 0.004 0.003 0.007 1.465 1.461 1.435 1.466 1.378 0.082 0.091 0.112 0.107 0.134 0.454 0.479 0.479 0.447 0.474 0.018 0.017 0.018 0.017 0.018 0.526 0.504 0.503 0.534 0.504 0.003 0.001 0.001 0.001 0.003 0.000 0.000 0.000 0.000 0.000 0.002 0.003 0.004 0.004 0.004 0.001 0.003 0.000 0.000 0.001 0.001 0.004 0.001 0.001 0.002 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 Average 76.822 77.196 76.408 77.738 74.404 73.651 73.654 72.127 73.554 69.369 73.749 49.518 46.953 45.976 49.065 45.297 49.576 53.665 51.298 51.200 54.431 51.520 4.127 4.588 5.604 5.383 6.768 455 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% W t% 3102 0.000 0.000 0.000 0.000 0.000 0.000 0.002 A I203 10.504 11.078 10.466 10.991 10.442 10.305 10.074 1102 0.013 0.095 0.075 0.026 0.013 0.010 0.084 C r203 59.114 58.427 58.766 57.168 58.837 58.277 58.754 F e2 0 3 1.463 1.471 1.788 2.762 1.625 2.081 1.463 FeO 18.758 18.778 19.130 19.019 19.264 20.224 19.961 MnO 0.678 0.670 0.618 0.664 0.616 0.631 0.681 MgO 9.313 9.298 9.091 9.295 8.965 8.247 8.466 NiO 0.042 0.073 0.000 0.037 0.021 0.078 0.057 CaO 0.007 0.004 0.000 0.000 0.000 0.000 0.013 V 203 0.173 0.147 0.136 0.193 0.205 0.148 0.151 N b205 0.000 0.000 0.000 0.104 0.000 0.000 0.201 ZnO 0.032 0.106 0.108 0.018 0.150 0.206 0.241 P t0 2 0.049 0.000 0.000 0.000 0.025 0.000 0.000 T otal 100.148 100.147 100.179 100.277 100.163 100.206 100.147 C ations Si4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.410 0.431 0.409 0.428 0.409 0.405 0.397 Ti4+ 0.000 0.002 0.002 0.001 0.000 0.000 0.002 Cr3+ 1.548 1.526 1.541 1.493 1.545 1.538 1.551 Fe3+ 0.036 0.037 0.045 0.069 0.041 0.052 0.037 Fe2+ 0.519 0.519 0.531 0.525 0.535 0.565 0.557 Mn2+ 0.019 0.019 0.017 0.019 0.017 0.018 0.019 Mg2+ 0.460 0.458 0.449 0.458 0.444 0.410 0.421 Ni2+ 0.001 0.002 0.000 0.001 0.001 0.002 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.005 0.004 0.004 0.005 0.005 0.004 0.004 Nb5+ 0.000 0.000 0.000 0.002 0.000 0.000 0.003 Zn2+ 0.001 0.003 0.003 0.000 0.004 0.005 0.006 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 T otal 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 79.058 77.964 79.022 77.724 79.080 79.139 79.643 Cr*# 77.613 76.534 77.254 75.042 77.469 77.066 78.168 M g# 45.265 45.190 43.863 43.519 43.536 39.951 41.495 M g"# 46.951 46.882 45.860 46.557 45.342 42.093 43.053 Fe3+ 1.829 1.834 2.238 3.451 2.036 2.619 1.853 Table C.55: Sample Z8>Sh11 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 456 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C WSU-1 WSU-2 WSU-3 t % W t% Wt% W t% Wt% Wt% W t% Wt% W t% 0.000 0.000 0.021 0.000 0.010 0.000 0.027 0.075 0.048 9.729 9.411 9.668 10.045 9.821 9.689 10.649 9.821 10.252 0.062 0.048 0.084 0.088 0.061 0.075 0.035 0.031 0.079 58.271 58.927 57.790 58.387 58.348 59.124 58.089 59.171 57.672 2.422 2.281 3.284 2.313 2.477 1.973 2.030 2.298 3.133 21.034 20.075 20.030 19.744 19.837 19.653 18.746 18.991 19.603 0.660 0.655 0.741 0.616 0.689 0.627 0.322 0.279 0.333 7.652 8.266 8.332 8.523 8.496 8.544 9.445 9.391 8.931 0.054 0.050 0.000 0.023 0.057 0.042 0.000 0.014 0.021 0.000 0.000 0.020 0.000 0.000 0.000 0.024 0.000 0.013 0.141 0.173 0.173 0.151 0.118 0.151 0.187 0.200 0.167 0.000 0.030 0.007 0.015 0.029 0.000 0.000 0.000 0.000 0.218 0.230 0.162 0.319 0.158 0.273 0.121 0.211 0.260 0.000 0.080 0.016 0.008 0.147 0.049 0.000 0.000 0.000 100.243 100.226 100.328 100.231 100.249 100.199 99.675 100.483 100.511 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.002 0.002 0.385 0.372 0.381 0.395 0.387 0.382 0.417 0.383 0.401 0.002 0.001 0.002 0.002 0.002 0.002 0.001 0.001 0.002 1.548 1.562 1.528 1.540 1.542 1.562 1.525 1.549 1.512 0.061 0.058 0.083 0.058 0.062 0.050 0.051 0.057 0.078 0.591 0.563 0.560 0.551 0.554 0.549 0.521 0.526 0.543 0.019 0.019 0.021 0.017 0.020 0.018 0.009 0.008 0.009 0.383 0.413 0.415 0.424 0.423 0.426 0.467 0.463 0.441 0.001 0.001 0.000 0.001 0.002 0.001 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.004 0.005 0.005 0.004 0.003 0.004 0.005 0.005 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.006 0.004 0.008 0.004 0.007 0.003 0.005 0.006 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.071 80.771 80.039 79.589 79.942 80.368 78.537 80.165 79.053 77.612 78.436 76.718 77.270 77.440 78.367 76.538 77.858 75.948 37.012 39.972 39.252 41.043 40.701 41.547 45.006 44.287 41.521 39.338 42.330 42.578 43.488 43.294 43.662 47.317 46.850 44.816 3.071 2.890 4.150 2.914 3.129 2.489 2.546 2.878 3.927 457 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% Wt% 3102 0.000 0.000 0.011 0.000 0.006 0.000 0.000 AI203 10.945 11.033 10.961 11.307 10.893 10.833 10.858 T i02 0.062 0.166 0.073 0.110 0.133 0.100 0.023 C r203 57.756 57.947 58.423 57.525 58.586 58.059 58.266 F e203 2.942 2.183 2.234 2.716 1.919 2.406 2.713 FeO 16.578 17.043 17.109 17.000 17.457 17.400 16.934 MnO 0.720 0.730 0.698 0.655 0.677 0.573 0.624 MgO 10.745 10.522 10.396 10.486 10.263 10.396 10.574 NiO 0.098 0.057 0.066 0.115 0.019 0.059 0.043 CaO 0.000 0.000 0.000 0.015 0.004 0.000 0.000 V203 0.108 0.121 0.137 0.134 0.113 0.140 0.089 N b205 0.112 0.245 0.016 0.000 0.074 0.194 0.007 ZnO 0.143 0.172 0.100 0.095 0.047 0.082 0.074 P t0 2 0.082 0.000 0.000 0.115 0.000 0.000 0.066 Total 100.293 100.218 100.225 100.273 100.191 100.242 100.270 C ations 314+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.422 0.426 0.424 0.436 0.422 0.419 0.419 TI4+ 0.002 0.004 0.002 0.003 0.003 0.002 0.001 Cr3+ 1.495 1.502 1.514 1.489 1.521 1.507 1.509 Fe3+ 0.072 0.054 0.055 0.067 0.047 0.059 0.067 Fe2+ 0.454 0.467 0.469 0.465 0.479 0.478 0.464 Mn2+ 0.020 0.020 0.019 0.018 0.019 0.016 0.017 Mg2+ 0.524 0.514 0.508 0.512 0.502 0.509 0.517 NI2+ 0.003 0.001 0.002 0.003 0.001 0.002 0.001 Ca2+ 0.000 0.000 0.000 0.001 0.000 0.000 0.000 V3+ 0.003 0.003 0.004 0.004 0.003 0.004 0.002 Nb5+ 0.002 0.004 0.000 0.000 0.001 0.003 0.000 Zn2+ 0.003 0.004 0.002 0.002 0.001 0.002 0.002 Pt4+ 0.001 0.000 0.000 0.001 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 77.973 77.893 78.145 77.339 78.298 78.238 78.261 C r # 75.133 75.777 75.984 74.741 76.433 75.895 75.638 M g# 49.907 49.669 49.221 49.014 48.814 48.643 49.312 Mg"# 53.604 52.394 51.997 52.370 51.172 51.575 52.676 Fe3+ 3.643 2.717 2.765 3.359 2.382 2.994 3.352 Table C.56: Sample Z8-Sh12 Chromite bearing Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 458 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% Wt% Wt% Wt% Wt% W t% Wt% Wt% 0.028 0.024 0.043 0.000 0.056 0.024 0.000 0.000 10.452 10.852 10.732 11.169 10.703 10.566 10.755 11.124 0.143 0.088 0.084 0.063 0.123 0.105 0.159 0.115 59.289 58.691 58.435 58.864 58.967 59.522 59.038 58.628 1.183 1.835 2.484 1.541 1.593 1.519 1.730 1.591 17.726 17.362 17.236 17.419 17.820 16.908 16.782 17.137 0.596 0.596 0.701 0.532 0.664 0.696 0.644 0.644 10.124 10.412 10.279 10.334 9.982 10.490 10.644 10.453 0.118 0.082 0.055 0.046 0.000 0.023 0.020 0.051 0.000 0.000 0.015 0.000 0.031 0.000 0.000 0.000 0.079 0.104 0.044 0.071 0.128 0.136 0.157 0.126 0.211 0.122 0.000 0.000 0.000 0.014 0.083 0.099 0.071 0.000 0.139 0.067 0.076 0.147 0.160 0.143 0.098 0.016 0.000 0.049 0.016 0.000 0.000 0.050 100.118 100.184 100.249 100.154 100.160 100.151 100.172 100.160 0.001 0.001 0.001 0.000 0.002 0.001 0.000 0.000 0.406 0.420 0.415 0.432 0.415 0.409 0.415 0.430 0.004 0.002 0.002 0.002 0.003 0.003 0.004 0.003 1.546 1.523 1.517 1.526 1.535 1.545 1.530 1.520 0.029 0.045 0.061 0.038 0.039 0.038 0.043 0.039 0.489 0.476 0.473 0.478 0.491 0.464 0.460 0.470 0.017 0.017 0.020 0.015 0.019 0.019 0.018 0.018 0.498 0.509 0.503 0.505 0.490 0.513 0.520 0.511 0.003 0.002 0.001 0.001 0.000 0.001 0.001 0.001 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.002 0.003 0.001 0.002 0.003 0.004 0.004 0.003 0.003 0.002 0.000 0.000 0.000 0.000 0.001 0.001 0.002 0.000 0.003 0.002 0.002 0.004 0.004 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.190 78.392 78.507 77.952 78.705 79.075 78.644 77.953 78.017 76.606 76.090 76.466 77.144 77.585 76.956 76.414 48.991 49.397 48.481 49.485 48.032 50.573 50.850 50.089 50.448 51.667 51.529 51.399 49.965 52.515 53.064 52.094 1.481 2.279 3.078 1.905 1.983 1.885 2.147 1.974 459 CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-' CR10-A2-I CR11-A1-' CR11-A2-I CR12-A1-* % Wt% wt% wt% wt% wt% wt% wt% 0.000 0.000 0.017 0.028 0.009 0.000 0.000 0.019 10.156 10.884 9.923 10.713 11.035 10.772 10.403 10.472 0.133 0.158 0.078 0.133 0.082 0.116 0.047 0.093 59.427 58.557 59.288 58.513 58.482 59.693 59.818 59.023 1.828 1.814 2.236 2.327 2.147 1.169 1.553 2.007 17.761 17.064 18.005 17.118 16.833 17.005 17.091 17.307 0.633 0.628 0.628 0.681 0.643 0.697 0.646 0.677 9.918 10.544 9.804 10.434 10.541 10.355 10.425 10.180 0.048 0.059 0.000 0.013 0.042 0.102 0.047 0.036 0.008 0.006 0.001 0.003 0.011 0.008 0.000 0.000 0.180 0.163 0.080 0.178 0.131 0.051 0.117 0.153 0.000 0.180 0.000 0.000 0.000 0.000 0.000 0.000 0.089 0.115 0.081 0.067 0.227 0.150 0.009 0.210 0.000 0.008 0.082 0.024 0.033 0.000 0.000 0.024 100.181 100.181 100.223 100.233 100.214 100.117 100.157 100.200 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.001 0.395 0.421 0.387 0.414 0.426 0.417 0.403 0.406 0.003 0.004 0.002 0.003 0.002 0.003 0.001 0.002 1.551 1.518 1.551 1.518 1.515 1.550 1.554 1.536 0.045 0.045 0.056 0.057 0.053 0.029 0.038 0.050 0.490 0.468 0.498 0.470 0.461 0.467 0.470 0.476 0.018 0.017 0.018 0.019 0.018 0.019 0.018 0.019 0.488 0.515 0.484 0.510 0.515 0.507 0.511 0.500 0.001 0.002 0.000 0.000 0.001 0.003 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.005 0.004 0.002 0.005 0.003 0.001 0.003 0.004 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.003 0.002 0.002 0.005 0.004 0.000 0.005 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.698 78.305 80.033 78.560 78.048 78.803 79.413 79.084 77.881 76.538 77.798 76.291 75.976 77.662 77.884 77.110 47.672 50.131 46.612 49.191 50.034 50.550 50.128 48.704 49.885 52.414 49.254 52.075 52.747 52.049 52.091 51.185 2.280 2.257 2.792 2.888 2.654 1.447 1.925 2.496 460 CR12-A2-I CR13-A1-' CR13-A2-R Wt % Wt % Wt % 0.000 0.024 0.000 10.907 10.646 10.713 0.110 0.101 0.047 58.115 59.466 59.142 2.686 1.315 1.571 16.841 17.131 17.142 0.609 0.796 0.604 10.629 10.321 10.436 0.057 0.094 0.051 0.000 0.006 0.003 0.109 0.125 0.202 0.037 0.000 0.107 0.120 0.000 0.139 0.049 0.108 0.000 100.269 100.133 100.157 0.000 0.001 0.000 0.421 0.412 0.415 0.003 0.002 0.001 1.505 1.546 1.535 0.066 0.033 0.039 0.461 0.471 0.471 0.017 0.022 0.017 0.519 0.506 0.511 0.001 0.002 0.001 0.000 0.000 0.000 0.003 0.003 0.005 0.001 0.000 0.002 0.003 0.000 0.003 0.000 0.001 0.000 3.000 3.000 3.000 Average 78.139 78.935 78.738 75.542 77.646 77.202 76.631 49.593 50.115 50.065 49.357 52.942 51.784 52.045 3.324 1.634 1.951 461 Label CR1-A1-C CR1-A1-R CR2-A1-C CR2-A1-R CR3-A1-C CR3-A2-R CR4-A1-C O xides W t% Wt% Wt% Wt% Wt% Wt% Wt% SI02 0.000 0.002 0.000 0.000 0.024 0.004 0.000 AI203 12.240 11.167 12.255 11.027 12.323 10.463 12.145 TI02 0.077 0.077 0.070 0.106 0.139 0.073 0.116 C r203 58.772 60.275 59.013 60.535 58.862 60.519 58.997 Fe203 2.191 1.457 1.881 0.883 1.469 1.859 1.808 FeO 12.548 13.515 12.658 13.890 13.318 13.750 12.908 MnO 0.590 0.610 0.610 0.584 0.570 0.583 0.671 MgO 13.625 12.799 13.557 12.659 13.205 12.596 13.274 NIC 0.056 0.079 0.022 0.083 0.062 0.116 0.119 CaO 0.000 0.003 0.003 0.004 0.000 0.000 0.001 V203 0.104 0.085 0.121 0.137 0.092 0.106 0.131 N b205 0.000 0.000 0.000 0.142 0.084 0.000 0.000 ZnO 0.000 0.077 0.000 0.036 0.000 0.050 0.012 P t02 0.016 0.000 0.000 0.000 0.000 0.065 0.000 Total 100.219 100.147 100.189 100.088 100.148 100.184 100.181 C ations SI4+ 0.000 0.000 0.000 0.000 0.001 0.000 0.000 AI3+ 0.460 0.424 0.461 0.420 0.465 0.399 0.458 TI4+ 0.002 0.002 0.002 0.003 0.003 0.002 0.003 Cr3+ 1.482 1.536 1.489 1.546 1.489 1.549 1.492 Fe3+ 0.053 0.035 0.045 0.021 0.035 0.045 0.044 Fe2+ 0.335 0.364 0.338 0.375 0.356 0.372 0.345 Mn2+ 0.016 0.017 0.016 0.016 0.015 0.016 0.018 Mg2+ 0.648 0.615 0.645 0.610 0.630 0.608 0.633 NB+ 0.001 0.002 0.001 0.002 0.002 0.003 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.002 0.003 0.004 0.002 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.002 0.001 0.000 0.000 Zn2+ 0.000 0.002 0.000 0.001 0.000 0.001 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 76.309 78.360 76.362 78.644 76.215 79.509 76.519 Cr"# 74.297 76.972 74.633 77.794 74.860 77.703 74.849 Mg# 62.586 60.613 62.742 60.579 61.654 59.282 61.948 Mg"# 65.936 62.800 65.626 61.900 63.866 62.022 64.703 Fe3+ 2.636 1.771 2.264 1.081 1.778 2.272 2.183 Table C.57: Sample Z8-Sh13.2 Maasive Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 462 CR4-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R WSU-1 1% Wt% Wt% Wt% Wt% W t% W t% Wt% 0.000 0.195 0.000 0.000 0.000 0.019 0.006 0.066 10.552 12.546 10279 12.203 12.113 11.841 10.925 11.584 0.086 0.130 0.060 0.063 0.194 0.080 0.100 0.099 60.360 58.579 61.138 59.230 59.256 59.495 60.302 59.309 2.132 1.239 1.073 1.584 1.438 1.342 1.686 1.524 13.194 13.252 14.561 13.162 13.213 13.597 13.421 13.213 0.689 0.607 0.630 0.593 0.550 0.659 0.653 0.185 12.943 13.291 12.117 13.234 13.196 12.862 12.860 13.237 0.045 0.011 0.064 0.019 0.075 0.041 0.000 0.070 0.000 0.000 0.001 0.000 0.003 0.013 0.015 0.024 0.077 0.146 0.060 0.071 0.041 0.144 0.118 0.092 0.045 0.000 0.104 0.000 0.046 0.000 0.007 0.000 0.091 0.128 0.021 0.000 0.021 0.000 0.075 0.040 0.000 0.000 0.000 0.000 0.000 0.041 0.000 0.000 100.215 100.124 100.107 100.159 100.145 100.134 100.168 99.445 0.000 0.006 0.000 0.000 0.000 0.001 0.000 0.002 0.401 0.472 0.394 0.460 0.457 0.448 0.415 0.441 0.002 0.003 0.001 0.002 0.005 0.002 0.002 0.002 1.541 1.479 1.572 1.498 1.500 1.512 1.538 1.513 0.052 0.030 0.026 0.038 0.035 0.032 0.041 0.037 0.356 0.354 0.396 0.352 0.354 0.365 0.362 0.357 0.019 0.016 0.017 0.016 0.015 0.018 0.018 0.005 0.623 0.633 0.587 0.631 0.630 0.616 0.618 0.637 0.001 0.000 0.002 0.000 0.002 0.001 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.002 0.004 0.002 0.002 0.001 0.004 0.003 0.002 0.001 0.000 0.002 0.000 0.001 0.000 0.000 0.000 0.002 0.003 0.001 0.000 0.000 0.000 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.328 75.800 79.961 76.505 76.645 77.120 78.736 77.450 77.267 74.660 78.906 75.043 75.311 75.864 77.120 76.010 60.422 62.250 58.178 61.791 61.854 60.765 60.545 61.801 63.619 64.128 59.732 64.187 64.033 62.774 63.073 64.103 2.598 1.503 1.319 1.910 1.740 1.628 2.053 1.859 463 5U-2 WSU-3 WSU-4 CrZ8-Sh13, Ave % W t% Wt% 0.101 0.106 0.097 0.034 12.297 12.436 12.281 11.704 0.096 0.110 0.104 0.099 58.074 58.290 58.108 59.395 1.691 1.919 1.667 1.602 13.289 12.878 12.978 13.297 0.166 0.185 0.175 0.517 13.273 13.657 13.437 13.101 0.062 0.077 0.068 0.059 0.008 0.000 0.000 0.004 0.116 0.089 0.123 0.103 0.000 0.000 0.000 0.024 0.033 0.047 0.042 0.037 0.000 0.000 0.000 0.007 99.207 99.795 99.078 99.985 0.003 0.003 0.003 0.001 0.467 0.469 0.467 0.443 0.002 0.003 0.003 0.002 1.480 1.473 1.481 1.510 0.041 0.046 0.040 0.039 0.358 0.344 0.350 0.357 0.005 0.005 0.005 0.014 0.638 0.651 0.646 0.628 0.002 0.002 0.002 0.002 0.000 0.000 0.000 0.000 0.003 0.002 0.003 0.003 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 76.008 75.871 76.043 77.299 74.440 74.109 74.496 75.796 61.502 62.502 62.327 61.297 64.035 65.402 64.859 63.711 2.063 2.323 2.034 1.945 464 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% W t% Si02 0.000 0.027 0.000 0.021 0.032 0.000 0.000 AI203 11.163 11.590 11.353 11.288 11.085 11.530 10.220 Ti02 0.074 0.101 0.173 0.162 0.105 0.063 0.065 Cr203 59.376 57.996 59.199 59.087 58.624 57.503 58.205 Fe203 1.212 1.913 0.295 1.330 1.265 2.449 2.717 FeO 16.731 16.337 17.630 16.289 17.638 17.224 19.255 MnO 0.640 0.574 0.644 0.718 0.536 0.550 0.565 MgO 10.729 11.123 10.145 10.937 10.307 10.474 9.093 NiO 0.041 0.087 0.038 0.023 0.057 0.060 0.000 CaO 0.003 0.000 0.003 0.004 0.000 0.000 0.001 V203 0.093 0.120 0.068 0.128 0.054 0.150 0.149 N b205 0.016 0.083 0.179 0.000 0.195 0.038 0.000 ZnO 0.045 0.059 0.232 0.143 0.097 0.134 0.002 P t0 2 0.000 0.181 0.073 0.000 0.132 0.074 0.000 Total 100.121 100.191 100.032 100.131 100.126 100.246 100.271 C ations Si4+ 0.000 0.001 0.000 0.001 0.001 0.000 0.000 AI3+ 0.430 0.445 0.440 0.434 0.429 0.444 0.400 Ti4+ 0.002 0.002 0.004 0.004 0.003 0.002 0.002 Cr3+ 1.535 1.494 1.538 1.524 1.523 1.487 1.527 Fe3+ 0.030 0.047 0.007 0.033 0.031 0.060 0.068 Fe2+ 0.458 0.445 0.484 0.445 0.485 0.471 0.534 Mn2+ 0.018 0.016 0.018 0.020 0.015 0.015 0.016 Mg2+ 0.523 0.540 0.497 0.532 0.505 0.511 0.450 NK+ 0.001 0.002 0.001 0.001 0.002 0.002 0.000 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.002 0.003 0.002 0.003 0.001 0.004 0.004 Nb5+ 0.000 0.001 0.003 0.000 0.003 0.001 0.000 Zn2+ 0.001 0.001 0.006 0.003 0.002 0.003 0.000 Pt4+ 0.000 0.002 0.001 0.000 0.001 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 78.110 77.048 77.769 77.834 78.011 76.988 79.255 Cr*# 76.942 75.228 77.483 76.558 76.781 74.658 76.559 M g# 51.764 52.338 50.261 52.719 49.458 49.007 42.758 Mg"# 53.339 54.827 50.635 54.481 51.022 52.015 45.706 Fe3+ 1.495 2.362 0.368 1.840 1.577 3.026 3.402 Table C.58: Sample Z8-Sh13 Dunite Microprobe Analyaie & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 465 CR4-A2-R CR6-A1-C CR6-A2-R CR7-A1-C t% W t% Wt% Wt% 0.000 0.009 0.000 0.000 9.429 11.074 10.920 11.132 0.090 0.114 0.129 0.076 58.430 57.428 57.151 57.787 3.401 3.188 3.435 3.126 19.161 17.421 17.751 15.983 0.527 0.537 0.622 0.593 9.096 10.325 10.012 11.141 0.000 0.031 0.079 0.113 0.000 0.000 0.012 0.006 0.125 0.083 0.157 0.107 0.000 0.000 0.000 0.000 0.026 0.110 0.077 0.164 0.058 0.000 0.000 0.084 100.342 100.320 100.345 100.314 0.000 0.000 0.000 0.000 0.370 0.428 0.423 0.428 0.002 0.003 0.003 0.002 1.538 1.488 1.485 1.489 0.085 0.079 0.085 0.077 0.534 0.477 0.488 0.436 0.015 0.015 0.017 0.016 0.451 0.504 0.490 0.541 0.000 0.001 0.002 0.003 0.000 0.000 0.000 0.000 0.003 0.002 0.004 0.003 0.000 0.000 0.000 0.000 0.001 0.003 0.002 0.004 0.001 0.000 0.000 0.001 3.000 3.000 3.000 3.000 Avew/oCR4-A1&2 80.608 77.873 77.832 77.890 77.162 74.611 74.514 74.701 75.720 42.184 47.588 48.131 51.377 50.069 45.834 51.375 50.136 55.410 4.275 3.942 4.282 3.847 466 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C O xides Wt% Wt% W t% Wt% Wt% W t% Wt% S i0 2 0.000 0.000 0.019 0.000 0.013 0.000 0.000 AI203 9.470 9.503 9.119 8.714 8.670 8.669 9.079 TI02 0.125 0.080 0.075 0.085 0.057 0.147 0.108 C r203 59.170 58.400 59.033 59.415 59.223 59.091 58.892 F e203 2.649 3.928 3.128 2.784 3.947 4.101 3.768 FeO 18.011 17.464 18.639 19.419 17.859 17.292 17.732 MnO 0.734 0.644 0.765 0.750 0.717 0.883 0.640 MgO 9.798 10.067 9.191 8.633 9.610 9.826 9.891 NiO 0.042 0.080 0.085 0.109 0.066 0.150 0.009 CaO 0.000 0.010 0.000 0.000 0.013 0.000 0.000 V203 0.096 0.057 0.069 0.110 0.041 0.086 0.106 N b205 0.172 0.000 0.067 0.120 0.000 0.000 0.044 ZnO 0.000 0.056 0.115 0.140 0.181 0.166 0.106 P t0 2 0.000 0.106 0.008 0.000 0.000 0.000 0.000 Total 100.266 100.393 100.312 100.278 100.396 100.411 100.377 C ations Si4+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 Ai3+ 0.370 0.370 0.358 0.344 0.340 0.339 0.355 Ti4+ 0.003 0.002 0.002 0.002 0.001 0.004 0.003 Cr3+ 1.551 1.527 1.555 1.575 1.558 1.552 1.544 Fe3+ 0.066 0.098 0.078 0.070 0.099 0.103 0.094 Fe2+ 0.499 0.483 0.519 0.544 0.497 0.480 0.492 Mn2+ 0.021 0.018 0.022 0.021 0.020 0.025 0.018 Mg2+ 0.484 0.496 0.457 0.431 0.477 0.487 0.489 Ni2+ 0.001 0.002 0.002 0.003 0.002 0.004 0.000 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.002 0.002 0.003 0.001 0.002 0.003 Nb5+ 0.003 0.000 0.001 0.002 0.000 0.000 0.001 Zn2+ 0.000 0.001 0.003 0.003 0.004 0.004 0.003 Pt4+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 80.738 80.478 81.282 82.059 82.086 82.055 81.313 cr# 78.052 76.535 78.082 79.162 78.024 77.836 77.476 M g# 46.132 46.079 43.301 41.242 44.448 45.499 45.496 Mg"# 49.232 50.679 46.780 44.210 48.959 50.322 49.858 Fe3+ 3.326 4.899 3.937 3.530 4.949 5.141 4.718 Table C.59: Sample Z8-Sh14 Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 467 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 0.002 0.002 0.000 0.000 0.009 0.018 0.000 0.000 9.642 9.326 9.607 9.319 9.394 9.696 9.427 9.185 0.060 0.156 0.145 0.133 0.124 0.087 0.080 0.063 57.624 58.904 58.315 58.528 58.434 56.569 58.147 58.286 4.566 3.234 3.788 3.536 3.223 5.097 3.877 3.915 17.741 17.925 17.583 18.510 18.817 18.304 18.592 18.398 0.680 0.630 0.649 0.640 0.659 0.704 0.661 0.701 9.894 9.694 10.025 9.360 9.232 9.525 9.347 9.441 0.081 0.147 0.057 0.105 0.091 0.122 0.023 0.017 0.000 0.011 0.000 0.000 0.000 0.001 0.000 0.014 0.126 0.153 0.059 0.081 0.078 0.151 0.000 0.134 0.000 0.037 0.060 0.043 0.164 0.109 0.074 0.083 0.041 0.104 0.091 0.079 0.099 0.127 0.134 0.106 0.000 0.000 0.000 0.016 0.000 0.000 0.024 0.049 100.456 100.324 100.379 100.352 100.324 100.509 100.387 100.394 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.376 0.365 0.374 0.365 0.368 0.379 0.369 0.360 0.001 0.004 0.004 0.003 0.003 0.002 0.002 0.002 1.506 1.545 1.524 1.539 1.538 1.482 1.528 1.532 0.114 0.081 0.094 0.088 0.081 0.127 0.097 0.098 0.490 0.497 0.486 0.515 0.524 0.507 0.517 0.512 0.019 0.018 0.018 0.018 0.019 0.020 0.019 0.020 0.488 0.479 0.494 0.464 0.458 0.471 0.463 0.468 0.002 0.004 0.002 0.003 0.002 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.004 0.002 0.002 0.002 0.004 0.000 0.004 0.000 0.001 0.001 0.001 0.002 0.002 0.001 0.001 0.001 0.003 0.002 0.002 0.002 0.003 0.003 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.036 80.905 80.284 80.819 80.668 79.649 80.536 80.978 75.480 77.623 76.488 77.229 77.391 74.556 76.620 76.992 44.665 45.337 45.985 43.477 43.109 42.588 43.006 43.431 49.852 49.085 50.406 47.407 46.653 48.124 47.262 47.774 5.692 4.057 4.729 4.441 4.062 6.394 4.863 4.922 468 g s « CM E 5 1 Qi co 00 05 co o CM CM o CO co o o o co o o co T- CM o 05 C75 o o co o y — o o KN CM p ÇO rü in o o o N 05 o o o tn o co o co o co 00 o N o o o o o o o e> 00 CO CM co p r. tn co o p M- P p p p p p p co p p o tn P p p p p p p p p P o o> o o6 cb m o (» o o d o o o o o d o d d o O o o o o o o co e (O #g CO w 5 tn co N- ons è? o ü ü (O CM y — y — 05 CM tn o o 05 o O) o CM O) CM N 00 •M’05 CO o o co o tn o o a o y - tn o CM 05 O) CM Tf- co tn o o o o o o tn o (O o co 00 o N o o o o o o o tn O s p P in tn p tn p p p p p co p co p tn p tn P p o p p p p p P P p o 05 O e ô cô m o o> o o O xides Wt% Wt% Wt% Wt% W t% Wt% W t% 3102 0.036 0.032 0.030 0.000 0.049 0.000 0.163 AI203 10.132 10.389 10.093 10.449 10.685 10.638 9.634 T i02 0.045 0.023 0.108 0.027 0.078 0.132 0.047 C r203 56.791 56.382 56.790 56.664 56.620 57.020 57.081 F e203 1.350 1.286 1.316 1.224 0.901 0.663 1.583 FeO 26.147 26.422 26.186 25.904 25.952 25.954 25.623 MnO 1.345 1.311 1.365 1.363 1.359 1.300 1.205 MgO 4.003 3.889 4.082 4.106 4.227 4.190 4.560 NiO 0.094 0.000 0.013 0.001 0.000 0.023 0.070 CaO 0.000 0.008 0.000 0.003 0.015 0.000 0.000 V203 0.152 0.143 0.066 0.024 0.154 0.062 0.143 N b205 0.000 0.073 0.082 0.060 0.000 0.000 0.044 ZnO 0.041 0.172 0.000 0.274 0.050 0.085 0.006 P t0 2 0.000 0.000 0.000 0.024 0.000 0.000 0.000 Total 100.135 100.128 100.132 100.124 100.090 100.067 100.159 C ations Si4+ 0.001 0.001 0.001 0.000 0.002 0.000 0.006 AI3+ 0.411 0.422 0.410 0.423 0.432 0.430 0.390 Ti4+ 0.001 0.001 0.003 0.001 0.002 0.003 0.001 Cr3+ 1.546 1.535 1.546 1.540 1.535 1.547 1.551 Fe3+ 0.035 0.033 0.034 0.032 0.023 0.017 0.041 Fe2+ 0.753 0.761 0.754 0.745 0.744 0.745 0.736 Mn2+ 0.039 0.038 0.040 0.040 0.039 0.038 0.035 Mg2+ 0.205 0.200 0.209 0.210 0.216 0.214 0.234 Ni2+ 0.003 0.000 0.000 0.000 0.000 0.001 0.002 Ca2+ 0.000 0.000 0.000 0.000 0.001 0.000 0.000 V3+ 0.004 0.004 0.002 0.001 0.004 0.002 0.004 Nb5+ 0.000 0.001 0.001 0.001 0.000 0.000 0.001 Zn2+ 0.001 0.004 0.000 0.007 0.001 0.002 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Totai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 78.993 78.452 79.056 78.439 78.045 78.240 79.898 Cr*# 77.606 77.139 77.701 77.194 77.134 77.569 78.248 M g# 20.684 20.086 21.002 21.325 21.968 21.956 23.108 Mg"# 21.439 20.782 21.745 22.032 22.499 22.348 24.083 Fe3+ 1.756 1.674 1.714 1.588 1.168 0.859 2.066 Table C.60: Sample Z8*Sh15 Chromite bearing Talc Microprobe Analyaie & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 470 :R4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C t% Wt% W t% Wt% W t% Wt% Wt% Wt% 0.123 0.168 0.187 0.074 0.106 0.078 0.548 0.102 9.733 9.726 10.182 10.148 9.962 10.131 9.923 10.203 0.134 0.087 0.055 0.107 0.117 0.111 0.149 0.101 56.607 56.988 56.435 57.057 56.219 57.880 56.266 56.637 1.886 1.158 1.318 1.792 2.372 2.099 0.787 1.037 25.938 26.359 25.848 23.367 25.631 21.259 26.948 26.497 1.253 1.384 1.353 1.101 1.118 0.828 1.090 1.170 4.184 4.005 4.257 6.082 4.608 7.629 3.942 4.034 0.036 0.013 0.019 0.053 0.027 0.060 0.142 0.028 0.000 0.000 0.020 0.015 0.000 0.000 0.017 0.000 0.084 0.078 0.024 0.053 0.032 0.071 0.095 0.065 0.000 0.030 0.044 0.156 0.000 0.000 0.007 0.118 0.194 0.006 0.269 0.125 0.006 0.000 0.163 0.095 0.016 0.113 0.121 0.049 0.041 0.064 0.000 0.016 100.188 100.117 100.131 100.178 100.238 100.210 100.077 100.105 0.004 0.006 0.006 0.003 0.004 0.003 0.019 0.004 0.395 0.396 0.413 0.406 0.403 0.401 0.403 0.414 0.003 0.002 0.001 0.003 0.003 0.003 0.004 0.003 1.541 1.555 1.534 1.531 1.524 1.535 1.532 1.542 0.049 0.030 0.034 0.046 0.061 0.053 0.020 0.027 0.747 0.761 0.743 0.663 0.735 0.596 0.776 0.763 0.037 0.040 0.039 0.032 0.032 0.024 0.032 0.034 0.215 0.206 0.218 0.308 0.236 0.382 0.202 0.207 0.001 0.000 0.001 0.001 0.001 0.002 0.004 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.001 0.000 0.002 0.002 0.001 0.001 0.001 0.002 0.003 0.002 0.000 0.000 0.001 0.002 0.000 0.000 0.000 0.002 0.005 0.000 0.007 0.003 0.000 0.000 0.004 0.002 0.000 0.001 0.001 0.000 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.599 79.718 78.805 79.044 79.104 79.307 79.184 78.830 77.639 78.508 77.448 77.220 76.668 77.194 78.358 77.761 21.254 20.671 21.917 30.288 22.829 37.008 20.281 20.771 22.334 21.313 22.694 31.693 24.269 39.013 20.683 21.347 2.462 1.518 1.722 2.308 3.080 2.884 1.043 1.358 471 :R8-A2-R CR9-A1-C CR9-A2-R CR10-A1-C CR10-A2-R WSU-1 WSU-2 WSU-3 WSU-4 t% W t% W t% Wt% W t% Wt% Wt% Wt% Wt% 0.110 0.041 0.033 0.015 0.013 0.119 0.148 0.127 0.137 10.444 9.974 10.489 10.906 11.099 10.467 10.372 10.586 10.420 0.127 0.047 0.048 0.085 0.058 0.056 0.097 0.057 0.040 55.569 58.129 56.142 58.552 58.154 55.800 55.684 55.743 55.061 1.852 1.986 2.373 1.327 0.642 2.442 1.552 2.311 2.336 26.147 21.432 24.312 19.235 21.817 22.060 26.419 23.676 25.399 1.198 0.862 1.102 0.702 0.891 0.594 0.813 0.674 0.960 4.347 7.371 5.404 9.078 7.193 6.978 4.130 6.003 4.689 0.043 0.070 0.047 0.048 0.052 0.088 0.088 0.087 0.065 0.004 0.008 0.000 0.007 0.014 0.030 0.011 0.011 0.000 0.087 0.082 0.163 0.124 0.052 0.128 0.112 0.068 0.119 0.201 0.000 0.014 0.045 0.000 0.000 0.000 0.000 0.000 0.055 0.106 0.107 0.000 0.081 0.000 0.088 0.061 0.036 0.000 0.090 0.000 0.008 0.000 0.000 0.000 0.000 0.000 100.185 100.199 100.237 100.132 100.065 98.761 99.514 99.404 99.262 0.004 0.001 0.001 0.001 0.000 0.004 0.005 0.004 0.005 0.422 0.396 0.421 0.426 0.439 0.420 0.422 0.426 0.424 0.003 0.001 0.001 0.002 0.001 0.001 0.003 0.001 0.001 1.507 1.546 1.510 1.533 1.542 1.504 1.521 1.503 1.502 0.048 0.050 0.061 0.033 0.016 0.063 0.040 0.059 0.061 0.750 0.603 0.692 0.533 0.612 0.629 0.763 0.675 0.733 0.035 0.025 0.032 0.020 0.025 0.017 0.024 0.019 0.028 0.222 0.370 0.274 0.448 0.360 0.355 0.213 0.305 0.241 0.001 0.002 0.001 0.001 0.001 0.002 0.002 0.002 0.002 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.002 0.002 0.004 0.003 0.001 0.003 0.003 0.002 0.003 0.003 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.003 0.003 0.000 0.002 0.000 0.002 0.002 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 78.115 79.632 78.216 78.268 77.852 78.148 78.268 77.937 77.997 76.225 77.622 75.830 76.969 77.220 75.685 76.676 75.612 75.615 21.789 36.138 26.700 44.200 36.410 33.897 20.928 29.351 23.308 22.860 38.006 28.380 45.690 37.017 36.056 21.793 31.127 24.759 2.418 2.524 3.051 1.660 0.811 3.152 2.034 2.984 3.054 472 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C Dunite Section Oxides Wt% Wt% Wt% Wt% Wt% W t% W t% 3102 0.043 0.000 0.000 0.000 0.017 0.000 0.015 AI203 8.869 9.953 10.059 10.526 9.356 9.726 9.257 TI02 0.088 0.081 0.115 0.129 0.098 0.088 0.083 Cr203 59.649 58.770 58.703 57.442 59.136 58.349 58.922 Fe203 3.229 2.207 2.942 3.678 3.542 3.817 3.162 FeO 17.507 18.535 17.263 17.237 16.945 16.741 17.945 MnO 0.655 0.563 0.710 0.652 0.653 0.652 0.660 MgO 9.979 9.542 10.198 10.396 10.436 10.599 9.707 NIO 0.099 0.058 0.073 0.000 0.078 0.105 0.113 CaO 0.000 0.000 0.000 0.000 0.003 0.010 0.000 V203 0.113 0.123 0.088 0.111 0.078 0.051 0.166 Nb205 0.014 0.145 0.037 0.061 0.014 0.098 0.114 ZnO 0.076 0.092 0.106 0.072 0.000 0.056 0.165 Pt02 0.000 0.150 0.000 0.066 0.000 0.091 0.008 Total 100.321 100.221 100.296 100.368 100.356 100.382 100.316 Cations SM+ 0.001 0.000 0.000 0.000 0.001 0.000 0.001 AI3+ 0.347 0.389 0.391 0.407 0.364 0.377 0.362 TI4+ 0.002 0.002 0.003 0.003 0.002 0.002 0.002 Cr3+ 1.564 1.541 1.530 1.492 1.542 1.519 1.546 Fe3+ 0.081 0.055 0.073 0.091 0.088 0.095 0.079 Fe2+ 0.486 0.514 0.476 0.473 0.467 0.461 0.498 Mn2+ 0.018 0.016 0.020 0.018 0.018 0.018 0.019 Mg2+ 0.493 0.472 0.501 0.509 0.513 0.520 0.480 NI2+ 0.003 0.002 0.002 0.000 0.002 0.003 0.003 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.003 0.002 0.003 0.002 0.001 0.004 Nb5+ 0.000 0.002 0.001 0.001 0.000 0.001 0.002 Zn2+ 0.002 0.002 0.003 0.002 0.000 0.001 0.004 Pt4+ 0.000 0.001 0.000 0.001 0.000 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 81.857 79.843 79.654 78.545 80.917 80.097 81.025 cr# 78.545 77.627 76.738 74.957 77.349 76.292 77.805 Mg# 46.566 45.322 47.728 47.422 48.027 48.360 45.423 Mg”# 50.400 47.854 51.293 51.810 52.333 53.021 49.089 Fe3+ 4.047 2.775 3.661 4.568 4.410 4.750 3.974 Table C.61 ; Sample Z8-Sh16 Dunite & Chromitite MIeroprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 473 IR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR7-A1-C CR7-A2-R WSU-dl WSU-d2 t% W t% W t% W t% W t% W t% W t% W t% 0.030 0.026 0.002 0.000 0.000 0.019 0.064 0.073 8.991 8.840 9.166 9.531 10.080 10.151 9.608 9.526 0.064 0.020 0.148 0.074 0.136 0.073 0.117 0.098 57.686 59.700 58.479 59.896 58.974 58.112 58.390 57.707 3.787 3.453 3.416 2.498 3.045 3.819 3.397 4.356 20.797 16.861 19.343 17.002 16.135 16.265 17.231 17.297 0.656 0.709 0.683 0.671 0.719 0.690 0.265 0.329 7.895 10.296 8.862 10.305 10.850 10.979 10.367 10.321 0.027 0.098 0.000 0.074 0.207 0.057 0.042 0.073 0.003 0.000 0.000 0.000 0.000 0.004 0.020 0.000 0.077 0.083 0.074 0.083 0.097 0.109 0.088 0.081 0 /5 9 0.014 0.085 0.000 0.000 0.046 0.000 0.000 0.207 0.177 0.084 0.117 0.062 0.000 0.117 0.125 0.000 0.066 0.000 0.000 0.000 0.057 0.000 0.000 100.379 100.344 100.342 100.251 100.305 100.381 99.705 99.985 0.001 0.001 0.000 0.000 0.000 0.001 0.002 0.002 0.357 0.345 0.361 0.371 0.390 0.392 0.375 0.372 0.002 0.001 0.004 0.002 0.003 0.002 0.003 0.002 1.535 1.563 1.544 1.563 1.529 1.505 1.530 1.510 0.096 0.086 0.086 0.062 0.075 0.094 0.085 0.109 0.585 0.467 0.540 0.469 0.443 0.446 0.478 0.479 0.019 0.020 0.019 0.019 0.020 0.019 0.007 0.009 0.396 0.508 0.441 0.507 0.530 0.536 0.512 0.509 0.001 0.003 0.000 0.002 0.005 0.002 0.001 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.002 0.002 0.002 0.002 0.003 0.003 0.002 0.002 0.002 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.005 0.004 0.002 0.003 0.002 0.000 0.003 0.003 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 81.146 81.918 81.061 80.828 79.695 79.341 80.303 80.253 77.230 78.382 77.565 78.315 76.691 75.590 76.884 75.877 36.765 47.894 41.340 48.831 50.610 49.833 47.668 46.443 40.358 52.120 44.956 51.934 54.519 54.612 51.749 51.543 4.826 4.316 4.313 3.108 3.769 4.728 4.258 5.452 474 WSU-d3 CrZ8-Sh16 CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R CR10-A1-C CR10-A2-R Ave Dies. Chromitite Section W t% Dunite W t% W t% W t% Wt% W t% W t% 0.064 0.022 0.015 0.000 0.000 0.000 0.030 0.000 9.314 9.559 9.736 10.659 9.873 10.278 9.596 9.867 0.132 0.097 0.038 0.081 0.126 0.141 0.060 0.096 58.405 58.645 59.882 58.941 60.350 60.134 59.544 58.748 3.676 3.377 2.984 2.021 2.464 1.909 1.536 1.995 17.132 17.515 15.183 17.008 14.736 14.728 20.031 19.676 0.250 0.595 0.685 0.621 0.563 0.627 0.702 0.795 10.425 10.072 11.569 10.592 11.958 12.019 8.392 8.452 0.050 0.072 0.047 0.063 0.085 0.032 0.075 0.085 0.010 0.003 0.000 0.000 0.000 0.004 0.000 0.018 0.082 0.094 0.029 0.066 0.086 0.082 0.038 0.091 0.000 0.049 0.031 0.107 0.007 0.091 0.067 0.000 0.052 0.094 0.102 0.000 0.000 0.044 0.081 0.193 0.000 0.027 0.000 0.042 0.000 0.100 0.000 0.181 99.592 100.222 100.300 100.201 100.248 100.191 100.153 100.199 0.000 0.000 0.002 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.365 0.373 0.375 0.412 0.379 0.394 0.378 0.389 0.003 0.002 0.001 0.002 0.003 0.003 0.002 0.002 1.534 1.534 1.548 1.529 1.555 1.548 1.575 1.553 0.092 0.084 0.073 0.050 0.060 0.047 0.039 0.050 0.476 0.485 0.415 0.467 0.402 0.401 0.561 0.550 0.007 0.017 0.019 0.017 0.016 0.017 0.020 0.023 0.516 0.497 0.564 0.518 0.581 0.583 0.419 0.421 0.001 0.002 0.001 0.002 0.002 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.002 0.002 0.001 0.002 0.002 0.002 0.001 0.002 0.000 0.001 0.000 0.002 0.000 0.001 0.001 0.000 0.001 0.002 0.002 0.000 0.000 0.001 0.002 0.005 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.002 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 0.000 80.794 60.455 60.491 76.766 60.394 79.695 60.630 79.977 77.064 77.057 77.531 76.792 77.959 77.820 79.065 77.961 47.622 46.616 53.576 50.072 55.702 56.574 41.130 41.233 52.033 50.602 57.595 52.610 59.127 59.262 42.754 43.364 4.617 4.223 3.677 2.506 3.030 2.352 1.941 2.520 475 CR11-A1-C CR11-A2-R CR12-A1-C CR12-A2-R CR13-A1-C CR13-A2-R CR14-A1-C CR14-A2-R :% W t% W t% Wt% W t% W t% W t% W t% 0.000 0.027 0.000 0.006 0.000 0.004 0.000 0.000 10.199 10.409 10.281 10.503 10.176 10.871 10.113 10.247 0.144 0.109 0.115 0.088 0.040 0.047 0.051 0.064 59.934 59.200 60.880 60.859 60.609 59.259 61.288 60.488 2.539 3.115 1.494 0.929 1.920 2.351 1.011 1.575 14.474 14.400 13.956 15.501 14.180 14.410 15.066 15.176 0.668 0.619 0.634 0.619 0.616 0.636 0.569 0.602 12.077 12.235 12.462 11.525 12.372 12.213 11.795 11.576 0.100 0.090 0.024 0.000 0.074 0.161 0.058 0.115 0.007 0.013 0.000 0.000 0.024 0.007 0.000 0.000 0.079 0.032 0.066 0.065 0.058 0.068 0.035 0.128 0.000 0.054 0.061 0.000 0.121 0.137 0.085 0.031 0.000 0.011 0.112 0.000 0.000 0.071 0.031 0.157 0.033 0.000 0.066 0.000 0.000 0.000 0.000 0.000 100.254 100.314 100.150 100.094 100.191 100.234 100.101 100.158 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.391 0.398 0.393 0.404 0.389 0.415 0.389 0.394 0.004 0.003 0.003 0.002 0.001 0.001 0.001 0.002 1.541 1.518 1.562 1.569 1.556 1.518 1.581 1.561 0.062 0.076 0.036 0.023 0.047 0.057 0.025 0.039 0.394 0.391 0.379 0.423 0.385 0.391 0.411 0.414 0.018 0.017 0.017 0.017 0.017 0.017 0.016 0.017 0.585 0.592 0.603 0.560 0.599 0.590 0.574 0.563 0.003 0.002 0.001 0.000 0.002 0.004 0.002 0.003 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.001 0.002 0.002 0.002 0.002 0.001 0.003 0.000 0.001 0.001 0.000 0.002 0.002 0.001 0.000 0.000 0.000 0.003 0.000 0.000 0.002 0.001 0.004 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.766 79.233 79.890 79.539 79.982 78.527 80.259 79.839 77.280 76.209 78.427 78.630 78.098 76.266 79.261 78.290 56.228 55.905 59.216 55.705 58.094 56.847 56.824 55.430 59.796 60.233 61.417 56.997 60.865 60.171 58.256 57.623 3.116 3.816 1.831 1.142 2.355 2.880 1.244 1.940 476 CR15-A1-C CR15-A1-R CR16-A1-C CR16-A2-R CR17-A1-C CR17-A2-R WSU-C1 WSU-C2 WSU-C3 W t% W t% W t% W t% Wt% W t% W t% W t% 0.000 0.000 0.000 0.009 0.000 0.000 0.076 0.072 0.074 9.820 10.568 9.907 10.281 10.104 10.728 10.694 10.379 10.313 0.159 0.077 0.068 0.093 0.162 0.119 0.126 0.091 0.117 61.112 60.249 60.794 60.025 59.590 58.935 59.541 58.759 57.876 1.566 1.675 1.655 2.067 2.718 2.802 2.422 3.004 2.908 14.436 14.478 15.150 14.778 15.087 14.962 13.801 14.306 14.937 0.655 0.624 0.713 0.738 0.596 0.487 0.210 0.211 0.234 12.055 12.210 11.606 11.841 11.762 12.037 12.841 12.352 11.741 0.042 0.031 0.052 0.059 0.043 0.034 0.036 0.058 0.056 0.000 0.000 0.008 0.003 0.000 0.000 0.020 0.007 0.011 0.050 0.120 0.073 0.115 0.026 0.090 0.086 0.072 0.089 0.090 0.037 0.023 0.046 0.046 0.089 0.000 0.000 0.000 0.169 0.000 0.017 0.103 0.047 0.000 0.098 0.097 0.039 0.000 0.100 0.100 0.049 0.091 0.000 0.000 0.000 0.000 100.155 100.170 100.166 100.208 100.271 100.281 99.950 99.407 98.397 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.002 0.002 0.377 0.404 0.382 0.395 0.388 0.410 0.408 0.400 0.402 0.004 0.002 0.002 0.002 0.004 0.003 0.003 0.002 0.003 1.575 1.546 1.571 1.546 1.537 1.512 1.523 1.518 1.515 0.038 0.041 0.041 0.051 0.067 0.068 0.059 0.074 0.072 0.394 0.393 0.414 0.403 0.412 0.406 0.373 0.391 0.414 0.018 0.017 0.020 0.020 0.016 0.013 0.006 0.006 0.007 0.586 0.591 0.566 0.575 0.572 0.582 0.619 0.602 0.579 0.001 0.001 0.001 0.002 0.001 0.001 0.001 0.002 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.003 0.002 0.003 0.001 0.002 0.002 0.002 0.002 0.001 0.001 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.004 0.000 0.000 0.002 0.001 0.000 0.002 0.002 0.001 0.000 0.001 0.001 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.675 79.273 80.456 79.660 79.824 78.657 78.881 79.157 79.013 79.119 77.644 78.813 77.634 77.151 75.954 76.544 76.222 76.135 57.560 57.655 55.425 55.921 54.460 55.103 58.889 56.419 54.384 59.817 60.053 57.728 58.819 58.154 58.917 62.387 60.617 58.353 1.929 2.055 2.042 2.544 3.349 3.437 2.963 3.709 3.642 477 Label CR1-A1-C CR2-A1-C CR2-A2-R CR3-A1-C CR4-A1-C CR4-A2-R CR5-A1-C Oxides W t% Wt% Wt% Wt% W t% W t% W t% SI02 0.028 0.002 0.012 0.002 0.000 0.002 0.088 AI203 11.262 11.357 11.096 10.187 10.378 11.471 10.803 TI02 0.063 0.033 0.177 0.094 0.082 0.089 0.027 Cr203 57.500 57.508 57.181 59.596 59.017 56.323 58.380 Fe203 2.485 2.524 2.898 1.655 1.956 3.591 1.391 FeO 18.163 17.800 17.638 17.905 18.253 18.344 19.512 MnO 0.657 0.576 0.588 0.616 0.592 0.654 0.633 MgO 9.803 10.091 10.055 9.897 9.689 9.668 8.879 NiO 0.000 0.000 0.072 0.059 0.004 0.051 0.005 CaO 0.006 0.000 0.001 0.001 0.003 0.015 0.020 V203 0.124 0.174 0.145 0.048 0.100 0.055 0.106 Nb205 0.000 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.117 0.115 0.246 0.000 0.080 0.096 0.189 Pt02 0.042 0.074 0.180 0.105 0.041 0.000 0.107 Total 100.250 100.252 100.290 100.166 100.196 100.359 100.140 Cations SI4+ 0.001 0.000 0.000 0.000 0.000 0.000 0.003 AI3+ 0.436 0.439 0.430 0.397 0.404 0.444 0.422 TI4+ 0.002 0.001 0.004 0.002 0.002 0.002 0.001 Cr3+ 1.495 1.492 1.486 1.557 1.542 1.463 1.532 Fe3+ 0.061 0.062 0.072 0.041 0.049 0.089 0.035 Fe2+ 0.499 0.488 0.485 0.495 0.504 0.504 0.541 Mn2+ 0.018 0.016 0.016 0.017 0.017 0.018 0.018 Mg2+ 0.481 0.494 0.493 0.487 0.477 0.474 0.439 NI2+ 0.000 0.000 0.002 0.002 0.000 0.001 0.000 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.001 0.001 V3+ 0.003 0.005 0.004 0.001 0.003 0.001 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.003 0.003 0.006 0.000 0.002 0.002 0.005 Pt4+ 0.000 0.001 0.002 0.001 0.000 0.000 0.001 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 77.402 77.257 77.564 79.694 79.231 76.711 78.379 Cr*# 75.014 74.842 74.766 78.050 77.298 73.299 77.011 M g# 46.140 47.263 46.959 47.636 46.321 44.407 43.254 Mg'# 49.035 50.263 50.403 49.631 48.617 48.441 44.786 Fe3+ 3.086 3.127 3.607 2.063 2.439 4.448 1.746 Table C.62: Sample Z8«Sh18 Dunite MIeroprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the Ideal chromite formula) 478 CR5-A2-R CR6-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R t% W t% Wt % Wt % W t% W t% W t% 0.006 0.009 0.000 0.015 0.002 0.034 0.000 11.606 12.369 12.988 11.304 11.355 10.926 11.828 0.212 0.126 0.076 0.017 0.038 0.072 0.078 56.233 55.309 54.906 58.477 57.315 57.670 56.133 3.147 3.235 3.334 1.899 2.824 2.348 3.258 18.366 18.991 18.139 16.838 17.718 18.652 18.412 0.713 0.585 0.654 0.617 0.646 0.622 0.642 9.605 9.348 9.981 10.555 10.025 9.474 9.671 0.068 0.076 0.070 0.062 0.074 0.055 0.081 0.013 0.018 0.008 0.024 0.000 0.010 0.000 0.143 0.130 0.118 0.146 0.087 0.155 0.106 0.007 0.000 0.000 0.000 0.000 0.016 0.000 0.131 0.128 0.042 0.234 0.159 0.083 0.076 0.065 0.000 0.016 0.000 0.042 0.116 0.041 100.315 100.323 100.333 100.189 100.284 100.234 100.326 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.450 0.478 0.499 0.436 0.439 0.425 0.458 0.005 0.003 0.002 0.000 0.001 0.002 0.002 1.462 1.435 1.414 1.512 1.487 1.506 1.457 0.078 0.080 0.082 0.047 0.070 0.058 0.080 0.505 0.521 0.494 0.461 0.486 0.515 0.505 0.020 0.016 0.018 0.017 0.018 0.017 0.018 0.471 0.457 0.485 0.515 0.490 0.466 0.473 0.002 0.002 0.002 0.002 0.002 0.001 0.002 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.004 0.003 0.003 0.004 0.002 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.003 0.001 0.006 0.004 0.002 0.002 0.001 0.000 0.000 0.000 0.000 0.001 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 76.473 74.998 73.930 77.830 77.201 77.977 78.098 73.479 71.992 70.901 75.811 74.504 75.690 73.028 74.692 44.682 43.210 45.701 50.359 48.888 44.851 44.881 45.881 48.248 46.738 49.517 52.773 50.214 47.518 48.355 3.914 4.008 4.097 2.344 3.494 2.934 4.034 479 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A1-R CR3-A1-C CR3-A2-R CR4-A1-C Oxides W t% W t% W t% W t% W t% W t% W t% 3102 0.013 0.000 0.017 0.000 0.000 0.024 0.002 AI203 10.894 10.694 10.894 10.349 10.633 10.971 10.921 TI02 0.087 0.058 0.112 0.094 0.130 0.085 0.085 Cr203 60.383 61.496 60.893 62.742 60.801 60.953 61.083 Fe203 2.065 0.701 1.256 -1.831 1.629 1.431 0.966 FeO 12.101 13.333 12.728 17.275 12.485 12.289 12.712 MnO 0.681 0.638 0.534 0.581 0.528 0.615 0.609 MgO 13.631 12.871 13.299 10.313 13.542 13.585 13.300 NiO 0.087 0.108 0.120 0.094 0.143 0.119 0.170 CaO 0.010 0.006 0.015 0.000 0.000 0.034 0.010 V203 0.096 0.109 0.081 0.100 0.085 0.026 0.200 Nb205 0.000 0.000 0.000 0.075 0.143 0.000 0.037 ZnO 0.120 0.000 0.103 0.024 0.045 0.011 0.000 Pt02 0.041 0.057 0.074 0.000 0.000 0.000 0.000 Total 100.208 100.070 100.125 99.816 100.162 100.143 100.096 Cations 314+ 0.000 0.000 0.001 0.000 0.000 0.001 0.000 AI3+ 0.412 0.407 0.413 0.402 0.403 0.415 0.414 TI4+ 0.002 0.001 0.003 0.002 0.003 0.002 0.002 Cr3+ 1.532 1.571 1.549 1.635 1.546 1.546 1.554 Fe3+ 0.050 0.017 0.030 -0.045 0.039 0.035 0.023 Fe2+ 0.325 0.360 0.343 0.476 0.336 0.330 0.342 Mn2+ 0.019 0.017 0.015 0.016 0.014 0.017 0.017 Mg2+ 0.652 0.620 0.638 0.507 0.649 0.650 0.638 NI2+ 0.002 0.003 0.003 0.002 0.004 0.003 0.004 Ca2+ 0.000 0.000 0.001 0.000 0.000 0.001 0.000 V3+ 0.002 0.003 0.002 0.003 0.002 0.001 0.005 Nb5+ 0.000 0.000 0.000 0.001 0.002 0.000 0.001 Zn2+ 0.003 0.000 0.002 0.001 0.001 0.000 0.000 Pt4+ 0.000 0.000 0.001 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 78.806 79.414 78.946 80.265 79.321 78.845 78.956 Cr*# 76.836 78.736 77.742 82.095 77.748 77.480 78.029 Mg# 63.513 62.166 63.109 54.051 63.374 64.076 63.580 Mg**# 66.755 63.246 65.066 51.554 65.911 66.336 65.097 Fe3+ 2.501 0.854 1.526 -2.280 1.983 1.731 1.174 Table C.63: Sample V8-1 Nodular chromitite (massive section & more dunitic f Microprobe Analysis & Caiculated Formuia (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calcuiated by assuming the ideai chromite formula) 480 CR4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C % W t% W t% W t% W t% W t% W t% W t% 0.000 0.019 0.000 0.017 0.000 0.024 0.006 0.000 11.425 10.962 10.171 10.761 10.939 10.754 10.869 10.890 0.137 0.098 0.023 0.118 0.117 0.153 0.120 0.076 61.226 60.325 61.699 60.775 60.766 60.851 61.730 60.705 -0.568 1.954 1.189 1.510 1.277 1.380 0.502 1.761 13.856 12.225 13.229 12.471 12.891 12.500 12.804 12.375 0.560 0.513 0.631 0.673 0.548 0.557 0.492 0.554 12.824 13.643 12.870 13.463 13.169 13.593 13.316 13.535 0.088 0.157 0.111 0.092 0.112 0.069 0.143 0.104 0.000 0.011 0.000 0.000 0.000 0.003 0.007 0.000 0.122 0.202 0.081 0.166 0.132 0.060 0.028 0.082 0.271 0.000 0.037 0.007 0.023 0.097 0.016 0.000 0.002 0.086 0.080 0.000 0.155 0.000 0.000 0.087 0.000 0.000 0.000 0.099 0.000 0.099 0.016 0.008 99.943 100.195 100.120 100.151 100.129 100.139 100.050 100.176 0.000 0.001 0.000 0.001 0.000 0.001 0.000 0.000 0.434 0.414 0.388 0.408 0.415 0.407 0.412 0.412 0.003 0.002 0.001 0.003 0.003 0.004 0.003 0.002 1.561 1.530 1.579 1.545 1.547 1.546 1.571 1.541 -0.014 0.047 0.029 0.037 0.031 0.033 0.012 0.043 0.374 0.328 0.358 0.335 0.347 0.336 0.345 0.332 0.015 0.014 0.017 0.018 0.015 0.015 0.013 0.015 0.617 0.652 0.621 0.645 0.632 0.651 0.639 0.648 0.002 0.004 0.003 0.002 0.003 0.002 0.004 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.005 0.002 0.004 0.003 0.002 0.001 0.002 0.004 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.002 0.002 0.000 0.004 0.000 0.000 0.002 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 78.238 78.686 80.274 79.117 78.842 79.148 79.210 78.902 78.782 76.822 79.109 77.664 77.618 77.819 78.728 77.219 63.140 63.492 61.604 63.443 62.575 63.811 64.168 63.347 62.260 66.546 63.427 65.806 64.553 65.969 64.961 66.097 -0.696 2.369 1.451 1.836 1.553 1.680 0.609 2.132 ioction) 481 R8-A2-F CR9-A1-C CR9-A2-R CR10-A1-* CR10-A2-I CR11-A1-' CR11-A2-I CR12-A1-* t% W t% Wt% W t% W t% W t% W t% W t% 0.026 0.017 0.006 0.000 0.527 0.000 0.000 0.002 11.009 10.532 10.482 11.050 9.432 10.851 10.636 10.915 0.020 0.143 0.093 0.140 0.124 0.062 0.082 0.088 60.936 61.707 61.848 60.342 64.240 61.429 61.376 61.482 0.945 0.509 0.902 1.587 -2.269 0.490 0.970 0.511 13.033 13.445 12.343 12.765 14.318 13.387 13.155 13.115 0.595 0.533 0.582 0.580 0.622 0.597 0.562 0.533 13.201 12.902 13.603 13.263 12.496 12.828 12.998 13.088 0.115 0.055 0.017 0.078 0.033 0.065 0.084 0.120 0.000 0.000 0.000 0.020 0.000 0.000 0.000 0.000 0.084 0.135 0.140 0.178 0.125 0.091 0.149 0.181 0.076 0.000 0.000 0.000 0.000 0.060 0.000 0.000 0.000 0.000 0.000 0.115 0.128 0.189 0.088 0.017 0.057 0.073 0.075 0.041 0.000 0.000 0.000 0.000 100.096 100.050 100.091 100.161 99.774 100.049 100.099 100.051 0.001 0.001 0.000 0.000 0.017 0.000 0.000 0.000 0.418 0.401 0.397 0.419 0.362 0.413 0.405 0.414 0.000 0.003 0.002 0.003 0.003 0.002 0.002 0.002 1.551 1.577 1.573 1.534 1.653 1.569 1.566 1.566 0.023 0.012 0.022 0.038 -0.056 0.012 0.024 0.012 0.351 0.363 0.332 0.343 0.390 0.362 0.355 0.353 0.016 0.015 0.016 0.016 0.017 0.016 0.015 0.015 0.633 0.622 0.652 0.636 0.606 0.618 0.625 0.629 0.003 0.001 0.000 0.002 0.001 0.002 0.002 0.003 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.004 0.004 0.005 0.003 0.002 0.004 0.005 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.003 0.003 0.005 0.002 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 78.784 79.718 79.831 78.557 82.043 79.156 79.471 79.073 77.878 79.223 78.956 77.041 84.370 78.684 78.532 78.582 62.895 62.325 64.830 82.487 64.470 62.319 62.288 63.218 64.357 63.108 66.268 64.939 60.872 63.076 63.786 64.015 1.150 0.621 1.096 1.929 •2.837 0.597 1.182 0.821 482 R12-A2-I CR13-A1-' CR13-A2-I CR14-A1-' CR14-A2-I CR15-A1-* CR15-A2-I CR16-A1-' t% Wt% W t% W t% W t% Wt% W t% W t% 0.000 0.017 0.000 0.009 0.030 0.002 0.000 0.000 10.865 10.552 10.273 10.960 9.856 10.557 10.380 11.064 0.095 0.143 0.134 0.101 0.140 0.102 0.078 0.102 61.783 61.424 61.846 60.882 63.646 61.140 61.779 60.679 0.139 0.873 0.396 1.245 -1.685 1.279 0.290 1.419 13.516 12.979 13.391 12.479 15.841 13.069 14.168 12.764 0.523 0.653 0.601 0.581 0.539 0.642 0.635 0.578 12.858 13.133 12.995 13.557 11.152 12.975 12.311 13.333 0.069 0.065 0.000 0.000 0.163 0.130 0.074 0.099 0.007 0.011 0.003 0.001 0.012 0.004 0.022 0.006 0.159 0.122 0.163 0.094 0.112 0.156 0.118 0.041 0.000 0.023 0.181 0.046 0.000 0.000 0.097 0.000 0.000 0.000 0.000 0.088 0.025 0.071 0.077 0.000 0.000 0.091 0.057 0.083 0.000 0.000 0.000 0.057 100.014 100.087 100.040 100.125 99.830 100.128 100.028 100.143 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.413 0.401 0.392 0.415 0.381 0.402 0.397 0.419 0.002 0.003 0.003 0.002 0.003 0.002 0.002 0.002 1.577 1.567 1.582 1.546 1.652 1.561 1.586 1.542 0.003 0.021 0.010 0.030 -0.042 0.031 0.007 0.034 0.365 0.350 0.362 0.335 0.435 0.353 0.385 0.343 0.014 0.018 0.016 0.016 0.015 0.018 0.017 0.016 0.619 0.632 0.627 0.649 0.546 0.624 0.596 0.639 0.002 0.002 0.000 0.000 0.004 0.003 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.004 0.003 0.004 0.002 0.003 0.004 0.003 0.001 0.000 0.000 0.003 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.001 0.002 0.002 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.231 79.613 80.153 78.843 81.245 79.529 79.970 78.629 79.096 78.765 79.763 77.651 82.943 78.289 79.685 77.276 62.691 62.974 62.756 63.991 58.120 61.927 60.332 62.863 62.906 64.334 63.367 65.948 55.652 63.896 60.767 65.060 0.170 1.066 0.486 1.511 >2.091 1.559 0.356 1.720 483 R16-A2-I CR17-A1-' CR17-A2-I CR18-A1-' CR18-A2-I CR19-A1-' CR19-A2-I CR20-A1-' :% Wt% Wt% Wt% Wt% Wt% W t% W t% 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.017 10.685 10.764 10.615 10.644 10.494 10.390 10.158 10.544 0.102 0.123 0.136 0.098 0.096 0.120 0.181 0.130 61.184 60.367 61.013 61.146 61.931 61.985 62.365 61.764 1.205 1.842 1.352 1.373 0.283 0.129 0.597 0.431 12.853 12.833 13.030 12.874 13.499 13.689 12.686 13.456 0.587 0.576 0.640 0.553 0.465 0.535 0.496 0.555 13.193 13.237 13.159 13.152 12.997 12.711 13.328 12.775 0.116 0.070 0.032 0.092 0.005 0.053 0.062 0.093 0.000 0.010 0.010 0.000 0.007 0.006 0.006 0.000 0.119 0.144 0.065 0.060 0.051 0.138 0.088 0.115 0.000 0.077 0.083 0.000 0.167 0.113 0.023 0.000 0.045 0.143 0.000 0.144 0.032 0.103 0.067 0.129 0.033 0.000 0.000 0.000 0.000 0.041 0.000 0.033 100.122 100.186 100.136 100.137 100.027 100.013 100.059 100.042 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.406 0.408 0.403 0.404 0.400 0.397 0.386 0.402 0.002 0.003 0.003 0.002 0.002 0.003 0.004 0.003 1.559 1.537 1.555 1.558 1.582 1.588 1.591 1.580 0.029 0.045 0.033 0.033 0.007 0.003 0.014 0.010 0.346 0.346 0.351 0.347 0.365 0.371 0.342 0.364 0.016 0.016 0.017 0.015 0.013 0.015 0.014 0.015 0.634 0.635 0.632 0.632 0.626 0.614 0.641 0.616 0.003 0.002 0.001 0.002 0.000 0.001 0.002 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.004 0.002 0.002 0.001 0.004 0.002 0.003 0.000 0.001 0.001 0.000 0.002 0.002 0.000 0.000 0.001 0.003 0.000 0.003 0.001 0.002 0.002 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 79.344 79.001 79.406 79.397 79.835 80.009 80.463 79.714 78.182 77.229 78.097 78.072 79.559 79.882 79.878 79.294 62.790 61.954 62.212 62.428 62.750 62.141 64.243 62.192 64.661 64.774 64.288 64.552 63.186 62.339 65.190 62.858 1.465 2.243 1.648 1.668 0.346 0.156 0.728 0.527 484 CR20-A2-I CR21-A1-* CR21-A2-R Wt % Wt % Wt % 0.015 0.000 0.000 8.858 10.399 10.533 0.091 0.111 0.205 64.566 60.892 60.954 -0.044 1.497 0.610 12.174 14.084 14.797 0.534 0.541 0.474 13.437 12.413 12.089 0.086 0.028 0.065 0.000 0.000 0.007 0.129 0.083 0.132 0.000 0.000 0.106 0.149 0.101 0.015 0.000 0.000 0.073 99.996 100.149 100.061 0.000 0.000 0.000 0.339 0.397 0.404 0.002 0.003 0.005 1.656 1.561 1.567 -0.001 0.037 0.015 0.330 0.382 0.402 0.015 0.015 0.013 0.650 0.600 0.586 0.002 0.001 0.002 0.000 0.000 0.000 0.003 0.002 0.003 0.000 0.000 0.002 0.004 0.002 0.000 0.000 0.000 0.001 3.000 3.000 3.000 83.021 79.708 79.517 83.065 78.249 78.919 78.466 66.375 58.914 58.407 62.762 66.303 61.106 59.290 •0.054 1.831 0.752 485 Label CR1-A1-C CR1-A2-R CR2-A1-C CR4-A1-C CR4-A2-R CR5-A1-C CR5-A2-R Oxides W t% W t% Wt% W t% W t% W t% W t% Si02 0.004 0.027 0.024 0.000 0.009 0.000 0.000 AI203 9.990 8.072 10.510 10.259 10.356 10.179 10.370 Ti02 0.165 0.043 0.079 0.081 0.062 0.163 0.092 Cr203 61.338 65.267 60.852 60.909 61.325 61.153 61.490 Fe203 1.566 0.078 1.611 1.750 1.479 1.681 1.205 FeO 13.404 12.362 13.439 13.295 13.054 13.241 13.338 MnO 0.666 0.576 0.577 0.510 0.532 0.616 0.585 MgO 12.798 13.334 12.868 13.069 13.106 12.932 12.898 NiO 0.079 0.082 0.098 0.015 0.043 0.043 0.050 CaO 0.000 0.000 0.003 0.000 0.007 0.004 0.018 V203 0.092 0.131 0.085 0.070 0.118 0.140 0.074 Nb205 0.054 0.038 0.016 0.156 0.000 0.000 0.000 ZnO 0.000 0.000 0.000 0.058 0.058 0.015 0.000 Pt02 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 100.157 100.009 100.162 100.173 100.150 100.166 100.121 Cations Si4+ 0.000 0.001 0.001 0.000 0.000 0.000 0.000 AI3+ 0.381 0.310 0.400 0.391 0.394 0.388 0.395 Ti4+ 0.004 0.001 0.002 0.002 0.002 0.004 0.002 Cr3+ 1.571 1.680 1.554 1.556 1.565 1.564 1.571 Fe3+ 0.038 0.002 0.039 0.043 0.036 0.041 0.029 Fe2+ 0.363 0.337 0.363 0.359 0.352 0.358 0.361 Mn2+ 0.018 0.016 0.016 0.014 0.015 0.017 0.016 Mg2+ 0.618 0.647 0.620 0.630 0.631 0.623 0.622 Ni2+ 0.002 0.002 0.003 0.000 0.001 0.001 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 0.001 V3+ 0.002 0.003 0.002 0.002 0.003 0.004 0.002 Nb5+ 0.001 0.001 0.000 0.002 0.000 0.000 0.000 Zn2+ 0.000 0.000 0.000 0.001 0.001 0.000 0.000 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Totai 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 80.465 84.434 79.525 79.931 79.890 80.119 79.911 Cr*# 78.922 84.353 77.962 78.221 78.451 78.475 78.738 M g# 60.632 65.659 60.641 61.039 61.892 60.975 61.453 Mg"# 62.991 65.785 63.058 63.667 64.154 63.516 63.287 Fe3+ 1.918 0.095 1.965 2.139 1.801 2.053 1.468 Table C.64: Sample V8-10 Nodular chromitite Microprobe Analysis & Calcuiated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 486 CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R CR8-A1-C CR8-A2-R CR9-A1-C CR9-A2-R W t% W t% W t% W t% W t% W t% W t% 0.011 0.000 0.006 0.046 0.000 0.000 0.000 0.017 10.196 10.225 10.153 9.625 10.329 10.315 10.030 10.001 0.098 0.121 0.093 0.183 0.108 0.140 0.075 0.055 61.508 61.649 61.323 62.341 60.928 61.406 61.768 61.916 1.125 0.838 1.419 0.150 1.769 1.246 1.112 1.062 13.431 13.566 13.781 14.829 12.978 13.402 13.419 13.689 0.541 0.580 0.551 0.594 0.527 0.522 0.562 0.518 12.849 12.782 12.646 11.920 13.169 12.891 12.807 12.631 0.076 0.079 0.000 0.062 0.084 0.042 0.089 0.042 0.000 0.000 0.000 0.021 0.000 0.000 0.006 0.008 0.094 0.160 0.107 0.143 0.122 0.096 0.104 0.050 0.000 0.084 0.000 0.099 0.083 0.016 0.067 0.000 0.026 0.000 0.030 0.000 0.080 0.050 0.073 0.116 0.156 0.000 0.033 0.000 0.000 0.000 0.000 0.000 100.113 100.084 100.143 100.014 100.176 100.125 100.110 100.106 0.000 0.000 0.000 0.002 0.000 0.000 0.000 0.001 0.389 0.390 0.388 0.371 0.393 0.393 0.383 0.382 0.002 0.003 0.002 0.004 0.003 0.003 0.002 0.001 1.575 1.579 1.572 1.610 1.555 1.570 1.582 1.588 0.027 0.020 0.035 0.004 0.043 0.030 0.027 0.026 0.364 0.367 0.374 0.405 0.350 0.362 0.364 0.371 0.015 0.016 0.015 0.016 0.014 0.014 0.015 0.014 0.620 0.617 0.611 0.580 0.634 0.621 0.619 0.611 0.002 0.002 0.000 0.002 0.002 0.001 0.002 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.002 0.004 0.003 0.004 0.003 0.002 0.003 0.001 0.000 0.001 0.000 0.001 0.001 0.000 0.001 0.000 0.001 0.000 0.001 0.000 0.002 0.001 0.002 0.003 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 80.185 80.177 80.205 81.291 79.826 79.974 80.512 80.594 79.082 79.354 78.813 81.140 78.103 78.758 79.417 79.547 61.329 61.406 59.953 58.677 61.703 61.274 61.289 60.591 63.037 62.680 62.060 58.897 64.398 63.162 62.981 62.191 1.378 1.027 1.736 0.186 2.159 1.521 1.360 1.299 487 R10-A2-1 CR11-A1-* CR11-A2-I CR12-A1-I CR12-A2-I CR13-A1-' CR13-A2-I t% W t% Wt % Wt % W t% W t% W t% 0.000 0.000 0.009 0.011 0.046 0.000 0.011 10.782 10.765 10.555 9.903 10.460 10.348 10.114 0.120 0.089 0.053 0.128 0.132 0.066 0.058 60.219 61.187 60.371 61.859 61.489 61.727 62.005 1.990 0.791 2.214 0.563 0.365 0.703 0.424 12.943 13.608 13.125 14.108 14.223 14.153 14.091 0.567 0.527 0.616 0.503 0.594 0.510 0.499 13.211 12.779 13.007 12.543 12.431 12.427 12.504 0.089 0.050 0.103 0.004 0.054 0.032 0.050 0.000 0.000 0.003 0.011 0.001 0.000 0.000 0.106 0.167 0.111 0.092 0.134 0.095 0.162 0.023 0.000 0.007 0.235 0.107 0.000 0.076 0.031 0.058 0.051 0.073 0.000 0.011 0.000 0.117 0.057 0.000 0.024 0.000 0.000 0.049 100.199 100.078 100.224 100.057 100.036 100.071 100.042 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.409 0.410 0.401 0.379 0.400 0.396 0.387 0.003 0.002 0.001 0.003 0.003 0.002 0.001 1.534 1.563 1.540 1.590 1.577 1.583 1.592 0.048 0.019 0.054 0.014 0.009 0.017 0.010 0.349 0.368 0.354 0.384 0.386 0.384 0.383 0.015 0.014 0.017 0.014 0.016 0.014 0.014 0.634 0.616 0.626 0.608 0.601 0.601 0.605 0.002 0.001 0.003 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.004 0.003 0.002 0.003 0.002 0.004 0.000 0.000 0.000 0.003 0.002 0.000 0.001 0.001 0.001 0.001 0.002 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Average 76.933 79.223 79.327 80.734 79.772 80.006 80.440 77.021 78.458 77.189 80.173 79.414 79.318 80.021 79.133 61.515 61.402 60.534 60.471 60.362 59.972 60.632 61.064 64.534 62.604 63.855 61.311 60.908 61.016 61.267 2.423 0.965 2.695 0.695 0.449 0.859 0.520 488 Label Z9-Sc1,4 chromites in dunite portion CrZ9-Sc1 Z9-Sc1,4 chromites in Dunite Section Ave Chromitite Section Oxides W t% W t% Wt % Wt % Dunite W t% W t% SI02 0.059 0.065 0.085 0.062 0.068 0.093 0.037 AI203 7.519 7.971 8.225 7.966 7.920 9.394 8.898 Ti02 0.090 0.081 0.061 0.086 0.079 0.101 0.065 Cr203 60.527 61.346 60.583 60.641 60.774 61.750 62.277 Fe203 3.062 2.825 3.368 3.028 3.071 1.245 2.056 FeO 19.142 18.209 17.170 16.975 17.874 13.611 13.111 MnO 0.333 0.263 0.251 0.292 0.285 0.200 0.162 MgO 8.909 9.848 10.466 10.369 9.898 12.757 13.129 NiO 0.058 0.067 0.018 0.055 0.050 0.084 0.058 CaO 0.032 0.000 0.004 0.009 0.011 0.011 0.027 V203 0.118 0.144 0.120 0.123 0.126 0.107 0.126 Nb205 0.000 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.075 0.059 0.152 0.076 0.091 0.044 0.048 Pt02 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 99.924 100.879 100.502 99.682 100.247 99.400 99.994 Cations Si4+ 0.002 0.002 0.003 0.002 0.002 0.003 0.001 AI3+ 0.299 0.311 0.321 0.313 0.311 0.362 0.341 Ti4+ 0.002 0.002 0.002 0.002 0.002 0.002 0.002 Cr3+ 1.614 1.608 1.585 1.601 1.602 1.596 1.601 Fe3+ 0.078 0.070 0.084 0.076 0.077 0.031 0.050 Fe2+ 0.540 0.505 0.475 0.474 0.498 0.372 0.357 Mn2+ 0.010 0.007 0.007 0.008 0.008 0.006 0.004 Mg2+ 0.448 0.487 0.516 0.516 0.492 0.622 0.637 Ni2+ 0.002 0.002 0.000 0.001 0.001 0.002 0.002 Ca2+ 0.001 0.000 0.000 0.000 0.000 0.000 0.001 V3+ 0.003 0.004 0.003 0.003 0.003 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.002 0.001 0.004 0.002 0.002 0.001 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 C r# 84.375 83.773 83.189 83.825 83.738 81.514 82.441 Cr*# 81.081 80.806 79.663 80.428 80.495 80.259 80.360 M g# 42.036 45.829 48.013 48.408 48.071 80.888 81.004 Mg"# 45.343 49.087 52.074 52.126 49.658 62.557 64.095 Fe3+ 3.904 3.542 4.215 3.823 3.871 1.540 2.525 Table C.65: Sample Z9*Sc1 Dunite & Massive chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 489 chromitite portion CrZ9-Sc1 Ave % W t% Chromitite 0.033 0.083 0.062 7.053 8.857 8.551 0.043 0.012 0.055 64.404 62.505 62.734 0.297 1.609 1.302 17.556 13.317 14.399 0.253 0.136 0.188 9.993 13.004 12.221 0.035 0.068 0.061 0.011 0.025 0.019 0.143 0.107 0.121 0.000 0.000 0.000 0.045 0.039 0.044 0.000 0.000 0.000 99.865 99.762 99.755 0.001 0.003 0.002 0.279 0.340 0.331 0.001 0.000 0.001 1.707 1.612 1.629 0.007 0.039 0.032 0.492 0.363 0.396 0.007 0.004 0.005 0.499 0.632 0.597 0.001 0.002 0.002 0.000 0.001 0.001 0.004 0.003 0.003 0.000 0.000 0.000 0.001 0.001 0.001 0.000 0.000 0.000 3.000 3.000 3.000 85.966 82.561 83.121 85.643 80.924 81.796 49.987 61.088 58.192 50.365 63.512 60.132 0.376 1.983 1.606 490 Label Z9-Sc2,4 chromites CrZ9-Sc2 Ave Oxides W t% W t% W t% W t% Si02 0.045 0.087 0.041 0.033 0.051 AI203 8.672 8.798 8.715 8.032 8.554 TI02 0.000 0.007 0.009 0.031 0.012 Cr203 60.045 59.994 59.958 60.996 60.248 Fe203 2.197 1.915 2.258 1.452 1.956 FeO 20.607 20.494 20.478 19.494 20.269 MnO 0.364 0.328 0.386 0.329 0.351 MgO 8.172 8.265 8.233 8.674 8.336 NiO 0.028 0.001 0.008 0.010 0.012 CaO 0.015 0.000 0.000 0.000 0.004 V203 0.345 0.372 0.331 0.316 0.341 Nb205 0.000 0.000 0.000 0.000 0.000 ZnO 0.189 0.282 0.235 0.101 0.202 Pt02 0.000 0.000 0.000 0.000 0.000 Totai 100.681 100.542 100.653 99.467 100.336 0.000 Cations 0.000 Si4+ 0.002 0.003 0.001 0.001 0.002 AI3+ 0.342 0.347 0.344 0.320 0.338 TÎ4+ 0.000 0.000 0.000 0.001 0.000 Cr3+ 1.590 1.589 1.587 1.631 1.599 Fe3+ 0.055 0.048 0.057 0.037 0.049 Fe2+ 0.577 0.574 0.573 0.551 0.569 Mn2+ 0.010 0.009 0.011 0.009 0.010 Mg2+ 0.408 0.413 0.411 0.437 0.417 Ni2+ 0.001 0.000 0.000 0.000 0.000 Ca2+ 0.001 0.000 0.000 0.000 0.000 V3+ 0.009 0.010 0.009 0.009 0.009 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.005 0.007 0.006 0.003 0.005 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 Cr# 82.285 82.061 82.191 83.592 82.532 cr# 79.992 80.064 79.838 82.039 80.483 Mg# 39.209 39.872 39.465 42.640 40.297 Mg"# 41.413 41.823 41.747 44.234 42.304 Fe3+ 2.786 2.433 2.862 1.858 2.485 Table C.66: Sample Z9-Sc2 Hanburgite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite;(Mg, Fe)Cr204. (Fe203 Is calculated by assuming tlie ideal chromite formuia) 491 Label WSU-1 WSU-2 WSU-3 WSU-4 Oxides wt% W t% W t% Wt% 5102 0.089 0.114 0.071 0.056 AI203 7.469 7.259 7.198 7.032 TI02 0.028 0.058 0.066 0.068 Cr203 65.774 64.822 65.291 65.411 Fe203 0.057 0.822 0.584 0.794 FeO 12.492 12.102 12.571 12.738 MnO 0.172 0.210 0.186 0.156 MgO 13.400 13.458 13.216 13.126 NIO 0.074 0.098 0.079 0.138 CaO 0.021 0.000 0.007 0.020 V203 0.115 0.140 0.086 0.119 Nb205 0.000 0.000 0.000 0.000 ZnO 0.012 0.105 0.041 0.000 Pt02 0.000 0.000 0.000 0.000 Total 99.703 99.189 99.396 99.659 Cations 814+ 0.003 0.004 0.002 0.002 AI3+ 0.288 0.281 0.279 0.272 TI4+ 0.001 0.001 0.002 0.002 Cr3+ 1.701 1.686 1.698 1.700 Fe3+ 0.001 0.020 0.014 0.020 Fe2+ 0.342 0.333 0.346 0.350 Mn2+ 0.005 0.006 0.005 0.004 Mg2+ 0.653 0.660 0.648 0.643 NI2+ 0.002 0.003 0.002 0.004 Ca2+ 0.001 0.000 0.000 0.001 V3+ 0.003 0.004 0.002 0.003 Nb5+ 0.000 0.000 0.000 0.000 Zn2+ 0.000 0.003 0.001 0.000 Pt4+ 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 Cr# 85.523 85.694 85.886 86.188 Cr"# 85.462 84.817 85.262 85.338 85.220 Mg# 65.566 65.134 64.272 63.494 64.617 Mg"# 65.661 66.469 65.207 64.750 Fe3+ 0.071 1.023 0.726 0.986 Table C.67: Sample Z9-Sc4 Massive Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 Is calculated by assuming the ideal chromite formula) 492 Label WSU-1 WSU-2 WSU-3 WSU-4 CrZ9-Sc6 Ave Oxides wt% W t% W t% W t% Si02 0.089 0.087 0.093 0.113 0.095 AI203 8.959 8.921 8.880 9.100 8.965 Ti02 0.100 0.091 0.070 0.069 0.083 Cr203 62.294 62.825 62.918 62.792 62.707 Fe203 1.776 1.842 1.414 1.588 1.655 FeO 11.567 11.812 11.714 11.809 11.726 MnO 0.172 0.154 0.100 0.177 0.151 MgO 14.033 14.039 14.015 14.024 14.028 NiO 0.077 0.090 0.111 0.095 0.093 CaO 0.023 0.023 0.008 0.023 0.019 V203 0.087 0.107 0.099 0.122 0.104 Nb205 0.000 0.000 0.000 0.000 0.000 ZnO 0.000 0.004 0.022 0.069 0.024 Pt02 0.000 0.000 0.000 0.000 0.000 Total 99.177 99.994 99.445 99.982 99.649 0.000 Cations 0.000 SM+ 0.003 0.003 0.003 0.004 0.003 AI3+ 0.344 0.340 0.340 0.346 0.342 TI4+ 0.002 0.002 0.002 0.002 0.002 Cr3+ 1.602 1.605 1.615 1.603 1.606 Fe3+ 0.043 0.045 0.035 0.039 0.040 Fe2+ 0.315 0.319 0.318 0.319 0.318 Mn2+ 0.005 0.004 0.003 0.005 0.004 Mg2+ 0.681 0.676 0.678 0.675 0.678 NI2+ 0.002 0.002 0.003 0.002 0.002 Ca2+ 0.001 0.001 0.000 0.001 0.001 V3+ 0.002 0.003 0.003 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.000 0.000 0.001 0.002 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 0.000 Cr# 82.346 82.531 82.618 82.235 82.432 cr# 80.546 80.673 81.183 80.639 80.760 Mg# 65.516 65.011 65.798 65.379 65.426 Mg"# 68.379 67.935 68.079 67.918 68.078 Fe3+ 2.186 2.251 1.736 1.941 2.029 Table C.68: Sample Z9-Sc6 Maeaive Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 493 Label WSU-1 WSU-2 WSU-3 WSU-4 CrZ9-Sc7 Ave Oxides wt% W t% W t% W t% Si02 0.076 0.083 0.096 0.081 0.084 AI203 10.063 10.624 9.236 10.595 10.130 TI02 0.036 0.024 0.008 0.020 0.022 Cr203 58.433 58.473 57.333 57.657 57.974 Fe203 2.890 2.348 4.206 2.970 3.104 FeO 17.529 18.256 20.211 18.917 18.728 MnO 0.299 0.287 0.364 0.307 0.314 MgO 10.260 9.949 8.394 9.519 9.530 NiO 0.043 0.038 0.040 0.029 0.037 CaO 0.011 0.031 0.000 0.000 0.010 V203 0.185 0.173 0.177 0.180 0.179 Nb205 0.000 0.000 0.000 0.000 0.000 ZnO 0.138 0.135 0.271 0.137 0.171 Pt02 0.000 0.000 0.000 0.000 0.000 Total 99.963 100.422 100.335 100.413 100.283 Cations SW+ 0.002 0.003 0.003 0.003 0.003 AI3+ 0.392 0.412 0.365 0.412 0.395 Ti4+ 0.001 0.001 0.000 0.000 0.001 Cr3+ 1.526 1.520 1.518 1.504 1.517 Fe3+ 0.072 0.058 0.106 0.074 0.077 Fe2+ 0.484 0.502 0.566 0.522 0.518 Mn2+ 0.008 0.008 0.010 0.009 0.009 Mg2+ 0.505 0.488 0.419 0.468 0.470 NK+ 0.001 0.001 0.001 0.001 0.001 Ca2+ 0.000 0.001 0.000 0.000 0.000 V3+ 0.005 0.005 0.005 0.005 0.005 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.003 0.003 0.007 0.003 0.004 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 Cr# 79.572 78.688 80.636 78.498 79.349 Cr*# 76.700 76.390 76.338 75.589 76.254 Mg# 47.605 46.544 38.408 44.008 44.141 Mg"# 51.061 49.276 42.541 47.285 47.541 Fe3+ 3.610 2.920 5.331 3.706 3.892 Table C.69; Sample Z9*Sc7 Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 494 Label WSU-1 WSU-2 WSU-3 WSU-4 CrZ9-Sc9 Ave Oxides wt% W t% W t% W t% 3102 0.090 0.107 0.095 0.122 0.103 AI203 8.547 9.153 8.763 8.193 8.664 TI02 0.063 0.081 0.091 0.083 0.080 Cr203 62.281 62.256 63.021 61.710 62.317 Fe203 2.278 1.953 2.197 3.090 2.380 FeO 13.708 13.214 13.418 14.040 13.595 MnO 0.211 0.237 0.185 0.205 0.209 MgO 12.797 13.202 13.199 12.516 12.929 NIO 0.023 0.061 0.070 0.048 0.051 CaO 0.000 0.005 0.037 0.028 0.018 V203 0.125 0.087 0.073 0.126 0.103 Nb205 0.000 0.000 0.000 0.000 0.000 ZnO 0.040 0.042 0.008 0.093 0.046 Pt02 0.000 0.000 0.000 0.000 0.000 Total 100.164 100.400 101.158 100.255 100.494 Cations SI4+ 0.003 0.003 0.003 0.004 0.003 AI3+ 0.328 0.349 0.332 0.316 0.331 TI4+ 0.002 0.002 0.002 0.002 0.002 Cr3+ 1.605 1.592 1.604 1.595 1.599 Fe3+ 0.056 0.048 0.053 0.076 0.058 Fe2+ 0.374 0.357 0.361 0.384 0.369 Mn2+ 0.006 0.006 0.005 0.006 0.006 Mg2+ 0.622 0.637 0.633 0.610 0.625 NB+ 0.001 0.002 0.002 0.001 0.001 Ca2+ 0.000 0.000 0.001 0.001 0.001 V3+ 0.003 0.002 0.002 0.003 0.003 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.001 0.001 0.000 0.002 0.001 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 Cr* 83.017 82.023 82.831 83.478 82.838 Cr** 80.685 80.062 80.615 80.284 80.412 M g* 59.143 61.118 60.447 57.015 59.431 Mg"* 62.463 64.041 63.682 61.376 62.891 Fe3+ 2.809 2.391 2.876 3.827 2.926 Table C.70: Sample Z9*Sc9 Olsaeminated Chromitite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 495 Label WSU-1 WSU-2 WSU-3 WSU-4 CrZ9-Sc10 Ave Oxides wt% Wt% Wt% Wt% Wt% 3102 0.144 0.167 0.155 0.158 0.156 AI203 24.200 24.004 22.446 24.039 23.672 TI02 0.035 0.035 0.073 0.069 0.053 Cr203 44.672 44.965 47.063 46.072 45.693 Fe203 1.638 1.297 1.188 1.074 1.299 FeO 15.359 14.620 15.784 15.063 15.206 MnO 0.195 0.201 0.187 0.189 0.193 MgO 13.235 13.575 12.817 13.604 13.308 NiO 0.044 0.057 0.084 0.054 0.060 CaO 0.004 0.000 0.016 0.028 0.012 V203 0.201 0.181 0.182 0.209 0.193 Nb205 0.000 0.000 0.000 0.000 0.000 ZnO 0.190 0.200 0.189 0.136 0.179 Pt02 0.000 0.000 0.000 0.000 0.000 Total 99.917 99.303 100.182 100.693 100.024 Cations SI4+ 0.004 0.005 0.005 0.005 0.005 AI3+ 0.870 0.866 0.813 0.857 0.852 TI4+ 0.001 0.001 0.002 0.002 0.001 Cr3+ 1.078 1.088 1.144 1.102 1.103 Fe3+ 0.038 0.030 0.027 0.024 0.030 Fe2+ 0.392 0.374 0.406 0.381 0.388 Mn2+ 0.005 0.005 0.005 0.005 0.005 Mg2+ 0.602 0.620 0.587 0.614 0.606 NK+ 0.001 0.001 0.002 0.001 0.001 Ca2+ 0.000 0.000 0.001 0.001 0.000 V3+ 0.005 0.004 0.004 0.005 0.005 Nb5+ 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.004 0.005 0.004 0.003 0.004 Pt4+ 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 Cr# 55.324 55.686 58.448 56.250 56.427 Cr*# 54.275 54.848 57.638 55.556 55.579 Mg# 58.359 60.519 57.550 60.204 59.158 Mg"# 60.568 62.339 59.142 61.684 60.933 Fe3+ 1.895 1.505 1.384 1.233 1.504 Table C.71: Sample Z9*Sc10 Harzburgite Microprobe Analytie & Calculated Formula (bated on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 496 Label CR1-A1-C CR1-A2-R CR2-A1-C CR2-A2-R CR3-A1-C CR3-A2-R CR4-A1-C Chromitite Section Oxides W t% W t% W t% W t% W t% W t% W t% 8102 0.000 0.000 0.000 0.013 0.000 0.000 0.006 AI203 8.409 7.953 8.461 7.686 8.486 7.470 8.259 TI02 0.074 0.013 0.061 0.010 0.023 0.082 0.092 Cr203 64.166 64.544 64.281 65.018 64.109 64.994 64.587 Fe203 0.555 1.024 0.288 0.464 0.485 0.698 0.361 FeO 12.832 12.532 13.106 13.293 13.074 13.416 13.015 MnO 0.468 0.554 0.605 0.591 0.645 0.608 0.648 MgO 13.079 13.141 12.851 12.667 12.895 12.515 12.838 NIO 0.109 0.141 0.118 0.039 0.065 0.096 0.088 CaO 0.006 0.017 0.000 0.000 0.000 0.006 0.001 V203 0.123 0.084 0.174 0.059 0.122 0.087 0.081 Nb205 0.110 0.007 0.082 0.000 0.120 0.000 0.000 ZnO 0.101 0.011 0.002 0.030 0.024 0.000 0.000 Pt02 0.024 0.080 0.000 0.177 0.000 0.097 0.057 Total 100.056 100.102 100.029 100.046 100.048 100.070 100.034 Cations SI4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 AI3+ 0.323 0.306 0.325 0.297 0.326 0.289 0.318 TI4+ 0.002 0.000 0.001 0.000 0.001 0.002 0.002 Cr3+ 1.653 1.665 1.658 1.686 1.653 1.688 1.668 Fe3+ 0.014 0.025 0.007 0.011 0.012 0.017 0.009 Fe2+ 0.350 0.342 0.358 0.365 0.357 0.368 0.355 Mn2+ 0.013 0.015 0.017 0.016 0.018 0.017 0.018 Mg2+ 0.635 0.639 0.625 0.619 0.627 0.613 0.625 Ni2+ 0.003 0.004 0.003 0.001 0.002 0.003 0.002 Ca2+ 0.000 0.001 0.000 0.000 0.000 0.000 0.000 V3+ 0.003 0.002 0.005 0.002 0.003 0.002 0.002 Nb5+ 0.002 0.000 0.001 0.000 0.002 0.000 0.000 Zn2+ 0.002 0.000 0.000 0.001 0.001 0.000 0.000 R4+ 0.000 0.001 0.000 0.002 0.000 0.001 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 83.658 84.482 83.597 85.019 83.520 85.373 83.991 Cr"# 83.085 83.418 83.300 84.531 83.020 84.635 83.617 Mg# 63.620 63.519 63.154 62.220 62.982 61.368 63.175 Mg"# 64.499 65.148 63.609 62.944 63.744 62.447 63.746 Fe3+ 0.684 1.260 0.355 0.574 0.598 0.866 0.444 Table C.72: Sample Z8-Bs1 Massive chromitite & Amphibollte Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromlte:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the Ideal chromite formula) 497 R4-A2-R CR5-A1-C CR5-A2-R CR6-A1-C CR6-A2-R CR7-A1-C CR7-A2-R t% W t% W t% W t% W t% W t% W l% 0.004 0.002 0.000 0.000 0.000 0.006 0.000 8.561 9.551 7.492 9.023 8.880 10.329 7.590 0.023 0.093 0.023 0.017 0.000 0.127 0.028 64.493 63.761 66.064 63.160 64.122 62.327 65.420 0.423 -0.312 -0.892 0.987 0.193 0.254 0.018 12.416 13.114 14.418 12.864 13.155 13.263 13.888 0.610 0.479 0.548 0.574 0.617 0.527 0.666 13.190 12.973 11.790 13.039 12.788 12.954 12.169 0.073 0.073 0.123 0.108 0.107 0.093 0.102 0.028 0.000 0.066 0.001 0.022 0.024 0.007 0.051 0.057 0.065 0.097 0.109 0.107 0.024 0.000 0.000 0.044 0.030 0.000 0.016 0.000 0.137 0.080 0.097 0.066 0.011 0.000 0.000 0.033 0.098 0.073 0.131 0.016 0.000 0.091 100.042 99.968 99.910 100.099 100.019 100.026 100.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.328 0.365 0.292 0.346 0.341 0.394 0.294 0.001 0.002 0.001 0.000 0.000 0.003 0.001 1.659 1.637 1.725 1.624 1.651 1.593 1.702 0.010 -0.008 -0.022 0.024 0.005 0.006 0.000 0.338 0.356 0.398 0.350 0.358 0.359 0.382 0.017 0.013 0.015 0.016 0.017 0.014 0.019 0.640 0.628 0.580 0.632 0.621 0.624 0.597 0.002 0.002 0.003 0.003 0.003 0.002 0.003 0.001 0.000 0.002 0.000 0.001 0.001 0.000 0.001 0.001 0.002 0.003 0.003 0.003 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.003 0.002 0.002 0.002 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.000 0.000 0.001 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Ave 83.481 81.747 85.540 82.443 82.889 80.190 85.256 83.048 82.059 86.491 81.444 82.693 79.941 85.237 83.323 84.756 64.309 60.684 62.827 63.105 63.120 60.941 62.841 65.442 63.812 59.310 64.373 63.409 63.517 60.968 0.519 •0.382 -1.111 1.212 0.236 0.310 0.022 498 Label WSU-1 WSU-2 WSU-3 WSU-4 WSU-5 CrWad9-1 Ave Oxides wt% W t% W t% Wt% W t% Si02 0.036 0.057 0.078 0.086 0.072 0.066 AI203 9.058 10.052 9.423 9.645 10.207 9.677 Ti02 0.063 0.037 0.041 0.030 0.049 0.044 Cr203 58.212 57.568 58.278 57.716 55.770 57.509 Fe203 2.182 1.981 1.793 2.224 2.875 2.211 FeO 23.134 21.648 21.916 21.077 23.029 22.161 MnO 0.487 0.380 0.449 0.372 0.479 0.433 MgO 6.330 7.349 7.092 7.743 6.380 6.979 NiO 0.004 0.006 0.018 0.001 0.064 0.019 CaO 0.011 0.000 0.011 0.000 0.000 0.004 V203 0.248 0.224 0.233 0.243 0.244 0.239 Nb205 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.212 0.349 0.302 0.181 0.239 0.257 Pt02 0.000 0.000 0.000 0.000 0.000 0.000 Total 99.977 99.652 99.633 99.318 99.410 99.598 0.000 Cations 0.000 SM+ 0.001 0.002 0.003 0.003 0.002 0.002 AI3+ 0.364 0.400 0.377 0.385 0.410 0.387 Ti4+ 0.002 0.001 0.001 0.001 0.001 0.001 Cr3+ 1.569 1.538 1.564 1.545 1.503 1.544 Fe3+ 0.056 0.050 0.046 0.057 0.074 0.057 Fe2+ 0.660 0.612 0.622 0.597 0.657 0.629 Mn2+ 0.014 0.011 0.013 0.011 0.014 0.012 Mg2+ 0.322 0.370 0.359 0.391 0.324 0.353 Ni2+ 0.000 0.000 0.000 0.000 0.002 0.001 Ca2+ 0.000 0.000 0.000 0.000 0.000 0.000 V3+ 0.007 0.006 0.006 0.007 0.007 0.006 Nb5+ 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.005 0.009 0.008 0.005 0.006 0.006 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 81.172 79.347 80.578 80.057 78.565 79.944 cr# 78.887 77.337 78.721 77.773 75.648 77.673 M g# 31.016 35.862 34.952 37.425 30.746 34.000 Mg"# 32.786 37.702 36.583 39.572 33.059 35.941 Fe3+ 2.815 2.533 2.305 2.853 3.712 2.844 Table C.73: Sample Wad9>1 Dunite Microprobe Analysis & Calculated Formula (based on 4 oxygens) of chromite:(Mg, Fe)Cr204. (Fe203 is calculated by assuming the ideal chromite formula) 499 Label WSU-1 WSU-2 WSU-3 WSU-4 WSU-5 WSU-6 CrZ9-5 Ave Oxidet wt% W t% W t% W t% W t% W t% 8102 0.098 0.094 0.103 0.093 0.093 0.082 0.094 AI203 11.732 11.560 12.578 11.403 12.571 12.243 12.014 TI02 0.099 0.117 0.099 0.093 0.097 0.111 0.103 Cr203 51.567 51.703 49.808 52.231 50.942 50.249 51.083 Fe203 6.729 6.742 7.197 6.269 6.382 7.657 6.829 FeO 21.855 22.217 22.604 21.789 22.577 22.462 22.251 MnO 0.388 0.376 0.372 0.413 0.383 0.359 0.382 MgO 7.585 7.369 7.198 7.583 7.316 7.375 7.404 NIO 0.067 0.072 0.036 0.019 0.051 0.013 0.043 CaO 0.032 0.021 0.026 0.025 0.000 0.000 0.017 V203 0.259 0.243 0.275 0.265 0.272 0.278 0.265 Nb205 0.000 0.000 0.000 0.000 0.000 0.000 0.000 ZnO 0.225 0.206 0.215 0.184 0.170 0.250 0.208 Pt02 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 100.637 100.719 100.511 100.365 100.855 101.079 100.694 Catlont 814+ 0.003 0.003 0.003 0.003 0.003 0.003 0.003 AI3+ 0.460 0.454 0.493 0.449 0.491 0.478 0.471 TI4+ 0.002 0.003 0.002 0.002 0.002 0.003 0.003 Cr3+ 1.356 1.362 1.310 1.378 1.334 1.316 1.343 Fe3+ 0.168 0.169 0.180 0.157 0.159 0.191 0.171 Fe2+ 0.608 0.619 0.629 0.608 0.625 0.622 0.619 Mn2+ 0.011 0.011 0.010 0.012 0.011 0.010 0.011 Mg2+ 0.376 0.366 0.357 0.377 0.361 0.364 0.367 NI2+ 0.002 0.002 0.001 0.001 0.001 0.000 0.001 Ca2+ 0.001 0.001 0.001 0.001 0.000 0.000 0.001 V3+ 0.007 0.006 0.007 0.007 0.007 0.007 0.007 NbS+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Zn2+ 0.006 0.005 0.005 0.005 0.004 0.006 0.005 Pt4+ 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.000 3.000 3.000 3.000 3.000 3.000 3.000 Cr# 74.674 75.003 72.652 75.447 73.107 73.358 74.040 Cr*# 68.336 68.616 66.052 69.460 67.245 66.303 67.669 M g# 32.634 31.716 30.615 33.011 31.531 30.934 31.740 Mg"# 38.220 37.158 36.210 38.285 36.615 36.920 37.235 Fe3+ 8.487 8.516 9.085 7.935 8.019 9.617 8.610 Table C.74: Sample Z9-5 Pyroxenite Microprobe Analyeis & Calculated Formula (bated on 4 oxygéna) of chromlte:(Mg, Fe)Cr204. (Fe203 it calculated by attumfng the ideal chromite formula) 500 Calculating Olivine Structural Formula: (Mg, Fe)2SI04 Sample: Z7-20 (A) (B) Analyzed Point Label 0L1-A1-C Oxides W t% Si02 38.728 AI203 0.028 TI02 0 Cr203 0 FeOtot. 8.101 MgO 50.113 MnO 0.139 NIO 0.426 CaO 0.017 Na20 0.036 (0) (D) (E) (F) (G) (H) Total 97.588 Mol. Wt. Mol.Prop. Ox.Mole Ox.ProD. No.of Anic Cat.Aetoc Normalized oxides Wt. % B/C D*E (F*4)/Tot.FCat./Ox Si02 39.68521 60.0843 0.660492 2 1.320984 1.942466 0.5 AI203 0.028692 101.9613 0.000281 3 0.000844 0.001241 0-Jan Ti02 0 79.8988 0 2 0 0 0-Jan Cr203 0 151.9902 0 3 0 0 0.666667 FeOtot. 8.301226 71.8464 0.115541 1 0.115541 0.1699 MgO 51.3516 40.3044 1.274094 1 1.274094 1.873515 MnO 0.142436 70.9374 0.002008 1 0.002008 0.002953 NiO 0.436529 74.6994 0.005844 1 0.005844 0.008593 CaO 0.01742 56.0794 0.000311 1 0.000311 0.000457 Na20 0.03689 61.97894 0.000595 1 0.000595 0.000875 Norm.Cat. 2.720221 Cations (J*3)/Tot.J Si 0.971233 0.96214 AI 0.000828 0.00082 Ti 0 0 Cr 0 0 Fe 0.1699 0.168309 Mg 1.873515 1.855974 Mn 0.002953 0.002925 NI 0.008593 0.008513 Ca 0.000457 0.000453 Na 0.000875 0.000867 Total 3.028353 3 M g# 91.6855 Figure C2.1.: Sample form of the Olivine formula calculation and. related 501 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C Oxides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 3102 40.115 40.215 41.664 40.164 40.446 40.187 39.852 AI203 0.009 0.036 0.040 0.011 0.000 0.025 0.000 TI02 0.000 0.012 0.000 0.000 0.000 0.003 0.008 Cr203 0.000 0.000 0.000 0.003 0.000 0.018 0.000 FeOtot. 8.380 8.190 8.125 8.159 8.234 8.141 8.352 MgO 50.989 50.169 51.199 51.561 51.068 50.312 50.936 MnO 0.132 0.124 0.145 0.115 0.134 0.130 0.137 NiO 0.461 0.391 0.375 0.531 0.331 0.354 0.437 CaO 0.034 0.025 0.028 0.021 0.021 0.024 0.027 Na20 0.000 0.000 0.009 0.000 0.003 0.009 0.007 Total 100.120 99.162 101.585 100.565 100.237 99.203 99.756 Normalized oxides 8102 40.067 40.555 41.014 39.938 40.350 40.510 39.949 AI203 0.009 0.036 0.039 0.011 0.000 0.025 0.000 TI02 0.000 0.012 0.000 0.000 0.000 0.003 0.008 Cr203 0.000 0.000 0.000 0.003 0.000 0.018 0.000 FeOtot. 8.370 8.259 7.998 8.113 8.215 8.206 8.372 MgO 50.928 50.593 50.400 51.271 50.947 50.716 51.061 MnO 0.132 0.125 0.143 0.114 0.134 0.131 0.137 NIO 0.460 0.394 0.369 0.528 0.330 0.357 0.438 CaO 0.034 0.025 0.028 0.021 0.021 0.024 0.027 Na20 0.000 0.000 0.009 0.000 0.003 0.009 0.007 Cations SI 0.980 0.989 0.998 0.976 0.985 0.988 0.977 AI 0.000 0.001 0.001 0.000 0.000 0.001 0.000 TI 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.171 0.168 0.163 0.166 0.168 0.167 0.171 Mg 1.856 1.840 1.828 1.868 1.853 1.844 1.862 Mn 0.003 0.003 0.003 0.002 0.003 0.003 0.003 NI 0.009 0.008 0.007 0.010 0.006 0.007 0.009 Ca 0.001 0.001 0.001 0.001 0.001 0.001 0.001 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.020 3.010 3.001 3.024 3.015 3.011 3.023 Fo 91.559 91.610 91.825 91.847 91.705 91.678 91.576 Table C2.1 : Sample: Z7*P14A Chromite bearing dunite Microprobe Analysis A Calculated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2SI04. Fo"Mg'100/(Mg+Fetot) 502 .4-A2-LF 0L6-A1-C OL6-A2-R 0L8-A1-C OL8-A2-R 0L9-A1-C OL9-A2-LF 0L11-A1-( % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 40.934 38.790 38.756 38.213 39.503 38.656 37.877 40.352 0.002 0.000 0.002 0.019 0.021 0.021 0.159 0.011 0.000 0.000 0.032 0.000 0.000 0.000 0.023 0.015 0.004 0.000 0.004 0.000 0.025 0.019 0.000 0.001 8.667 8.528 8.547 8.441 8.311 8.385 8.347 8.680 51.649 51.070 50.017 51.065 49.803 50.859 51.441 49.277 0.127 0.119 0.164 0.168 0.152 0.111 0.143 0.124 0.476 0.459 0.374 0.361 0.438 0.393 0.532 0.378 0.036 0.008 0.035 0.014 0.003 0.007 0.000 0.000 0.070 0.000 0.007 0.000 0.000 0.000 0.000 0.000 101.965 98.974 97.938 98.281 98.256 98.451 98.522 98.838 40.145 39.192 39.572 38.881 40.204 39.264 38.445 40.826 0.002 0.000 0.002 0.019 0.021 0.021 0.161 0.011 0.000 0.000 0.033 0.000 0.000 0.000 0.023 0.015 0.004 0.000 0.004 0.000 0.025 0.019 0.000 0.001 8.500 8.616 8.727 8.589 8.459 8.517 8.472 8.782 50.654 51.599 51.070 51.958 50.687 51.659 52.213 49.856 0.125 0.120 0.167 0.171 0.155 0.113 0.145 0.125 0.467 0.464 0.382 0.367 0.446 0.399 0.540 0.382 0.035 0.008 0.036 0.014 0.003 0.007 0.000 0.000 0.069 0.000 0.007 0.000 0.000 0.000 0.000 0.000 0.982 0.962 0.970 0.955 0.983 0.963 0.945 0.997 0.000 0.000 0.000 0.001 0.001 0.001 0.005 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.174 0.177 0.179 0.176 0.173 0.175 0.174 0.179 1.847 1.888 1.867 1.902 1.847 1.888 1.914 1.815 0.003 0.002 0.003 0.004 0.003 0.002 0.003 0.003 0.009 0.009 0.008 0.007 0.009 0.008 0.011 0.008 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.018 3.038 3.029 3.045 3.016 3.037 3.052 3.002 91.396 91.435 91.252 91.514 91.440 91.534 91.657 91.007 503 0L11-A2-R 0L5-A1-C OL5-A2-R Wt. % Wt. % W t % 41.426 38.104 37.520 0.000 0.017 0.008 0.000 0.015 0.008 0.009 0.000 0.023 8.523 8.423 8.563 49.596 51.201 50.169 0.146 0.139 0.176 0.323 0.386 0.421 0.017 0.024 0.017 0.000 0.000 0.000 100.040 98.309 96.905 41.409 38.759 38.718 0.000 0.017 0.008 0.000 0.015 0.008 0.009 0.000 0.024 8.520 8.568 8.836 49.576 52.082 51.771 0.146 0.141 0.182 0.323 0.393 0.434 0.017 0.024 0.018 0.000 0.000 0.000 1.008 0.952 0.953 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.173 0.176 0.182 1.800 1.907 1.899 0.003 0.003 0.004 0.006 0.008 0.009 0.000 0.001 0.000 0.000 0.000 0.000 2.992 3.047 3.047 Average 91.207 91.515 91.551 91.262 504 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C Chromititic Section Oxides Wt % Wt % Wt% W t% Wt% Wt% W t% 5102 38.870 39.257 39.458 40.429 38.042 38.003 37.449 AI203 0.000 0.011 0.000 0.006 0.004 0.028 0.006 TI02 0.025 0.000 0.020 0.008 0.000 0.017 0.000 Cr203 0.016 0.004 0.023 0.000 0.000 0.042 0.000 FeOtot. 6.557 6.588 6.552 6.522 6.564 6.288 6.660 MgO 52.392 52.952 52.859 53.138 52.053 51.959 51.917 MnO 0.099 0.092 0.142 0.098 0.098 0.106 0.096 NiO 0.477 0.465 0.477 0.504 0.411 0.495 0.414 CaO 0.021 0.011 0.021 0.008 0.000 0.018 0.010 Na20 0.026 0.000 0.000 0.000 0.016 0.003 0.000 Total 98.483 99.380 99.552 100.713 97.188 96.959 96.552 Normalized oxides Si02 39.469 39.502 39.636 40.143 39.143 39.195 38.786 AI203 0.000 0.011 0.000 0.006 0.004 0.029 0.006 Ti02 0.025 0.000 0.020 0.008 0.000 0.018 0.000 Cr203 0.016 0.004 0.023 0.000 0.000 0.043 0.000 FeOtot. 6.658 6.629 6.581 6.476 6.754 6.485 6.898 MgO 53.199 53.282 53.097 52.762 53.559 53.589 53.771 MnO 0.101 0.093 0.143 0.097 0.101 0.109 0.099 NiO 0.484 0.468 0.479 0.500 0.423 0.511 0.429 CaO 0.021 0.011 0.021 0.008 0.000 0.019 0.010 Na20 0.026 0.000 0.000 0.000 0.016 0.003 0.000 Cations Si 0.960 0.961 0.964 0.974 0.953 0.954 0.946 AI 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Fe 0.135 0.135 0.134 0.131 0.138 0.132 0.141 Mg 1.930 1.932 1.925 1.908 1.945 1.944 1.956 Mn 0.002 0.002 0.003 0.002 0.002 0.002 0.002 Ni 0.009 0.009 0.009 0.010 0.008 0.010 0.008 Ca 0.001 0.000 0.001 0.000 0.000 0.000 0.000 Na 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.039 3.039 3.036 3.026 3.047 3.045 3.054 M g# 93.440 93.476 93.499 93.558 93.393 93.643 93.287 Table C2.2: Sample: Z7-P15.1 Chromitite & Dunite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. Fo"Mg*100/(Mg+Fetot) 505 L4-A2-R 0L5-A1-C OL5-A2-R 0L6-A1-C OL6-A2-R OL9-A1-C OL9-A2-R OL0-A1-C Dunitic Se % Wt% Wt% Wt% Wt% W t% Wt% W t% 38.970 37.274 36.352 38.810 37.194 39.024 39.944 38.686 0.000 0.004 0.002 0.019 0.000 0.017 0.000 0.013 0.000 0.000 0.037 0.000 0.020 0.025 0.003 0.000 0.000 0.000 0.022 0.000 0.012 0.012 0.032 0.009 6.645 6.386 6.501 7.000 7.095 7.258 6.992 7.494 52.086 52.128 52.622 51.960 51.834 52.314 52.018 51.990 0.124 0.083 0.121 0.090 0.106 0.093 0.089 0.133 0.442 0.627 0.509 0.481 0.414 0.495 0.504 0.417 0.039 0.011 0.027 0.029 0.022 0.032 0.022 0.013 0.000 0.000 0.000 0.013 0.000 0.009 0.000 0.016 98.306 96.513 96.193 98.402 96.697 99.279 99.604 98.771 39.642 38.621 37.791 39.440 38.464 39.307 40.103 39.167 0.000 0.004 0.002 0.019 0.000 0.017 0.000 0.013 0.000 0.000 0.038 0.000 0.021 0.025 0.003 0.000 0.000 0.000 0.023 0.000 0.012 0.012 0.032 0.009 6.760 6.617 6.758 7.114 7.337 7.311 7.020 7.587 52.984 54.011 54.705 52.804 53.605 52.694 52.225 52.637 0.126 0.086 0.126 0.091 0.110 0.094 0.089 0.135 0.450 0.650 0.529 0.489 0.428 0.499 0.506 0.422 0.040 0.011 0.028 0.029 0.023 0.032 0.022 0.013 0.000 0.000 0.000 0.013 0.000 0.009 0.000 0.016 0.964 0.942 0.925 0.961 0.941 0.959 0.975 0.957 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.138 0.135 0.138 0.145 0.150 0.149 0.143 0.155 1.921 1.965 1.996 1.919 1.955 1.917 1.893 1.918 0.003 0.002 0.003 0.002 0.002 0.002 0.002 0.003 0.009 0.013 0.010 0.010 0.008 0.010 0.010 0.008 0.001 0.000 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.036 3.057 3.074 3.038 3.058 3.040 3.024 3.042 93.321 93.570 93.519 92.974 92.869 92.779 92.988 92.519 506 L8-A2-R OL10-A1-C OL10-A2-R 0L11-A1-C 0L11-A2-R 0L12-A1-C 0L12-A2-R 0L13-A1-C OL13-A2-R @n t% Wt% Wt% Wt% Wt% Wt% W t% W t% Wt% 38.393 38.382 37.793 38.630 38.035 38.867 38.829 38.091 37.150 0.000 0.034 0.000 0.011 0.015 0.004 0.015 0.013 0.002 0.000 0.000 0.000 0.000 0.028 0.000 0.000 0.088 0.020 0.007 0.012 0.003 0.000 0.009 0.016 0.000 0.022 0.000 7.427 7.482 7.700 7.675 7.567 7.862 7.781 7.785 7.773 52.426 52.052 50.841 51.174 50.642 51.397 51.108 51.164 49.985 0.116 0.137 0.123 0.120 0.106 0.134 0.173 0.146 0.121 0.430 0.473 0.403 0.463 0.349 0.509 0.391 0.406 0.448 0.035 0.039 0.027 0.027 0.007 0.022 0.032 0.043 0.049 0.000 0.000 0.000 0.000 0.005 0.024 0.000 0.000 0.000 98.834 98.611 96.890 98.100 96.763 98.835 98.329 97.758 95.548 38.846 38.923 39.006 39.378 39.307 39.325 39.489 38.965 38.881 0.000 0.034 0.000 0.011 0.016 0.004 0.015 0.013 0.002 0.000 0.000 0.000 0.000 0.029 0.000 0.000 0.090 0.021 0.007 0.012 0.003 0.000 0.009 0.016 0.000 0.023 0.000 7.515 7.587 7.947 7.824 7.820 7.955 7.913 7.964 8.135 53.044 52.785 52.473 52.165 52.336 52.003 51.977 52.337 52.314 0.117 0.139 0.127 0.122 0.110 0.136 0.176 0.149 0.127 0.435 0.480 0.416 0.472 0.361 0.515 0.398 0.415 0.469 0.035 0.040 0.028 0.028 0.007 0.022 0.033 0.044 0.051 0.000 0.000 0.000 0.000 0.005 0.024 0.000 0.000 0.000 0.950 0.952 0.955 0.963 0.961 0.962 0.965 0.954 0.953 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.154 0.155 0.163 0.160 0.160 0.163 0.162 0.163 0.167 1.934 1.925 1.915 1.901 1.907 1.897 1.894 1.911 1.912 0.002 0.003 0.003 0.003 0.002 0.003 0.004 0.003 0.003 0.009 0.009 0.008 0.009 0.007 0.010 0.008 0.008 0.009 0.001 0.001 0.001 0.001 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 3.050 3.047 3.045 3.037 3.038 3.037 3.034 3.044 3.046 92.638 92.538 92.169 92.239 92.266 92.097 92.131 92.136 91.976 507 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C 0L3-A1-C OL3-A2-R 0L4-A1-C 0L5-A1-C Oxides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 8102 39.342 40.406 39.929 38.455 39.372 39.034 40.175 AI203 0.000 0.000 0.000 0.013 0.000 0.000 0.083 TI02 0.000 0.055 0.000 0.043 0.035 0.000 0.015 Cr203 0.023 0.000 0.000 0.007 0.000 0.028 0.000 FeOtot. 7.195 7.384 7.429 7.446 7.541 7.720 7.759 MgO 51.453 52.033 51.232 50.798 50.952 51.597 51.130 MnO 0.130 0.146 0.085 0.115 0.123 0.146 0.115 NiO 0.484 0.384 0.420 0.333 0.486 0.477 0.415 CaO 0.015 0.020 0.029 0.049 0.017 0.048 0.039 Na20 0.000 0.000 0.000 0.012 0.003 0.000 0.000 Total 98.642 100.428 99.124 97.271 98.529 99.050 99.731 Normalized oxides 5102 39.884 40.234 40.282 39.534 39.960 39.408 40.283 AI203 0.000 0.000 0.000 0.013 0.000 0.000 0.083 TI02 0.000 0.055 0.000 0.044 0.036 0.000 0.015 Cr203 0.023 0.000 0.000 0.007 0.000 0.028 0.000 FeOtot. 7.294 7.353 7.495 7.655 7.654 7.794 7.780 MgO 52.161 51.811 51.685 52.223 51.713 52.092 51.268 MnO 0.132 0.145 0.086 0.118 0.125 0.147 0.115 NIO 0.491 0.382 0.424 0.342 0.493 0.482 0.416 CaO 0.015 0.020 0.029 0.050 0.017 0.048 0.039 Na20 0.000 0.000 0.000 0.012 0.003 0.000 0.000 Cations Si 0.972 0.979 0.981 0.965 0.975 0.964 0.982 AI 0.000 0.000 0.000 0.000 0.000 0.000 0.002 Ti 0.000 0.001 0.000 0.001 0.001 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Fe 0.149 0.150 0.153 0.156 0.156 0.159 0.159 Mg 1.895 1.879 1.876 1.900 1.880 1.899 1.862 Mn 0.003 0.003 0.002 0.002 0.003 0.003 0.002 Ni 0.010 0.007 0.008 0.007 0.010 0.009 0.008 Ca 0.000 0.001 0.001 0.001 0.000 0.001 0.001 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.028 3.020 3.019 3.034 3.025 3.036 3.017 M g# 92.726 92.626 92.477 92.402 92.334 92.257 92.155 Table C2.3: Sample; Z7*P17 Dunite Microprobe Analysis & Calculated Formula (txased on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. Fo«Mg'100/(Mg*Fetot) 508 OL5-A2-R 0L6-A1-C OL6-A2-R 0L7-A1-C OL7-A2-R 0L8-A1-C OL8-A2-R 0L9-A1-C Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 39.584 39.394 40.560 39.214 39.432 38.161 39.058 39.195 0.030 0.000 0.000 0.000 0.178 0.000 0.011 0.000 0.000 0.055 0.000 0.000 0.015 0.015 0.023 0.023 0.019 0.000 0.029 0.004 0.000 0.000 0.016 0.007 7.575 7.611 7.656 7.518 7.637 7.613 7.664 7.620 51.087 51.155 51.604 51.058 50.649 51.315 50.463 51.544 0.108 0.088 0.121 0.123 0.139 0.152 0.093 0.118 0.414 0.452 0.440 0.434 0.482 0.487 0.377 0.391 0.038 0.034 0.027 0.046 0.041 0.041 0.025 0.038 0.003 0.042 0.000 0.000 0.000 0.000 0.000 0.012 98.858 98.831 100.437 98.397 98.573 97.784 97.730 98.948 40.041 39.860 40.384 39.853 40.003 39.026 39.965 39.612 0.030 0.000 0.000 0.000 0.181 0.000 0.011 0.000 0.000 0.056 0.000 0.000 0.015 0.015 0.024 0.023 0.019 0.000 0.029 0.004 0.000 0.000 0.016 0.007 7.663 7.701 7.623 7.640 7.748 7.786 7.842 7.701 51.677 51.760 51.379 51.890 51.382 52.478 51.635 52.092 0.109 0.089 0.120 0.125 0.141 0.155 0.095 0.119 0.419 0.457 0.438 0.441 0.489 0.498 0.386 0.395 0.038 0.034 0.027 0.047 0.042 0.042 0.026 0.038 0.003 0.042 0.000 0.000 0.000 0.000 0.000 0.012 0.976 0.973 0.983 0.972 0.976 0.955 0.975 0.967 0.001 0.000 0.000 0.000 0.005 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.156 0.157 0.155 0.156 0.158 0.159 0.160 0.157 1.878 1.883 1.865 1.887 1.868 1.915 1.878 1.896 0.002 0.002 0.002 0.003 0.003 0.003 0.002 0.002 0.008 0.009 0.009 0.009 0.010 0.010 0.008 0.008 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.023 3.026 3.016 3.028 3.021 3.044 3.024 3.032 92.321 92.297 92.317 92.370 92.201 92.317 92.149 92.342 509 OL9-A2-R OL10-A1-( OL10-A2-F 0L11-A1-C % wt. % Wt. % Wt. % 38.562 39.646 39.017 39.060 0.006 0.000 0.000 0.000 0.047 0.000 0.000 0.000 0.000 0.009 0.000 0.000 7.320 7.179 7.122 7.541 50.652 51.541 50.312 51.456 0.083 0.045 0.085 0.141 0.396 0.396 0.448 0.448 0.015 0.020 0.014 0.011 0.003 0.000 0.005 0.000 97.084 98.836 97.003 98.657 39.720 40.113 40.222 39.592 0.006 0.000 0.000 0.000 0.048 0.000 0.000 0.000 0.000 0.009 0.000 0.000 7.540 7.264 7.342 7.644 52.173 52.148 51.866 52.156 0.085 0.046 0.088 0.143 0.408 0.401 0.462 0.454 0.015 0.020 0.014 0.011 0.003 0.000 0.005 0.000 0.969 0.976 0.979 0.967 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.154 0.148 0.149 0.156 1.897 1.891 1.882 1.898 0.002 0.001 0.002 0.003 0.008 0.008 0.009 0.009 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.030 3.024 3.021 3.033 Average 92.501 92.753 92.643 92.403 92.399 510 Label 0L2-A1-C 0L4-A1-C OL4-A2-R 0L5-A1-C OL5-A2-R 0L6-A1-C 0L7-A1-C Oxides Wt. % Wt.. % Wt.. % Wt. % Wt. % Wt. % Wt. % SI02 37.749 39.710 39.886 40.451 40.200 39.969 38.844 AI203 0.000 0.000 0.021 0.006 0.000 0.030 0.002 TI02 0.052 0.020 0.012 0.000 0.000 0.000 0.003 Cr203 0.000 0.029 0.004 0.000 0.054 0.003 0.012 FeOtot. 5.176 4.972 5.017 5.060 4.887 5.119 5.570 MgO 52.367 52.667 52.995 53.464 54.154 53.236 52.415 MnO 0.062 0.088 0.097 0.056 0.087 0.074 0.057 NIO 0.570 0.568 0.582 0.662 0.631 0.513 0.533 CaO 0.035 0.024 0.027 0.001 0.008 0.020 0.022 Na20 0.018 0.009 0.000 0.000 0.000 0.005 0.000 Total 96.029 98.087 98.641 99.700 100.021 98.969 97.458 Normalized oxides 8102 39.310 40.484 40.436 40.573 40.192 40.385 39.857 AI203 0.000 0.000 0.021 0.006 0.000 0.030 0.002 TI02 0.054 0.020 0.012 0.000 0.000 0.000 0.003 Cr203 0.000 0.030 0.004 0.000 0.054 0.003 0.012 FeOtot. 5.390 5.069 5.086 5.075 4.886 5.172 5.715 MgO 54.532 53.694 53.725 53.625 54.143 53.791 53.782 MnO 0.065 0.090 0.098 0.056 0.087 0.075 0.058 NIO 0.594 0.579 0.590 0.664 0.631 0.518 0.547 CaO 0.036 0.024 0.027 0.001 0.008 0.020 0.023 Na20 0.019 0.009 0.000 0.000 0.000 0.005 0.000 Cations Si 0.952 0.976 0.975 0.978 0.969 0.974 0.965 AI 0.000 0.000 0.001 0.000 0.000 0.001 0.000 TI 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.001 0.000 0.000 0.001 0.000 0.000 Fe 0.109 0.102 0.103 0.102 0.099 0.104 0.116 Mg 1.970 1.930 1.931 1.927 1.947 1.934 1.941 Mn 0.001 0.002 0.002 0.001 0.002 0.002 0.001 NI 0.012 0.011 0.011 0.013 0.012 0.010 0.011 Ca 0.001 0.001 0.001 0.000 0.000 0.001 0.001 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.047 3.023 3.024 3.022 3.030 3.026 3.035 Mg# 94.747 94.970 94.957 94.958 95.182 94.882 94.374 Table C2.4: Sample Z7-P19.2 Disseminated chromitite Microprolie Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2Si04. Fo"MgMOO/(Mg+Fetot) 511 0L8-A1-C OL8-A2-R 0L9-A1-C OL10-A1-C 0L12-A1-( OL12-A2-R % wt.. % Wt. % Wt. % Wt., % Wt. % 39.762 40.102 39.032 39.772 39.287 39.013 0.000 0.000 0.008 0.000 0.000 0.025 0.015 0.028 0.000 0.003 0.000 0.017 0.007 0.019 0.016 0.015 0.000 0.000 5.937 5.838 5.690 5.896 5.869 5.861 52.430 53.176 52.324 52.773 52.164 52.569 0.097 0.101 0.080 0.093 0.098 0.090 0.499 0.501 0.501 0.512 0.601 0.513 0.027 0.001 0.022 0.034 0.020 0.027 0.000 0.012 0.012 0.000 0.012 0.000 98.774 99.778 97.685 99.098 98.051 98.115 40.256 40.191 39.957 40.134 40.068 39.763 0.000 0.000 0.008 0.000 0.000 0.025 0.015 0.028 0.000 0.003 0.000 0.017 0.007 0.019 0.016 0.015 0.000 0.000 6.011 5.851 5.825 5.950 5.986 5.974 53.081 53.294 53.564 53.253 53.201 53.579 0.098 0.101 0.082 0.094 0.100 0.092 0.505 0.502 0.513 0.517 0.613 0.523 0.027 0.001 0.023 0.034 0.020 0.028 0.000 0.012 0.012 0.000 0.012 0.000 0.975 0.973 0.968 0.972 0.971 0.964 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.122 0.118 0.118 0.120 0.121 0.121 1.916 1.923 1.934 1.922 1.922 1.936 0.002 0.002 0.002 0.002 0.002 0.002 0.010 0.010 0.010 0.010 0.012 0.010 0.001 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 3.025 3.027 3.032 3.028 3.029 3.035 Average 94.027 94.199 94.250 94.102 94.063 94.114 94.525 512 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C Oxides Wt. % WL% Wt. % Wt. % Wt. % Wt. % Wt. % 8102 38.373 38.540 38.728 39.126 39.197 38.626 38.842 AI203 0.002 0.000 0.028 0.000 0.036 0.000 0.026 TI02 0.000 0.012 0.000 0.000 0.055 0.008 0.032 Cr203 0.012 0.037 0.000 0.018 0.000 0.009 0.031 FeOtot. 8.402 8.333 8.101 7.934 8.335 8.097 8.188 MgO 49.907 50.579 50.113 50.373 49.649 48.985 49.463 MnO 0.127 0.146 0.139 0.136 0.139 0.181 0.137 NiO 0.325 0.392 0.426 0.421 0.271 0.379 0.447 CaO 0.008 0.011 0.017 0.010 0.011 0.001 0.001 Na20 0.000 0.000 0.036 0.000 0.007 0.031 0.000 Total 97.156 98.050 97.588 98.018 97.700 96.317 97.167 Normalized oxides SI02 39.496 39.306 39.685 39.917 40.120 40.103 39.974 AI203 0.002 0.000 0.029 0.000 0.037 0.000 0.027 TI02 0.000 0.012 0.000 0.000 0.056 0.008 0.033 Cr203 0.012 0.038 0.000 0.018 0.000 0.009 0.032 FeOtot. 8.648 8.499 8.301 8.094 8.531 8.407 8.427 MgO 51.368 51.585 51.352 51.392 50.818 50.858 50.905 MnO 0.131 0.149 0.142 0.139 0.142 0.188 0.141 NIO 0.335 0.400 0.437 0.430 0.277 0.393 0.460 CaO 0.008 0.011 0.017 0.010 0.011 0.001 0.001 Na20 0.000 0.000 0.037 0.000 0.007 0.032 0.000 Cations SI 0.968 0.964 0.971 0.975 0.981 0.981 0.978 AI 0.000 0.000 0.001 0.000 0.001 0.000 0.001 Tl 0.000 0.000 0.000 0.000 0.001 0.000 0.001 Cr 0.000 0.001 0.000 0.000 0.000 0.000 0.001 Fe 0.177 0.174 0.170 0.165 0.174 0.172 0.172 Mg 1.877 1.885 1.874 1.872 1.852 1.854 1.856 Mn 0.003 0.003 0.003 0.003 0.003 0.004 0.003 NI 0.007 0.008 0.009 0.008 0.005 0.008 0.009 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.001 0.000 0.000 0.001 0.000 Total 3.032 3.036 3.028 3.025 3.018 3.019 3.021 Mg# 91.371 91.540 91.685 91.882 91.393 91.514 91.503 Table C2.S: Sample: Z7-P20 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2SI04. Fo-Mg*100/(Mg+Fetot) 513 0L4B-A1-I 0L6-A1-C OL6-A2-R 0L7-A1-C OL7-A2-R 0L8-A1-C OL8-A2-R OL10-A1-( Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 39.522 39.625 39.640 38.078 38.904 38.168 38.378 39.173 0.000 0.015 0.004 0.015 0.000 0.008 0.000 0.000 0.000 0.000 0.028 0.012 0.020 0.000 0.023 0.000 0.034 0.013 0.006 0.000 0.037 0.019 0.035 0.000 8.110 8.513 8.227 8.245 8.434 8.448 8.527 8.455 50.199 50.534 50.495 50.526 50.869 50.481 50.682 50.390 0.136 0.143 0.129 0.179 0.164 0.119 0.150 0.145 0.374 0.401 0.443 0.406 0.398 0.321 0.459 0.420 0.000 0.022 0.013 0.000 0.008 0.000 0.000 0.004 0.000 0.000 0.012 0.000 0.000 0.000 0.000 0.000 98.375 99.266 98.997 97.461 98.834 97.564 98.254 98.587 40.175 39.918 40.042 39.070 39.363 39.121 39.060 39.734 0.000 0.015 0.004 0.015 0.000 0.008 0.000 0.000 0.000 0.000 0.028 0.012 0.020 0.000 0.023 0.000 0.035 0.013 0.006 0.000 0.037 0.019 0.036 0.000 8.244 8.576 8.310 8.460 8.534 8.659 8.679 8.576 51.028 50.908 51.007 51.842 51.469 51.741 51.583 51.112 0.138 0.144 0.130 0.184 0.166 0.122 0.153 0.147 0.380 0.404 0.447 0.417 0.403 0.329 0.467 0.426 0.000 0.022 0.013 0.000 0.008 0.000 0.000 0.004 0.000 0.000 0.012 0.000 0.000 0.000 0.000 0.000 0.981 0.977 0.979 0.959 0.965 0.960 0.959 0.973 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.168 0.176 0.170 0.174 0.175 0.178 0.178 0.176 1.858 1.858 1.859 1.896 1.881 1.893 1.889 1.866 0.003 0.003 0.003 0.004 0.003 0.003 0.003 0.003 0.007 0.008 0.009 0.008 0.008 0.006 0.009 0.008 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.018 3.023 3.020 3.041 3.034 3.040 3.040 3.027 91.690 91.366 91.626 91.613 91.491 91.418 91.376 91.397 514 OL10-A2-f 0L13-A1-( OL13-A2-R Wt. % Wt. % Wt. % 39.263 38.795 38.917 0.145 0.000 0.011 0.000 0.000 0.000 0.013 0.000 0.000 8.470 8.371 8.520 50.103 49.980 50.354 0.129 0.129 0.137 0.369 0.442 0.398 0.015 0.001 0.021 0.046 0.000 0.007 98.553 97.718 98.365 39.839 39.701 39.564 0.147 0.000 0.011 0.000 0.000 0.000 0.013 0.000 0.000 8.594 8.566 8.662 50.839 51.147 51.191 0.131 0.132 0.139 0.374 0.452 0.405 0.015 0.001 0.021 0.047 0.000 0.007 0.975 0.973 0.970 0.004 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.176 0.175 0.178 1.855 1.868 1.871 0.003 0.003 0.003 0.007 0.009 0.008 0.000 0.000 0.001 0.001 0.000 0.000 3.023 3.027 3.030 Average 91.338 91.411 91.331 91.497 515 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C 0L5-A1-C OL5-A2-R 0L6-A1-C 0L7-A1-C Oxides W t% W t% Wt% W t% Wt% Wt% Wt% 3102 39.415 40.536 40.123 40.196 39.980 39.648 39.362 AI203 0.034 0.015 0.017 0.015 0.185 0.000 0.002 TI02 0.028 0.028 0.000 0.000 0.000 0.035 0.008 Cr203 0.000 0.000 0.000 0.000 0.000 0.023 0.023 FeO tot 8.327 8.304 8.017 8.394 8.666 8.318 8.511 MgO 48.163 47.956 49.211 48.966 47.359 48.641 48.856 MnO 0.116 0.125 0.114 0.114 0.084 0.154 0.097 NiO 0.401 0.417 0.403 0.398 0.411 0.387 0.476 CaO 0.018 0.011 0.003 0.017 0.017 0.010 0.000 Na20 0.018 0.000 0.000 0.000 0.000 0.000 0.000 Total 96.520 97.392 97.888 98.100 96.702 97.216 97.335 Normalized oxides SI02 40.836 41.621 40.989 40.975 41.344 40.783 40.440 AI203 0.035 0.015 0.017 0.015 0.191 0.000 0.002 TI02 0.029 0.029 0.000 0.000 0.000 0.036 0.008 Cr203 0.000 0.000 0.000 0.000 0.000 0.024 0.024 FeOtot. 8.627 8.526 8.190 8.557 8.962 8.556 8.744 MgO 49.900 49.240 50.273 49.914 48.974 50.034 50.194 MnO 0.120 0.128 0.116 0.116 0.087 0.158 0.100 NiO 0.415 0.428 0.412 0.406 0.425 0.398 0.489 CaO 0.019 0.011 0.003 0.017 0.018 0.010 0.000 Na20 0.019 0.000 0.000 0.000 0.000 0.000 0.000 Cations Si 0.997 1.013 0.998 0.999 1.009 0.996 0.989 AI 0.001 0.000 0.000 0.000 0.006 0.000 0.000 Tl 0.001 0.001 0.000 0.000 0.000 0.001 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.176 0.174 0.167 0.175 0.183 0.175 0.179 Mg 1.816 1.787 1.825 1.815 1.781 1.821 1.830 Mn 0.002 0.003 0.002 0.002 0.002 0.003 0.002 Ni 0.008 0.008 0.008 0.008 0.008 0.008 0.010 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.002 2.986 3.001 3.000 2.989 3.004 3.010 Mg# 91.159 91.146 91.626 91.227 90.691 91.247 91.097 Table C2.6: Sample: Z7P21 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine. (Mg. Fe)2Si04. Fo#Mg*100/(Mg+Fetot) 516 OL7-A2-R 0L8-A1-C 0L9-A1-C OL9-A2-R OL10-A1-( OL10-A2-R % Wt% Wt% Wt% Wt% W t% 39.804 39.543 40.110 40.008 40.130 40.853 0.021 0.013 0.006 0.000 0.013 0.023 0.048 0.023 0.023 0.000 0.000 0.000 0.003 0.000 0.015 0.004 0.000 0.026 8.474 8.173 8.206 8.528 8.421 8.538 49.271 48.720 49.058 48.820 49.291 50.077 0.116 0.112 0.094 0.142 0.129 0.128 0.372 0.514 0.425 0.421 0.407 0.344 0.017 0.020 0.010 0.006 0.001 0.000 0.000 0.013 0.000 0.000 0.000 0.000 98.126 97.131 97.947 97.929 98.392 99.989 40.564 40.711 40.951 40.854 40.786 40.857 0.021 0.013 0.006 0.000 0.013 0.023 0.049 0.024 0.023 0.000 0.000 0.000 0.003 0.000 0.015 0.004 0.000 0.026 8.636 8.414 8.378 8.708 8.559 8.539 50.212 50.159 50.086 49.852 50.097 50.083 0.118 0.115 0.096 0.145 0.131 0.128 0.379 0.529 0.434 0.430 0.414 0.344 0.017 0.021 0.010 0.006 0.001 0.000 0.000 0.013 0.000 0.000 0.000 0.000 0.991 0.994 0.998 0.998 0.996 0.997 0.001 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.176 0.172 0.171 0.178 0.175 0.174 1.829 1.825 1.820 1.815 1.823 1.821 0.002 0.002 0.002 0.003 0.003 0.003 0.007 0.010 0.009 0.008 0.008 0.007 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.008 3.006 3.001 3.002 3.004 3.003 Average 91.201 91.399 91.421 91.075 91.254 91.270 91.216 517 Label 0L1-A1-C 0L2-A1-C OL3-A2-R OL4-A2-R 0L5-A1-I OL5-A2-R 0L7-A1-C Ounitic Section Oxides Wt. % Wt. % Wt. % Wt. % Wt. % W t% Wt. % SI02 38.251 38.290 39.407 40.001 40.038 40.012 39.507 AI203 0.000 0.017 0.036 0.026 0.009 0.000 0.000 TI02 0.052 0.000 0.000 0.023 0.012 0.000 0.028 Cr203 0.001 0.012 0.000 0.000 0.000 0.000 0.007 FeOtot. 7.517 7.525 7.464 6.071 6.358 7.432 7.423 MgO 49.161 49.352 48.342 51.926 51.743 51.234 50.241 MnO 0.079 0.130 0.114 0.098 0.083 0.129 0.123 NiO 0.377 0.458 0.437 0.423 0.361 0.372 0.425 CaO 0.022 0.000 0.038 0.000 0.011 0.034 0.007 Na20 0.000 0.000 0.000 0.000 0.020 0.003 0.000 Total 95.460 95.784 95.838 98.568 98.635 99.216 97.761 Normalized oxides SI02 40.070 39.975 41.118 40.582 40.592 40.328 40.412 AI203 0.000 0.018 0.038 0.026 0.009 0.000 0.000 TI02 0.054 0.000 0.000 0.023 0.012 0.000 0.029 Cr203 0.001 0.013 0.000 0.000 0.000 0.000 0.007 FeOtot. 7.875 7.856 7.788 6.159 6.446 7.491 7.593 MgO 51.499 51.524 50.441 52.680 52.459 51.639 51.392 MnO 0.083 0.136 0.119 0.099 0.084 0.130 0.126 NiO 0.395 0.478 0.456 0.429 0.366 0.375 0.435 CaO 0.023 0.000 0.040 0.000 0.011 0.034 0.007 Na20 0.000 0.000 0.000 0.000 0.020 0.003 0.000 Cations Si 0.977 0.976 1.000 0.982 0.983 0.981 0.984 Ai 0.000 0.001 0.001 0.001 0.000 0.000 0.000 Ti 0.001 0.000 0.000 0.000 0.000 0.000 0.001 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.161 0.160 0.158 0.125 0.131 0.152 0.155 Mg 1.873 1.875 1.828 1.900 1.893 1.874 1.865 Mn 0.002 0.003 0.002 0.002 0.002 0.003 0.003 Ni 0.008 0.009 0.009 0.008 0.007 0.007 0.009 Ca 0.001 0.000 0.001 0.000 0.000 0.001 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.022 3.024 3.000 3.018 3.017 3.019 3.016 Mg# 92.100 92.120 92.029 93.845 93.551 92.475 92.346 Table C2.7: Sample: Z7-P23 Dunite & massive chromitite Microprobe Analysis & Calcuiated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. Fo»Mg*100/(Mg+Fetot) 518 OL7-A2-R 0L8-A1-C 0L9-A1-C OL9-A2-R OL10-A1-( 0L11-A1-I 0L11-A24 0L14-A1-( Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 39.507 40.025 39.263 39.633 39.603 40.027 39.124 39.135 0.000 0.015 0.361 0.021 0.011 0.028 0.019 0.023 0.028 0.000 0.000 0.020 0.032 0.000 0.000 0.028 0.007 0.018 0.013 0.028 0.000 0.015 0.013 0.018 7.423 7.547 6.555 7.144 6.939 6.508 6.647 6.321 50.241 50.703 48.641 51.279 50.763 51.262 50.770 51.057 0.123 0.105 0.079 0.125 0.105 0.105 0.097 0.105 0.425 0.392 0.378 0.409 0.426 0.415 0.459 0.456 0.007 0.043 0.025 0.035 0.028 0.041 0.045 0.038 0.000 0.000 0.034 0.009 0.000 0.000 0.000 0.000 97.761 98.848 95.349 98.703 97.907 98.401 97.174 97.181 40.412 40.491 41.178 40.154 40.450 40.677 40.262 40.270 0.000 0.015 0.379 0.021 0.011 0.028 0.020 0.024 0.029 0.000 0.000 0.020 0.033 0.000 0.000 0.029 0.007 0.018 0.014 0.028 0.000 0.015 0.013 0.019 7.593 7.635 6.875 7.238 7.087 6.614 6.840 6.504 51.392 51.294 51.014 51.953 51.848 52.095 52.246 52.538 0.126 0.106 0.083 0.127 0.107 0.107 0.100 0.108 0.435 0.397 0.396 0.414 0.435 0.422 0.472 0.469 0.007 0.044 0.026 0.035 0.029 0.042 0.046 0.039 0.000 0.000 0.036 0.009 0.000 0.000 0.000 0.000 0.984 0.986 0.996 0.977 0.983 0.986 0.978 0.977 0.000 0.000 0.011 0.001 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.155 0.155 0.139 0.147 0.144 0.134 0.139 0.132 1.865 1.861 1.840 1.884 1.878 1.882 1.892 1.900 0.003 0.002 0.002 0.003 0.002 0.002 0.002 0.002 0.009 0.008 0.008 0.008 0.009 0.008 0.009 0.009 0.000 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.016 3.014 2.998 3.022 3.017 3.014 3.022 3.022 92.346 92.293 92.971 92.751 92.878 93.352 93.158 93.506 519 OL14-A3-R2 SRP1-BE1 SRP2-BE1 SRP3-BETCHR M. Chromitite Section Wt. % Wt. % Wt. % Wt. % 40.098 39.852 39.787 38.619 0.000 0.442 0.873 0.130 0.032 0.052 0.000 0.040 0.007 0.234 0.151 0.085 6.386 3.543 3.903 2.738 52.375 39.296 39.711 41.672 0.102 0.056 0.057 0.013 0.429 0.285 0.232 0.500 0.007 0.020 0.003 0.032 0.000 0.003 0.062 0.000 99.436 83.783 84.779 83.829 40.325 47.566 46.930 46.069 0.000 0.528 1.030 0.155 0.032 0.062 0.000 0.048 0.007 0.279 0.178 0.101 6.422 4.229 4.604 3.266 52.672 46.902 46.841 49.711 0.103 0.067 0.067 0.016 0.431 0.340 0.274 0.596 0.007 0.024 0.004 0.038 0.000 0.004 0.073 0.000 0.977 1.117 1.105 1.084 0.000 0.015 0.029 0.004 0.001 0.001 0.000 0.001 0.000 0.005 0.003 0.002 0.130 0.083 0.091 0.064 1.903 1.642 1.644 1.744 0.002 0.001 0.001 0.000 0.008 0.006 0.005 0.011 0.000 0.001 0.000 0.001 0.000 0.000 0.002 0.000 3.022 2.872 2.879 2.912 1st Average 2nd Average 93.598 92.832 95.186 94.775 96.445 520 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C 0L2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C Oxides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Si02 40.466 40.267 39.766 40.992 40.354 39.794 39.208 AI203 0.000 0.006 0.000 0.009 0.000 0.000 0.011 TI02 0.000 0.000 0.000 0.012 0.000 0.000 0.000 Cr203 0.000 0.000 0.000 0.019 0.007 0.022 0.045 FeOtot. 8.515 8.580 8.626 8.452 8.510 8.362 8.317 MgO 51.282 50.155 51.334 51.208 51.050 50.558 51.070 MnO 0.139 0.137 0.142 0.164 0.136 0.116 0.105 NiO 0.349 0.360 0.466 0.425 0.369 0.363 0.454 CaO 0.025 0.029 0.008 0.004 0.024 0.017 0.018 Na20 0.000 0.000 0.000 0.000 0.000 0.003 0.000 Total 100.776 99.534 100.342 101.285 100.450 99.235 99.228 Normalized oxides Si02 40.154 40.456 39.630 40.472 40.173 40.101 39.513 AI203 0.000 0.006 0.000 0.009 0.000 0.000 0.011 TI02 0.000 0.000 0.000 0.012 0.000 0.000 0.000 Cr203 0.000 0.000 0.000 0.019 0.007 0.022 0.045 FeOtot. 8.449 8.620 8.597 8.345 8.472 8.426 8.382 MgO 50.887 50.390 51.159 50.558 50.821 50.948 51.467 MnO 0.138 0.138 0.142 0.162 0.135 0.117 0.106 NIO 0.346 0.362 0.464 0.420 0.367 0.366 0.458 CaO 0.025 0.029 0.008 0.004 0.024 0.017 0.018 Na20 0.000 0.000 0.000 0.000 0.000 0.003 0.000 Cations Si 0.981 0.989 0.971 0.988 0.982 0.980 0.968 AI 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Tl 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Fe 0.173 0.176 0.176 0.170 0.173 0.172 0.172 Mg 1.854 1.836 1.869 1.840 1.852 1.857 1.879 Mn 0.003 0.003 0.003 0.003 0.003 0.002 0.002 NI 0.007 0.007 0.009 0.008 0.007 0.007 0.009 Ca 0.001 0.001 0.000 0.000 0.001 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.019 3.011 3.029 3.011 3.018 3.020 3.032 Mg# 91.479 91.244 91.386 91.526 91.448 91.509 91.629 Table C2.8: Sample: Z7P26 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2Si04. Fo"Mg'100/(Mg+Fetot) 521 -4-A2-R 0L6-A1-C 0L8-A1-C OL8-A2-R 0L9-A1-C 0L9-A2-R 0L12-A1-C 0L13-A1-C % Wt. % Wt. % Wt. % Wt. % Wt. % W t% Wt. % 39.466 39.248 40.577 39.205 37.898 38.386 38.906 38.232 0.004 0.000 0.015 0.000 0.011 0.040 0.000 0.000 0.075 0.020 0.003 0.023 0.020 0.000 0.032 0.000 0.020 0.023 0.010 0.000 0.012 0.022 0.000 0.000 8.259 8.411 8.403 8.394 8.529 8.486 8.439 8.460 50.292 50.455 50.579 49.573 49.113 50.577 49.859 50.417 0.138 0.099 0.172 0.130 0.154 0.092 0.128 0.150 0.403 0.373 0.332 0.416 0.439 0.305 0.308 0.458 0.011 0.000 0.000 0.020 0.022 0.001 0.000 0.020 0.000 0.000 0.000 0.003 0.000 0.009 0.000 0.000 98.668 98.629 100.091 97.764 96.198 97.918 97.672 97.737 39.999 39.794 40.540 40.102 39.396 39.202 39.833 39.117 0.004 0.000 0.015 0.000 0.011 0.041 0.000 0.000 0.076 0.020 0.003 0.024 0.021 0.000 0.033 0.000 0.020 0.023 0.010 0.000 0.012 0.022 0.000 0.000 8.370 8.528 8.395 8.586 8.866 8.666 8.640 8.656 50.971 51.156 50.533 50.707 51.054 51.652 51.047 51.584 0.140 0.100 0.172 0.133 0.160 0.094 0.131 0.153 0.408 0.378 0.332 0.426 0.456 0.311 0.315 0.469 0.011 0.000 0.000 0.020 0.023 0.001 0.000 0.020 0.000 0.000 0.000 0.003 0.000 0.009 0.000 0.000 0.978 0.974 0.989 0.981 0.967 0.961 0.975 0.961 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.171 0.175 0.171 0.176 0.182 0.178 0.177 0.178 1.858 1.867 1.839 1.849 1.869 1.889 1.863 1.888 0.003 0.002 0.004 0.003 0.003 0.002 0.003 0.003 0.008 0.007 0.007 0.008 0.009 0.006 0.006 0.009 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.020 3.025 3.010 3.018 3.032 3.038 3.024 3.039 91.565 91.448 91.475 91.325 91.123 91.397 91.328 91.397 522 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C 0L3-A1-C OL3-A2-R 0L4-A1-C OL4-A2-R Oxides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 3102 41.330 40.836 41.129 41.084 40.442 40.478 40.639 AI203 0.000 0.026 0.004 0.026 0.000 0.302 0.013 TI02 0.000 0.000 0.000 0.015 0.000 0.000 0.000 Cr203 0.000 0.016 0.000 0.000 0.000 0.000 0.000 FeOtot. 7.617 7.482 7.324 7.604 7.266 7.610 7.447 MgO 51.445 50.373 51.191 51.504 50.539 51.627 50.315 MnO 0.123 0.132 0.139 0.145 0.143 0.110 0.094 NIO 0.496 0.426 0.406 0.431 0.456 0.405 0.426 CaO 0.011 0.020 0.001 0.008 0.010 0.000 0.006 Na20 0.000 0.000 0.005 0.000 0.000 0.000 0.000 Total 101.022 99.311 100.199 100.817 98.856 100.532 98.940 Normalized oxides 3102 40.912 41.119 41.047 40.751 40.910 40.264 41.074 AI203 0.000 0.026 0.004 0.026 0.000 0.300 0.013 TI02 0.000 0.000 0.000 0.015 0.000 0.000 0.000 Cr203 0.000 0.016 0.000 0.000 0.000 0.000 0.000 FeOtot. 7.540 7.534 7.309 7.542 7.350 7.570 7.527 MgO 50.925 50.722 51.089 51.087 51.124 51.354 50.854 MnO 0.122 0.133 0.139 0.144 0.145 0.109 0.095 NiO 0.491 0.429 0.405 0.428 0.461 0.403 0.431 CaO 0.011 0.020 0.001 0.008 0.010 0.000 0.006 Na20 0.000 0.000 0.005 0.000 0.000 0.000 0.000 Cations 3i 0.994 0.999 0.996 0.991 0.994 0.980 0.997 AI 0.000 0.001 0.000 0.001 0.000 0.009 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.153 0.153 0.148 0.153 0.149 0.154 0.153 Mg 1.845 1.836 1.848 1.852 1.851 1.863 1.841 Mn 0.003 0.003 0.003 0.003 0.003 0.002 0.002 Ni 0.010 0.008 0.008 0.008 0.009 0.008 0.008 Ca 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.006 3.001 3.004 3.009 3.006 3.016 3.002 M g# 92.331 92.309 92.570 92.351 92.537 92.363 92.334 Table C2.9: Sample: Z7-P29A Chromite bearing dunite Mlcroprot>e Analysis & Calculated Formula (based on 4 Oxygens) of Olivine. (Mg, Fe)2SI04. Fo"MgMOO/(Mg+Fetot) 523 0L5-A1-C 0L6-A1-C OL6-A2-R 0L7-A1-C OL7-A2-R 0L8-A1-C OL8-A2-R 0L9-A1-C Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 40.911 40.652 40.125 40.620 39.871 40.100 39.546 40.641 0.000 0.004 0.000 0.011 0.000 0.019 0.000 0.000 0.008 0.000 0.035 0.003 0.000 0.003 0.032 0.023 0.018 0.000 0.000 0.003 0.009 0.000 0.009 0.000 7.588 7.644 7.662 7.289 7.730 7.521 7.341 7.850 51.329 51.362 50.015 51.045 49.521 51.360 50.110 51.135 0.128 0.108 0.124 0.114 0.134 0.097 0.098 0.148 0.340 0.387 0.364 0.424 0.337 0.377 0.370 0.378 0.011 0.010 0.014 0.000 0.000 0.006 0.006 0.004 0.000 0.000 0.000 0.051 0.000 0.000 0.000 0.000 100.333 100.167 98.339 99.560 97.602 99.483 97.512 100.179 40.775 40.584 40.803 40.800 40.851 40.308 40.555 40.568 0.000 0.004 0.000 0.011 0.000 0.019 0.000 0.000 0.008 0.000 0.036 0.003 0.000 0.003 0.033 0.023 0.018 0.000 0.000 0.003 0.009 0.000 0.009 0.000 7.563 7.631 7.791 7.321 7.920 7.560 7.528 7.836 51.159 51.276 50.860 51.271 50.738 51.627 51.389 51.044 0.128 0.108 0.126 0.115 0.137 0.098 0.101 0.148 0.339 0.386 0.370 0.426 0.345 0.379 0.379 0.377 0.011 0.010 0.014 0.000 0.000 0.006 0.006 0.004 0.000 0.000 0.000 0.051 0.000 0.000 0.000 0.000 0.991 0.987 0.993 0.991 0.994 0.981 0.986 0.988 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.154 0.155 0.159 0.149 0.161 0.154 0.153 0.160 1.854 1.860 1.845 1.857 1.841 1.873 1.863 1.853 0.003 0.002 0.003 0.002 0.003 0.002 0.002 0.003 0.007 0.008 0.007 0.008 0.007 0.007 0.007 0.007 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.009 3.013 3.007 3.009 3.006 3.019 3.013 3.012 92.342 92.294 92.086 92.584 91.948 92.409 92.406 92.071 524 OL10-A1-( OL10-A2-I 0L11-A1-( 0L11-A2-f 0L12 Wt. % Wt. % Wt. % Wt. % Wt. % 39.567 39.347 41.039 40.988 39.640 0.000 0.000 0.000 0.017 0.000 0.000 0.035 0.000 0.000 0.000 0.000 0.000 0.013 0.026 0.013 7.360 7.378 7.360 7.598 7.243 51.080 50.284 51.163 52.080 50.926 0.103 0.090 0.114 0.092 0.150 0.424 0.421 0.370 0.407 0.421 0.013 0.015 0.000 0.000 0.006 0.027 0.030 0.000 0.005 0.000 98.574 97.600 100.059 101.213 98.399 40.139 40.315 41.015 40.497 40.285 0.000 0.000 0.000 0.017 0.000 0.000 0.036 0.000 0.000 0.000 0.000 0.000 0.013 0.026 0.013 7.466 7.559 7.356 7.507 7.361 51.819 51.520 51.133 51.456 51.755 0.104 0.092 0.114 0.091 0.152 0.430 0.431 0.370 0.402 0.428 0.013 0.015 0.000 0.000 0.006 0.027 0.031 0.000 0.005 0.000 0.978 0.982 0.995 0.985 0.980 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.152 0.154 0.149 0.153 0.150 1.881 1.870 1.850 1.866 1.878 0.002 0.002 0.002 0.002 0.003 0.008 0.008 0.007 0.008 0.008 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 3.022 3.018 3.004 3.014 3.020 Average 92.521 92.395 92.533 92.435 92.611 92.371 525 Label 0L1-A1-C 0L1-A2-LI 0L2-A1-C 0L3-A1-C OL3-A2-R 0L4-A1-C OL4-A2-R Oxides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 5102 37.930 38.354 37.438 37.896 36.953 35.513 36.041 AI203 0.000 0.000 0.006 0.006 0.009 0.000 0.000 TI02 0.000 0.015 0.000 0.047 0.003 0.027 0.063 Cr203 0.026 0.000 0.000 0.010 0.023 0.000 0.000 FeOtot. 9.038 9.337 9.170 9.466 9.303 9.274 9.566 MgO 50.146 50.549 49.999 50.055 49.024 50.224 49.514 MnO 0.174 0.092 0.114 0.142 0.114 0.127 0.152 NiO 0.374 0.345 0.344 0.396 0.358 0.433 0.300 CaO 0.001 0.018 0.010 0.021 0.010 0.022 0.010 Na20 0.000 0.000 0.013 0.000 0.000 0.000 0.000 Total 97.689 98.710 97.094 98.039 95.797 95.620 95.646 Normalized oxides 3102 38.827 38.855 38.559 38.654 38.574 37.140 37.682 AI203 0.000 0.000 0.006 0.006 0.009 0.000 0.000 TI02 0.000 0.015 0.000 0.048 0.003 0.028 0.066 Cr203 0.027 0.000 0.000 0.010 0.024 0.000 0.000 FeOtot. 9.252 9.459 9.444 9.655 9.711 9.699 10.001 MgO 51.332 51.210 51.495 51.056 51.175 52.525 51.768 MnO 0.178 0.093 0.117 0.145 0.119 0.133 0.159 NIO 0.383 0.350 0.354 0.404 0.374 0.453 0.314 CaO 0.001 0.018 0.010 0.021 0.010 0.023 0.010 Na20 0.000 0.000 0.013 0.000 0.000 0.000 0.000 Cations SI 0.956 0.957 0.951 0.954 0.952 0.921 0.934 AI 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Tl 0.000 0.000 0.000 0.001 0.000 0.001 0.001 Cr 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.191 0.195 0.195 0.199 0.200 0.201 0.207 Mg 1.885 1.881 1.893 1.879 1.883 1.943 1.913 Mn 0.004 0.002 0.002 0.003 0.002 0.003 0.003 Ni 0.008 0.007 0.007 0.008 0.007 0.009 0.006 Ca 0.000 0.000 0.000 0.001 0.000 0.001 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.043 3.042 3.049 3.045 3.047 3.078 3.065 Mg# 90.818 90.611 90.671 90.409 90.379 90.614 90.222 Table C2.10: Sample: Z7*P31 Harzburgite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2SI04. Fo-Mg*100/(Mg+Fetot) 526 0L5-A1-C OL5-A2-R 0L7-A1-C OL7-A2-R 0L8-A1-C OL8-A2-R 0L11-A1-( 0L11-A2-F % wt. % Wt. % Wt. % Wt. % Wt.. % Wt.. % Wt. % 37.648 37.571 37.734 37.096 38.234 38.786 36.987 37.173 0.004 0.000 0.000 0.000 0.009 0.015 0.009 0.000 0.000 0.000 0.003 0.000 0.020 0.008 0.000 0.000 0.009 0.018 0.000 0.000 0.004 0.000 0.006 0.045 9.421 9.551 9.241 9.162 9.088 9.312 9.317 9.407 50.271 50.639 50.242 48.904 50.223 49.791 49.591 50.141 0.150 0.174 0.143 0.123 0.159 0.129 0.142 0.172 0.364 0.330 0.402 0.410 0.416 0.491 0.351 0.354 0.015 0.022 0.008 0.006 0.000 0.000 0.000 0.013 0.009 0.000 0.050 0.020 0.000 0.000 0.000 0.007 97.891 98.305 97.823 95.721 98.153 98.532 96.403 97.312 38.459 38.219 38.574 38.754 38.953 39.364 38.367 38.200 0.004 0.000 0.000 0.000 0.009 0.015 0.009 0.000 0.000 0.000 0.003 0.000 0.020 0.008 0.000 0.000 0.009 0.018 0.000 0.000 0.004 0.000 0.006 0.046 9.624 9.716 9.447 9.572 9.259 9.451 9.665 9.667 51.354 51.512 51.360 51.090 51.168 50.533 51.441 51.526 0.153 0.177 0.146 0.128 0.162 0.131 0.147 0.177 0.372 0.336 0.411 0.428 0.424 0.498 0.364 0.364 0.015 0.022 0.008 0.006 0.000 0.000 0.000 0.013 0.009 0.000 0.051 0.021 0.000 0.000 0.000 0.007 0.950 0.945 0.952 0.956 0.959 0.969 0.948 0.944 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.199 0.201 0.195 0.197 0.191 0.195 0.200 0.200 1.890 1.898 1.889 1.879 1.878 1.854 1.894 1.899 0.003 0.004 0.003 0.003 0.003 0.003 0.003 0.004 0.007 0.007 0.008 0.008 0.008 0.010 0.007 0.007 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.050 3.055 3.048 3.044 3.040 3.031 3.052 3.055 90.487 90.432 90.647 90.490 90.784 90.505 90.465 90.478 527 0L13-A1-C 0L14-A1-( OL14-A2-R % W t% Wt. % 37.490 37.222 37.550 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.010 0.000 9.288 9.312 9.061 50.077 49.841 50.176 0.118 0.147 0.152 0.457 0.346 0.435 0.017 0.018 0.000 0.000 0.000 0.000 97.451 96.896 97.374 38.471 38.414 38.563 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.010 0.000 9.531 9.610 9.305 51.387 51.438 51.529 0.121 0.152 0.156 0.469 0.357 0.447 0.017 0.019 0.000 0.000 0.000 0.000 0.950 0.949 0.951 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.197 0.198 0.192 1.891 1.893 1.894 0.003 0.003 0.003 0.009 0.007 0.009 0.000 0.000 0.000 0.000 0.000 0.000 3.050 3.051 3.049 Average 90.576 90.513 90.801 90.550 528 Label 0L1-A1-C 0L1-A2-R 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C Oxides Wt. % Wt.% Wt. % Wt. % Wt. % Wt. % Wt. % SI02 40.960 41.253 39.819 40.010 39.122 39.180 38.891 AI203 0.006 0.026 0.000 0.036 0.008 0.002 0.000 TI02 0.015 0.043 0.003 0.015 0.000 0.000 0.000 Cr203 0.018 0.019 0.039 0.038 0.015 0.020 0.000 FeOtot. 5.883 6.071 5.982 5.756 6.270 6.174 6.359 MgO 48.873 48.674 51.652 51.173 51.045 52.007 51.004 MnO 0.099 0.110 0.103 0.053 0.092 0.116 0.075 NiO 0.537 0.573 0.573 0.514 0.669 0.570 0.585 CaO 0.000 0.004 0.010 0.000 0.000 0.001 0.000 Na20 0.000 0.000 0.000 0.000 0.000 0.004 0.000 Total 96.391 96.773 98.181 97.595 97.221 98.074 96.914 Normalized oxides Si02 42.494 42.629 40.557 40.996 40.240 39.949 40.129 Ai203 0.006 0.027 0.000 0.037 0.008 0.002 0.000 Ti02 0.016 0.044 0.003 0.015 0.000 0.000 0.000 Cr203 0.019 0.020 0.040 0.039 0.015 0.020 0.000 FeOtot. 6.103 6.273 6.093 5.898 6.449 6.295 6.561 MgO 50.703 50.297 52.609 52.434 52.504 53.028 52.628 MnO 0.103 0.114 0.105 0.054 0.095 0.118 0.077 NiO 0.557 0.592 0.584 0.527 0.688 0.581 0.604 CaO 0.000 0.004 0.010 0.000 0.000 0.001 0.000 Na20 0.000 0.000 0.000 0.000 0.000 0.004 0.000 Cations Si 1.022 1.026 0.982 0.990 0.977 0.970 0.974 AI 0.000 0.001 0.000 0.001 0.000 0.000 0.000 Ti 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.001 0.001 0.000 0.000 0.000 Fe 0.123 0.126 0.123 0.119 0.131 0.128 0.133 Mg 1.818 1.805 1.898 1.887 1.900 1.919 1.905 Mn 0.002 0.002 0.002 0.001 0.002 0.002 0.002 Ni 0.011 0.011 0.011 0.010 0.013 0.011 0.012 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 2.977 2.973 3.018 3.009 3.023 3.030 3.026 M g# 93.674 93.461 93.899 94.065 93.554 93.756 93.463 Table C2.11 : Sample: Z7-P32 Disseminated chromitite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine. (Mg. Fe)2Si04. Fo-Mg*100/(Mg+Fetot) 529 OL4-A2-R 0L5-A1-C OL5-A2-R 0L8-A1-I )L9-A1-IVS 0L11-A1-I 0L11-A2-R OL12-A1-C . % wt.. % Wt. % Wt.. % Wt. % Wt. % Wt.,% Wt. % 38.553 38.395 39.176 38.829 37.267 37.239 38.448 37.674 0.000 0.028 0.008 0.000 0.000 0.019 0.011 0.008 0.020 0.035 0.055 0.012 0.000 0.047 0.028 0.000 0.022 0.023 0.000 0.020 0.000 0.000 0.000 0.015 5.863 6.393 6.462 6.411 6.445 6.405 6.409 6.732 50.679 50.281 50.118 51.630 51.221 51.231 52.164 50.987 0.057 0.138 0.088 0.097 0.111 0.072 0.096 0.093 0.669 0.574 0.552 0.534 0.482 0.589 0.582 0.499 0.022 0.008 0.000 0.021 0.000 0.008 0.021 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.000 0.000 95.885 95.875 96.459 97.554 95.526 95.614 97.759 96.008 40.208 40.047 40.614 39.803 39.012 38.947 39.329 39.240 0.000 0.029 0.008 0.000 0.000 0.020 0.011 0.008 0.021 0.037 0.057 0.012 0.000 0.049 0.029 0.000 0.023 0.024 0.000 0.021 0.000 0.000 0.000 0.016 6.115 6.668 6.699 6.572 6.747 6.699 6.556 7.012 52.854 52.444 51.958 52.925 53.620 53.581 53.360 53.107 0.059 0.144 0.091 0.099 0.116 0.075 0.098 0.097 0.698 0.599 0.572 0.547 0.505 0.616 0.595 0.520 0.023 0.008 0.000 0.022 0.000 0.008 0.021 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.000 0.000 0.975 0.973 0.985 0.967 0.951 0.950 0.957 0.957 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.124 0.136 0.136 0.134 0.138 0.137 0.133 0.143 1.910 1.900 1.879 1.917 1.948 1.948 1.936 1.930 0.001 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.014 0.012 0.011 0.011 0.010 0.012 0.012 0.010 0.001 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.025 3.025 3.014 3.032 3.049 3.049 3.042 3.043 93.906 93.342 93.255 93.488 93.407 93.446 93.552 93.104 530 OL12-A2-R SRP1-BET FR 0L7-A1-I 0L8-A1-I 0L7-A1-I OL10-A1-I 0L13-A1-I Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 37.216 36.583 35.954 35.000 37.102 36.782 37.066 0.009 0.327 0.945 0.232 0.000 0.179 0.049 0.012 0.000 0.012 0.015 0.000 0.000 0.023 0.001 0.022 0.034 0.023 0.037 0.047 0.001 6.788 6.597 7.238 6.794 6.094 6.441 5.756 51.028 37.747 44.054 43.014 50.368 49.131 50.702 0.096 0.026 0.089 0.121 0.098 0.102 0.076 0.562 1.133 0.548 0.381 0.568 0.550 0.545 0.004 0.021 0.056 0.000 0.000 0.024 0.000 0.000 0.000 0.050 0.000 0.000 0.013 0.000 95.716 82.456 88.980 85.580 94.267 93.269 94.218 38.882 44.367 40.407 40.897 39.358 39.436 39.341 0.009 0.397 1.062 0.271 0.000 0.192 0.052 0.013 0.000 0.013 0.018 0.000 0.000 0.024 0.001 0.027 0.038 0.027 0.039 0.050 0.001 7.092 8.001 8.134 7.939 6.465 6.906 6.109 53.312 45.778 49.510 50.262 53.431 52.677 53.813 0.100 0.032 0.100 0.141 0.104 0.109 0.081 0.587 1.374 0.616 0.445 0.603 0.590 0.578 0.004 0.025 0.063 0.000 0.000 0.026 0.000 0.000 0.000 0.056 0.000 0.000 0.014 0.000 0.950 1.072 0.985 0.995 0.958 0.961 0.956 0.000 0.011 0.031 0.008 0.000 0.006 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.001 0.001 0.000 0.145 0.162 0.166 0.162 0.132 0.141 0.124 1.941 1.649 1.799 1.823 1.938 1.913 1.949 0.002 0.001 0.002 0.003 0.002 0.002 0.002 0.012 0.027 0.012 0.009 0.012 0.012 0.011 0.000 0.001 0.002 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.050 2.922 2.999 3.000 3.042 3.036 3.043 Average 93.056 93.527 91.071 91.561 91.861 93.644 93.149 94.013 531 Laiaei 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C OL4-A2-R 0L5-A1-C Oxides W t % Wt. % Wt. % Wt. % W t % Wt. % W t % Si02 38.741 39.051 37.081 37.933 38.191 37.580 38.992 AI203 0.000 0.000 0.000 0.000 0.009 0.008 0.000 TI02 0.000 0.000 0.000 0.003 0.000 0.000 0.008 Cr203 0.000 0.004 0.053 0.016 0.054 0.000 0.000 FeOtot. 8.154 8.074 8.266 8.509 7.607 7.230 7.567 MgO 50.917 50.725 50.942 50.463 51.616 52.073 51.622 MnO 0.130 0.133 0.174 0.097 0.077 0.068 0.098 NiO 0.393 0.347 0.453 0.426 0.568 0.398 0.365 CaO 0.022 0.014 0.017 0.006 0.008 0.000 0.017 Na20 0.000 0.000 0.000 0.000 0.000 0.000 0.020 Totai 98.357 98.348 96.986 97.453 98.130 97.357 98.689 Normalized oxides Si02 39.388 39.707 38.233 38.924 38.919 38.600 39.510 AI203 0.000 0.000 0.000 0.000 0.009 0.008 0.000 Ti02 0.000 0.000 0.000 0.003 0.000 0.000 0.008 Cr203 0.000 0.004 0.055 0.016 0.055 0.000 0.000 FeOtot. 8.290 8.210 8.523 8.731 7.752 7.426 7.668 MgO 51.768 51.577 52.525 51.782 52.600 53.487 52.308 MnO 0.132 0.135 0.179 0.100 0.078 0.070 0.099 NiO 0.400 0.353 0.467 0.437 0.579 0.409 0.370 CaO 0.022 0.014 0.018 0.006 0.008 0.000 0.017 Na20 0.000 0.000 0.000 0.000 0.000 0.000 0.020 Cations Si 0.965 0.971 0.941 0.956 0.953 0.944 0.965 AI 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.001 0.000 0.001 0.000 0.000 Fe 0.170 0.168 0.175 0.179 0.159 0.152 0.157 Mg 1.890 1.880 1.927 1.897 1.920 1.950 1.904 Mn 0.003 0.003 0.004 0.002 0.002 0.001 0.002 Ni 0.008 0.007 0.009 0.009 0.011 0.008 0.007 Ca 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Totai 3.035 3.029 3.058 3.043 3.046 3.056 3.035 M g# 91.757 91.803 91.657 91.358 92.364 92.774 92.402 Table C2.12: Sample: Z7-P37 Dunite Microprobe Analysis & Calculated Formula (liased on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. Fo-Mg‘100/(Mg<»Fetot) 532 OL5-A2-R 0L6-A1-C OL6-A2-R 0L7-A1-C 0L8-A1-C 0L8-A1-R 0L9-A1-C OL9-A2-R Wt. % Wt. % Wt. % WL % Wt. % Wt. % Wt. % Wt. % 38.752 38.450 38.955 38.470 38.420 38.437 38.576 39.561 0.000 0.006 0.002 0.000 0.000 0.015 0.000 0.036 0.023 0.000 0.000 0.047 0.012 0.000 0.000 0.000 0.000 0.000 0.018 0.018 0.000 0.006 0.000 0.000 7.414 7.454 7.914 7.332 8.137 7.884 8.201 8.176 49.687 50.742 50.821 50.949 50.387 50.700 51.106 50.697 0.125 0.111 0.115 0.127 0.115 0.099 0.138 0.111 0.416 0.405 0.411 0.442 0.388 0.325 0.409 0.472 0.001 0.018 0.024 0.000 0.013 0.021 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.009 96.418 97.186 98.260 97.385 97.472 97.487 98.433 99.062 40.192 39.563 39.645 39.503 39.416 39.428 39.190 39.936 0.000 0.006 0.002 0.000 0.000 0.015 0.000 0.036 0.024 0.000 0.000 0.048 0.012 0.000 0.000 0.000 0.000 0.000 0.018 0.018 0.000 0.006 0.000 0.000 7.689 7.670 8.054 7.529 8.348 8.087 8.332 8.253 51.533 52.211 51.721 52.317 51.694 52.007 51.920 51.177 0.130 0.114 0.117 0.130 0.118 0.102 0.140 0.112 0.431 0.417 0.418 0.454 0.398 0.333 0.416 0.476 0.001 0.019 0.024 0.000 0.013 0.022 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.009 0.980 0.966 0.969 0.964 0.965 0.964 0.961 0.976 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.157 0.157 0.165 0.154 0.171 0.165 0.171 0.169 1.872 1.900 1.885 1.904 1.887 1.896 1.897 1.865 0.003 0.002 0.002 0.003 0.002 0.002 0.003 0.002 0.008 0.008 0.008 0.009 0.008 0.007 0.008 0.009 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.020 3.034 3.031 3.035 3.034 3.035 3.039 3.023 92.276 92.387 91.966 92.530 91.693 91.977 91.741 91.704 533 OL10-A1-C OL5-A2-R OL10-A2-R Wt. % Wt. % Wt. % 38.155 36.439 31.204 0.000 0.612 5.336 0.000 0.035 0.015 0.000 0.013 0.000 7.835 7.828 4.465 51.428 39.686 42.029 0.114 0.083 0.107 0.476 0.510 0.307 0.008 0.000 0.060 0.000 0.000 0.013 98.016 85.206 83.536 38.927 42.766 37.354 0.000 0.718 6.388 0.000 0.041 0.018 0.000 0.015 0.000 7.994 9.187 5.345 52.469 46.577 50.312 0.116 0.097 0.128 0.486 0.599 0.368 0.008 0.000 0.072 0.000 0.000 0.016 0.954 1.040 0.900 0.000 0.021 0.181 0.000 0.001 0.000 0.000 0.000 0.000 0.164 0.187 0.108 1.916 1.688 1.807 0.002 0.002 0.003 0.010 0.012 0.007 0.000 0.000 0.002 0.000 0.000 0.000 3.046 2.949 3.009 Average 92.126 92.032 90.037 94.376 534 Label 0L1-A1-C 0L1-A1-C 0L1-A2-R 0L2-A1-C OL2-A2-R 0L2-A1-C OL2-A2-R O xides Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % Wt. % 5102 41.450 41.747 42.119 40.562 40.369 39.477 41.326 A I203 0.004 0.017 0.000 0.212 0.009 0.030 0.000 TI02 0.000 0.023 0.020 0.000 0.040 0.000 0.023 C r203 0.038 0.000 0.004 0.000 0.004 0.007 0.000 F eO tot. 5.469 5.582 5.385 5.945 5.847 5.209 5.286 MgO 52.441 52.876 53.408 52.756 50.932 52.879 52.241 MnO 0.098 0.074 0.077 0.052 0.056 0.125 0.066 NIO 0.643 0.542 0.589 0.496 0.546 0.501 0.648 CaO 0.000 0.003 0.000 0.011 0.000 0.000 0.000 N a20 0.009 0.000 0.000 0.000 0.000 0.027 0.000 Total 100.152 100.864 101.602 100.034 97.803 98.255 99.590 Normalized oxides S I0 2 41.387 41.389 41.455 40.548 41.276 40.178 41.496 A I203 0.004 0.017 0.000 0.212 0.009 0.031 0.000 T i02 0.000 0.023 0.020 0.000 0.041 0.000 0.023 C r203 0.038 0.000 0.004 0.000 0.004 0.007 0.000 F e O to t 5.461 5.534 5.300 5.943 5.978 5.302 5.308 MgO 52.361 52.423 52.566 52.738 52.076 53.818 52.456 MnO 0.098 0.073 0.076 0.052 0.057 0.127 0.066 NIO 0.642 0.537 0.580 0.496 0.558 0.510 0.651 CaO 0.000 0.003 0.000 0.011 0.000 0.000 0.000 N a20 0.009 0.000 0.000 0.000 0.000 0.027 0.000 C atio n s SI 0.997 0.997 0.997 0.980 0.996 0.970 0.998 AI 0.000 0.000 0.000 0.006 0.000 0.001 0.000 Tl 0.000 0.000 0.000 0.000 0.001 0.000 0.000 C r 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.110 0.111 0.107 0.120 0.121 0.107 0.107 Mg 1.880 1.882 1.885 1.900 1.873 1.938 1.882 Mn 0.002 0.001 0.002 0.001 0.001 0.003 0.001 NI 0.012 0.010 0.011 0.010 0.011 0.010 0.013 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.001 0.000 T otal 3.003 3.003 3.002 3.017 3.003 3.029 3.001 M g# 94.473 94.409 94.647 94.054 93.950 94.763 94.629 TableC2.13: Sample: Z7-P39 Disseminated chromitite Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2SI04. Fo-MgMOO/(Mg*Fetot) 535 0L4-A1-C OL4-A2-R 0L6-A1-C OL6-A2-R 0L8-A1-C OL8-A2-R 0L9-A1-C OL9-A2-R % W t% W t% WL% Wt. % W t % Wt. % Wt. % 40.104 40.534 40.361 40.688 38.803 40.369 38.816 40.027 0.004 0.002 0.480 0.000 0.000 0.038 0.019 0.023 0.000 0.015 0.047 0.000 0.008 0.000 0.000 0.000 0.003 0.000 0.007 0.001 0.000 0.020 0.000 0.020 6.413 6.191 5.694 5.188 5.866 5.856 6.337 6.130 51.821 52.390 50.985 52.672 52.740 52.693 52.997 52.887 0.085 0.108 0.076 0.098 0.059 0.052 0.050 0.094 0.494 0.414 0.557 0.598 0.534 0.585 0.604 0.607 0.008 0.000 0.000 0.004 0.013 0.000 0.015 0.013 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 98.932 99.654 98.207 99.249 98.023 99.613 98.838 99.801 40.537 40.675 41.098 40.996 39.586 40.526 39.272 40.107 0.004 0.002 0.489 0.000 0.000 0.038 0.019 0.023 0.000 0.015 0.048 0.000 0.008 0.000 0.000 0.000 0.003 0.000 0.007 0.001 0.000 0.020 0.000 0.020 6.482 6.212 5.798 5.227 5.984 5.879 6.412 6.142 52.380 52.572 51.916 53.071 53.804 52.898 53.620 52.992 0.086 0.108 0.077 0.099 0.060 0.052 0.051 0.094 0.499 0.415 0.567 0.603 0.545 0.587 0.611 0.608 0.008 0.000 0.000 0.004 0.013 0.000 0.015 0.013 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.982 0.984 0.991 0.988 0.960 0.980 0.955 0.972 0.000 0.000 0.014 0.000 0.000 0.001 0.001 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.131 0.126 0.117 0.105 0.121 0.119 0.130 0.125 1.892 1.896 1.866 1.906 1.946 1.907 1.945 1.915 0.002 0.002 0.002 0.002 0.001 0.001 0.001 0.002 0.010 0.008 0.011 0.012 0.011 0.011 0.012 0.012 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.018 3.016 3.001 3.012 3.040 3.019 3.044 3.027 93.508 93.783 94.104 94.764 94.127 94.131 93.714 93.895 536 Label Z7-47;0L1 0L1-A2-C 0L2-A1-C OL2-A2-R 0L3-A1-C OL3-A2-R 0L4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% Wt% S i0 2 40.438 40.192 40.254 40.412 39.830 40.087 40.294 A I203 0.006 0.021 0.000 0.000 0.006 0.000 0.000 T i0 2 0.017 0.000 0.008 0.020 0.000 0.000 0.020 C r2 0 3 0.000 0.000 0.000 0.000 0.000 0.016 0.000 F e O to t 8.692 8.794 8.884 8.789 8.477 8.528 8.124 MgO 48.468 48.818 48.510 48.384 47.503 49.004 48.384 MnO 0.142 0.160 0.121 0.088 0.129 0.143 0.121 NiO 0.417 0.458 0.417 0.462 0.395 0.448 0.774 CaO 0.000 0.014 0.010 0.001 0.000 0.001 0.000 N a20 0.000 0.007 0.000 0.000 0.000 0.000 0.000 T otal 98.180 98.464 98.204 98.156 96.340 98.227 97.717 Normalized oxides Si02 41.188 40.819 40.990 41.171 41.343 40.811 41.235 A I203 0.006 0.021 0.000 0.000 0.006 0.000 0.000 T i0 2 0.017 0.000 0.008 0.020 0.000 0.000 0.020 C r203 0.000 0.000 0.000 0.000 0.000 0.016 0.000 F eO tot. 8.853 8.931 9.046 8.954 8.799 8.682 8.314 MgO 49.366 49.580 49.397 49.293 49.308 49.889 49.514 MnO 0.145 0.162 0.123 0.090 0.134 0.146 0.124 NiO 0.425 0.465 0.425 0.471 0.410 0.456 0.792 CaO 0.000 0.014 0.010 0.001 0.000 0.001 0.000 N a20 0.000 0.007 0.000 0.000 0.000 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 C atio n s Si 1.005 0.998 1.002 1.005 1.008 0.997 1.006 AI 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 C r 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.181 0.183 0.185 0.183 0.179 0.177 0.170 Mg 1.796 1.807 1.800 1.794 1.793 1.817 1.800 Mn 0.003 0.003 0.003 0.002 0.003 0.003 0.003 Ni 0.008 0.009 0.008 0.009 0.008 0.009 0.016 C a 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 T otal 2.994 3.002 2.998 2.994 2.992 3.003 2.994 M g # 90.859 90.822 90.683 90.752 90.900 91.106 91.392 Table C2.14: Sample Z7*P47 Hanburglte Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. Fo«Mg*100/(Mg+Fetot) 537 0L5-A1-C OL6-A2-C 0L6-A1-C 0L7-A1-C OL7-A2-R 0L8-A1-C OL8-A2-R 0L9-A1-C % Wt % Wt % Wt% Wt% Wt% Wt% Wt% 39.255 40.337 39.907 40.386 40.795 40.538 40.211 38.983 0.019 0.000 0.000 0.000 0.017 0.004 0.002 0.025 0.000 0.008 0.043 0.008 0.068 0.000 0.017 0.003 0.000 0.000 0.025 0.000 0.000 0.000 0.000 0.007 8.935 8.585 8.832 8.829 8.376 8.541 8.755 8.617 47.918 47.753 48.349 49.551 50.712 49.924 49.355 48.077 0.130 0.154 0.142 0.151 0.128 0.156 0.155 0.182 0.417 0.509 0.387 0.468 0.428 0.438 0.364 0.403 0.020 0.003 0.021 0.000 0.007 0.001 0.014 0.020 0.000 0.009 0.001 0.000 0.000 0.032 0.000 0.001 96.694 97.358 97.707 99.393 100.531 99.634 98.873 96.318 40.597 41.432 40.844 40.633 40.580 40.687 40.669 40.473 0.020 0.000 0.000 0.000 0.017 0.004 0.002 0.026 0.000 0.008 0.044 0.008 0.068 0.000 0.017 0.003 0.000 0.000 0.026 0.000 0.000 0.000 0.000 0.007 9.240 8.818 9.039 8.883 8.332 8.572 8.855 8.946 49.556 49.049 49.484 49.854 50.444 50.107 49.918 49.915 0.134 0.158 0.145 0.152 0.127 0.157 0.157 0.189 0.431 0.523 0.396 0.471 0.426 0.440 0.368 0.418 0.021 0.003 0.021 0.000 0.007 0.001 0.014 0.021 0.000 0.009 0.001 0.000 0.000 0.032 0.000 0.001 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 0.994 1.011 0.999 0.994 0.990 0.994 0.994 0.991 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.189 0.180 0.185 0.182 0.170 0.175 0.181 0.183 1.809 1.784 1.804 1.818 1.835 1.825 1.819 1.821 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.004 0.008 0.010 0.008 0.009 0.008 0.009 0.007 0.008 0.001 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 3.005 2.989 3.000 3.006 3.008 3.006 3.005 3.009 90.530 90.839 90.705 90.913 91.520 91.243 90.949 90.864 538 OL10-A1-C OL5-A2-R OL6-A2-R OL6-A2-R OL10-A2-R w t% Wt% Wt% Wt% Wt% 39.154 35.840 34.905 30.727 38.677 0.019 0.077 0.132 0.138 0.030 0.020 0.035 0.028 0.000 0.000 0.000 0.000 0.082 0.000 0.015 8.927 7.540 9.332 11.168 4.181 49.281 36.230 36.868 32.497 38.669 0.141 0.030 0.037 0.088 0.041 0.434 0.381 0.351 0.433 0.423 0.010 0.000 0.027 0.127 0.007 0.000 0.000 0.000 0.011 0.003 97.986 80.133 81.762 75.189 82.046 39.959 44.726 42.691 40.866 47.141 0.019 0.096 0.161 0.184 0.037 0.020 0.044 0.034 0.000 0.000 0.000 0.000 0.100 0.000 0.018 9.110 9.409 11.414 14.853 5.096 50.294 45.212 45.092 43.220 47.131 0.144 0.037 0.045 0.117 0.050 0.443 0.475 0.429 0.576 0.516 0.010 0.000 0.033 0.169 0.009 0.000 0.000 0.000 0.015 0.004 100.000 100.000 100.000 100.000 100.000 0.980 1.082 1.047 1.024 1.113 0.001 0.003 0.005 0.005 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.002 0.000 0.000 0.187 0.190 0.234 0.311 0.101 1.839 1.630 1.649 1.614 1.659 0.003 0.001 0.001 0.002 0.001 0.009 0.009 0.008 0.012 0.010 0.000 0.000 0.001 0.005 0.000 0.000 0.000 0.000 0.000 0.000 3.019 2.916 2.949 2.974 2.886 Average 90.776 90.928 89.546 87.566 83.837 94.281 539 A/'He/ 0 / Wadi! MChromit MChromit MChromit MChromit MChromit MChromit Label H9-WI2.1, olivines O xides Wt % Wt % Wt% Wt% Wt% W t% Wt% S I02 40.784 40.208 41.278 40.818 41.648 40.888 40.386 AI203 0.002 0.011 0.000 0.020 0.015 0.006 0.017 TI02 0.000 0.000 0.000 0.000 0.002 0.000 0.000 C r203 0.009 0.002 0.009 0.000 0.000 0.024 0.019 FeO tot. 7.058 7.262 7.407 6.465 6.524 7.012 6.488 MgO 51.908 51.263 51,702 52.295 53.011 52.448 51.958 MnO 0.131 0.110 0.149 0.126 0.116 0.122 0.097 NIO 0.455 0.389 0.435 0.412 0.450 0.447 0.449 CaO 0.016 0.037 0.021 0.023 0.052 0.022 0.022 N a20 0.000 0.000 0.000 0.023 0.003 0.000 0.000 Total 100.362 99.282 101.001 100.182 101.822 100.970 99.438 Normalized oxides S I02 40.637 40.499 40.869 40.744 40.903 40.495 40.615 AI203 0.002 0.011 0.000 0.020 0.015 0.006 0.017 TI02 0.000 0.000 0.000 0.000 0.002 0.000 0.000 C r203 0.009 0.002 0.009 0.000 0.000 0.023 0.019 FeO tot. 7.032 7.314 7.334 6.453 6.407 6.944 6.525 MgO 51.721 51.634 51.189 52.200 52.062 51.944 52.252 MnO 0.131 0.111 0.148 0.126 0.114 0.121 0.098 NIO 0.453 0.392 0.430 0.411 0.442 0.443 0.452 CaO 0.016 0.037 0.021 0.023 0.051 0.022 0.023 N a20 0.000 0.000 0.000 0.023 0.003 0.000 0.000 C ations Si 0.987 0.984 0.993 0.986 0.990 0.983 0.984 AI 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.143 0.149 0.149 0.131 0.130 0.141 0.132 Mg 1.872 1.871 1.853 1.884 1.878 1.880 1.887 Mn 0.003 0.002 0.003 0.003 0.002 0.002 0.002 Ni 0.009 0.008 0.008 0.008 0.009 0.009 0.009 Ca 0.000 0.001 0.001 0.001 0.001 0.001 0.001 Na 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Total 3.013 3.015 3.007 3.013 3.010 3.017 3.016 M g# 92.913 92.638 92.561 93.515 93.542 93.023 93.453 Table C2.15: Collective analyses, Al'Hel Field Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2SI04. Fo«Mg*100/(Mg+Fetot) 540 MChromit MChromit MChromit MChromit Diss-D Diss-D Diss-D Diss-D H9-WI3, divine Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 40.493 40.166 40.532 39.957 40.629 40.829 39.933 40.774 0.007 0.000 0.014 0.037 0.017 0.026 0.025 0.004 0.001 0.006 0.005 0.014 0.005 0.002 0.018 0.003 0.000 0.010 0.018 0.000 0.000 0.000 0.004 0.007 7.170 7.488 7.444 7.330 7.732 7.653 7.630 7.551 51.967 51.683 51.487 51.581 51.413 51.676 51.664 51.691 0.114 0.118 0.138 0.093 0.108 0.140 0.124 0.142 0.428 0.386 0.393 0.413 0.360 0.344 0.390 0.349 0.031 0.027 0.021 0.005 0.033 0.009 0.039 0.020 0.024 0.017 0.000 0.000 0.000 0.006 0.000 0.000 100.235 99.901 100.051 99.429 100.297 100.686 99.827 100.541 40.398 40.206 40.511 40.186 40.508 40.551 40.002 40.554 0.007 0.000 0.014 0.037 0.017 0.026 0.025 0.004 0.001 0.006 0.005 0.014 0.005 0.002 0.018 0.003 0.000 0.010 0.018 0.000 0.000 0.000 0.004 0.007 7.153 7.495 7.440 7.372 7.709 7.601 7.643 7.510 51.845 51.734 51.461 51.877 51.260 51.324 51.753 51.413 0.114 0.118 0.138 0.094 0.108 0.139 0.124 0.142 0.427 0.386 0.393 0.416 0.359 0.342 0.391 0.347 0.031 0.027 0.021 0.005 0.033 0.009 0.039 0.020 0.024 0.017 0.000 0.000 0.000 0.006 0.000 0.000 0.982 0.979 0.985 0.978 0.986 0.986 0.975 0.986 0.000 0.000 0.000 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.145 0.153 0.151 0.150 0.157 0.155 0.156 0.153 1.878 1.878 1.866 1.882 1.860 1.861 1.881 1.864 0.002 0.002 0.003 0.002 0.002 0.003 0.003 0.003 0.008 0.008 0.008 0.008 0.007 0.007 0.008 0.007 0.001 0.001 0.001 0.000 0.001 0.000 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.018 3.021 3.014 3.021 3.014 3.013 3.024 3.014 92.816 92.483 92.498 92.617 92.220 92.329 92.349 92.426 541 Diss-0 Diss-D Diss-D Diss-D Diss-D Diss-D Dunite Dunite H9-WI4, olivines % wt % Wt% Wt% Wt % Wt % Wt% Wt% 40.298 40.342 40.847 40.718 40.629 40.010 39.613 40.887 0.013 0.000 0.010 0.000 0.009 0.012 0.025 0.004 0.010 0.015 0.005 0.000 0.000 0.003 0.003 0.012 0.004 0.011 0.004 0.000 0.000 0.009 0.000 0.005 7.327 7.338 7.663 7.648 7.602 7.451 8.595 8.522 51.591 51.657 50.993 51.161 51.342 51.091 49.366 50.788 0.135 0.142 0.108 0.119 0.127 0.104 0.130 0.144 0.366 0.377 0.344 0.365 0.396 0.417 0.378 0.323 0.040 0.023 0.029 0.041 0.017 0.015 0.248 0.091 0.007 0.005 0.029 0.017 0.013 0.000 0.000 0.018 99.792 99.910 100.032 100.069 100.136 99.111 98.358 100.793 40.382 40.379 40.834 40.689 40.574 40.369 40.274 40.566 0.013 0.000 0.010 0.000 0.009 0.012 0.025 0.004 0.010 0.015 0.005 0.000 0.000 0.003 0.003 0.011 0.004 0.011 0.004 0.000 0.000 0.009 0.000 0.005 7.342 7.344 7.661 7.643 7.592 7.518 8.739 8.455 51.698 51.703 50.977 51.126 51.272 51.549 50.190 50.388 0.136 0.142 0.108 0.119 0.127 0.105 0.132 0.143 0.366 0.377 0.343 0.365 0.395 0.420 0.384 0.320 0.040 0.023 0.029 0.041 0.017 0.015 0.252 0.090 0.007 0.005 0.029 0.017 0.013 0.000 0.000 0.018 0.982 0.982 0.993 0.990 0.987 0.983 0.986 0.990 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.149 0.149 0.156 0.155 0.154 0.153 0.179 0.173 1.874 1.875 1.848 1.854 1.860 1.870 1.831 1.834 0.003 0.003 0.002 0.002 0.003 0.002 0.003 0.003 0.007 0.007 0.007 0.007 0.008 0.008 0.008 0.006 0.001 0.001 0.001 0.001 0.000 0.000 0.007 0.002 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.018 3.018 3.007 3.010 3.013 3.017 3.014 3.009 92.621 92.620 92.225 92.262 92.331 92.437 91.102 91.397 542 Dunite Dunite Dunite Dunite Dunite Dunite Dunite Dunite Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 40.563 40.430 40.225 39.411 40.415 40.761 40.508 40.326 0.060 0.000 0.000 0.013 0.019 0.022 0.006 0.009 0.006 0.007 0.000 0.011 0.004 0.008 0.005 0.010 0.003 0.003 0.000 0.007 0.008 0.013 0.000 0.008 8.739 8.612 8.344 8.447 8.532 8.446 8.697 8.359 50.248 50.304 50.031 49.562 49.976 49.710 49.925 49.699 0.135 0.132 0.147 0.130 0.109 0.158 0.167 0.117 0.302 0.345 0.378 0.330 0.352 0.315 0.371 0.326 0.049 0.005 0.005 0.071 0.015 0.053 0.010 0.084 0.010 0.017 0.007 0.000 0.000 0.000 0.000 0.000 100.115 99.855 99.137 97.981 99.431 99.487 99.689 98.939 40.517 40.489 40.575 40.223 40.647 40.971 40.634 40.759 0.060 0.000 0.000 0.013 0.019 0.022 0.006 0.009 0.006 0.007 0.000 0.011 0.004 0.008 0.005 0.010 0.003 0.003 0.000 0.007 0.008 0.013 0.000 0.008 8.728 8.625 8.416 8.621 8.581 8.490 8.724 8.449 50.190 50.377 50.466 50.583 50.262 49.967 50.081 50.232 0.135 0.132 0.148 0.132 0.109 0.159 0.168 0.118 0.301 0.346 0.382 0.337 0.354 0.317 0.372 0.329 0.049 0.005 0.006 0.073 0.015 0.054 0.010 0.084 0.010 0.017 0.007 0.000 0.000 0.000 0.000 0.000 0.990 0.989 0.990 0.984 0.992 0.999 0.993 0.994 0.002 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.178 0.176 0.172 0.176 0.175 0.173 0.178 0.172 1.828 1.835 1.836 1.844 1.829 1.816 1.824 1.827 0.003 0.003 0.003 0.003 0.002 0.003 0.003 0.002 0.006 0.007 0.007 0.007 0.007 0.006 0.007 0.006 0.001 0.000 0.000 0.002 0.000 0.001 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.009 3.011 3.010 3.016 3.007 3.000 3.007 3.005 91.111 91.237 91.445 91.274 91.260 91.298 91.098 91.378 543 Harzb Harzb Harzb Harzb Harzb Harzb Harzb Harzb H9-WI5, cil H9-WI5, cii H9-WI5, cii H9-WI5, cii H9-WI5, c H9-WI5, cii H9-WI5, pi H9-WI6, oli Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 40.860 40.606 39.867 39.928 40.380 39.401 40.052 40.337 0.000 0.000 0.000 0.018 0.000 0.000 0.026 0.017 0.000 0.000 0.000 0.010 0.000 0.000 0.008 0.000 0.000 0.007 0.014 0.002 0.000 0.000 0.014 0.000 8.703 8.871 9.018 8.682 8.811 8.936 8.878 8.455 49.688 48.936 49.226 49.055 49.204 48.487 49.212 49.601 0.103 0.068 0.130 0.120 0.147 0.134 0.110 0.153 0.429 0.393 0.422 0.423 0.391 0.405 0.380 0.431 0.000 0.000 0.003 0.010 0.000 0.009 0.010 0.013 0.000 0.000 0.009 0.002 0.000 0.005 0.014 0.000 99.782 98.881 98.689 98.251 98.934 97.376 98.704 99.009 40.949 41.065 40.397 40.639 40.815 40.462 40.577 40.741 0.000 0.000 0.000 0.019 0.000 0.000 0.026 0.018 0.000 0.000 0.000 0.011 0.000 0.000 0.009 0.000 0.000 0.007 0.014 0.002 0.000 0.000 0.014 0.000 8.722 8.972 9.138 8.837 8.906 9.177 8.994 8.540 49.796 49.490 49.880 49.929 49.734 49.794 49.858 50.098 0.103 0.069 0.131 0.122 0.149 0.137 0.112 0.155 0.430 0.397 0.427 0.430 0.395 0.416 0.385 0.435 0.000 0.000 0.003 0.010 0.000 0.009 0.011 0.014 0.000 0.000 0.009 0.002 0.000 0.005 0.014 0.000 1.000 1.003 0.990 0.994 0.998 0.991 0.993 0.995 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.178 0.183 0.187 0.181 0.182 0.188 0.184 0.174 1.812 1.802 1.822 1.820 1.812 1.818 1.818 1.823 0.002 0.001 0.003 0.003 0.003 0.003 0.002 0.003 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 2.997 3.010 3.006 3.002 3.009 3.007 3.005 91.053 90.769 90.681 90.968 90.871 90.630 90.810 91.272 544 Harzb Harzb Harzb Iceberg Diss.Chron Diss.Chron Diss.Chron Diss.Chron ivine H8-I1, olivines Wt% Wt% Wt% Wt % Wt % Wt % Wt% Wt% 40.700 40.905 40.371 41.359 40.817 40.277 41.356 41.037 0.020 0.033 0.000 0.032 0.031 0.023 0.036 0.023 0.000 0.000 0.000 0.009 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.023 0.018 0.003 0.006 0.000 8.691 8.749 8.795 5.890 5.799 5.974 6.138 5.638 49.805 50.133 49.949 52.739 52.321 52.241 52.483 52.706 0.134 0.132 0.146 0.078 0.084 0.096 0.125 0.058 0.390 0.454 0.457 0.437 0.429 0.460 0.418 0.444 0.013 0.018 0.000 0.011 0.006 0.010 0.004 0.010 0.011 0.000 0.027 0.000 0.000 0.008 0.000 0.017 99.763 100.423 99.745 100.578 99.504 99.093 100.567 99.933 40.797 40.732 40.475 41.121 41.020 40.645 41.123 41.064 0.020 0.033 0.000 0.032 0.031 0.023 0.036 0.023 0.000 0.000 0.000 0.009 0.000 0.000 0.002 0.000 0.000 0.000 0.000 0.023 0.018 0.003 0.006 0.000 8.711 8.712 8.818 5.856 5.828 6.029 6.103 5.642 49.923 49.922 50.076 52.436 52.581 52.719 52.186 52.742 0.134 0.131 0.146 0.078 0.084 0.097 0.124 0.058 0.391 0.452 0.458 0.434 0.431 0.464 0.415 0.444 0.013 0.018 0.000 0.011 0.006 0.010 0.004 0.010 0.011 0.000 0.027 0.000 0.000 0.008 0.000 0.017 0.996 0.995 0.990 0.992 0.990 0.983 0.993 0.990 0.001 0.001 0.000 0.001 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.178 0.178 0.180 0.118 0.118 0.122 0.123 0.114 1.818 1.818 1.826 1.885 1.891 1.900 1.878 1.895 0.003 0.003 0.003 0.002 0.002 0.002 0.003 0.001 0.008 0.009 0.009 0.008 0.008 0.009 0.008 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.003 3.004 3.010 3.007 3.010 3.017 3.006 3.010 91.084 91.083 91.010 94.104 94.146 93.971 93.843 94.339 545 Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron H8-I10, olivines % Wt% Wt% Wt% Wt% Wt % Wt % Wt% 40.518 40.900 40.703 41.024 41.122 41.471 41.483 41.568 0.000 0.011 0.006 0.010 0.030 0.000 0.001 0.000 0.002 0.003 0.000 0.000 0.000 0.004 0.003 0.000 0.009 0.000 0.007 0.000 0.000 0.006 0.035 0.007 5.883 5.869 6.220 6.622 6.039 6.843 5.722 7.001 51.883 52.671 51.558 51.708 51.227 51.258 51.890 51.486 0.070 0.081 0.094 0.105 0.119 0.119 0.115 0.111 0.447 0.377 0.448 0.439 0.468 0.424 0.468 0.402 0.013 0.005 0.005 0.002 0.013 0.017 0.009 0.013 0.000 0.000 0.000 0.000 0.000 0.005 0.000 0.000 98.826 99.916 99.042 99.911 99.018 100.146 99.725 100.589 41.000 40.935 41.097 41.061 41.530 41.410 41.597 41.325 0.000 0.011 0.006 0.010 0.030 0.000 0.001 0.000 0.002 0.003 0.000 0.000 0.000 0.004 0.003 0.000 0.009 0.000 0.007 0.000 0.000 0.006 0.035 0.007 5.953 5.874 6.281 6.628 6.099 6.833 5.737 6.960 52.499 52.715 52.057 51.754 51.735 51.183 52.033 51.185 0.071 0.081 0.094 0.105 0.121 0.119 0.115 0.110 0.453 0.377 0.452 0.439 0.472 0.423 0.469 0.399 0.013 0.005 0.005 0.002 0.013 0.017 0.009 0.013 0.000 0.000 0.000 0.000 0.000 0.005 0.000 0.000 0.990 0.988 0.993 0.994 1.002 1.002 1.002 1.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.120 0.119 0.127 0.134 0.123 0.138 0.116 0.141 1.889 1.896 1.875 1.867 1.860 1.846 1.868 1.847 0.001 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.009 0.007 0.009 0.009 0.009 0.008 0.009 0.008 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.010 3.012 3.007 3.006 2.996 2.998 2.996 2.999 94.019 94.117 93.661 93.297 93.797 93.033 94.175 92.912 546 Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron H8-I5, circle 5, olivines H8-I5, random olivines H8-I2, olivir t% Wt% Wt % Wt % Wt % Wt % Wt % Wt% 41.276 41.310 40.649 40.418 40.239 40.988 40.326 40.898 0.000 0.016 0.000 0.000 0.039 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.000 0.015 0.007 0.011 0.011 0.000 0.021 0.045 0.000 6.985 5.881 6.816 6.458 6.745 6.423 5.739 5.921 51.419 52.358 51.939 51.657 51.518 51.871 51.909 52.076 0.122 0.068 0.085 0.056 0.112 0.090 0.066 0.061 0.434 0.447 0.436 0.437 0.385 0.399 0.455 0.456 0.000 0.014 0.000 0.019 0.010 0.012 0.001 0.028 0.009 0.004 0.000 0.001 0.000 0.000 0.002 0.000 100.260 100.104 99.935 99.056 99.046 99.804 98.547 99.441 41.169 41.267 40.675 40.803 40.626 41.068 40.920 41.128 0.000 0.016 0.000 0.000 0.039 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.000 0.015 0.007 0.011 0.011 0.000 0.021 0.045 0.000 6.967 5.875 6.820 6.520 6.810 6.436 5.824 5.954 51.286 52.304 51.972 52.149 52.014 51.973 52.675 52.369 0.122 0.068 0.085 0.056 0.113 0.090 0.067 0.062 0.433 0.446 0.436 0.441 0.388 0.399 0.462 0.459 0.000 0.014 0.000 0.019 0.010 0.012 0.001 0.028 0.009 0.004 0.000 0.001 0.000 0.000 0.002 0.000 0.997 0.995 0.986 0.988 0.985 0.993 0.988 0.992 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.141 0.118 0.138 0.132 0.138 0.130 0.118 0.120 1.852 1.880 1.879 1.882 1.880 1.873 1.895 1.884 0.002 0.001 0.002 0.001 0.002 0.002 0.001 0.001 0.008 0.009 0.009 0.009 0.008 0.008 0.009 0.009 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.002 3.005 3.014 3.012 3.014 3.007 3.012 3.008 92.919 94.073 93.143 93.446 93.158 93.504 94.160 94.004 547 Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron Diss.Chron l e s H9-I2, olivines % Wt% Wt% Wt% Wt% Wt% Wt% Wt% 40.917 40.711 40.964 41.068 41.140 40.957 40.787 40.544 0.000 0.020 0.000 0.008 0.016 0.017 0.008 0.003 0.005 0.000 0.000 0.014 0.025 0.000 0.008 0.011 0.010 0.011 0.007 0.000 0.019 0.021 0.015 0.015 6.057 6.113 6.245 5.973 5.488 6.491 7.373 8.773 51.643 52.100 51.823 52.521 52.424 51.015 50.369 49.742 0.095 0.058 0.079 0.056 0.083 0.097 0.141 0.117 0.388 0.454 0.431 0.430 0.482 0.441 0.334 0.282 0.007 0.010 0.008 0.004 0.007 0.005 0.000 0.028 0.000 0.003 0.034 0.000 0.008 0.000 0.020 0.000 99.122 99.480 99.590 100.074 99.690 99.043 99.055 99.514 41.280 40.924 41.133 41.037 41.267 41.353 41.176 40.742 0.000 0.020 0.000 0.008 0.016 0.017 0.008 0.003 0.005 0.000 0.000 0.014 0.025 0.000 0.008 0.011 0.011 0.011 0.007 0.000 0.019 0.021 0.015 0.015 6.111 6.145 6.270 5.969 5.505 6.554 7.443 8.816 52.101 52.372 52.036 52.482 52.587 51.508 50.850 49.985 0.096 0.058 0.079 0.056 0.084 0.098 0.142 0.118 0.391 0.456 0.432 0.429 0.484 0.445 0.337 0.283 0.007 0.010 0.008 0.004 0.007 0.005 0.000 0.029 0.000 0.003 0.034 0.000 0.008 0.000 0.021 0.000 0.996 0.989 0.994 0.990 0.994 1.000 0.999 0.995 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.123 0.124 0.127 0.120 0.111 0.132 0.151 0.180 1.874 1.887 1.874 1.888 1.888 1.856 1.840 1.820 0.002 0.001 0.002 0.001 0.002 0.002 0.003 0.002 0.008 0.009 0.008 0.008 0.009 0.009 0.007 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 3.004 3.011 3.006 3.009 3.005 3.000 3.000 3.005 93.827 93.824 93.668 94.003 94.453 93.338 92.412 90.997 548 Diss.Chron DIss.Chromit Wt % Wt % 40.683 39.680 0.000 0.017 0.002 0.000 0.008 0.005 8.495 7.891 49.898 50.167 0.109 0.149 0.336 0.329 0.000 0.005 0.000 0.000 99.531 98.243 40.875 40.390 0.000 0.017 0.002 0.000 0.008 0.005 8.535 8.032 50.133 51.065 0.109 0.152 0.338 0.334 0.000 0.005 0.000 0.000 0.997 0.985 0.000 0.000 0.000 0.000 0.000 0.000 0.174 0.164 1.823 1.856 0.002 0.003 0.007 0.007 0.000 0.000 0.000 0.000 3.003 3.015 91.282 91.892 549 Palace 01 Mchromit Mchromit Mchromit Disschrom Disschrom Disschrom Dunite Label Z9-P3, cire Z9-P3, cir(Z9-P3, circZ9-P4, cire Z9-P4, cire Z9-P4, ol, (Z9-P4, cl, c Oxides Wt% Wt% Wt% Wt% Wt% Wt% Wt% Si02 41.892 40.868 40.695 41.218 40.693 40.776 40.867 AI203 0.001 0.000 0.000 0.024 0.002 0.007 0.000 Ti02 0.008 0.006 0.000 0.002 0.000 0.000 0.000 Cr203 0.029 0.443 0.118 0.173 0.145 0.000 0.016 FeOtot. 4.423 3.386 4.169 4.629 4.746 5.693 7.060 MgO 54.081 53.881 53.379 53.384 52.812 52.301 51.355 MnO 0.070 0.046 0.043 0.062 0.075 0.063 0.134 NiO 0.844 1.121 0.905 0.631 0.656 0.473 0.455 CaO 0.000 0.003 0.001 0.002 0.016 0.010 0.030 Na20 0.000 0.000 0.000 0.000 0.000 0.007 0.000 Total 101.349 99.754 99.311 100.125 99.146 99.330 99.917 Normalized oxides Si02 41.335 40.969 40.977 41.167 41.044 41.051 40.901 AI203 0.001 0.000 0.000 0.024 0.002 0.007 0.000 Ti02 0.008 0.006 0.000 0.002 0.000 0.000 0.000 Cr203 0.029 0.444 0.119 0.173 0.147 0.000 0.016 FeOtot. 4.365 3.395 4.198 4.623 4.787 5.731 7.066 MgO 53.361 54.014 53.750 53.318 53.267 52.654 51.398 MnO 0.070 0.046 0.043 0.062 0.076 0.064 0.134 NiO 0.832 1.124 0.912 0.630 0.662 0.476 0.455 CaO 0.000 0.003 0.001 0.002 0.016 0.010 0.030 Na20 0.000 0.000 0.000 0.000 0.000 0.007 0.000 Cations Si 0.992 0.983 0.984 0.989 0.987 0.990 0.992 Al 0.000 0.000 0.000 0.001 0.000 0.000 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.001 0.008 0.002 0.003 0.003 0.000 0.000 Fe 0.088 0.068 0.084 0.093 0.096 0.116 0.143 Mg 1.909 1.931 1.925 1.910 1.910 1.893 1.859 Mn 0.001 0.001 0.001 0.001 0.002 0.001 0.003 Ni 0.016 0.022 0.018 0.012 0.013 0.009 0.009 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.007 3.013 3.014 3.009 3.011 3.010 3.007 M g# 95.613 96.594 95.802 95.361 95.201 94.245 92.840 Table 02.16: Collective analyses, E. Zikt Field Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2Si04. Fo»Mg'100/(Mg+Fetot) 550 nite Dunite Dunite Dunite Dunite Dunite Dunite Dunite ite portion Z9-P5, circZ9-P5, ancZ9-P5, single olivine, 5 points % Wt % Wt% Wt% Wt% Wt% Wt% Wt% 40.547 40.095 40.996 40.645 41.290 41.000 41.082 40.717 0.017 0.022 0.000 0.011 0.000 0.000 0.010 0.019 0.000 0.006 0.000 0.000 0.016 0.010 0.000 0.000 0.000 0.018 0.000 0.012 0.000 0.000 0.000 0.000 6.991 6.956 7.776 7.709 7.812 7.689 7.740 7.563 50.870 51.023 51.123 50.890 51.259 51.387 51.263 51.283 0.086 0.136 0.092 0.129 0.120 0.129 0.117 0.135 0.414 0.424 0.389 0.393 0.401 0.428 0.441 0.404 0.045 0.001 0.013 0.011 0.005 0.006 0.004 0.018 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 98.970 98.681 100.390 99.800 100.904 100.650 100.657 100.139 40.969 40.631 40.837 40.727 40.920 40.736 40.813 40.660 0.017 0.023 0.000 0.011 0.000 0.000 0.010 0.019 0.000 0.006 0.000 0.000 0.016 0.010 0.000 0.000 0.000 0.018 0.000 0.012 0.000 0.000 0.000 0.000 7.064 7.049 7.746 7.724 7.743 7.639 7.690 7.553 51.400 51.705 50.924 50.992 50.800 51.055 50.928 51.211 0.087 0.138 0.092 0.130 0.119 0.128 0.116 0.135 0.418 0.430 0.388 0.393 0.398 0.425 0.438 0.404 0.045 0.001 0.013 0.011 0.005 0.006 0.004 0.018 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.993 0.986 0.993 0.991 0.995 0.991 0.993 0.989 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.143 0.143 0.158 0.157 0.157 0.155 0.156 0.154 1.858 1.871 1.846 1.850 1.842 1.851 1.847 1.857 0.002 0.003 0.002 0.003 0.002 0.003 0.002 0.003 0.008 0.008 0.008 0.008 0.008 0.008 0.009 0.008 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.006 3.013 3.007 3.009 3.005 3.009 3.007 3.011 92.842 92.895 92.138 92.188 92.123 92.258 92.191 92.359 551 unite Harzb Harzb Harzb Harzb Z9-P6, 3 ol Z9-P6, ol, c ft% Wt% Wt% Wt% Wt% 40.992 40.884 40.622 40.743 40.933 0.000 0.029 0.027 0.000 0.016 0.004 0.005 0.000 0.005 0.000 0.000 0.004 0.003 0.007 0.005 7.944 7.650 7.803 7.736 7.971 51.199 51.168 50.821 50.907 51.697 0.100 0.129 0.121 0.117 0.128 0.404 0.376 0.370 0.407 0.391 0.003 0.015 0.014 0.012 0.011 0.000 0.008 0.000 0.017 0.006 100.645 100.269 99.782 99.951 101.157 40.729 40.774 40.711 40.763 40.464 0.000 0.029 0.027 0.000 0.016 0.004 0.005 0.000 0.005 0.000 0.000 0.004 0.003 0.007 0.005 7.893 7.630 7.820 7.740 7.880 50.870 51.030 50.932 50.932 51.105 0.099 0.129 0.121 0.117 0.126 0.401 0.375 0.371 0.408 0.387 0.003 0.015 0.014 0.012 0.011 0.000 0.008 0.000 0.017 0.005 0.992 0.991 0.991 0.992 0.986 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.161 0.155 0.159 0.157 0.161 1.846 1.850 1.848 1.847 1.856 0.002 0.003 0.003 0.002 0.003 0.008 0.007 0.007 0.008 0.008 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.008 3.008 3.009 3.008 3.014 91.993 92.262 92.070 92.144 92.039 552 Sharq 01 Harzb Harzb Harzb Dunite Dunite Dunite Dunite Label ZB-Shi 1, c Z8-Sh11. c Z8-Sh11, c Z8-Sh5, cir Z8-Sh5, cir Z8-Sh5, cir Z8-Sh5, cir Oxides Wt% Wt% Wt% Wt% Wt% W t% Wt% 8102 41.519 41.271 40.578 40.520 40.655 40.654 40.434 AI203 0.000 0.002 0.000 0.000 0.006 0.021 0.007 TI02 0.016 0.002 0.000 0.000 0.016 0.001 0.001 Cr203 0.016 0.015 0.000 0.025 0.002 0.015 0.000 FeOtot. 8.025 7.652 7.560 6.739 6.429 6.551 7.190 MgO 51.123 51.402 49.918 51.938 52.190 51.867 51.302 MnO 0.121 0.107 0.108 0.091 0.117 0.104 0.129 NiO 0.398 0.443 0.440 0.401 0.460 0.431 0.249 CaO 0.001 0.000 0.000 0.016 0.010 0.000 0.000 Na20 0.029 0.005 0.001 0.017 0.002 0.013 0.009 Total 101.247 100.899 98.605 99.747 99.887 99.657 99.322 Normalized oxides Si02 41.008 40.903 41.152 40.623 40.701 40.793 40.710 AI203 0.000 0.002 0.000 0.000 0.006 0.021 0.007 Ti02 0.015 0.002 0.000 0.000 0.016 0.001 0.001 Cr203 0.015 0.015 0.000 0.025 0.002 0.015 0.000 FeOtot. 7.926 7.584 7.667 6.756 6.436 6.574 7.239 MgO 50.493 50.944 50.624 52.069 52.249 52.046 51.653 MnO 0.119 0.106 0.110 0.091 0.117 0.104 0.130 NiO 0.393 0.439 0.446 0.402 0.461 0.432 0.250 CaO 0.001 0.000 0.000 0.016 0.010 0.000 0.000 Na20 0.029 0.005 0.001 0.017 0.002 0.013 0.010 Cations Si 0.998 0.994 1.000 0.985 0.986 0.988 0.988 AI 0.000 0.000 0.000 0.000 0.000 0.001 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.161 0.154 0.156 0.137 0.130 0.133 0.147 Mg 1.831 1.846 1.834 1.882 1.886 1.879 1.869 Mn 0.002 0.002 0.002 0.002 0.002 0.002 0.003 Ni 0.008 0.009 0.009 0.008 0.009 0.008 0.005 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.002 3.006 3.000 3.015 3.014 3.012 3.012 M g# 91.907 92.292 92.170 93.215 93.537 93.383 92.711 Table C2.17: Collective analyeea, B. Sharq Field (S. Zikt) MicroprolM Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2Si04. Fo*MgMOO/(Mg+Fetot) 553 nite Dunite Dunite Dunite Dunite Ctiromit Chromit DissChrom Sh5, raiZ8-Sh16, cZ8-Sh16, random olivines, dunite Z8-Sh16, random ol, cZ8-Sh8, cir % Wt% Wt% Wt% Wt% Wt% W t% Wt% 40.282 41.969 41.355 41.034 41.165 42.032 41.850 42.545 0.000 0.007 0.000 0.012 0.000 0.000 0.006 0.000 0.000 0.000 0.000 0.000 0.008 0.000 0.000 0.015 0.006 0.004 0.019 0.001 0.000 0.011 0.010 0.028 6.627 5.072 6.343 6.429 6.399 4.672 4.695 4.463 51.496 52.897 51.819 51.764 52.046 53.588 53.411 54234 0.123 0.048 0.043 0.106 0.116 0.058 0.056 0.039 0.385 0.503 0.418 0.428 0.440 0.499 0.504 0.490 0.000 0.024 0.076 0.038 0.046 0.013 0.012 0.008 0.013 0.000 0.000 0.000 0.006 0.004 0.000 0.006 98.933 100.524 100.073 99.814 100.226 100.876 100.544 101.828 40.717 41.750 41.325 41.110 41.072 41.667 41.623 41.782 0.000 0.007 0.000 0.012 0.000 0.000 0.006 0.000 0.000 0.000 0.000 0.000 0.008 0.000 0.000 0.014 0.006 0.004 0.019 0.001 0.000 0.011 0.010 0.028 6.699 5.045 6.338 6.441 6.384 4.632 4.670 4.383 52.052 52.621 51.781 51.861 51.929 53.122 53.122 53.260 0.125 0.047 0.043 0.106 0.116 0.057 0.056 0.039 0.389 0.500 0.418 0.429 0.439 0.495 0.501 0.481 0.000 0.024 0.076 0.038 0.046 0.013 0.012 0.008 0.013 0.000 0.000 0.000 0.006 0.003 0.000 0.006 0.987 1.002 0.998 0.994 0.993 0.999 0.998 1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.136 0.101 0.128 0.130 0.129 0.093 0.094 0.088 1.880 1.883 1.864 1.869 1.872 1.898 1.899 1.900 0.003 0.001 0.001 0.002 0.002 0.001 0.001 0.001 0.008 0.010 0.008 0.008 0.009 0.010 0.010 0.009 0.000 0.001 0.002 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.013 2.998 3.002 3.006 3.007 3.001 3.002 2.999 93.267 94.896 93.575 93.486 93.548 95.337 95.300 95.587 554 DissChrom DissChrom DissChrom DissChrom DissChrom DissChrom Mchromit Mchromit Z8-Sh8, cir Z8-Sh8, cir Z8-Sh8. cir Z8-Sh8, random ol Z8-Sh8, ZE Z8-Sh13.2, Z8-Sh13.2, % Wt% Wt% Wt% Wt% Wt% Wt% Wt% 40.482 41.765 41.730 41.507 41.864 41.731 42.070 42.024 0.016 0.000 0.000 0.008 0.002 0.003 0.011 0.010 0.000 0.000 0.002 0.010 0.000 0.004 0.000 0.003 0.134 0.342 0.296 0.005 0.017 0.047 0.006 0.014 4.306 3.676 4.451 5.030 5.036 4.295 3.929 4.154 52.720 53.771 53.839 53.298 52.899 53.805 53.907 53.838 0.072 0.057 0.073 0.095 0.101 0.039 0.031 0.053 0.483 0.536 0.475 0.478 0.498 0.505 0.651 0.660 0.033 0.015 0.043 0.024 0.030 0.025 0.000 0.000 0.000 0.008 0.000 0.007 0.000 0.001 0.015 0.004 98.247 100.168 100.908 100.462 100.446 100.452 100.620 100.759 41.204 41.695 41.355 41.317 41.679 41.543 41.811 41.707 0.016 0.000 0.000 0.008 0.002 0.003 0.011 0.010 0.000 0.000 0.002 0.010 0.000 0.004 0.000 0.003 0.137 0.341 0.293 0.005 0.017 0.046 0.006 0.014 4.383 3.670 4.411 5.007 5.013 4.275 3.905 4.123 53.661 53.680 53.354 53.053 52.664 53.562 53.575 53.432 0.074 0.057 0.072 0.094 0.100 0.039 0.031 0.053 0.491 0.535 0.470 0.476 0.496 0.503 0.647 0.655 0.034 0.015 0.042 0.024 0.029 0.025 0.000 0.000 0.000 0.008 0.000 0.007 0.000 0.001 0.015 0.004 0.988 0.996 0.992 0.993 1.001 0.995 0.999 0.998 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.003 0.006 0.006 0.000 0.000 0.001 0.000 0.000 0.088 0.073 0.088 0.101 0.101 0.086 0.078 0.083 1.919 1.912 1.908 1.901 1.885 1.912 1.909 1.906 0.001 0.001 0.001 0.002 0.002 0.001 0.001 0.001 0.009 0.010 0.009 0.009 0.010 0.010 0.012 0.013 0.001 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.010 3.000 3.005 3.007 2.999 3.005 3.000 3.001 95.618 96.307 95.568 94.972 94.930 95.714 96.072 95.851 555 Mchromit Mchromit Mchromit random divines W t% Wt% Wt% 42.505 41.460 41.335 0.000 0.027 0.000 0.015 0.000 0.000 0.020 0.037 0.024 3.862 3.527 4.213 53.564 54.220 52.882 0.063 0.029 0.036 0.595 0.674 0.677 0.009 0.000 0.000 0.000 0.004 0.001 100.633 99.978 99.169 42.237 41.469 41.682 0.000 0.027 0.000 0.015 0.000 0.000 0.020 0.037 0.024 3.837 3.528 4.249 53.227 54.232 53.325 0.063 0.029 0.037 0.592 0.674 0.683 0.009 0.000 0.000 0.000 0.004 0.001 1.008 0.991 0.998 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.077 0.070 0.085 1.894 1.932 1.904 0.001 0.001 0.001 0.011 0.013 0.013 0.000 0.000 0.000 0.000 0.000 0.000 2.992 3.008 3.002 96.113 96.480 95.722 556 Scorpion C MChromIt MChromIt MChromIt Dunite Dunite Dunite Harzb Label Z9-Sc1, clrZ9-Sc1, ramdom ol In Z9-Sc1, ol In dunite Z9-Sc2, oil' Oxides Wt% Wt% Wt% Wt% Wt% Wt% W t% 3102 41.749 41.175 40.811 40.922 41.211 40.978 41.470 AI203 0.003 0.000 0.032 0.015 0.000 0.000 0.000 TI02 0.005 0.000 0.010 0.001 0.004 0.000 0.005 Cr203 0.000 0.001 0.000 0.000 0.014 0.016 0.000 FeOtot. 4.897 5.458 6.058 5.960 6.254 6.514 8.351 MgO 53.470 52.735 52.234 52.160 52.148 51.952 51.004 MnO 0.056 0.081 0.094 0.092 0.107 0.121 0.172 NIO 0.546 0.468 0.479 0.474 0.402 0.485 0.375 CaO 0.021 0.016 0.000 0.000 0.000 0.000 0.000 Na20 0.004 0.000 0.017 0.000 0.004 0.000 0.000 Total 100.749 99.936 99.734 99.624 100.145 100.066 101.377 Normalized oxides 8102 41.438 41.202 40.920 41.076 41.152 40.951 40.906 AI203 0.003 0.000 0.032 0.015 0.000 0.000 0.000 TI02 0.005 0.000 0.010 0.001 0.004 0.000 0.005 Cr203 0.000 0.001 0.000 0.000 0.014 0.016 0.000 FeOtot. 4.860 5.462 6.075 5.982 6.245 6.510 8.238 MgO 53.072 52.769 52.373 52.357 52.073 51.918 50.311 MnO 0.056 0.081 0.094 0.093 0.107 0.121 0.170 NIO 0.542 0.468 0.480 0.475 0.402 0.485 0.370 CaO 0.021 0.016 0.000 0.000 0.000 0.000 0.000 Na20 0.004 0.000 0.017 0.000 0.004 0.000 0.000 Cations SI 0.995 0.992 0.989 0.992 0.994 0.991 0.997 AI 0.000 0.000 0.001 0.000 0.000 0.000 0.000 n 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.098 0.110 0.123 0.121 0.126 0.132 0.168 Mg 1.900 1.894 1.886 1.884 1.875 1.873 1.828 Mn 0.001 0.002 0.002 0.002 0.002 0.002 0.004 NI 0.010 0.009 0.009 0.009 0.008 0.009 0.007 Ca 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.005 3.008 3.011 3.008 3.006 3.009 3.003 M g# 95.114 94.512 93.891 93.976 93.697 93.428 91.587 Table C2.18: Collective analytes, B. Scorpion Field (S. Zikt) Microprolie Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg. Fe)2Si04. 557 Harzb Harzb Harzb MChromit MChromit MChromit MChromit MChromit vine Z9-Sc6, various olivines n% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 41.598 41.848 41.551 41.324 42.133 41.558 41.605 41.811 0.012 0.000 0.010 0.009 0.000 0.000 0.000 0.005 0.000 0.002 0.000 0.000 0.000 0.016 0.000 0.000 0.005 0.011 0.000 0.000 0.085 0.034 0.029 0.019 8.230 8.458 8.193 3.402 3.013 2.991 3.229 3.581 50.907 51.160 51.292 53.998 54.975 54.101 54.307 54.453 0.127 0.137 0.128 0.000 0.033 0.027 0.049 0.045 0.446 0.375 0.400 0.886 0.966 0.917 0.927 0.872 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.013 0.001 0.020 0.008 101.324 101.994 101.574 99.619 101.218 99.644 100.166 100.793 41.054 41.030 40.907 41.482 41.626 41.706 41.536 41.482 0.011 0.000 0.010 0.009 0.000 0.000 0.000 0.004 0.000 0.002 0.000 0.000 0.000 0.016 0.000 0.000 0.004 0.011 0.000 0.000 0.084 0.034 0.029 0.019 8.123 8.292 8.066 3.415 2.977 3.001 3.223 3.552 50.242 50.159 50.497 54.204 54.313 54.295 54.217 54.025 0.125 0.135 0.126 0.000 0.032 0.027 0.049 0.044 0.440 0.368 0.394 0.890 0.954 0.920 0.925 0.866 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.013 0.001 0.020 0.008 1.000 1.000 0.996 0.991 0.993 0.995 0.992 0.992 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.001 0.001 0.000 0.165 0.169 0.164 0.068 0.059 0.060 0.064 0.071 1.824 1.822 1.833 1.931 1.932 1.931 1.931 1.926 0.003 0.003 0.003 0.000 0.001 0.001 0.001 0.001 0.009 0.007 0.008 0.017 0.018 0.018 0.018 0.017 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.000 3.000 3.004 3.008 3.006 3.005 3.007 3.006 91.685 91.513 91.776 96.586 97.017 96.992 96.772 96.443 558 nite Dunite Dunite Dunite Dunite Dunite Dunite Dunite ■Sc7, clrZ9-Sc7, circle 12, olivine Z9-Sc9, cirZ9-Sc9, cir % Wt% Wt% Wt % Wt% Wt% Wt% Wt% 40.270 40.376 40.370 40.232 41.019 40.598 42.076 40.609 0.008 0.033 0.011 0.000 0.000 0.000 0.010 0.007 0.000 0.000 0.007 0.000 0.002 0.008 0.000 0.000 0.016 0.000 0.000 0.000 0.003 0.000 0.008 0.003 7.093 7.262 7.080 7.162 7.242 7.234 3.827 3.789 51.034 51.188 51.380 50.745 51.833 51.471 54.495 53.206 0.117 0.127 0.117 0.109 0.098 0.085 0.059 0.080 0.459 0.465 0.456 0.350 0.410 0.416 0.511 0.571 0.000 0.003 0.000 0.005 0.009 0.000 0.003 0.000 0.006 0.007 0.000 0.000 0.000 0.000 0.025 0.000 99.003 99.462 99.421 98.603 100.617 99.812 101.014 98.265 40.675 40.594 40.605 40.801 40.767 40.675 41.654 41.326 0.008 0.034 0.011 0.000 0.000 0.000 0.010 0.007 0.000 0.000 0.007 0.000 0.002 0.008 0.000 0.000 0.016 0.000 0.000 0.000 0.003 0.000 0.007 0.003 7.164 7.302 7.121 7.263 7.198 7.248 3.789 3.856 51.548 51.465 51.679 51.464 51.515 51.568 53.948 54.146 0.119 0.128 0.118 0.110 0.098 0.085 0.059 0.081 0.463 0.467 0.459 0.355 0.407 0.417 0.506 0.581 0.000 0.003 0.000 0.005 0.009 0.000 0.003 0.000 0.006 0.007 0.000 0.000 0.000 0.000 0.024 0.000 0.988 0.987 0.986 0.990 0.990 0.988 0.995 0.989 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.146 0.148 0.145 0.147 0.146 0.147 0.076 0.077 1.866 1.865 1.871 1.862 1.864 1.867 1.922 1.932 0.002 0.003 0.002 0.002 0.002 0.002 0.001 0.002 0.009 0.009 0.009 0.007 0.008 0.008 0.010 0.011 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 3.012 3.013 3.014 3.010 3.010 3.012 3.005 3.011 92.767 92.628 92.825 92.663 92.732 92.691 96.210 96.159 559 nite Dunite Dunite Dunite Dunite Dunite Harzb Harzb ■Sc9, circle 5, olivint Z9-Sc9, random olivine Z9-Sc10, cZ9-Sc10, c % Wt% Wt% Wt% Wt% Wt % Wt % Wt% 41.352 41.165 39.834 40.724 42.259 41.927 40.917 41.302 0.007 0.000 0.030 0.021 0.000 0.002 0.000 0.000 0.000 0.006 0.002 0.008 0.000 0.008 0.000 0.005 0.012 0.000 0.000 0.001 0.000 0.001 0.010 0.002 3.859 4.170 5.465 5.594 4.622 4.124 7.465 7.480 53.857 53.818 52.106 52.321 53.275 53.884 51.263 51.613 0.072 0.057 0.067 0.080 0.078 0.065 0.116 0.120 0.525 0.570 0.508 0.561 0.531 0.596 0.376 0.409 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.010 0.005 0.000 0.000 0.000 0.021 0.000 0.000 0.000 99.690 99.785 98.012 99.311 100.786 100.606 100.148 100.941 41.481 41.253 40.642 41.007 41.929 41.674 40.857 40.917 0.007 0.000 0.031 0.021 0.000 0.002 0.000 0.000 0.000 0.006 0.002 0.009 0.000 0.008 0.000 0.005 0.013 0.000 0.000 0.001 0.000 0.001 0.010 0.002 3.871 4.179 5.576 5.633 4.586 4.099 7.454 7.410 54.024 53.934 53.163 52.684 52.860 53.559 51.188 51.132 0.072 0.057 0.068 0.081 0.078 0.065 0.116 0.119 0.527 0.571 0.518 0.565 0.527 0.592 0.376 0.405 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.010 0.005 0.000 0.000 0.000 0.021 0.000 0.000 0.000 0.992 0.989 0.981 0.989 1.004 0.997 0.992 0.994 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.077 0.084 0.113 0.114 0.092 0.082 0.151 0.151 1.926 1.927 1.913 1.894 1.887 1.911 1.854 1.851 0.001 0.001 0.001 0.002 0.002 0.001 0.002 0.002 0.010 0.011 0.010 0.011 0.010 0.011 0.007 0.008 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.008 3.011 3.019 3.010 2.996 3.003 3.007 3.006 96.136 95.835 94.443 94.341 95.359 95.883 92.448 92.481 560 Harzb Harzb Harzb ircle 2, olivii Z9-Sc10, c Z9-Sc10, rs Wt% W t% Wt% 41.609 40.438 40.487 0.003 0.010 0.046 0.000 0.008 0.000 0.000 0.000 0.018 7.645 7.260 7.308 51.568 51.479 50.680 0.079 0.083 0.099 0.409 0.384 0.400 0.000 0.000 0.001 0.023 0.000 0.000 101.335 99.661 99.040 41.060 40.576 40.879 0.003 0.010 0.047 0.000 0.008 0.000 0.000 0.000 0.018 7.544 7.284 7.379 50.888 51.654 51.172 0.078 0.083 0.100 0.404 0.386 0.404 0.000 0.000 0.001 0.022 0.000 0.000 0.997 0.986 0.993 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.153 0.148 0.150 1.842 1.871 1.852 0.002 0.002 0.002 0.008 0.008 0.008 0.000 0.000 0.000 0.001 0.000 0.000 3.003 3.014 3.007 92.322 92.669 92.516 561 Others Wadi Al'Ab Dunite Dunite Dunite Dunite Dunite Dunite Label Wad9-1, olivines Oxides Wt % Wt % W t% W t% W t% W t% Wt% SI02 40.787 40.617 41.536 41.241 41.339 40.957 41.376 AI203 0.006 0.014 0.014 0.000 0.005 0.000 0.016 TI02 0.020 0.002 0.007 0.010 0.000 0.000 0.009 Cr203 0.000 0.000 0.000 0.000 0.000 0.000 0.006 FeOtot. 8.117 8.319 8.236 8.185 8.424 8.473 8.545 MgO 50.905 50.364 50.828 50.281 50.958 50.774 51.413 MnO 0.108 0.094 0.111 0.110 0.113 0.152 0.143 NiO 0.387 0.421 0.405 0.415 0.462 0.419 0.392 CaO 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Na20 0.000 0.012 0.000 0.011 0.006 0.000 0.004 Total 100.331 99.844 101.138 100.253 101.305 100.774 101.903 Normalized oxides Si02 40.652 40.680 41.068 41.137 40.806 40.643 40.603 AI203 0.006 0.014 0.014 0.000 0.005 0.000 0.015 Ti02 0.020 0.002 0.007 0.010 0.000 0.000 0.009 Cr203 0.000 0.000 0.000 0.000 0.000 0.000 0.005 FeOtot. 8.090 8.332 8.144 8.164 8.315 8.407 8.385 MgO 50.737 50.443 50.256 50.154 50.301 50.384 50.452 MnO 0.108 0.095 0.110 0.110 0.111 0.150 0.140 NiO 0.386 0.422 0.401 0.414 0.456 0.416 0.385 CaO 0.000 0.000 0.000 0.000 0.000 0.000 0.001 Na20 0.000 0.012 0.000 0.011 0.006 0.000 0.004 Cations Si 0.991 0.992 1.000 1.001 0.995 0.992 0.991 AI 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.165 0.170 0.166 0.166 0.170 0.172 0.171 Mg 1.843 1.834 1.824 1.820 1.829 1.833 1.835 Mn 0.002 0.002 0.002 0.002 0.002 0.003 0.003 Ni 0.008 0.008 0.008 0.008 0.009 0.008 0.008 Ca 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.009 3.007 3.000 2.998 3.005 3.006 3.009 Mg# 91.789 91.519 91.667 91.633 91.514 91.440 91.472 Table C2.19: Collective analyses, Other places In the upper mantle Microprobe Analysis & Calculated Formula (based on 4 Oxygens) of Olivine, (Mg, Fe)2Si04. 562 nite Dunite MasafI Lherzo Lherzo Lherzo Lherzo Lherzo Wad9-1, ol Mas9-3, cir Mas9-3, circle 3, ollvln Mas9-3, circle 4, ollvin Mas9-3, cit % W t% Wt% Wt% Wt% Wt% W t% W t% 41.012 41.061 41.549 40.693 40.307 40.490 39.875 40.730 0.024 0.004 0.000 0.000 0.026 0.011 0.006 0.000 0.003 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.002 0.000 0.000 0.009 0.000 0.000 0.009 0.004 8.240 8.535 9.623 11.484 11.670 10.430 12.080 12.395 51.128 50.680 50.096 47.736 47.522 48.551 47.335 47.886 0.138 0.121 0.178 0.200 0.180 0.173 0.178 0.236 0.352 0.368 0.511 0.371 0.341 0.400 0.365 0.330 0.000 0.000 0.041 0.005 0.002 0.000 0.000 0.021 0.004 0.000 0.000 0.006 0.005 0.000 0.018 0.000 100.901 100.769 101.997 100.504 100.053 100.054 99.865 101.607 40.645 40.748 40.735 40.489 40.286 40.468 39.929 40.086 0.024 0.004 0.000 0.000 0.026 0.011 0.006 0.000 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.004 0.002 0.000 0.000 0.009 0.000 0.000 0.009 0.004 8.166 8.469 9.435 11.426 11.664 10.424 12.096 12.199 50.671 50.293 49.115 47.497 47.497 48.525 47.399 47.128 0.136 0.120 0.174 0.199 0.180 0.173 0.178 0.232 0.349 0.365 0.501 0.369 0.341 0.400 0.366 0.324 0.000 0.000 0.040 0.005 0.002 0.000 0.000 0.021 0.004 0.000 0.000 0.006 0.005 0.000 0.018 0.000 0.991 0.994 0.999 1.001 0.997 0.996 0.991 0.995 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.166 0.173 0.193 0.236 0.241 0.215 0.251 0.253 1.841 1.829 1.795 1.750 1.753 1.781 1.754 1.744 0.003 0.002 0.004 0.004 0.004 0.004 0.004 0.005 0.007 0.007 0.010 0.007 0.007 0.008 0.007 0.006 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.009 3.006 3.001 2.999 3.003 3.004 3.009 3.005 91.709 91.368 90.272 88.109 87.892 89.245 87.477 87.320 563 îrzo Lherzo Lherzo Lherzo Lherzo Lherzo Lherzo Lherzo s9-3, cir Mas9-3, cir Mas9-3, cir Mas9-3, cir Mas9-5, cir Mas9-5, cir Mas9-5, cir Mas9-5, cir % W t% W t% W t% W t% W t% W t% W t% 39.798 39.828 39.094 38.817 41.308 40.878 40.791 41.142 0.000 0.005 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.020 0.013 0.035 0.000 0.018 0.000 0.021 0.002 0.000 0.009 0.003 12.170 11.913 11.783 12.305 9.556 9.893 9.469 9.553 47.244 47.030 46.781 47.761 49.295 49.741 48.782 49.453 0.236 0.243 0.213 0.221 0.116 0.147 0.131 0.155 0.365 0.259 0.340 0.331 0.365 0.368 0.400 0.409 0.000 0.033 0.004 0.010 0.041 0.003 0.000 0.000 0.026 0.005 0.003 0.008 0.000 0.007 0.000 0.028 99.839 99.332 98.218 99.475 100.690 101.058 99.594 100.779 39.862 40.095 39.804 39.022 41.025 40.450 40.958 40.823 0.000 0.005 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.006 0.020 0.013 0.035 0.000 0.018 0.000 0.021 0.002 0.000 0.009 0.003 12.190 11.993 11.997 12.370 9.491 9.789 9.507 9.479 47.320 47.346 47.630 48.014 48.957 49.221 48.981 49.071 0.237 0.244 0.217 0.223 0.115 0.146 0.131 0.154 0.366 0.260 0.346 0.333 0.362 0.365 0.402 0.406 0.000 0.033 0.004 0.010 0.041 0.003 0.000 0.000 0.026 0.005 0.003 0.008 0.000 0.007 0.000 0.028 0.990 0.994 0.988 0.973 1.004 0.993 1.003 1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.253 0.249 0.249 0.258 0.194 0.201 0.195 0.194 1.753 1.750 1.763 1.784 1.786 1.802 1.788 1.792 0.005 0.005 0.005 0.005 0.002 0.003 0.003 0.003 0.007 0.005 0.007 0.007 0.007 0.007 0.008 0.008 0.000 0.001 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.000 0.001 3.010 3.005 3.012 3.027 2.996 3.007 2.997 2.999 87.374 87.558 87.620 87.372 90.191 89.963 90.180 90.223 564 Lherzo Uqah Pyroxenite Pyroxenite Mas9-5, cirZ9-5, circle Z9-5, circle 2, ol Wt% Wt% Wt% Wt% 40.970 40.013 40.549 40.617 0.004 0.009 0.001 0.013 0.022 0.000 0.016 0.000 0.006 0.001 0.000 0.000 9.675 11.080 10.629 10.622 48.962 47.964 48.739 48.670 0.128 0.186 0.155 0.170 0.372 0.231 0.243 0.279 0.000 0.000 0.009 0.000 0.000 0.000 0.000 0.008 100.139 99.484 100.340 100.379 40.913 40.220 40.412 40.464 0.004 0.009 0.001 0.013 0.022 0.000 0.016 0.000 0.006 0.001 0.000 0.000 9.662 11.137 10.593 10.582 48.894 48.213 48.573 48.486 0.128 0.187 0.154 0.169 0.371 0.232 0.242 0.278 0.000 0.000 0.009 0.000 0.000 0.000 0.000 0.008 1.002 0.993 0.995 0.996 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.198 0.230 0.218 0.218 1.786 1.775 1.783 1.780 0.003 0.004 0.003 0.004 0.007 0.005 0.005 0.006 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.997 3.007 3.005 3.004 90.021 88.528 89.099 89.092 565 Calculating Pyroxene Structural Formula: (Mg, Fe)2SI206, based on 6 oxygen Sam ple: Z7-20 (A) (B) Analyzed Point Label A point from Roberts (1992) O xides W t% S I02 57.05 AI203 1.68 TI02 0.02 C r203 0.53 FeO tot. 5.46 MgO 34.14 MnO 0.14 NIO 0 CaO 0.74 N a20 0(C ) (D) (E) (F) (G) (H) Total 99.76 Mol. Wt. Mol.Proo. Ox.Mole Ox Proo. No.of Anic Cat Assoc Normalized oxides Wt. % B/C D*E (F*6)/Tot.F S i02 57.18725 60.0843 0.951784 2 1.903567 3.932204 0.5 AI203 1.684042 101.9613 0.016516 3 0.049549 0.102354 0-Jan T i02 0.020048 79.8988 0.000251 2 0.000502 0.001037 0-Jan C r203 0.531275 151.9902 0.003495 3 0.010486 0.021662 0.666667 FeO tot. 5.473136 71.8464 0.076178 1 0.076178 0.157362 MgO 34.22213 40.3044 0.849092 1 0.849092 1.753971 MnO 0.140337 70.9374 0.001978 1 0.001978 0.004087 NiO 0 74.6994 0 1 0 0 CaO 0.74178 56.0794 0.013227 1 0.013227 0.027324 N a20 0 61.97894 0 1 0 0 100 Norm.Cat. 2.90458 C ations G*H (B*4)/B43 Si 1.966102 1.970022 Ai 0.068236 0.068372 Ti 0.000518 0.000519 Cr 0.014441 0.01447 Fe 0.157362 0.157675 Mg 1.753971 1.757468 Mn 0.004087 0.004095 Ni 0 0 Ca 0.027324 0.027378 Na 0 0 Total 3.992041 4 M g# 91.76691 Mg#»Mg"100(Mg+Fe) En 90.47354 En » MgMOO(Mg+Fe+Ca) Fs 8.117049 Fs « FeMOO/(Mg+Fe+Ca) Wo 1.409415 Wo « Ca*100/(Mg+Fe4Ca) Figure C3.1.: Sample form of the Pyroxene formula calculation and relalMl Label PX1-A1-C PX2-A1-C PX2-A2-R PX3-A1-C PX4-A1-C PX4-A2-R PX5-A1-C O xides Wt % Wt % w t % w t % Wt % Wt % Wt % S I02 56.934 56.386 56.588 56.440 56.573 56.410 55.800 AI203 1.440 1.716 1.581 1.536 1.447 1.534 1.591 TI02 0.055 0.023 0.072 0.000 0.000 0.003 0.028 C r203 0.466 0.585 0.609 0.497 0.523 0.507 0.516 FeO tot. 5.416 5.258 5.520 5.495 5.605 5.466 5.563 MgO 34.683 33.529 33.965 33.847 34.167 34.447 34.209 MnO 0.160 0.129 0.172 0.159 0.132 0.141 0.108 NIO 0.108 0.129 0.061 0.023 0.094 0.048 0.064 CaO 0.487 1.444 0.375 0.809 0.737 0.876 1.005 N a20 0.000 0.023 0.000 0.019 0.000 0.000 0.000 Total 99.749 99.222 98.943 98.825 99.278 99.432 98.884 Normalized oxides 8102 57.077 56.828 57.193 57.111 56.984 56.732 56.430 AI203 1.444 1.729 1.598 1.554 1.458 1.543 1.609 TI02 0.055 0.023 0.073 0.000 0.000 0.003 0.028 C r203 0.467 0.590 0.616 0.503 0.527 0.510 0.522 FeO tot. 5.430 5.299 5.579 5.560 5.646 5.497 5.626 MgO 34.770 33.792 34.328 34.249 34.415 34.644 34.595 MnO 0.160 0.130 0.174 0.161 0.133 0.142 0.109 NIO 0.108 0.130 0.062 0.023 0.095 0.048 0.065 CaO 0.488 1.455 0.379 0.819 0.742 0.881 1.016 N a20 0.000 0.023 0.000 0.019 0.000 0.000 0.000 C ations SI 1.963 1.959 1.967 1.966 1.963 1.955 1.947 AI 0.059 0.070 0.065 0.063 0.059 0.063 0.065 TI 0.001 0.001 0.002 0.000 0.000 0.000 0.001 Cr 0.013 0.016 0.017 0.014 0.014 0.014 0.014 Fe 0.156 0.153 0.160 0.160 0.163 0.158 0.162 Mg 1.783 1.737 1.760 1.757 1.767 1.779 1.780 Mn 0.005 0.004 0.005 0.005 0.004 0.004 0.003 NI 0.003 0.004 0.002 0.001 0.003 0.001 0.002 Ca 0.018 0.054 0.014 0.030 0.027 0.033 0.038 Na 0.000 0.001 0.000 0.001 0.000 0.000 0.000 Total 4.000 3.997 3.991 3.996 4.000 4.007 4.012 M g# 91.945 91.914 91.645 91.653 91.573 91.826 91.640 En 91.100 89.371 90.983 90.232 90.291 90.310 89.901 F s 7.980 7.862 8.295 8.218 8.309 8.039 8.201 Wo 0.919 2.766 0.722 1.550 1.400 1.651 1.898 Tabel C3.1: Sample Z7*P21 Harzburgite Microprobe Analyais & Calculated Formula (based on 6 Oxygens) of Pyroxene, (Mg, Fe)2SI206. 567 PX6-A1-C PX6-A2-R PX7-A1-C PX7-A2-R PX8-A1-C PX8-A2-R PX9-A1-C PX9-A2-R % Wt% Wt% Wt% Wt% W t% W t% W t% 56.305 56.763 56.106 56.898 56.943 56.087 55.618 56.012 1.519 1.222 1.668 1.691 1.436 1.398 1.591 1.506 0.000 0.012 0.037 0.000 0.052 0.000 0.003 0.040 0.494 0.316 0.618 0.557 0.501 0.472 0.588 0.608 5.491 5.682 5.370 5.574 5.415 5.520 5.455 5.423 33.578 34.006 34.000 34.318 34.335 33.786 33.693 33.491 0.158 0.120 0.160 0.141 0.156 0.096 0.124 0.147 0.129 0.098 0.136 0.061 0.078 0.145 0.069 0.089 0.996 0.586 0.830 0.781 0.726 0.646 0.574 1.291 0.026 0.034 0.000 0.000 0.000 0.000 0.016 0.000 98.696 98.839 98.925 100.021 99.642 98.150 97.731 98.607 57.049 57.430 56.716 56.886 57.148 57.144 56.909 56.803 1.539 1.236 1.686 1.691 1.441 1.424 1.628 1.527 0.000 0.012 0.037 0.000 0.052 0.000 0.003 0.041 0.501 0.320 0.625 0.557 0.503 0.481 0.602 0.617 5.564 5.749 5.428 5.573 5.434 5.624 5.582 5.500 34.022 34.405 34.369 34.311 34.458 34.423 34.475 33.964 0.160 0.121 0.162 0.141 0.157 0.098 0.127 0.149 0.131 0.099 0.137 0.061 0.078 0.148 0.071 0.090 1.009 0.593 0.839 0.781 0.729 0.658 0.587 1.309 0.026 0.034 0.000 0.000 0.000 0.000 0.016 0.000 1.966 1.976 1.954 1.959 1.966 1.967 1.959 1.959 0.063 0.050 0.068 0.069 0.058 0.058 0.066 0.062 0.000 0.000 0.001 0.000 0.001 0.000 0.000 0.001 0.014 0.009 0.017 0.015 0.014 0.013 0.016 0.017 0.160 0.165 0.156 0.160 0.156 0.162 0.161 0.159 1.748 1.765 1.765 1.761 1.767 1.766 1.769 1.747 0.005 0.004 0.005 0.004 0.005 0.003 0.004 0.004 0.004 0.003 0.004 0.002 0.002 0.004 0.002 0.003 0.037 0.022 0.031 0.029 0.027 0.024 0.022 0.048 0.001 0.001 0.000 0.000 0.000 0.000 0.001 0.000 3.996 3.994 4.002 3.999 3.997 3.998 4.000 4.000 91.597 91.430 91.861 91.649 91.872 91.604 91.674 91.673 89.843 90.406 90.404 90.296 90.607 90.465 90.656 89.402 8.242 8.474 8.010 8.227 8.016 8.291 8.234 8.121 1.915 1.120 1.586 1.477 1.377 1.243 1.110 2.477 568 PX10-A1-I PX9-A2-R PX11-A1-( PX11-A2-I PX12-A1-( PX12-A2-R % Wt % Wt % Wt % Wt % W t% 56.421 57.043 56.864 56.945 56.990 57.486 1.464 1.489 1.447 1.589 1.512 1.043 0.017 0.000 0.000 0.032 0.012 0.017 0.512 0.512 0.503 0.507 0.468 0.244 5.375 5.579 5.537 5.578 5.623 5.879 33.636 34.079 34.078 34.212 34.393 34.699 0.120 0.103 0.176 0.134 0.121 0.143 0.037 0.115 0.041 0.033 0.140 0.064 1.248 0.749 0.914 0.681 0.684 0.456 0.018 0.000 0.022 0.000 0.000 0.000 98.848 99.669 99.582 99.711 99.943 100.031 57.079 57.232 57.103 57.110 57.023 57.468 1.481 1.494 1.453 1.594 1.513 1.043 0.017 0.000 0.000 0.032 0.012 0.017 0.518 0.514 0.505 0.508 0.468 0.244 5.438 5.598 5.560 5.594 5.626 5.877 34.028 34.192 34.221 34.311 34.413 34.688 0.121 0.103 0.177 0.134 0.121 0.143 0.037 0.115 0.041 0.033 0.140 0.064 1.263 0.751 0.918 0.683 0.684 0.456 0.018 0.000 0.022 0.000 0.000 0.000 1.966 1.970 1.967 1.965 1.963 1.977 0.060 0.061 0.059 0.065 0.061 0.042 0.000 0.000 0.000 0.001 0.000 0.000 0.014 0.014 0.014 0.014 0.013 0.007 0.157 0.161 0.160 0.161 0.162 0.169 1.747 1.754 1.757 1.760 1.766 1.779 0.004 0.003 0.005 0.004 0.004 0.004 0.001 0.003 0.001 0.001 0.004 0.002 0.047 0.028 0.034 0.025 0.025 0.017 0.001 0.000 0.001 0.000 0.000 0.000 3.996 3.993 3.997 3.995 3.999 3.998 91.773 91.589 91.647 91.620 91.599 91.320 91.672 89.581 90.283 90.056 90.435 90.415 90.539 8.030 8.291 8.208 8.271 8.293 8.605 2.389 1.426 1.736 1.294 1.292 0.855 569 Label PX5-A1-C PX7-A1-C PX7-A2-R PX11-A1-CPX11-A2-R Enst Enst Enst Diop Diop O xides Wt. % Wt. % Wt. % Wt. % Wt. % 5102 56.511 56.729 57.381 55.556 55.989 AI203 0.956 0.871 0.983 0.760 0.446 TI02 0.052 0.000 0.020 0.000 0.012 C r203 0.384 0.341 0.336 0.393 0.083 FeO tot. 5.426 5.266 5.594 1.576 1.571 MgO 35.245 34.260 35.699 24.067 22.818 MnO 0.160 0.136 0.128 0.075 0.070 NiO 0.060 0.104 0.205 0.094 0.108 CaO 1.090 1.465 0.701 15.208 16.359 N a20 0.000 0.000 0.000 0.093 0.040 Total 99.884 99.172 101.047 97.822 97.496 Normalized oxides S i0 2 56.577 57.203 56.786 56.793 57.427 AI203 0.957 0.878 0.973 0.777 0.457 T i02 0.052 0.000 0.020 0.000 0.012 C r203 0.384 0.344 0.333 0.402 0.085 FeO tot. 5.432 5.310 5.536 1.611 1.611 MgO 35.286 34.546 35.329 24.603 23.404 MnO 0.160 0.137 0.127 0.077 0.072 NiO 0.060 0.105 0.203 0.096 0.111 CaO 1.091 1.477 0.694 15.547 16.779 N a20 0.000 0.000 0.000 0.095 0.041 100.000 100.000 100.000 100.000 100.000 C ations Si 1.952 1.971 1.958 2.000 2.025 AI 0.039 0.036 0.040 0.032 0.019 Ti 0.001 0.000 0.001 0.000 0.000 Cr 0.010 0.009 0.009 0.011 0.002 Fe 0.157 0.153 0.160 0.047 0.048 Mg 1.815 1.775 1.816 1.292 1.230 Mn 0.005 0.004 0.004 0.002 0.002 Ni 0.002 0.003 0.006 0.003 0.003 Ca 0.040 0.055 0.026 0.587 0.634 Na 0.000 0.000 0.000 0.003 0.001 Total 4.022 4.006 4.017 3.978 3.964 E nst Ave Dioo Ave M g# 92.050 92.062 91.920 92.011 96.457 96.281 96.369 En 90.205 89.529 90.743 67.074 64.355 Fs 7.790 7.720 7.977 2.464 2.486 Wo 2.005 2.751 1.281 30.462 33.160 Tabel C3.2: Sample Z7*P26 Harzburgite Microprobe Analysis & Calculated Formula (based on 6 Oxygens) of Pyroxene, (Mg, Fe)2Si206. 570 Label PX4-A1-C PX4-A2-R PX5-A1-C PX5-A2-R PX6-A1-C PX6-A2-R PX7-A1-C O xides w t% W t% W t% W t% W t% W t% W t% 8102 55.047 53.950 54.172 55.736 54.508 55.071 54.170 AI203 0.741 0.761 0.777 0.714 0.792 0.686 0.816 TI02 0.077 0.003 0.033 0.020 0.012 0.057 0.000 C r203 0.310 0.379 0.364 0.281 0.341 0.339 0.395 FeO tot. 5.865 6.152 5.797 6.185 6.278 6.062 6.076 MgO 34.897 34.887 34.325 34.950 34.689 35.703 34.807 MnO 0.142 0.129 0.127 0.167 0.159 0.170 0.139 NiO 0.024 0.112 0.078 0.070 0.104 0.051 0.065 CaO 0.823 0.796 1.609 0.295 0.618 0.280 1.070 N a20 0.000 0.031 0.007 0.000 0.000 0.000 0.000 Total 97.926 97.200 97.289 98.418 97.501 98.419 97.538 Normalized oxides 8102 56.213 55.504 55.682 56.632 55.905 55.956 55.537 AI203 0.757 0.783 0.799 0.725 0.812 0.697 0.837 TI02 0.079 0.003 0.034 0.020 0.012 0.058 0.000 C r203 0.317 0.390 0.374 0.286 0.350 0.344 0.405 FeO tot. 5.989 6.329 5.959 6.284 6.439 6.159 6.229 MgO 35.636 35.892 35.281 35.512 35.578 36.277 35.686 MnO 0.145 0.133 0.131 0.170 0.163 0.173 0.143 NIO 0.025 0.115 0.080 0.071 0.107 0.052 0.067 CaO 0.840 0.819 1.654 0.300 0.634 0.284 1.097 N a20 0.000 0.032 0.007 0.000 0.000 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 C ations 81 1.945 1.928 1.933 1.957 1.939 1.937 1.928 AI 0.031 0.032 0.033 0.030 0.033 0.028 0.034 TI 0.002 0.000 0.001 0.001 0.000 0.002 0.000 C r 0.009 0.011 0.010 0.008 0.010 0.009 0.011 Fe 0.173 0.184 0.173 0.182 0.187 0.178 0.181 Mg 1.838 1.858 1.826 1.829 1.839 1.872 1.847 Mn 0.004 0.004 0.004 0.005 0.005 0.005 0.004 Ni 0.001 0.003 0.002 0.002 0.003 0.001 0.002 Ca 0.031 0.030 0.062 0.011 0.024 0.011 0.041 Na 0.000 0.001 0.000 0.000 0.000 0.000 0.000 Total 4.033 4.051 4.044 4.024 4.039 4.043 4.049 M g# 91.384 90.998 91.346 90.969 90.783 91.303 91.081 En 89.990 89.660 88.619 90.470 89.740 90.836 89.284 F s 8.484 8.870 8.396 8.981 9.111 8.652 8.743 Wo 1.525 1.470 2.986 0.549 1.149 0.512 1.973 Tabel C3.3; Sample Z7-P31 Haaburgite Microprobe Analysis & Calculated Formula (based on 6 Oxygens) of Pyroxene, (Mg, Fe)2SI206. 571 PX7-A2-R PX8-A1-C PX8-A2-R PX9-A1-C PX9-A2-R PX10-A1-( PX10-A1-I PX11-A1-( % W t% W t% W t% W t% W t% W t% W t% 55.670 53.430 53.118 55.321 54.936 53.381 53.969 54.142 0.879 0.854 0.758 0.778 0.729 0.760 0.737 0.767 0.000 0.000 0.017 0.000 0.000 0.028 0.003 0.017 0.362 0.395 0.354 0.368 0.213 0.380 0.341 0.351 6.174 5.996 6.008 5.973 6.052 5.986 6.037 6.155 35.033 34.562 34.772 34.923 35.094 34.719 34.588 35.194 0.209 0.172 0.145 0.199 0.163 0.158 0.177 0.196 0.090 0.028 0.097 0.071 0.006 0.080 0.108 0.112 0.831 0.483 0.753 0.501 0.288 0.859 0.627 0.505 0.004 0.000 0.000 0.000 0.001 0.012 0.000 0.000 99.252 95.920 96.022 98.134 97.482 96.363 96.587 97.439 56.090 55.703 55.319 56.373 56.355 55.396 55.876 55.565 0.886 0.890 0.789 0.793 0.748 0.789 0.763 0.787 0.000 0.000 0.018 0.000 0.000 0.029 0.003 0.017 0.365 0.412 0.369 0.375 0.219 0.394 0.353 0.360 6.221 6.251 6.257 6.087 6.208 6.212 6.250 6.317 35.297 36.032 36.213 35.587 36.000 36.029 35.810 36.119 0.211 0.179 0.151 0.203 0.167 0.164 0.183 0.201 0.091 0.029 0.101 0.072 0.006 0.083 0.112 0.115 0.837 0.504 0.784 0.511 0.295 0.891 0.649 0.518 0.004 0.000 0.000 0.000 0.001 0.012 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.944 1.930 1.921 1.949 1.948 1.924 1.937 1.928 0.036 0.036 0.032 0.032 0.030 0.032 0.031 0.032 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.010 0.011 0.010 0.010 0.006 0.011 0.010 0.010 0.180 0.181 0.182 0.176 0.179 0.180 0.181 0.183 1.823 1.862 1.875 1.835 1.855 1.865 1.851 1.868 0.006 0.005 0.004 0.006 0.005 0.005 0.005 0.006 0.003 0.001 0.003 0.002 0.000 0.002 0.003 0.003 0.031 0.019 0.029 0.019 0.011 0.033 0.024 0.019 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 4.033 4.046 4.057 4.029 4.034 4.054 4.042 4.051 91.003 91.131 91.164 91.245 91.179 91.181 91.082 91.066 89.613 90.304 89.888 90.395 90.691 89.726 90.014 90.218 8.859 8.789 8.713 8.673 8.774 8.678 8.814 8.851 1.528 0.907 1.399 0.932 0.535 1.595 1.173 0.930 572 PX13-A1-( PX13-A2-I PX15-A1-( PX15-A2-I PX16-A1-( PX16-A2-R % W t% W t% W t% W t% W t% 54.395 53.612 55.045 54.273 53.056 52.747 0.722 0.680 0.684 0.639 0.818 0.799 0.020 0.000 0.000 0.020 0.110 0.062 0.345 0.351 0.316 0.241 0.341 0.362 6.493 5.978 5.962 6.077 6.281 6.094 34.975 34.078 35.331 34.495 34.988 34.701 0.170 0.168 0.142 0.178 0.147 0.173 0.080 0.060 0.023 0.115 0.115 0.060 0.271 1.612 0.428 0.281 0.560 0.525 0.000 0.000 0.000 0.001 0.000 0.000 97.471 96.539 97.931 96.320 96.416 95.523 55.806 55.534 56.208 56.347 55.028 55.219 0.741 0.704 0.698 0.663 0.848 0.836 0.021 0.000 0.000 0.021 0.114 0.065 0.354 0.364 0.323 0.250 0.354 0.379 6.661 6.192 6.088 6.309 6.514 6.380 35.882 35.300 36.077 35.813 36.289 36.327 0.174 0.174 0.145 0.185 0.152 0.181 0.082 0.062 0.023 0.119 0.119 0.063 0.278 1.670 0.437 0.292 0.581 0.550 0.000 0.000 0.000 0.001 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 1.936 1.931 1.944 1.949 1.914 1.918 0.030 0.029 0.028 0.027 0.035 0.034 0.001 0.000 0.000 0.001 0.003 0.002 0.010 0.010 0.009 0.007 0.010 0.010 0.193 0.180 0.176 0.183 0.189 0.185 1.856 1.830 1.860 1.847 1.881 1.881 0.005 0.005 0.004 0.005 0.004 0.005 0.002 0.002 0.001 0.003 0.003 0.002 0.010 0.062 0.016 0.011 0.022 0.020 0.000 0.000 0.000 0.000 0.000 0.000 4.043 4.049 4.038 4.033 4.061 4.058 A verge 90.568 91.041 91.352 91.006 90.851 91.032 91.084 90.113 88.308 90.631 90.524 89.911 90.140 9.385 8.690 8.580 8.946 9.055 8.880 0.502 3.002 0.789 0.530 1.034 0.980 573 Label PX1-A1-C PX1-A2-R PX2-A1-C PX2-A2-R PX3-A1-C PX3-A2-R PX4-A1-C O xides Wt% Wt% Wt% Wt% Wt% Wt% Wt% 8102 54.579 55.867 56.162 57.060 54.840 55.676 56.977 AI203 1.009 0.924 0.896 0.571 0.896 0.954 0.984 TI02 0.040 0.020 0.000 0.028 0.028 0.020 0.000 C r203 0.457 0.434 0.351 0.208 0.389 0.444 0.421 F eO tot 5.893 5.781 5.628 5.457 5.850 5.666 5.713 MgO 32.638 33.272 34.403 34.413 33.335 34.335 34.588 MnO 0.150 0.174 0.198 0.112 0.136 0.150 0.146 NIO 0.108 0.085 0.095 0.048 0.084 0.094 0.132 CaO 0.462 0.523 0.476 0.283 0.488 0.511 0.772 N a20 0.036 0.001 0.000 0.000 0.000 0.001 0.000 Total 95.372 97.081 98.209 98.180 96.046 97.851 99.733 Normalized oxides 8102 57.227 57.547 57.186 58.118 57.098 56.899 57.130 AI203 1.058 0.952 0.912 0.582 0.933 0.975 0.987 TI02 0.042 0.021 0.000 0.029 0.029 0.020 0.000 Cr203 0.479 0.447 0.357 0.212 0.405 0.454 0.422 FeOtot. 6.179 5.955 5.731 5.558 6.091 5.790 5.728 MgO 34.222 34.272 35.030 35.051 34.707 35.089 34.681 MnO 0.157 0.179 0.202 0.114 0.142 0.153 0.146 NIO 0.113 0.088 0.097 0.049 0.087 0.096 0.132 CaO 0.484 0.539 0.485 0.288 0.508 0.522 0.774 Na20 0.038 0.001 0.000 0.000 0.000 0.001 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 C ations 81 1.974 1.982 1.970 1.994 1.970 1.962 1.969 AI 0.043 0.039 0.037 0.024 0.038 0.040 0.040 TI 0.001 0.001 0.000 0.001 0.001 0.001 0.000 Cr 0.013 0.012 0.010 0.006 0.011 0.012 0.012 Fe 0.178 0.172 0.165 0.159 0.176 0.167 0.165 Mg 1.760 1.760 1.799 1.793 1.785 1.804 1.782 Mn 0.005 0.005 0.006 0.003 0.004 0.004 0.004 NI 0.003 0.002 0.003 0.001 0.002 0.003 0.004 Ca 0.018 0.020 0.018 0.011 0.019 0.019 0.029 Na 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.997 3.992 4.007 3.991 4.005 4.012 4.005 M g# 90.803 91.119 91.594 91.831 91.038 91.527 91.520 En 89.972 90.190 90.768 91.335 90.174 90.640 90.196 Fs 9.113 8.791 8.330 8.125 8.877 8.391 8.357 Wo 0.915 1.019 0.903 0.540 0.949 0.970 1.447 Tabel C3.4: Sample Z7P47 Hanburglte Microprobe Analysis & Calculatsd Formula (based on 6 Oxygens) of Pyroxene, (Mg, Fe)2Si206. 574 PX4-A2-R PX5-A1-C PX5-A2-R PX6-A1-C PX6-A2-R PX7-A1-C PX7-A2-R PX8-A1-C t% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 57.144 56.451 56.964 56.416 56.059 56.284 56.444 56.707 0.958 0.986 0.945 0.871 0.975 0.882 0.947 0.911 0.043 0.000 0.017 0.000 0.037 0.028 0.000 0.040 0.450 0.419 0.409 0.443 0.433 0.457 0.421 0.417 5.522 5.796 5.608 5.856 5.865 5.799 5.986 5.635 34.607 34.147 32.789 33.386 33.942 33.263 33.436 33.726 0.118 0.137 0.096 0.119 0.156 0.128 0.179 0.129 0.078 0.059 0.095 0.168 0.070 0.085 0.116 0.085 0.558 0.645 2.001 0.494 0.530 0.660 0.799 1.750 0.000 0.005 0.001 0.000 0.000 0.013 0.026 0.000 99.478 98.645 98.925 97.753 98.067 97.599 98.354 99.400 57.444 57.226 57.583 57.713 57.164 57.669 57.389 57.049 0.963 1.000 0.955 0.891 0.994 0.904 0.963 0.916 0.043 0.000 0.017 0.000 0.038 0.029 0.000 0.040 0.452 0.425 0.413 0.453 0.442 0.468 0.428 0.420 5.551 5.876 5.669 5.991 5.981 5.942 6.086 5.669 34.789 34.616 33.145 34.153 34.611 34.081 33.996 33.930 0.119 0.139 0.097 0.122 0.159 0.131 0.182 0.130 0.078 0.060 0.096 0.172 0.071 0.087 0.118 0.086 0.561 0.654 2.023 0.505 0.540 0.676 0.812 1.761 0.000 0.005 0.001 0.000 0.000 0.013 0.026 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.976 1.972 1.987 1.987 1.971 1.986 1.980 1.971 0.039 0.041 0.039 0.036 0.040 0.037 0.039 0.037 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.001 0.012 0.012 0.011 0.012 0.012 0.013 0.012 0.011 0.160 0.169 0.164 0.173 0.172 0.171 0.176 0.164 1.784 1.778 1.705 1.753 1.779 1.750 1.749 1.748 0.003 0.004 0.003 0.004 0.005 0.004 0.005 0.004 0.002 0.002 0.003 0.005 0.002 0.002 0.003 0.002 0.021 0.024 0.075 0.019 0.020 0.025 0.030 0.065 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 3.998 4.002 3.987 3.988 4.002 3.989 3.995 4.004 91.784 91.306 91.245 91.042 91.163 91.091 90.873 91.430 90.818 90.188 87.734 90.169 90.240 89.923 89.477 88.416 8.129 8.588 8.418 8.872 8.747 8.794 8.986 8.287 1.052 1.224 3.848 0.959 1.013 1.282 1.537 3.297 575 PX9-A2-R PX10-A1-( PX10-A2-I PX11-A1-( PX12-A1-( PX12-A2-I PX13-AM PX13-A2-f % Wt % Wt % Wt % Wt % Wt % W t% Wt% 56.908 56.979 56.196 55.980 56.782 56.754 53.657 55.845 0.765 0.979 0.862 0.958 0.926 0.771 0.892 0.894 0.040 0.020 0.000 0.043 0.000 0.000 0.060 0.000 0.285 0.450 0.462 0.533 0.389 0.272 0.300 0.393 5.672 5.712 5.329 5.762 5.599 5.914 6.014 5.713 34.199 33.781 32.202 33.461 34.461 34.398 33.660 33.086 0.150 0.150 0.189 0.159 0.154 0.138 0.204 0.179 0.102 0.098 0.141 0.065 0.060 0.132 0.122 0.098 0.511 0.625 2.374 0.735 0.515 0.369 0.393 0.539 0.000 0.000 0.000 0.015 0.009 0.000 0.000 0.000 98.632 98.794 97.755 97.711 98.895 98.748 95.302 96.747 57.697 57.675 57.487 57.291 57.416 57.474 56.302 57.723 0.776 0.991 0.882 0.980 0.936 0.781 0.936 0.924 0.041 0.020 0.000 0.044 0.000 0.000 0.063 0.000 0.289 0.455 0.473 0.545 0.393 0.275 0.315 0.406 5.751 5.782 5.451 5.897 5.662 5.989 6.310 5.905 34.673 34.193 32.942 34.245 34.846 34.834 35.319 34.198 0.152 0.152 0.193 0.163 0.156 0.140 0.214 0.185 0.103 0.099 0.144 0.067 0.061 0.134 0.128 0.101 0.518 0.633 2.429 0.752 0.521 0.374 0.412 0.557 0.000 0.000 0.000 0.015 0.009 0.000 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.985 1.985 1.986 1.975 1.976 1.979 1.948 1.987 0.031 0.040 0.036 0.040 0.038 0.032 0.038 0.037 0.001 0.001 0.000 0.001 0.000 0.000 0.002 0.000 0.008 0.012 0.013 0.015 0.011 0.008 0.009 0.011 0.165 0.166 0.158 0.170 0.163 0.172 0.183 0.170 1.778 1.754 1.697 1.760 1.787 1.788 1.822 1.755 0.004 0.004 0.006 0.005 0.005 0.004 0.006 0.005 0.003 0.003 0.004 0.002 0.002 0.004 0.004 0.003 0.019 0.023 0.090 0.028 0.019 0.014 0.015 0.021 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.000 3.995 3.989 3.989 3.996 4.000 4.001 4.027 3.989 91.488 91.338 91.505 91.191 91.647 91.204 90.890 91.189 90.598 90.240 87.274 89.897 90.754 90.567 90.202 90.206 8.429 8.560 8.102 8.684 8.272 8.735 9.041 8.738 0.973 1.200 4.624 1.419 0.975 0.698 0.757 1.056 576 PX14-A1-{ PX14-A2-I PX15-A1-( PX16-A1-C % Wt % Wt % Wt % 55.535 54.463 56.953 56.196 0.886 0.801 0.911 0.913 0.003 0.023 0.000 0.000 0.355 0.257 0.469 0.487 5.727 5.941 5.729 5.581 33.335 33.204 34.499 34.124 0.152 0.165 0.169 0.119 0.090 0.088 0.116 0.094 1.277 0.456 0.586 0.613 0.003 0.000 0.000 0.000 97.363 95.398 99.432 98.127 57.039 57.090 57.278 57.269 0.910 0.840 0.916 0.930 0.003 0.024 0.000 0.000 0.365 0.269 0.472 0.496 5.882 6.228 5.762 5.688 34.238 34.806 34.696 34.775 0.156 0.173 0.170 0.121 0.092 0.092 0.117 0.096 1.312 0.478 0.589 0.625 0.003 0.000 0.000 0.000 100.000 100.000 100.000 100.000 1.970 1.970 1.973 1.972 0.037 0.034 0.037 0.038 0.000 0.001 0.000 0.000 0.010 0.007 0.013 0.014 0.170 0.180 0.166 0.164 1.763 1.791 1.782 1.785 0.005 0.005 0.005 0.004 0.003 0.003 0.003 0.003 0.049 0.018 0.022 0.023 0.000 0.000 0.000 0.000 4.006 4.008 4.002 4.002 A v#m g# 91.209 90.878 91.478 91.596 91.295 88.975 90.070 90.468 90.526 8.575 9.041 8.428 8.306 2.450 0.889 1.104 1.169 577 Label H9-WI5, circle 1, pyx Un 170 H9-WI5, cIrclUn 173 H9-WI5, circlUn 174 H Al'Hel Px 9WI5PX2 9WI5PX3 9WI5PX4 9WI5PX5 9WI5PX6 9WI5PX7 O xides W t% W t% W t% W t% W t% W t% W t% S I02 56.782 56.247 55.820 56.299 55.144 55.726 57.088 AI203 1.354 1.297 1.367 1.333 1.187 1.242 1.410 TI02 0.013 0.014 0.002 0.010 0.019 0.024 0.017 C r203 0.518 0.483 0.463 0.455 0.529 0.441 0.562 F e O to t 5.867 5.947 6.014 5.890 5.759 5.834 5.963 MgO 34.330 33.825 33.733 33.812 32.941 33.986 34.294 MnO 0.119 0.204 0.143 0.144 0.150 0.140 0.102 NIO 0.072 0.101 0.119 0.096 0.070 0.071 0.091 CaO 0.850 1.117 0.808 1.180 2.333 0.846 0.701 N a20 0.041 0.000 0.003 0.000 0.003 0.000 0.000 Total 99.947 99.234 98.472 99.219 98.133 98.312 100.228 Normalized oxides S I02 56.812 56.682 56.686 56.743 56.192 56.683 56.958 AI203 1.355 1.307 1.388 1.343 1.209 1.264 1.407 TI02 0.013 0.014 0.002 0.010 0.020 0.025 0.017 C r203 0.519 0.487 0.471 0.459 0.539 0.449 0.560 F e O to t 5.870 5.993 6.108 5.936 5.869 5.934 5.950 MgO 34.348 34.086 34.256 34.078 33.567 34.569 34.216 MnO 0.119 0.205 0.146 0.145 0.152 0.143 0.102 NIO 0.072 0.102 0.121 0.097 0.071 0.073 0.091 CaO 0.851 1.125 0.820 1.189 2.377 0.861 0.700 N a20 0.041 0.000 0.003 0.000 0.003 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 C atio n s Si 1.960 1.960 1.958 1.960 1.950 1.957 1.964 AI 0.055 0.053 0.057 0.055 0.049 0.051 0.057 TI 0.000 0.000 0.000 0.000 0.001 0.001 0.000 Cr 0.014 0.013 0.013 0.013 0.015 0.012 0.015 Fe 0.169 0.173 0.176 0.172 0.170 0.171 0.172 Mg 1.767 1.757 1.764 1.755 1.737 1.779 1.759 Mn 0.003 0.006 0.004 0.004 0.004 0.004 0.003 Ni 0.002 0.003 0.003 0.003 0.002 0.002 0.003 Ca 0.031 0.042 0.030 0.044 0.088 0.032 0.026 Na 0.001 0.000 0.000 0.000 0.000 0.000 0.000 Total 4.005 4.007 4.007 4.006 4.017 4.010 3.999 M g# 91.252 91.023 90.907 91.098 91.068 91.216 91.112 En 89.793 89.099 89.507 89.063 87.034 89.751 89.908 Fs 8.608 8.787 8.953 8.703 8.536 8.643 8.770 Wo 1.598 2.114 1.540 2.233 4.430 1.606 1.322 Tabel C3.5: Collective analytee. Al'Hel Field Microprobe Analyeie & Calculated Formula (baaed on 6 Oxygene) of Pyroxene, (Mg, Fe)2SI206. 578 9-WI5, CirclUn 181 H Un 184 H9-WI5, circiUn 186 H9-WI5, circle 11. pyx Un 191 H 9WI5PX8 9WI5PX9 9WI5Px10 9WI5Px11 9WI5Px12 9WI5Px13 9WI5Px14 9WI5Px15 % W t% W t% W t% W t% W t% W t% W t% 54.849 54.882 54.775 54.395 54.118 54.328 54.194 54.656 1.273 1.229 1.356 1.475 1.355 1.361 1.348 1.390 0.010 0.000 0.017 0.009 0.019 0.014 0.018 0.018 0.494 0.440 0.474 0.617 0.534 0.529 0.511 0.526 5.863 5.851 5.753 5.957 5.436 5.996 5.882 5.902 33.568 33.437 33.522 33.415 30.493 33.290 33.377 33.476 0.144 0.136 0.176 0.170 0.166 0.085 0.158 0.118 0.076 0.065 0.092 0.126 0.088 0.098 0.055 0.099 0.869 1.194 0.845 0.855 4.001 0.779 0.788 1.147 0.000 0.010 0.005 0.000 0.000 0.000 0.017 0.000 97.147 97.243 97.014 97.020 96.210 96.479 96.347 97.331 56.460 56.437 56.461 56.066 56.249 56.311 56.249 56.155 1.310 1.264 1.398 1.521 1.408 1.411 1.399 1.428 0.010 0.000 0.018 0.009 0.020 0.014 0.018 0.018 0.509 0.453 0.489 0.636 0.555 0.548 0.530 0.541 6.035 6.017 5.930 6.140 5.651 6.215 6.105 6.064 34.554 34.385 34.553 34.441 31.694 34.505 34.642 34.394 0.149 0.139 0.181 0.176 0.173 0.088 0.164 0.121 0.078 0.066 0.094 0.130 0.092 0.101 0.057 0.101 0.894 1.228 0.871 0.881 4.159 0.807 0.817 1.179 0.000 0.010 0.005 0.000 0.000 0.000 0.018 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.952 1.952 1.951 1.942 1.958 1.948 1.946 1.944 0.053 0.052 0.057 0.062 0.058 0.058 0.057 0.058 0.000 0.000 0.000 0.000 0.001 0.000 0.000 0.000 0.014 0.012 0.013 0.017 0.015 0.015 0.015 0.015 0.174 0.174 0.171 0.178 0.165 0.180 0.177 0.176 1.781 1.773 1.780 1.778 1.645 1.779 1.786 1.775 0.004 0.004 0.005 0.005 0.005 0.003 0.005 0.004 0.002 0.002 0.003 0.004 0.003 0.003 0.002 0.003 0.033 0.046 0.032 0.033 0.155 0.030 0.030 0.044 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 4.014 4.016 4.013 4.019 4.004 4.015 4.018 4.019 91.077 91.061 91.218 90.908 90.908 90.823 91.003 91.000 89.560 88.981 89.734 89.413 83.729 89.457 89.620 89.005 8.775 8.735 8.639 8.942 8.374 9.039 8.860 8.803 1.665 2.284 1.626 1.645 7.897 1.504 1.520 2.192 579 Un 192 H9-WI6, circle 2, middle and rim of 2 mm pyx for line scan Un 193 H 9WI6PX1 9WI6PX2 9WI6PX3 9WI6PX4 9WI6PX5 9WI6PX6 9WI6PX7 9WI6PX8 W t% W t% W t% W t% W t% W t% W t% W t% 55.865 54.522 57.513 55.057 57.292 57.048 55.962 56.975 1.511 1.344 1.580 1.421 1.492 1.571 1.443 1.412 0.007 0.009 0.021 0.022 0.014 0.017 0.012 0.016 0.577 0.524 0.524 0.516 0.590 0.596 0.535 0.402 5.981 5.801 5.806 5.863 5.620 5.546 5.590 5.973 34.186 33.121 34.568 33.468 34.715 34.473 33.820 34.802 0.144 0.108 0.138 0.163 0.132 0.103 0.182 0.142 0.099 0.087 0.055 0.080 0.032 0.107 0.111 0.071 0.984 1.047 1.544 1.205 1.585 1.639 1.148 0.820 0.004 0.000 0.000 0.000 0.000 0.000 0.001 0.000 99.357 96.563 101.749 97.796 101.472 101.101 98.804 100.613 56.226 56.463 56.524 56.297 56.461 56.427 56.640 56.627 1.520 1.391 1.553 1.453 1.470 1.554 1.460 1.404 0.007 0.009 0.021 0.023 0.014 0.017 0.012 0.016 0.580 0.542 0.515 0.528 0.581 0.590 0.542 0.400 6.020 6.007 5.706 5.996 5.539 5.486 5.658 5.937 34.408 34.300 33.974 34.222 34.211 34.098 34.229 34.590 0.145 0.112 0.136 0.167 0.130 0.102 0.184 0.141 0.100 0.091 0.054 0.082 0.031 0.106 0.113 0.071 0.990 1.085 1.517 1.232 1.562 1.621 1.162 0.815 0.004 0.000 0.000 0.000 0.000 0.000 0.001 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.945 1.952 1.953 1.948 1.951 1.950 1.956 1.955 0.062 0.057 0.063 0.059 0.060 0.063 0.059 0.057 0.000 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.016 0.015 0.014 0.014 0.016 0.016 0.015 0.011 0.174 0.174 0.165 0.174 0.160 0.159 0.163 0.171 1.775 1.768 1.750 1.765 1.762 1.756 1.762 1.780 0.004 0.003 0.004 0.005 0.004 0.003 0.005 0.004 0.003 0.003 0.002 0.002 0.001 0.003 0.003 0.002 0.037 0.040 0.056 0.046 0.058 0.060 0.043 0.030 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 4.016 4.012 4.006 4.014 4.011 4.010 4.007 4.011 91.063 91.054 91.390 91.051 91.674 91.722 91.514 91.218 89.379 89.208 88.785 88.955 88.997 88.934 89.515 89.830 8.772 8.764 8.365 8.743 8.083 8.027 8.301 8.649 1.849 2.028 2.850 2.302 2.920 3.039 2.184 1.521 580 Un 194 H9-WI6, circlUn 198 H9-WI6, circlUn 200 H9-WI6, circiH9-WI6, ci H8-I1, amp 9WI6PX9 9WI6PX10 9WI6PX11 9WI6Px12 9WI6Px13 9WI6Px14 9WI6Px15 811 Px1 Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 55.739 55.518 55.482 55.969 55.631 57.117 56.873 55.767 1.436 1.476 1.676 1.634 1.590 1.472 1.313 2.687 0.011 0.025 0.022 0.022 0.012 0.022 0.025 0.094 0.523 0.553 0.644 0.611 0.584 0.431 0.373 0.996 5.746 5.562 5.711 5.633 5.423 6.067 5.714 1.406 33.705 33.977 33.944 34.396 32.599 34.596 34.880 22.956 0.165 0.183 0.170 0.125 0.127 0.175 0.120 0.000 0.072 0.084 0.085 0.083 0.084 0.096 0.082 0.107 1.233 1.079 1.605 1.196 3.773 0.840 0.496 13.164 0.019 0.000 0.025 0.016 0.003 0.000 0.009 0.249 98.650 98.456 99.365 99.685 99.825 100.816 99.884 97.427 56.502 56.389 55.837 56.145 55.729 56.654 56.939 57.240 1.456 1.499 1.686 1.640 1.593 1.460 1.314 2.758 0.012 0.025 0.022 0.022 0.012 0.022 0.025 0.096 0.530 0.562 0.648 0.613 0.585 0.428 0.373 1.023 5.825 5.649 5.748 5.651 5.433 6.018 5.720 1.443 34.167 34.510 34.161 34.505 32.656 34.316 34.920 23.562 0.167 0.185 0.171 0.125 0.127 0.173 0.120 0.000 0.073 0.085 0.086 0.083 0.084 0.095 0.082 0.109 1.250 1.096 1.615 1.200 3.780 0.834 0.497 13.511 0.019 0.000 0.025 0.016 0.003 0.000 0.009 0.256 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.953 1.948 1.935 1.941 1.939 1.957 1.961 1.998 0.059 0.061 0.069 0.067 0.065 0.059 0.053 0.113 0.000 0.001 0.001 0.001 0.000 0.001 0.001 0.003 0.014 0.015 0.018 0.017 0.016 0.012 0.010 0.028 0.168 0.163 0.167 0.163 0.158 0.174 0.165 0.042 1.761 1.777 1.765 1.778 1.694 1.767 1.793 1.226 0.005 0.005 0.005 0.004 0.004 0.005 0.003 0.000 0.002 0.002 0.002 0.002 0.002 0.003 0.002 0.003 0.046 0.041 0.060 0.044 0.141 0.031 0.018 0.505 0.001 0.000 0.001 0.001 0.000 0.000 0.000 0.009 4.010 4.013 4.021 4.017 4.020 4.007 4.007 3.928 91.271 91.590 91.375 91.585 91.464 91.044 91.584 98.878 89.132 89.715 88.623 89.536 84.997 89.619 90.734 69.133 8.524 8.238 8.365 8.226 7.933 8.816 8.338 2.375 2.344 2.047 3.012 2.238 7.071 1.565 0.928 28.492 581 I (784) & py H8-I2, pyx H8-I2, circl H9-I2, pyroxenes & 2 amp (951,952) Px2 8l2Px1 8l2Px2 9l2Px1 9l2Px2 9l2Px3 9l2Px4 9l2Px5 % W t% Wt% Wt% Wt% Wt% W t% W t% 53.108 52.708 52.929 52.393 53.967 51.959 52.566 53.514 1.209 1.868 2.296 2.702 1.078 2.602 2.239 2.007 0.065 0.047 0.088 0.680 0.286 0.721 0.610 0.449 0.752 1.039 1.008 0.812 0.507 0.669 0.804 0.553 1.501 1.621 1.592 3.181 3.151 3.538 3.532 3.770 17.600 17.774 18.257 16.501 16.916 16.017 16.131 16.467 0.043 0.062 0.004 0.103 0.138 0.115 0.139 0.148 0.050 0.034 0.007 0.048 0.039 0.034 0.016 0.021 24.672 21.699 22.989 23.183 23.309 23.090 23.668 23.008 0.083 0.250 0.364 0.277 0.285 0.322 0.267 0.299 99.084 97.101 99.535 99.882 99.675 99.067 99.974 100.237 53.599 54.281 53.176 52.455 54.142 52.448 52.580 53.388 1.220 1.923 2.307 2.706 1.082 2.627 2.240 2.002 0.066 0.048 0.089 0.681 0.287 0.728 0.610 0.448 0.759 1.070 1.013 0.813 0.508 0.675 0.804 0.552 1.515 1.670 1.599 3.185 3.161 3.571 3.533 3.761 17.763 18.305 18.342 16.520 16.971 16.168 16.136 16.429 0.044 0.064 0.004 0.103 0.138 0.116 0.139 0.147 0.051 0.035 0.007 0.048 0.039 0.034 0.016 0.021 24.900 22.347 23.096 23.211 23.385 23.307 23.674 22.954 0.084 0.258 0.366 0.278 0.286 0.325 0.267 0.299 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.950 1.959 1.927 1.916 1.973 1.920 1.927 1.950 0.052 0.082 0.099 0.116 0.046 0.113 0.097 0.086 0.002 0.001 0.002 0.019 0.008 0.020 0.017 0.012 0.022 0.031 0.029 0.023 0.015 0.020 0.023 0.016 0.046 0.050 0.048 0.097 0.096 0.109 0.108 0.115 0.963 0.985 0.991 0.900 0.922 0.882 0.881 0.894 0.001 0.002 0.000 0.003 0.004 0.004 0.004 0.005 0.001 0.001 0.000 0.001 0.001 0.001 0.000 0.001 0.970 0.864 0.897 0.908 0.913 0.914 0.929 0.898 0.003 0.009 0.013 0.010 0.010 0.012 0.009 0.011 4.011 3.984 4.007 3.995 3.989 3.994 3.997 3.987 95.435 95.132 95.337 90.240 90.540 88.975 89.059 88.819 48.655 51.852 51.180 47.216 47.736 46.297 45.928 46.892 2.327 2.654 2.503 5.107 4.988 5.737 5.642 6.022 49.018 45.495 46.317 47.677 47.276 47.966 48.430 47.086 582 H9-12, chrcH9-l2, pyx >Px6 9l2Px7 9l2Px8 9l2Px9 i% W t% W t% W t% 53.046 52.217 53.226 52.246 0.991 2.907 1.729 2.813 0.075 0.702 0.409 0.720 0.351 0.881 0.644 0.639 1.599 3.761 3.105 3.055 17.319 17.288 16.792 16.897 0.065 0.155 0.115 0.119 0.032 0.048 0.006 0.005 25.294 21.380 23.879 22.924 0.109 0.381 0.198 0.286 98.881 99.720 100.103 99.704 53.646 52.363 53.171 52.401 1.002 2.916 1.728 2.821 0.076 0.704 0.409 0.722 0.355 0.884 0.643 0.641 1.617 3.772 3.102 3.064 17.515 17.336 16.775 16.947 0.066 0.156 0.115 0.119 0.032 0.048 0.006 0.005 25.580 21.440 23.854 22.992 0.110 0.382 0.198 0.287 100.000 100.000 100.000 100.000 1.955 1.910 1.943 1.912 0.043 0.125 0.074 0.121 0.002 0.019 0.011 0.020 0.010 0.025 0.019 0.018 0.049 0.115 0.095 0.093 0.951 0.943 0.914 0.922 0.002 0.005 0.004 0.004 0.001 0.001 0.000 0.000 0.999 0.838 0.934 0.899 0.004 0.014 0.007 0.010 4.016 3.995 4.000 3.999 95.076 89.123 90.602 90.791 47.587 49.730 47.043 48.159 2.465 6.069 4.880 4.884 49.948 44.201 48.077 46.957 583 Label Z9-P5, circle 3, two dk Z9-P6, 3 ol and 2 py (i Un 65 Z9-P6, pyx In circle 1 Palace 9P5Px1 9P5Px2 9P6Px1 9P6Px2 9P6PX3 9P6Px4 9P6Px5 Oxides W t% W t% W t% W t% W t% W t% W t% SI02 54.380 54.283 57.435 58.124 56.657 57.276 57.364 AI2G3 0.942 0.299 1.001 1.117 1.201 1.089 1.089 Ti02 0.048 0.037 0.026 0.023 0.000 0.013 0.017 Cr203 0.529 0.109 0.318 0.416 0.461 0.431 0.505 FeOtot. 1.302 1.103 5.187 5.141 5.346 5.133 5.135 MgO 17.195 17.650 35.677 35.648 35.701 35.919 35.222 MnO 0.022 0.030 0.107 0.143 0.142 0.126 0.137 NIO 0.046 0.067 0.062 0.072 0.090 0.084 0.119 CaO 25.192 25.391 0.639 0.861 0.303 0.587 1.040 N a20 0.201 0.011 0.000 0.000 0.001 0.010 0.001 Total 99.856 98.981 100.452 101.545 99.902 100.667 100.627 Normalized oxides Si02 54.458 54.842 57.177 57.239 56.713 56.896 57.006 AI203 0.944 0.302 0.997 1.100 1.202 1.081 1.083 Ti02 0.048 0.037 0.026 0.022 0.000 0.013 0.017 Cr203 0.530 0.111 0.317 0.409 0.461 0.428 0.501 FeOtot. 1.303 1.114 5.164 5.063 5.351 5.099 5.103 MgO 17.219 17.832 35.516 35.105 35.736 35.681 35.002 MnO 0.022 0.030 0.106 0.141 0.143 0.125 0.136 NiO 0.046 0.067 0.062 0.071 0.090 0.083 0.118 CaO 25.228 25.653 0.636 0.848 0.303 0.583 1.033 Na20 0.201 0.011 0.000 0.000 0.001 0.010 0.001 100.000 100.000 100.000 100.000 100.000 100.000 100.000 Cations Si 1.976 1.988 1.965 1.967 1.952 1.956 1.962 Al 0.040 0.013 0.040 0.045 0.049 0.044 0.044 Ti 0.001 0.001 0.001 0.001 0.000 0.000 0.000 Cr 0.015 0.003 0.009 0.011 0.013 0.012 0.014 Fe 0.040 0.034 0.148 0.145 0.154 0.147 0.147 Mg 0.932 0.964 1.819 1.798 1.833 1.829 1.796 Mn 0.001 0.001 0.003 0.004 0.004 0.004 0.004 Ni 0.001 0.002 0.002 0.002 0.002 0.002 0.003 Ca 0.981 0.996 0.023 0.031 0.011 0.021 0.038 Na 0.007 0.000 0.000 0.000 0.000 0.000 0.000 Total 3.995 4.003 4.010 4.005 4.018 4.016 4.009 M g# 95.926 96.613 92.459 92.515 92.251 92.578 92.440 En 47.723 48.333 91.372 91.052 91.735 91.582 90.662 Fs 2.027 1.694 7.452 7.366 7.706 7.342 7.415 Wo 50.251 49.972 1.176 1.581 0.559 1.076 1.923 Tabel C3.6: CoHacUve analysa*, E. Zlkt Fiald Microproba Analysis & Caleulatad Formula (basad on 6 Oxygans) of Pyroxana, (Mg, Fa)2Si206. 584 Z9-P6, pyxZ9-P6, pyxZ9-P6, pyxZ9-P6, pyxZ9-P6, pyxZ9-P6, pyxZ9-P6, pyx, circle 10 9P6PX6 9P6Px7 9P6Px8 9P6Px9 9P6PX10 9P6Px11 9P6PX12 W t% W t% W t% W t% W t% W t% W t% 57.356 56.909 56.880 56.641 55.851 56.393 56.023 1.095 0.961 1.063 1.053 1.134 1.187 1.271 0.017 0.019 0.023 0.013 0.016 0.011 0.005 0.452 0.351 0.453 0.368 0.466 0.488 0.514 5.209 5.086 5.100 5.281 4.893 5.228 4.982 35.544 35.285 35.477 35.569 35.014 35.212 35.275 0.118 0.137 0.174 0.144 0.130 0.122 0.089 0.089 0.100 0.065 0.100 0.068 0.098 0.091 0.926 0.830 0.868 0.796 0.677 1.040 0.826 0.000 0.008 0.000 0.000 0.004 0.000 0.000 100.806 99.687 100.103 99.965 98.251 99.779 99.074 56.897 57.088 56.821 56.660 56.845 56.518 56.546 1.086 0.964 1.062 1.053 1.154 1.190 1.283 0.017 0.019 0.023 0.013 0.016 0.011 0.005 0.448 0.352 0.453 0.368 0.474 0.489 0.518 5.167 5.102 5.094 5.283 4.980 5.239 5.028 35.260 35.395 35.441 35.581 35.637 35.290 35.605 0.117 0.137 0.174 0.144 0.132 0.123 0.090 0.088 0.100 0.065 0.100 0.069 0.098 0.092 0.919 0.833 0.867 0.796 0.689 1.042 0.833 0.000 0.009 0.000 0.000 0.004 0.000 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.958 1.963 1.956 1.952 1.954 1.949 1.946 0.044 0.039 0.043 0.043 0.047 0.048 0.052 0.000 0.001 0.001 0.000 0.000 0.000 0.000 0.012 0.010 0.012 0.010 0.013 0.013 0.014 0.149 0.147 0.147 0.152 0.143 0.151 0.145 1.809 1.815 1.819 1.827 1.827 1.814 1.827 0.003 0.004 0.005 0.004 0.004 0.004 0.003 0.002 0.003 0.002 0.003 0.002 0.003 0.003 0.034 0.031 0.032 0.029 0.025 0.038 0.031 0.000 0.000 0.000 0.000 0.000 0.000 0.000 4.013 4.012 4.016 4.021 4.015 4.020 4.020 92.404 92.519 92.538 92.311 92.731 92.312 92.659 90.832 91.094 91.056 90.961 91.551 90.538 91.237 7.467 7.366 7.343 7.577 7.177 7.541 7.228 1.701 1.540 1.602 1.463 1.272 1.921 1.535 585 Label Z8-Sh11, cZ8-Sh11, cZ8-Sh11, circle 4, pyx Sharq 8Sh1lPx1 8Sh11Px2 8Sh11Px3 8Sh11Px4 Oxides W t% W t% W t% W t% 8102 57.951 57.230 57.089 57.702 AI203 0.649 0.653 0.649 0.579 Ti02 0.020 0.000 0.000 0.023 Cr203 0.304 0.332 0.320 0.317 FeOtot. 5.179 4.988 4.980 5.003 MgO 35.471 35.785 35.458 35.335 MnO 0.127 0.158 0.115 0.106 NiO 0.072 0.074 0.087 0.094 CaO 0.970 0.616 0.669 1.177 N a20 0.000 0.010 0.000 0.007 Total 100.742 99.846 99.367 100.343 Normalized oxides Si02 57.524 57.318 57.453 57.504 AI203 0.645 0.654 0.653 0.577 Ti02 0.019 0.000 0.000 0.022 Cr203 0.302 0.333 0.322 0.316 FeOtot. 5.141 4.996 5.011 4.986 MgO 35.209 35.840 35.684 35.214 MnO 0.126 0.158 0.116 0.106 NiO 0.071 0.074 0.087 0.094 CaO 0.963 0.617 0.673 1.173 Na20 0.000 0.010 0.000 0.007 100.000 100.000 100.000 100.000 Cations Si 1.977 1.969 1.973 1.977 Al 0.026 0.026 0.026 0.023 Ti 0.001 0.000 0.000 0.001 Cr 0.008 0.009 0.009 0.009 Fe 0.148 0.144 0.144 0.143 Mg 1.804 1.835 1.827 1.805 Mn 0.004 0.005 0.003 0.003 Ni 0.002 0.002 0.002 0.003 Ca 0.035 0.023 0.025 0.043 Na 0.000 0.000 0.000 0.000 Total 4.005 4.013 4.009 4.007 M g# 92.430 92.748 92.697 92.641 En 90.781 91.695 91.546 90.631 Fs 7.435 7.170 7.212 7.199 Wo 1.784 1.135 1.241 2.171 Tabel C3.7: Collective analyeee, B. Sharq (S. Zlkt) Fiald Microprobe Analyaia & Calculated Formula (baeed on 6 Oxygéna) of Pyroxene, (Mg, Fe)2SI206. 586 Label Z9-Sc2, circle 1, pyx Un 52 Z9*Sc2, circle Un 54 Z9-Sc2, circle Un 55 ZS Scorpion 9Sc2Px1 9Sc2Px2 9Sc2Px3 9Sc2Px4 9Sc2Px5 9Sc2Px6 9Sc2Px7 Oxides W t% Wt% Wt% Wt% Wt% W t% W t% Si02 57.054 57.223 57.111 57.513 57.342 58.013 57.830 AI203 0.439 0.424 0.416 0.416 0.418 0.453 0.435 Ti02 0.000 0.000 0.000 0.000 0.000 0.018 0.005 Cr203 0.241 0.223 0.245 0.254 0.240 0.261 0.239 FeOlot. 5.344 5.189 5.495 5.394 5.254 5.366 5.283 MgO 35.217 34.836 35.527 35.193 35.259 35.447 35.567 MnO 0.130 0.124 0.139 0.141 0.122 0.134 0.152 NiO 0.100 0.092 0.094 0.063 0.083 0.099 0.099 CaO 0.752 1.018 0.550 0.794 0.724 0.607 0.835 N a20 0.007 0.013 0.000 0.000 0.012 0.004 0.000 Total 99.284 99.142 99.578 99.768 99.454 100.402 100.446 Normalized oxides Si02 57.465 57.718 57.353 57.647 57.657 57.780 57.573 AI203 0.442 0.428 0.418 0.417 0.420 0.452 0.433 Ti02 0.000 0.000 0.000 0.000 0.000 0.018 0.005 Cr203 0.243 0.225 0.246 0.255 0.242 0.260 0.238 FeOtot. 5.383 5.234 5.518 5.407 5.283 5.344 5.260 MgO 35.471 35.137 35.677 35.275 35.452 35.305 35.409 MnO 0.131 0.125 0.140 0.142 0.123 0.133 0.151 NiO 0.101 0.093 0.095 0.063 0.083 0.099 0.099 CaO 0.758 1.026 0.553 0.795 0.728 0.604 0.832 N a20 0.007 0.013 0.000 0.000 0.012 0.004 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 Cations Si 1.977 1.984 1.974 1.983 1.982 1.985 1.980 AI 0.018 0.017 0.017 0.017 0.017 0.018 0.018 Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cr 0.007 0.006 0.007 0.007 0.007 0.007 0.006 Fe 0.155 0.150 0.159 0.155 0.152 0.154 0.151 Mg 1.819 1.801 1.831 1.809 1.816 1.808 1.815 Mn 0.004 0.004 0.004 0.004 0.004 0.004 0.004 Ni 0.003 0.003 0.003 0.002 0.002 0.003 0.003 Ca 0.028 0.038 0.020 0.029 0.027 0.022 0.031 Na 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Total 4.011 4.004 4.014 4.008 4.007 4.002 4.008 M g# 92.155 92.288 92.018 92.083 92.285 92.173 92.308 En 90.870 90.534 91.083 90.729 91.044 91.139 90.892 Fs 7.735 7.565 7.903 7.801 7.611 7.739 7.574 Wo 1.395 1.901 1.014 1.470 1.344 1.121 1.534 T#b#l C3.8: Collective analyeee, B. Scorpion (S. Zlkt) Field Microprobe Analysle & Calculated Formula (baaad on 6 Oxygane) of Pyroxana, (Mg, Fa)2SI206. 587 )-Sc2, circle Z9-Sc2, circle 7, pyx Z9-Sc2, circle 6, pyx Z9-Sc7, cir Z9-Sc7, cir Z9-Sc7, cir c2Px8 9Sc2Px9 9Sc2Px10 9Sc2Px11 9Sc2Px12 9Sc7Px1 9Sc7Px2 9Sc7Px3 % W t% W t% W t% W t% W t% W t% W t% 57.019 57.515 57.541 57.877 57.853 58.151 58.328 58.249 0.444 0.377 0.370 0.435 0.375 0.506 0.659 0.591 0.003 0.002 0.003 0.000 0.010 0.002 0.012 0.031 0.271 0.236 0.182 0.227 0.181 0.220 0.347 0.283 5.320 5.387 5.605 5.181 5.525 4.754 4.523 4.789 35.139 35.614 35.665 34.812 35.437 35.678 35.602 36.240 0.148 0.098 0.126 0.143 0.148 0.137 0.098 0.117 0.110 0.105 0.085 0.057 0.054 0.064 0.093 0.116 0.782 0.507 0.470 1.451 0.514 0.454 1.306 0.488 0.006 0.003 0.000 0.000 0.000 0.001 0.000 0.026 99.242 99.843 100.048 100.183 100.097 99.966 100.968 100.929 57.455 57.605 57.514 57.771 57.797 58.171 57.769 57.713 0.448 0.377 0.370 0.435 0.375 0.506 0.653 0.585 0.003 0.002 0.003 0.000 0.010 0.002 0.012 0.031 0.273 0.236 0.182 0.227 0.181 0.220 0.344 0.281 5.360 5.396 5.603 5.172 5.520 4.755 4.480 4.745 35.407 35.670 35.648 34.748 35.402 35.690 35.261 35.906 0.149 0.098 0.126 0.143 0.148 0.137 0.097 0.116 0.111 0.105 0.085 0.057 0.054 0.064 0.092 0.114 0.788 0.508 0.470 1.448 0.514 0.454 1.294 0.484 0.006 0.003 0.000 0.000 0.000 0.001 0.000 0.025 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.977 1.980 1.979 1.987 1.986 1.991 1.981 1.978 0.018 0.015 0.015 0.018 0.015 0.020 0.026 0.024 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.007 0.006 0.005 0.006 0.005 0.006 0.009 0.008 0.154 0.155 0.161 0.149 0.159 0.136 0.128 0.136 1.816 1.828 1.828 1.782 1.814 1.821 1.803 1.835 0.004 0.003 0.004 0.004 0.004 0.004 0.003 0.003 0.003 0.003 0.002 0.002 0.001 0.002 0.003 0.003 0.029 0.019 0.017 0.053 0.019 0.017 0.048 0.018 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 4.010 4.009 4.011 4.001 4.004 3.996 4.001 4.006 92.172 92.178 91.898 92.294 91.957 93.046 93.347 93.099 90.833 91.317 91.105 89.812 91.083 92.261 91.105 92.267 7.714 7.749 8.033 7.499 7.967 6.896 6.493 6.840 1.453 0.934 0.863 2.690 0.950 0.843 2.402 0.893 588 Z9-Sc7, circle 5, pyx Z9-Sc7, cir Z9-Sc7, cir Z9-Sc7, cir Z9-Sc7, cir Z9-Sc9, cir Z9-Sc10, c c7Px4 9Sc7Px5 9Sc7Px6 9Sc7Px7 9Sc7Px8 9Sc7Px9 9Sc9Px1 9Sc10Px1 % W t% W t% W t% W t% W t% W t% W t% 56.850 58.188 57.379 56.377 57.605 56.219 58.746 41.009 0.587 0.604 0.602 0.502 0.731 0.570 2.033 0.000 0.008 0.012 0.003 0.012 0.002 0.014 0.024 0.000 0.354 0.286 0.308 0.211 0.372 0.291 0.183 0.010 4.544 4.844 4.798 4.565 4.826 4.772 1.243 7.498 35.221 35.848 35.685 34.220 35.579 35.010 25.254 51.453 0.086 0.137 0.192 0.110 0.148 0.122 0.037 0.116 0.117 0.058 0.102 0.093 0.064 0.065 0.107 0.376 1.397 0.639 0.575 1.751 1.210 0.663 11.896 0.000 0.000 0.011 0.000 0.000 0.013 0.000 0.577 0.000 99.164 100.627 99.643 97.841 100.549 97.725 100.100 100.462 57.329 57.825 57.585 57.622 57.290 57.528 58.687 40.821 0.592 0.601 0.604 0.513 0.727 0.583 2.031 0.000 0.008 0.012 0.003 0.012 0.002 0.014 0.024 0.000 0.357 0.284 0.309 0.216 0.370 0.297 0.183 0.010 4.583 4.814 4.816 4.666 4.799 4.883 1.242 7.463 35.518 35.625 35.812 34.975 35.384 35.825 25.229 51.217 0.087 0.136 0.193 0.112 0.147 0.125 0.037 0.115 0.118 0.057 0.102 0.095 0.064 0.066 0.107 0.374 1.409 0.635 0.577 1.790 1.203 0.678 11.884 0.000 0.000 0.011 0.000 0.000 0.013 0.000 0.577 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.970 1.982 1.976 1.981 1.969 1.974 2.032 1.488 0.024 0.024 0.024 0.021 0.029 0.024 0.083 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.000 0.010 0.008 0.008 0.006 0.010 0.008 0.005 0.000 0.132 0.138 0.138 0.134 0.138 0.140 0.036 0.227 1.820 1.820 1.832 1.792 1.813 1.833 1.302 2.782 0.003 0.004 0.006 0.003 0.004 0.004 0.001 0.004 0.003 0.002 0.003 0.003 0.002 0.002 0.003 0.011 0.052 0.023 0.021 0.066 0.044 0.025 0.441 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.019 0.000 4.013 4.002 4.008 4.008 4.011 4.010 3.923 4.512 93.250 92.953 92.986 93.037 92.929 92.897 97.313 92.443 90.836 91.860 91.995 89.959 90.866 91.737 73.199 92.443 6.575 6.964 6.940 6.732 6.914 7.014 2.021 7.557 2.589 1.177 1.066 3.308 2.220 1.248 24.780 0.000 589 ircle 1, oliviZ9-Sc10, circle 3, pyx Z9-Sc10, circle 4, pyx Z9*Sc10, circle 6, pyx Un 137 Z! 9Sc10Px2 9Sc10Px3 9Sc10Px4 9Sc10Px5 9Sc10Px6 9Sc10Px7 9Sc10Px8 9Sc10Px9 t % w t % W t% W t% W t% W t% W t% W t% 58.110 56.547 56.539 56.651 56.640 56.345 56.624 56.638 1.268 1.895 1.901 1.734 1.666 1.677 1.648 1.833 0.012 0.012 0.020 0.012 0.028 0.045 0.016 0.020 0.250 0.593 0.599 0.528 0.513 0.481 0.514 0.569 5.181 4.947 5.086 4.998 4.886 5.079 4.887 5.041 36.069 35.305 35.465 35.495 34.788 35.137 35.411 35.443 0.091 0.100 0.110 0.105 0.128 0.110 0.151 0.133 0.087 0.096 0.099 0.111 0.108 0.096 0.087 0.067 0.315 0.466 0.454 0.515 1.539 0.660 0.364 0.559 0.000 0.009 0.006 0.009 0.000 0.002 0.000 0.004 101.383 99.971 100.277 100.157 100.297 99.633 99.702 100.305 57.318 56.564 56.383 56.562 56.473 56.553 56.793 56.465 1.250 1.896 1.896 1.732 1.661 1.683 1.653 1.827 0.012 0.012 0.020 0.012 0.028 0.045 0.016 0.019 0.246 0.594 0.597 0.527 0.512 0.483 0.515 0.568 5.111 4.948 5.071 4.990 4.872 5.098 4.902 5.026 35.577 35.315 35.367 35.439 34.685 35.267 35.517 35.335 0.090 0.100 0.109 0.105 0.128 0.111 0.152 0.132 0.085 0.096 0.098 0.111 0.108 0.096 0.087 0.067 0.311 0.466 0.452 0.514 1.534 0.663 0.365 0.557 0.000 0.009 0.006 0.009 0.000 0.002 0.000 0.004 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.966 1.943 1.939 1.944 1.946 1.945 1.950 1.941 0.051 0.077 0.077 0.070 0.067 0.068 0.067 0.074 0.000 0.000 0.001 0.000 0.001 0.001 0.000 0.001 0.007 0.016 0.016 0.014 0.014 0.013 0.014 0.015 0.147 0.142 0.146 0.143 0.140 0.147 0.141 0.145 1.819 1.809 1.813 1.816 1.781 1.808 1.818 1.811 0.003 0.003 0.003 0.003 0.004 0.003 0.004 0.004 0.002 0.003 0.003 0.003 0.003 0.003 0.002 0.002 0.011 0.017 0.017 0.019 0.057 0.024 0.013 0.021 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 4.005 4.010 4.014 4.013 4.013 4.013 4.009 4.013 92.543 92.712 92.555 92.679 92.696 92.499 92.814 92.610 92.008 91.904 91.774 91.792 90.042 91.357 92.183 91.649 7.414 7.224 7.383 7.251 7.095 7.409 7.137 7.313 0.578 0.872 0.843 0.957 2.863 1.234 0.680 1.038 590 9-Sc10, circUn 138 ZUn 139 ZiUn 143 ZZQ-ScIO, circle 12, pyx 9Sc1 OPxl ( 9Sc1 OPxl - 9Sc1 OPxl Î 9Sc10Px1C 9Sc10Px14 W t% W t% W t% W t% W t% 56.891 55.289 57.065 57.278 56.811 1.814 1.682 1.822 1.748 1.895 0.015 0.024 0.034 0.021 0.016 0.529 0.575 0.557 0.503 0.564 4.835 3.903 4.928 5.056 4.948 35.466 30.876 35.788 35.337 35.554 0.121 0.094 0.085 0.120 0.096 0.077 0.068 0.040 0.113 0.083 0.380 6.929 0.478 0.739 0.395 0.000 0.014 0.004 0.002 0.000 100.128 99.452 100.800 100.918 100.362 56.819 55.593 56.612 56.757 56.606 1.812 1.691 1.808 1.732 1.889 0.015 0.024 0.033 0.021 0.016 0.529 0.578 0.553 0.498 0.562 4.828 3.925 4.888 5.010 4.930 35.420 31.046 35.504 35.015 35.425 0.121 0.095 0.084 0.119 0.095 0.077 0.068 0.040 0.112 0.083 0.379 6.967 0.474 0.732 0.394 0.000 0.014 0.004 0.002 0.000 100.000 100.000 100.000 100.000 100.000 1.949 1.938 1.944 1.951 1.944 0.073 0.069 0.073 0.070 0.076 0.000 0.001 0.001 0.001 0.000 0.014 0.016 0.015 0.014 0.015 0.139 0.114 0.140 0.144 0.142 1.811 1.614 1.817 1.794 1.813 0.004 0.003 0.002 0.003 0.003 0.002 0.002 0.001 0.003 0.002 0.014 0.260 0.017 0.027 0.014 0.000 0.000 0.000 0.000 0.000 4.007 4.018 4.011 4.007 4.010 02.896 93.378 92.830 92.570 92.758 92.237 81.156 92.010 91.300 92.076 7.053 5.755 7.107 7.328 7.189 0.710 13.089 0.883 1.372 0.735 591 Label H9-1, circle 1, pyx (988,989,991); Un 433 H Un 280 H9-1, circle 2, small pyx, Others 9HlPx1 9HlPx2 9H1Px3 9H1Px4 9HlPx5 9HlPx6 9H1Px7 Oxides W t% W t% Wt% Wt% W t% Wt% W t% Si02 50.274 51.018 52.943 52.125 52.274 52.979 52.674 AI203 0.526 0.524 1.010 0.646 1.172 1.021 0.956 Ti02 0.108 0.129 0.156 0.135 0.113 0.200 0.190 Cr203 0.000 0.000 0.000 0.003 0.001 0.000 0.004 FeOtot. 26.315 26.474 11.141 26.579 26.657 11.837 11.169 MgO 18.595 18.717 13.151 18.722 18.672 13.212 13.089 MnO 0.677 0.698 0.308 0.695 0.609 0.299 0.321 NIO 0.023 0.042 0.000 0.000 0.032 0.000 0.000 CaO 1.080 0.957 21.646 0.994 0.889 21.225 21.460 N a20 0.006 0.000 0.263 0.027 0.022 0.220 0.228 Total 97.603 98.560 100.619 99.927 100.441 100.992 100.091 Normalized oxides SI02 51.509 51.764 52.617 52.163 52.045 52.459 52.625 AI203 0.538 0.532 1.004 0.647 1.167 1.011 0.955 TI02 0.111 0.131 0.155 0.135 0.113 0.198 0.190 Cr203 0.000 0.000 0.000 0.003 0.001 0.000 0.004 FeOtot. 26.961 26.861 11.072 26.598 26.540 11.721 11.159 MgO 19.052 18.991 13.071 18.736 18.590 13.082 13.077 MnO 0.693 0.709 0.306 0.696 0.606 0.296 0.321 NIO 0.023 0.043 0.000 0.000 0.032 0.000 0.000 CaO 1.106 0.971 21.513 0.994 0.885 21.016 21.441 N a20 0.006 0.000 0.262 0.027 0.022 0.218 0.227 100.000 100.000 100.000 100.000 100.000 100.000 100.000 Cations SI 1.970 1.977 1.979 1.987 1.980 1.976 1.979 AI 0.024 0.024 0.045 0.029 0.052 0.045 0.042 TI 0.003 0.004 0.004 0.004 0.003 0.006 0.005 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Fe 0.862 0.858 0.348 0.847 0.844 0.369 0.351 Mg 1.086 1.081 0.733 1.064 1.054 0.735 0.733 Mn 0.022 0.023 0.010 0.022 0.020 0.009 0.010 NI 0.001 0.001 0.000 0.000 0.001 0.000 0.000 Ca 0.045 0.040 0.867 0.041 0.036 0.848 0.864 Na 0.000 0.000 0.010 0.001 0.001 0.008 0.008 Total 4.015 4.007 3.995 3.995 3.991 3.996 3.994 M g» 55.746 55.758 67.786 55.667 55.528 66.551 67.628 En 54.479 54.638 37.620 54.510 54.493 37.633 37.636 Fs 43.248 43.354 17.878 43.411 43.643 18.915 18.015 Wo 2.273 2.007 44.502 2.079 1.864 43.452 44.348 TatMl C3.9: Colleetiva analyMs. Oiffarant plaças in the manWa saction Microproba Analysis & Calculalad Formula (baaad on 6 Oxygana) of Pyroxana. (Mg, Fa)2SI206. 592 mps (99 Un 282 H9-1, circle 5 Un 285 H9-1, circled Un 290 HUn 291 H9-1, circle 6 HPxB 9H1PX9 9H1PX10 9HlPx11 9H1PX12 9H1PX13 9H1PX14 9H1PX15 t% W t% Wt% Wt% Wt% W t% W t% W t% 51.908 51.673 52.412 52.038 51.049 51.977 51.366 52.025 0.542 0.550 0.536 0.649 0.654 0.587 0.552 0.529 0.100 0.116 0,097 0.140 0.161 0.132 0.106 0.097 0.004 0.000 0.019 0.000 0.002 0.002 0.008 0.008 26.756 27.000 26.741 26.117 26.217 26.188 26.560 26.436 18.648 18.430 18.746 18.576 18.498 18.523 18.627 18.898 0.722 0.692 0.698 0.652 0.713 0.751 0.716 0.716 0.001 0.000 0.006 0.018 0.000 0.019 0.030 0.026 0.903 1.088 1.042 1.466 1.428 1.101 1.034 1.027 0.033 0.017 0.040 0.020 0.009 0.000 0.020 0.031 99.616 99.566 100.336 99.675 98.732 99.280 99.018 99.794 52.108 51.898 52.236 52.207 51.705 52.354 51.875 52.132 0.544 0.552 0.534 0.651 0.663 0.591 0.557 0.530 0.100 0.117 0.097 0.141 0.163 0.133 0.107 0.098 0.004 0.000 0.019 0.000 0.002 0.002 0.008 0.008 26.859 27.118 26.652 26.202 26.553 26.378 26.823 26.491 18.720 18.510 18.683 18.636 18.735 18.657 18.812 18.937 0.725 0.695 0.696 0.654 0.723 0.757 0.723 0.718 0.001 0.000 0.006 0.018 0.000 0.019 0.030 0.026 0.907 1.093 1.038 1.471 1.447 1.109 1.044 1.029 0.033 0.017 0.040 0.020 0.009 0.000 0.020 0.032 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.987 1.983 1.990 1.987 1.974 1.992 1.981 1.986 0.024 0.025 0.024 0.029 0.030 0.026 0.025 0.024 0.003 0.003 0.003 0.004 0.005 0.004 0.003 0.003 0.000 0.000 0.001 0.000 0.000 0.000 0.000 0.000 0.857 0.867 0.849 0.834 0.848 0.839 0.856 0.844 1.064 1.055 1.061 1.057 1.066 1.058 1.071 1.075 0.023 0.022 0.022 0.021 0.023 0.024 0.023 0.023 0.000 0.000 0.000 0.001 0.000 0.001 0.001 0.001 0.037 0.045 0.042 0.060 0.059 0.045 0.043 0.042 0.001 0.001 0.001 0.001 0.000 0.000 0.001 0.001 3.998 4.001 3.995 3.994 4.008 3.991 4.004 3.999 55.405 54.889 55.548 55.908 55.708 55.789 55.559 58.030 54.357 53.640 54.342 54.187 54.037 54.471 54.355 54.830 43.751 44.084 43.488 42.739 42.964 43.201 43.477 43.028 1.892 2.276 2.170 3.074 2.999 2.328 2.168 2.141 593 Un 294 H9-1, circle 7 Un 295 H H9-1, circle 8,1 mm cpx H9-1, circk H9-2, circk 9H1PX16 9H1PX17 9H1PX18 9H1PX19 9H1PX20 9H1PX21 9H1PX22 9H2PX1 W t% W t% Wt% Wt% W t% W t% W t% W t% 53.187 51.887 51.430 51.971 52.353 52.984 51.341 54.975 0.866 1.025 0.567 1.074 0.966 0.980 0.562 1.795 0.173 0.186 0.108 0.171 0.186 0.178 0.136 0.196 0.013 0.013 0.000 0.020 0.034 0.008 0.007 0.052 11.202 11.562 26.481 10.982 11.043 10.740 26.914 8.742 13.430 13.088 18.731 12.927 12.984 12.902 18.235 16.455 0.342 0.316 0.651 0.320 0.320 0.344 0.694 0.349 0.001 0.015 0.005 0.000 0.000 0.000 0.005 0.015 21.482 21.356 1.013 21.717 21.926 21.607 0.995 16.704 0.272 0.251 0.028 0.255 0.204 0.241 0.000 0.152 100.968 99.698 99.014 99.437 100.017 99.982 98.888 99.435 52.677 52.044 51.942 52.265 52.344 52.993 51.919 55.287 0.857 1.028 0.572 1.080 0.966 0.980 0.568 1.805 0.171 0.187 0.109 0.172 0.186 0.178 0.138 0.197 0.013 0.013 0.000 0.020 0.034 0.008 0.007 0.052 11.094 11.597 26.745 11.044 11.042 10.742 27.216 8.792 13.301 13.127 18.918 13.001 12.982 12.904 18.440 16.548 0.339 0.317 0.657 0.322 0.320 0.344 0.701 0.351 0.001 0.015 0.005 0.000 0.000 0.000 0.005 0.015 21.276 21.420 1.023 21.840 21.922 21.611 1.006 16.799 0.270 0.252 0.028 0.256 0.204 0.241 0.000 0.153 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.980 1.965 1.981 1.969 1.972 1.989 1.984 2.015 0.038 0.046 0.026 0.048 0.043 0.043 0.026 0.078 0.005 0.005 0.003 0.005 0.005 0.005 0.004 0.005 0.000 0.000 0.000 0.001 0.001 0.000 0.000 0.002 0.349 0.366 0.853 0.348 0.348 0.337 0.870 0.268 0.745 0.739 1.076 0.730 0.729 0.722 1.051 0.899 0.011 0.010 0.021 0.010 0.010 0.011 0.023 0.011 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.857 0.866 0.042 0.882 0.885 0.869 0.041 0.656 0.010 0.009 0.001 0.009 0.007 0.009 0.000 0.005 3.996 4.007 4.003 4.002 4.001 3.965 3.999 3.940 68.123 66.863 55.770 67.725 67.699 68.168 54.708 77.040 38.203 37.477 54.586 37.259 37.165 37.445 53.557 49.319 17.876 18.573 43.291 17.756 17.732 17.486 44.343 14.699 43.921 43.950 2.122 44.985 45.103 45.069 2.101 35.982 594 H9-2,circUH9-2,circle2, scuzzy Un 309 HUn 313 H9-2, circle^Un 317 H9-2, circle6 9H2PX2 9H2PX3 9H2PX4 9H2PX5 9H2PX6 9H2Px7 9H2PX8 9H2PX9 Wt% Wt% Wt% Wt% Wt% Wt% Wt% Wt% 53.283 54.212 55.990 52.809 53.712 53.687 52.524 51.423 1.842 1.971 4.864 1.828 0.290 0.334 1.464 2.350 0.203 0.091 0.072 0.176 0.042 0.051 0.107 0.184 0.272 0.071 0.056 0.197 0.068 0.087 0.204 0.171 4.880 7.285 7.004 5.143 4.675 5.135 5.129 5.279 16.382 18.158 14.238 16.078 15.542 15.620 16.187 15.818 0.133 0.191 0.203 0.157 0.190 0.197 0.180 0.147 0.000 0.023 0.023 0.022 0.011 0.000 0.019 0.006 23.158 15.915 15.184 23.641 25.402 24.957 23.376 22.678 0.225 0.194 0.167 0.138 0.084 0.083 0.174 0.239 100.377 98.111 97.799 100.190 100.015 100.151 99.366 98.296 53.083 55.256 57.250 52.709 53.704 53.606 52.859 52.315 1.835 2.009 4.973 1.824 0.290 0.334 1.473 2.390 0.202 0.093 0.073 0.176 0.042 0.051 0.108 0.187 0.271 0.072 0.057 0.196 0.068 0.087 0.206 0.174 4.861 7.426 7.162 5.133 4.674 5.127 5.162 5.371 16.320 18.508 14.559 16.048 15.539 15.596 16.291 16.092 0.133 0.194 0.208 0.157 0.190 0.196 0.181 0.150 0.000 0.024 0.024 0.022 0.011 0.000 0.020 0.006 23.071 16.221 15.525 23.596 25.398 24.920 23.525 23.071 0.224 0.197 0.170 0.138 0.084 0.083 0.175 0.243 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.948 1.999 2.043 1.941 1.982 1.980 1.947 1.927 0.079 0.086 0.209 0.079 0.013 0.015 0.064 0.104 0.006 0.003 0.002 0.005 0.001 0.001 0.003 0.005 0.008 0.002 0.002 0.006 0.002 0.003 0.006 0.005 0.149 0.225 0.214 0.158 0.144 0.158 0.159 0.165 0.893 0.998 0.774 0.881 0.855 0.859 0.895 0.884 0.004 0.006 0.006 0.005 0.006 0.006 0.006 0.005 0.000 0.001 0.001 0.001 0.000 0.000 0.001 0.000 0.907 0.629 0.594 0.931 1.004 0.986 0.929 0.910 0.008 0.007 0.006 0.005 0.003 0.003 0.006 0.009 4.003 3.955 3.850 4.012 4.010 4.010 4.015 4.014 85.682 81.827 78.373 84.787 85.582 84.429 84.907 84.230 45.807 53.908 48.963 44.718 42.673 42.867 45.134 45.093 7.654 12.134 13.511 8.024 7.201 7.906 8.023 8.443 46.539 33.958 37.526 47.258 50.126 49.227 46.844 46.464 595 ),Capyx H9-2,circU IV«d9-T,(Mas9-5,c/iUn 382 Mas9-5,circle 1,cpx Un 385 M 9H2Px10 9H2Px11 9Wad 1 Px19Mas5Px1 9Mas5Px2 9Mas6Px3 9Mas5Px4 9Mas5Px5 % Wt% Wt% Wt% Wt% Wt% Wt% W t% 52.598 52.432 54.920 52.636 51.562 51.134 51.930 50.395 1.392 1.951 0.097 4.026 4.512 5.142 6.289 6.835 0.097 0.157 0.000 0.388 0.354 0.543 0.527 0.537 0.264 0.155 0.193 0.544 0.600 0.769 0.813 0.863 4.929 5.020 1.366 2.059 2.228 2.072 2.377 2.213 16.360 16.567 18.487 16.628 15.874 16.038 15.520 15.081 0.150 0.120 0.081 0.097 0.085 0.084 0.088 0.073 0.006 0.012 0.071 0.042 0.005 0.037 0.031 0.032 23.397 22.379 24.810 23.493 22.508 23.503 21.947 22.594 0.153 0.250 0.016 0.903 1.009 0.594 1.046 0.951 99.346 99.042 100.041 100.814 98.738 99.916 100.567 99.575 52.944 52.939 54.897 52.211 52.221 51.177 51.637 50.610 1.401 1.970 0.097 3.994 4.570 5.146 6.253 6.865 0.098 0.158 0.000 0.385 0.359 0.544 0.524 0.540 0.266 0.156 0.193 0.539 0.608 0.769 0.808 0.867 4.961 5.069 1.365 2.042 2.256 2.074 2.364 2.223 16.468 16.727 18.479 16.494 16.077 16.051 15.433 15.146 0.151 0.122 0.081 0.096 0.087 0.084 0.087 0.073 0.006 0.012 0.071 0.041 0.005 0.037 0.031 0.033 23.551 22.595 24.800 23.303 22.796 23.523 21.823 22.690 0.154 0.252 0.016 0.895 1.022 0.594 1.040 0.955 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.948 1.942 1.989 1.899 1.897 1.864 1.872 1.841 0.061 0.085 0.004 0.171 0.196 0.221 0.267 0.294 0.003 0.004 0.000 0.011 0.010 0.015 0.014 0.015 0.008 0.005 0.006 0.016 0.017 0.022 0.023 0.025 0.153 0.156 0.041 0.062 0.069 0.063 0.072 0.068 0.903 0.915 0.998 0.894 0.871 0.872 0.834 0.821 0.005 0.004 0.002 0.003 0.003 0.003 0.003 0.002 0.000 0.000 0.002 0.001 0.000 0.001 0.001 0.001 0.929 0.888 0.963 0.908 0.887 0.918 0.847 0.884 0.006 0.009 0.001 0.032 0.036 0.021 0.037 0.034 4.015 4.008 4.008 3.997 3.988 3.999 3.989 3.985 85.543 85.471 98.021 93.505 92.701 93.242 92.087 92.393 45.521 46.712 49.851 47.965 47.668 47.043 47.568 46.317 7.693 7.940 2.066 3.332 3.753 3.409 4.087 3.813 46.786 45.348 48.083 48.704 48.579 49.548 48.344 49.870 596 Un 386 Mas9-5, circl Un 388 M Un 389 Mas9-S, circi Un 390 Mas9-5, circi Un 394 M 9Mas5Px6 9Mas5Px7 9MasSPx8 9Mas5Px9 9Mas5Px1'9Ma85Px1 9Ma85Px1:9Mas5Px1: t % W t% Wt% W t% Wt% W t% W t% Wt% 56.622 56.114 53.179 51.770 51.869 56.480 56.970 53.445 1.266 2.449 4.314 6.461 6.688 2.239 2.115 5.057 0.045 0.093 0.360 0.494 0.489 0.066 0.044 0.094 0.145 0.146 0.488 0.788 0.804 0.133 0.153 0.444 6.661 6.896 2.265 2.336 2.189 7.110 6.899 6.700 33.342 33.930 16.341 15.292 15.241 34.535 34.352 32.446 0.187 0.217 0.074 0.070 0.066 0.155 0.187 0.143 0.071 0.081 0.060 0.055 0.039 0.066 0.074 0.062 3.400 0.400 22.247 21.854 22.578 0.331 0.325 0.293 0.034 0.028 0.964 1.135 0.890 0.003 0.005 0.000 101.773 100.353 100.291 100.255 100.853 101.118 101.124 98.683 55.635 55.917 53.025 51.638 51.431 55.856 56.337 54.158 1.244 2.440 4.301 6.444 6.631 2.214 2.091 5.125 0.044 0.092 0.359 0.493 0.485 0.065 0.044 0.095 0.143 0.146 0.486 0.786 0.798 0.132 0.152 0.450 6.545 6.871 2.259 2.330 2.170 7.031 6.822 6.789 32.761 33.810 16.293 15.253 15.112 34.153 33.970 32.878 0.184 0.216 0.074 0.070 0.065 0.153 0.185 0.145 0.070 0.081 0.060 0.055 0.039 0.065 0.074 0.062 3.341 0.399 22.182 21.799 22.387 0.327 0.321 0.297 0.034 0.028 0.961 1.132 0.883 0.003 0.005 0.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.943 1.936 1.919 1.871 1.864 1.935 1.948 1.876 0.051 0.100 0.184 0.275 0.283 0.090 0.085 0.209 0.001 0.002 0.010 0.013 0.013 0.002 0.001 0.002 0.004 0.004 0.014 0.023 0.023 0.004 0.004 0.012 0.191 0.199 0.068 0.071 0.066 0.204 0.197 0.197 1.705 1.745 0.879 0.824 0.817 1.764 1.751 1.698 0.005 0.006 0.002 0.002 0.002 0.004 0.005 0.004 0.002 0.002 0.002 0.002 0.001 0.002 0.002 0.002 0.125 0.015 0.860 0.846 0.869 0.012 0.012 0.011 0.001 0.001 0.034 0.040 0.031 0.000 0.000 0.000 4.029 4.010 3.972 3.987 3.970 4.016 4.006 4.011 89.922 89.766 92.784 92.107 92.544 89.646 89.674 89.618 84.362 89.088 48.632 47.330 46.614 89.096 89.329 89.100 9.455 10.157 3.782 4.056 3.755 10.290 10.064 10.321 6.182 0.756 47.586 48.614 49.630 0.614 0.607 0.578 597 las9-5, circle 4, very large pyx, ed{ Un 396 MUn 397 Mas9-5, circle 5, several large cpx 9Mas5Px1 • 9Mas5Px1 : 9Mas5Px1 * 9Mas5Px1 9Mas5Px1 : 9Mas5Px1 : 9Mas5Px2' 9Mas5Px2 t % W t% W t% Wt % Wt % Wt % Wt% W t% 53.116 52.740 54.951 56.430 53.288 53.482 53.067 53.844 6.995 6.940 5.066 2.649 5.891 6.182 6.493 5.712 0.134 0.158 0.136 0.067 0.125 0.126 0.190 0.143 0.655 0.687 0.416 0.144 0.612 0.608 0.614 0.546 6.508 6.378 6.588 6.748 6.267 6.438 6.298 6.165 31.228 30.967 33.336 34.182 31.756 31.876 31.806 31.917 0.152 0.116 0.122 0.152 0.129 0.125 0.087 0.141 0.054 0.100 0.069 0.086 0.073 0.068 0.091 0.074 1.362 2.067 0.780 0.427 1.444 0.988 1.951 1.823 0.039 0.114 0.038 0.024 0.174 0.034 0.031 0.002 100.243 100.266 101.501 100.909 99.760 99.927 100.627 100.367 52.987 52.601 54.138 55.921 53.416 53.521 52.736 53.647 6.978 6.922 4.991 2.625 5.905 6.186 6.452 5.691 0.134 0.158 0.134 0.066 0.125 0.126 0.188 0.143 0.653 0.685 0.410 0.142 0.614 0.609 0.610 0.544 6.492 6.361 6.490 6.688 6.282 6.443 6.259 6.143 31.153 30.885 32.843 33.875 31.832 31.899 31.608 31.800 0.152 0.115 0.121 0.151 0.130 0.125 0.087 0.140 0.054 0.099 0.068 0.085 0.073 0.068 0.090 0.074 1.359 2.061 0.769 0.423 1.448 0.989 1.939 1.817 0.038 0.114 0.038 0.024 0.175 0.034 0.031 0.002 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.840 1.831 1.876 1.934 1.855 1.855 1.834 1.862 0.286 0.284 0.204 0.107 0.242 0.253 0.265 0.233 0.004 0.004 0.003 0.002 0.003 0.003 0.005 0.004 0.018 0.019 0.011 0.004 0.017 0.017 0.017 0.015 0.188 0.185 0.188 0.193 0.182 0.187 0.182 0.178 1.612 1.603 1.696 1.746 1.648 1.648 1.639 1.645 0.004 0.003 0.004 0.004 0.004 0.004 0.003 0.004 0.002 0.003 0.002 0.002 0.002 0.002 0.003 0.002 0.051 0.077 0.029 0.016 0.054 0.037 0.072 0.068 0.001 0.004 0.001 0.001 0.006 0.001 0.001 0.000 4.005 4.013 4.013 4.009 4.013 4.007 4.020 4.011 89.533 89.643 90.020 90.029 90.032 89.823 90.002 90.223 87.089 85.948 88.678 89.307 87.458 88.060 86.568 87.000 10.181 9.930 9.831 9.891 9.683 9.978 9.616 9.428 2.730 4.122 1.491 0.802 2.859 1.962 3.816 3.572 598 Un 399 MUn 401 Mas9*5, circle 6, large cpx, edge-cti Un 405 MUn 406 MMasO-S, cir 9Mas5Px2 9Mas5Px2:9Mas5Px2> 9Mas5Px2 9Mas5Px2' 9Mas5Px2 9Ma85Px2i 9Ma85Px2: t % Wt % Wt % Wt % Wt % W t% Wt% W t% 55.857 52.971 52.180 53.803 53.819 55.683 53.531 52.256 2.806 7.448 6.435 5.681 4.589 2.775 5.651 5.765 0.054 0.247 0.192 0.116 0.100 0.067 0.104 0.174 0.168 0.683 0.644 0.564 0.375 0.216 0.563 0.576 6.600 6.024 6.088 6.753 6.810 6.939 6.546 6.215 33.935 29.934 30.830 32.740 32.640 34.082 32.948 31.224 0.160 0.135 0.151 0.144 0.162 0.202 0.140 0.155 0.076 0.053 0.084 0.063 0.102 0.051 0.075 0.096 0.366 2.999 2.944 0.519 0.322 0.264 0.248 2.000 0.013 0.060 0.042 0.000 0.005 0.000 0.015 0.050 100.036 100.555 99.590 100.384 98.923 100.279 99.822 98.510 55.837 52.678 52.395 53.597 54.405 55.528 53.627 53.047 2.805 7.407 6.462 5.659 4.639 2.767 5.661 5.852 0.054 0.246 0.193 0.115 0.101 0.067 0.104 0.176 0.168 0.679 0.647 0.562 0.379 0.216 0.564 0.585 6.598 5.991 6.113 6.727 6.885 6.919 6.557 6.309 33.923 29.769 30.957 32.615 32.995 33.987 33.007 31.696 0.160 0.134 0.151 0.143 0.164 0.201 0.140 0.157 0.076 0.053 0.084 0.063 0.103 0.051 0.076 0.098 0.366 2.983 2.956 0.517 0.326 0.263 0.249 2.030 0.013 0.059 0.042 0.000 0.005 0.000 0.015 0.051 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.930 1.833 1.828 1.859 1.885 1.923 1.857 1.847 0.114 0.304 0.266 0.231 0.189 0.113 0.231 0.240 0.001 0.006 0.005 0.003 0.003 0.002 0.003 0.005 0.005 0.019 0.018 0.015 0.010 0.006 0.015 0.016 0.191 0.174 0.178 0.195 0.200 0.200 0.190 0.184 1.748 1.544 1.610 1.686 1.705 1.755 1.704 1.645 0.005 0.004 0.004 0.004 0.005 0.006 0.004 0.005 0.002 0.001 0.002 0.002 0.003 0.001 0.002 0.003 0.014 0.111 0.111 0.019 0.012 0.010 0.009 0.076 0.000 0.002 0.001 0.000 0.000 0.000 0.001 0.002 4.009 3.999 4.025 4.015 4.012 4.018 4.017 4.021 90.163 89.856 90.027 89.829 89.521 89.750 89.973 89.958 89.537 84.394 84.788 88.722 88.957 89.304 89.537 86.379 9.769 9.528 9.393 10.266 10.412 10.199 9.979 9.645 0.694 6.078 5.819 1.012 0.631 0.497 0.485 3.976 599 rcle 8, 2 lar; Kor9-1, cir< Un 416 Kor9-1, circle 3, pyx & 1 Un 421 Kor9-1, circle 4, pyx & 1 las5Px@9KorlPx1 9Kor1Px2 9Kor1Px3 9Kor1 Px4 9KorlPx5 9Kor1Px6 9KorlPx7 % W t% W t% Wt% W t% W t% Wt% W t% 52.788 48.948 49.505 50.296 50.285 50.107 50.353 50.600 6.509 3.498 2.993 2.909 3.183 3.185 3.284 3.146 0.143 0.709 0.672 0.569 0.682 0.753 0.737 0.670 0.666 0.000 0.026 0.000 0.019 0.011 0.000 0.007 6.084 8.687 7.357 7.734 8.519 8.042 7.786 7.548 31.089 14.074 14.455 15.082 15.145 14.097 14.363 14.484 0.117 0.252 0.221 0.297 0.284 0.285 0.229 0.247 0.084 0.015 0.013 0.014 0.011 0.015 0.000 0.029 2.021 20.958 22.180 21.598 20.526 21.164 21.564 21.895 0.095 0.321 0.291 0.307 0.446 0.347 0.421 0.313 99.597 97.461 97.713 98.806 99.098 98.007 98.736 98.938 53.002 50.223 50.663 50.904 50.742 51.126 50.998 51.143 6.535 3.589 3.063 2.944 3.212 3.250 3.326 3.180 0.144 0.727 0.688 0.576 0.688 0.768 0.747 0.677 0.669 0.000 0.027 0.000 0.019 0.011 0.000 0.007 6.109 8.913 7.530 7.828 8.596 8.206 7.886 7.629 31.215 14.440 14.793 15.264 15.282 14.383 14.546 14.640 0.118 0.259 0.227 0.301 0.287 0.291 0.232 0.249 0.085 0.015 0.014 0.014 0.011 0.016 0.000 0.029 2.029 21.503 22.699 21.859 20.713 21.595 21.840 22.130 0.095 0.329 0.298 0.310 0.450 0.354 0.426 0.317 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.842 1.878 1.888 1.895 1.890 1.903 1.897 1.901 0.268 0.158 0.135 0.129 0.141 0.143 0.146 0.139 0.004 0.020 0.019 0.016 0.019 0.021 0.021 0.019 0.018 0.000 0.001 0.000 0.001 0.000 0.000 0.000 0.178 0.279 0.235 0.244 0.268 0.255 0.245 0.237 1.617 0.805 0.822 0.847 0.849 0.798 0.807 0.811 0.003 0.008 0.007 0.009 0.009 0.009 0.007 0.008 0.002 0.000 0.000 0.000 0.000 0.000 0.000 0.001 0.076 0.862 0.907 0.872 0.827 0.861 0.870 0.881 0.003 0.012 0.011 0.011 0.016 0.013 0.015 0.011 4.011 4.022 4.025 4.024 4.020 4.004 4.009 4.010 90.108 74.280 77.789 77.859 78.014 75.755 76.880 77.379 86.467 41.383 41.871 43.161 43.675 41.682 41.961 42.039 9.493 14.329 11.955 12.417 13.782 13.340 12.761 12.289 4.040 44.289 46.174 44.423 42.543 44.977 45.278 45.672 600 amp (1396Z9-5, circle 1400.000 1401.000 Un 427 Z9*5, circle 2, py 9Kor1Px8 9Z5Px1 9Z5PX2 9Z5Px3 9Z5Px4 9Z5Px5 9Z5Px6 9Z5Px7 Wt % Wt % W t% W t% Wt % Wt % W t% Wt% 52.197 56.745 57.240 56.729 55.826 56.866 56.006 56.010 2.620 0.608 0.884 0.780 0.814 0.755 0.813 0.791 0.524 0.011 0.023 0.016 0.013 0.000 0.029 0.025 0.000 0.223 0.316 0.290 0.320 0.292 0.385 0.295 7.317 7.272 7.102 7.369 7.194 7.153 7.228 7.085 14.417 34.184 34.236 34.159 33.530 33.844 33.449 33.710 0.309 0.171 0.186 0.185 0.170 0.155 0.147 0.189 0.023 0.063 0.068 0.075 0.074 0.047 0.054 0.089 22.307 0.469 0.996 0.783 1.082 0.877 0.939 1.088 0.280 0.000 0.027 0.004 0.000 0.001 0.008 0.021 99.995 99.746 101.079 100.389 99.024 99.988 99.058 99.303 52.200 56.890 56.629 56.509 56.376 56.872 56.538 56.403 2.620 0.610 0.875 0.777 0.822 0.755 0.821 0.797 0.524 0.011 0.022 0.016 0.014 0.000 0.029 0.025 0.000 0.223 0.313 0.289 0.323 0.292 0.389 0.298 7.318 7.291 7.026 7.341 7.265 7.154 7.296 7.135 14.418 34.271 33.870 34.027 33.861 33.847 33.767 33.946 0.309 0.172 0.184 0.184 0.172 0.155 0.149 0.190 0.023 0.063 0.068 0.075 0.075 0.047 0.055 0.090 22.308 0.470 0.986 0.780 1.093 0.877 0.948 1.096 0.280 0.000 0.027 0.004 0.000 0.001 0.008 0.021 100.000 100.000 100.000 100.000 100.000 100.000 100.000 100.000 1.935 1.973 1.965 1.964 1.960 1.973 1.965 1.961 0.114 0.025 0.036 0.032 0.034 0.031 0.034 0.033 0.015 0.000 0.001 0.000 0.000 0.000 0.001 0.001 0.000 0.006 0.009 0.008 0.009 0.008 0.011 0.008 0.227 0.211 0.204 0.213 0.211 0.208 0.212 0.207 0.797 1.772 1.752 1.763 1.755 1.750 1.749 1.759 0.010 0.005 0.005 0.005 0.005 0.005 0.004 0.006 0.001 0.002 0.002 0.002 0.002 0.001 0.002 0.003 0.886 0.017 0.037 0.029 0.041 0.033 0.035 0.041 0.010 0.000 0.001 0.000 0.000 0.000 0.000 0.001 3.993 4.011 4.012 4.016 4.018 4.008 4.012 4.018 77.838 89.338 89.578 89.204 89.257 89.400 89.189 89.453 41.724 88.558 87.928 87.913 87.446 87.936 87.612 87.634 11.879 10.569 10.232 10.640 10.526 10.426 10.620 10.333 46.396 0.873 1.839 1.447 2.028 1.638 1.768 2.033 601 AIH0I H9-WI5, circle 1, trem Un 166 H9-WI5, circle 2, tremollUn 169 HUn 175 H Label 9WI5Am1 9WI5Am2 9WI5Am3 9WI5Am4 9WI5Am5 9WI5Am6 9WI5Am7 Oxidaa SIG2 57.713 56.102 56.417 55.924 56.679 57.134 55.734 AI203 0.537 1.467 0.578 1.339 0.814 0.646 0.625 TI02 0.014 0.015 0.018 0.006 0.010 0.007 0.015 Cr203 0.400 0.903 0.125 0.454 0.344 0.500 0.226 FaCtot. 2.041 2.531 2.951 3.984 4.907 2.592 2.690 MgO 23.356 22.723 22.761 21.448 21.427 23.383 22.057 MnO 0.078 0.102 0.165 0.149 0.179 0.111 0.115 NIO 0.039 0.021 0.026 0.051 0.023 0.041 0.054 CaO 12.792 12.375 12.188 12.600 12.136 12.717 12.715 N a20 0.069 0.199 0.129 0.199 0.031 0.094 0.103 K 20 0.002 0.011 0.001 0.008 0.007 0.010 0.004 Total 97.041 96.448 95.358 96.161 96.556 97.235 94.338 Catlona SI 7.936 7.799 7.923 7.846 7.926 7.874 7.920 AI 0.067 0.240 0.096 0.221 0.134 0.105 0.105 TI 0.001 0.002 0.002 0.001 0.001 0.001 0.002 Cr 0.044 0.099 0.014 0.050 0.038 0.054 0.025 Fa 0.235 0.294 0.347 0.467 0.574 0.299 0.320 Mg 4.788 4.709 4.765 4.486 4.467 4.804 4.672 Mn 0.009 0.012 0.020 0.018 0.021 0.013 0.014 NI 0.004 0.002 0.003 0.006 0.003 0.004 0.006 Ca 1.885 1.843 1.834 1.894 1.818 1.878 1.936 Na 0.018 0.054 0.035 0.054 0.008 0.025 0.028 K 0.000 0.002 0.000 0.001 0.001 0.002 0.001 Total 15.007 15.057 15.038 15.045 14.992 15.059 15.028 Na+K 0.019 0.056 0.035 0.055 0.010 0.027 0.029 M g# 95.327 94.119 93.220 90.564 88.616 94.145 93.597 C a# 27.286 26.921 26.403 27.661 26.511 26.900 27.942 A n # 99.014 97.074 98.110 97.153 99.473 98.598 98.524 Tabel C4.1 : Collectiva analysM, Al'Hal Field Microproba Anaiysia & Calcuiatad Formula (baaad on 23 Oxygana) of Amphlbola, AB2CST8022(0H.F)2. Mg#=Mg'100/(Mg+Fa) Ca #s CaMOW(Ca+Mg+Fa) An«sCa*100/(Ca+Na+K) 602 Un 182 H Un 187 H H9-WI5, ci H8-11, ampH8-l2, tremolite IncI in H8-I2, circie 1, temoliti 9WI5Am8 9WI5Am9 9WI5Am1C8l1Am1 8l2Am1 8l2Am2 8l2Am3 8l2Am4 55.864 54.832 54.682 55.659 53.696 52.967 57.060 53.540 0.829 1.007 1.164 2.687 2.783 3.959 2.382 5.270 0.044 0.024 0.034 0.094 0.144 0.107 0.069 0.188 0.292 0.720 0.622 0.996 0.944 1.457 0.989 1.421 2.108 3.120 3.598 1.406 0.968 1.530 1.237 1.975 22.839 22.163 21.794 22.933 22.522 22.025 23.367 21.678 0.091 0.150 0.137 0.000 0.000 0.013 0.021 0.031 0.066 0.050 0.046 0.107 0.089 0.101 0.153 0.103 12.941 12.126 12.430 13.172 12.342 11.979 13.252 12.974 0.077 0.142 0.183 0.249 0.185 0.312 0.215 0.389 0.005 0.006 0.001 0.134 0.076 0.027 0.010 0.058 95.156 94.340 94.692 97.439 93.748 94.476 98.755 97.627 7.859 7.819 7.794 7.653 7.645 7.512 7.718 7.384 0.137 0.169 0.196 0.435 0.467 0.662 0.380 0.857 0.005 0.003 0.004 0.010 0.015 0.011 0.007 0.020 0.032 0.081 0.070 0.108 0.106 0.163 0.106 0.155 0.248 0.372 0.429 0.162 0.115 0.181 0.140 0.228 4.790 4.712 4.631 4.701 4.780 4.656 4.712 4.457 0.011 0.018 0.017 0.000 0.000 0.002 0.002 0.004 0.008 0.006 0.005 0.012 0.010 0.012 0.017 0.011 1.951 1.853 1.896 1.940 1.883 1.820 1.921 1.917 0.021 0.039 0.051 0.066 0.051 0.086 0.056 0.104 0.001 0.001 0.000 0.023 0.014 0.005 0.002 0.010 15.062 15.073 15.095 15.111 15.086 15.110 15.061 15.147 0.022 0.041 0.051 0.090 0.065 0.091 0.058 0.114 95.078 92.881 91.524 98.875 97.845 98.249 97.118 95.138 27.912 26.710 27.281 28.525 27.775 27.339 28.358 29.039 98.893 97.860 97.395 95.572 96.888 95.258 97.065 94.378 603 einclinchrU n 239 HUn 246 HH8-I5, circle 1, amp Un 225 Hi AmS 8l2Am6 8l2Am7 8l5Am1 8l5Am2 8l5Am3 8l5Am4 8l5Am5 55.451 53.685 54.311 54.953 54.461 56.284 53.365 53.195 3.027 4.186 3.715 4.515 3.941 2.078 3.746 4.448 0.095 0.154 0.124 0.402 0.633 0.361 0.921 0.233 1.252 1.140 1.238 0.143 0.136 0.000 0.102 0.633 1.615 1.687 1.847 2.960 3.641 3.149 5.473 2.158 22.779 22.100 22.243 21.243 20.967 21.959 20.543 21.932 0.043 0.023 0.019 0.018 0.097 0.017 0.131 0.026 0.117 0.105 0.091 0.110 0.049 0.285 0.065 0.123 13.071 13.085 12.905 12.735 12.557 12.892 11.846 12.562 0.406 0.406 0.239 0.569 0.555 0.290 0.462 0.779 0.030 0.047 0.070 0.019 0.017 0.023 0.041 0.032 97.885 96.617 96.800 97.667 97.054 97.337 96.695 96.120 7.603 7.472 7.537 7.563 7.572 7.775 7.512 7.451 0.489 0.687 0.608 0.732 0.646 0.338 0.622 0.734 0.010 0.016 0.013 0.042 0.066 0.037 0.097 0.024 0.136 0.125 0.136 0.016 0.015 0.000 0.011 0.070 0.185 0.196 0.214 0.341 0.423 0.364 0.644 0.253 4.656 4.585 4.602 4.359 4.346 4.522 4.311 4.580 0.005 0.003 0.002 0.002 0.011 0.002 0.016 0.003 0.013 0.012 0.010 0.012 0.005 0.032 0.007 0.014 1.920 1.951 1.919 1.878 1.871 1.908 1.787 1.885 0.108 0.110 0.064 0.152 0.150 0.078 0.126 0.211 0.005 0.008 0.012 0.003 0.003 0.004 0.007 0.006 15.131 15.165 15.117 15.099 15.108 15.059 15.141 15.231 0.113 0.118 0.077 0.155 0.153 0.082 0.134 0.217 96.175 95.894 95.550 92.749 91.123 92.555 88.998 94.788 28.399 28.981 28.492 28.552 28.172 28.085 26.500 28.063 94.435 94.298 98.182 92.372 92.458 95.893 93.047 89.888 604 8-15, circle 2, chlorite: î Un 226 H8-I5, circle 3, tremolite H8-I5, not Un 261 H9-I2, chrom 8l5Am6 8l5Am7 8l5Am8 8l5Am9 8l5Am10 8l5Am11 9l2Am11 912Ami 2 54.521 53.160 56.275 57.372 57.076 56.794 46.603 44.788 3.252 3.754 1.062 1.312 0.945 1.025 11.292 11.129 0.821 0.962 0.063 0.090 0.067 0.069 1.264 1.534 0.105 0.105 0.313 0.305 0.268 0.294 2.123 2.378 4.346 5.540 1.483 1.560 1.252 1.420 2.716 2.776 21.648 20.569 23.727 23.957 23.536 23.691 19.609 18.672 0.097 0.123 0.019 0.070 0.063 0.056 0.051 0.051 0.096 0.073 0.113 0.079 0.000 0.043 0.079 0.090 12.221 11.709 12.265 12.878 12.941 12.726 12.379 12.233 0.405 0.480 0.150 0.238 0.162 0.152 2.247 2.108 0.044 0.040 0.003 0.000 0.000 0.000 0.053 0.048 97.555 96.513 95.473 97.861 96.308 96.270 98.416 95.809 7.566 7.500 7.849 7.820 7.887 7.859 6.509 6.445 0.532 0.624 0.175 0.211 0.154 0.167 1.859 1.888 0.086 0.102 0.007 0.009 0.007 0.007 0.133 0.166 0.011 0.012 0.035 0.033 0.029 0.032 0.234 0.271 0.504 0.654 0.173 0.178 0.145 0.164 0.317 0.334 4.479 4.326 4.934 4.868 4.848 4.887 4.083 4.006 0.011 0.015 0.002 0.008 0.007 0.007 0.006 0.006 0.011 0.008 0.013 0.009 0.000 0.005 0.009 0.010 1.817 1.770 1.833 1.881 1.916 1.887 1.852 1.886 0.109 0.131 0.041 0.063 0.043 0.041 0.608 0.588 0.008 0.007 0.001 0.000 0.000 0.000 0.010 0.009 15.135 15.149 15.060 15.080 15.036 15.055 15.621 15.608 0.117 0.138 0.041 0.063 0.043 0.041 0.618 0.597 89.879 86.874 96.613 96.475 97.103 96.747 92.791 92.301 26.722 26.222 26.413 27.152 27.731 27.193 29.627 30.294 93.953 92.744 97.810 96.765 97.789 97.885 74.987 75.956 605 Palace Z9-P4, three 30 micron amps, meZ9-P4, trerZ9-P4, honZ9-P4, adj Z9-P5, circ Label 9P4Am1h 9P4Am2 9P4Am3 9P4Am4 9P4Am5h 9P4Am6 9P5Am1 Wt% Wt% Wt% Wt% Wt% Wt% Wt% S i0 2 48.304 56.620 55.117 59.123 50.164 59.545 58.425 AI203 10.524 3.700 3.312 0.065 8.324 0.057 0.998 TI02 0.248 0.119 0.072 0.023 0.220 0.027 0.023 Cr203 2.273 0.789 1.201 0.037 1.828 0.028 0.239 FeOtot. 1.895 1.426 1.343 0.797 1.686 0.693 1.449 MgO 19.601 22.905 22.025 23.778 20.312 24.054 23.370 MnO 0.022 0.038 0.004 0.024 0.046 0.054 0.020 NIO 0.140 0.122 0.093 0.106 0.129 0.100 0.104 CaO 12.729 12.566 13.082 13.467 13.007 13.658 13.447 Na20 1.815 0.652 0.532 0.000 1.311 0.029 0.297 K20 0.230 0.042 0.070 0.000 0.161 0.003 0.042 Total 97.779 98.976 96.849 97.420 97.188 98.248 98.415 Cations SI 6.743 7.639 7.626 8.042 7.006 8.033 7.914 AI 1.731 0.588 0.540 0.010 1.370 0.009 0.159 TI 0.026 0.012 0.007 0.002 0.023 0.003 0.002 Cr 0.251 0.084 0.131 0.004 0.202 0.003 0.026 Fe 0.221 0.161 0.155 0.091 0.197 0.078 0.164 Mg 4.079 4.607 4.543 4.822 4.229 4.837 4.719 Mn 0.003 0.004 0.001 0.003 0.005 0.006 0.002 NI 0.016 0.013 0.010 0.012 0.014 0.011 0.011 Ca 1.904 1.816 1.939 1.963 1.946 1.974 1.951 Na 0.491 0.170 0.143 0.000 0.355 0.008 0.078 K 0.041 0.007 0.012 0.000 0.029 0.001 0.007 Total 15.506 15.102 15.108 14.948 15.377 14.962 15.034 Na+K 0.532 0.178 0.155 0.000 0.384 0.008 0.085 M g# 94.857 98.625 96.893 98.155 95.550 98.410 96.638 C a# 30.686 27.588 29.217 28.548 30.544 28.653 28.552 A n# 78.157 91.088 92.803 100.000 83.532 99.587 95.813 Tabel C4.2: Collective analyeee, E. Zlkt Field Microprobe Analyeie & Calculated Formula (baaed on 23 Oxygene) of Amphibole, AB2CST8022(0H,F)2. Mg#=MgMOQ/(Mg+Fe) Ca » s Ca'10W(Ca+Mg+Fe) An«sCa*100/!(Ca+Na^K) 606 Z9-P5, circZ9-P5, circle 5, tremolite 9P5Am2 9P5Am3 Wt % Wt % 58.433 58.514 0.428 0.087 0.039 0.014 0.138 0.033 1.502 0.959 24.004 23.886 0.000 0.039 0.057 0.098 13.385 13.799 0.095 0.037 0.032 0.002 98.111 97.467 7.934 7.983 0.068 0.014 0.004 0.001 0.015 0.004 0.171 0.109 4.859 4.858 0.000 0.005 0.006 0.011 1.947 2.017 0.025 0.010 0.006 0.000 15.035 15.012 0.031 0.010 96.600 97.798 27.906 28.880 96.433 99.502 607 Shërq Z8-Sh5, cii Z8-Sh8, cii Z8-Sh8, cii Z8-Sh8, cil Z8-SH11, circle 6, tren Z8-Sh11, c Label 8Sh5Am1 8Sh8Am1 8Sh8Am2 8Sh8Am3 8Sh1lAm18Sh11AmZ8Sh11AmS O xides Wt % Wt % Wt % Wt % Wt % Wt % Wt % S I02 56.997 58.844 58.980 56.989 54.996 53.527 55.312 AI203 0.748 0.009 0.657 2.026 2.887 2.992 2.831 TI02 0.020 0.000 0.015 0.026 0.046 0.037 0.055 C r203 0.232 0.022 0.202 0.370 0.996 1.027 0.701 FeOtot. 1.365 0.765 0.929 1.070 1.985 1.853 1.671 MgO 24.069 24.505 24.950 24.137 22.934 22.423 22.824 MnO 0.062 0.040 0.015 0.017 0.076 0.049 0.027 NIO 0.088 0.104 0.099 0.148 0.110 0.068 0.061 CaO 12.803 13.437 12.860 13.100 12.501 12.563 12.990 N a20 0.220 0.034 0.231 0.522 0.676 0.670 0.650 K20 0.031 0.004 0.024 0.019 0.023 0.012 0.060 Total 96.635 97.763 98.962 98.423 97.227 95.220 97.183 Cations Si 7.863 7.987 7.911 7.728 7.601 7.562 7.635 AI 0.122 0.001 0.104 0.324 0.470 0.498 0.460 Ti 0.002 0.000 0.002 0.003 0.005 0.004 0.006 Cr 0.025 0.002 0.021 0.040 0.109 0.115 0.077 Fe 0.157 0.087 0.104 0.121 0.229 0.219 0.193 Mg 4.950 4.959 4.989 4.880 4.725 4.722 4.697 Mn 0.007 0.005 0.002 0.002 0.009 0.006 0.003 Ni 0.010 0.011 0.011 0.016 0.012 0.008 0.007 Ca 1.892 1.954 1.848 1.903 1.851 1.902 1.921 Na 0.059 0.009 0.060 0.137 0.181 0.183 0.174 K 0.006 0.001 0.004 0.003 0.004 0.002 0.011 Total 15.094 15.016 15.056 15.157 15.197 15.221 15.183 Na+K 0.064 0.010 0.064 0.141 0.185 0.186 0.184 M g# 96.917 98.279 97.954 97.574 95.370 95.570 96.055 C a# 27.034 27.918 26.626 27.568 27.200 27.790 28.208 A n# 96.712 99.515 96.643 93.122 90.913 91.109 91.239 Tabel C4.3: Collective analyses, B. Sharq (S. Zlkt) Field Microprobe Analysis & Calculated Formula (based on 23 Oxygens) of Amphibole, AB2C5T8022(0H,F)2. Mg#=Mg"10W(Mg+Fe) Ca « s Ca'10W(Ca+Mg+Fe) An* = Ca'10W(Ca+Na*K) 608 Z8-SH16, cZ8-Sh16, cZ8*Sh16, circle 4, tremolite 8Sh16Am18Sh16Am2 8Sh16Am£ 8Sh16Am4 8Sh16Am5 % Wt % wt % Wt % Wt % 59.175 57.055 57.941 57.009 58.366 0.073 1.634 0.230 0.427 0.074 0.006 0.030 0.013 0.041 0.003 0.014 0.125 0.057 0.229 0.075 1.244 0.776 1.006 0.817 0.884 24.386 23.866 24.126 23.686 24.584 0.094 0.000 0.065 0.039 0.021 0.143 0.112 0.103 0.136 0.131 13.242 13.174 13.204 13.489 13.325 0.029 0.114 0.053 0.098 0.006 0.008 0.019 0.001 0.008 0.005 98.414 96.904 96.798 95.979 97.474 7.991 7.823 7.955 7.909 7.955 0.012 0.264 0.037 0.070 0.012 0.001 0.003 0.001 0.004 0.000 0.001 0.014 0.006 0.025 0.008 0.141 0.089 0.115 0.095 0.101 4.909 4.878 4.938 4.898 4.995 0.011 0.000 0.008 0.005 0.002 0.015 0.012 0.011 0.015 0.014 1.916 1.935 1.942 2.005 1.946 0.008 0.030 0.014 0.026 0.002 0.001 0.003 0.000 0.001 0.001 15.006 15.052 15.029 15.054 15.036 0.009 0.034 0.014 0.028 0.002 97.217 98.208 97.715 98.102 98.023 27.505 28.037 27.764 28.650 27.633 99.529 98.289 99.278 98.829 99.874 609 Scorpion Z9-Sc1, cir Z9*Sc1, circle 6, IreirxZQ-Scl, lrcZ9-Sc2, circle 2, trerTKZ9*Sc2, tre Label 9SclAm1 9Sc1Am2 9Sc1Am3 9SclAm4 9Sc2Am1 9Sc2Am2 9Sc2Afn3 Oxidee Wt % h? W t% W t% Wt % h? Wt% W t% W t% S I02 52.478 56.600 56.954 51.822 58.128 58.454 57.205 AI203 5.246 2.451 1.479 4.602 0.442 0.399 0.663 TI02 0.061 0.028 0.014 0.093 0.000 0.004 0.005 C r203 1.689 0.490 0.320 1.386 0.209 0.210 0.279 F eO tot 1.224 1.431 1.482 1.143 1.591 1.549 1.565 MgO 23.103 24.216 25.040 22.831 24.369 24.204 23.565 MnO 0.040 0.030 0.056 0.028 0.027 0.041 0.025 NiO 0.174 0.114 0.143 0.109 0.090 0.091 0.069 CaO 11.483 11.832 11.322 11.907 13.305 13.068 13.380 N a20 1.233 0.684 0.426 1.165 0.018 0.011 0.012 K 20 0.134 0.056 0.035 0.089 0.002 0.000 0.004 Total 96.863 97.931 97.272 95.175 98.181 98.030 96.773 Catlona SI 7.291 7.705 7.787 7.330 7.896 7.938 7.889 AI 0.859 0.393 0.238 0.767 0.071 0.064 0.108 TI 0.006 0.003 0.001 0.010 0.000 0.000 0.000 Cr 0.185 0.053 0.035 0.155 0.022 0.023 0.030 Fe 0.142 0.163 0.169 0.135 0.181 0.176 0.181 Mg 4.785 4.915 5.104 4.814 4.935 4.900 4.844 Mn 0.005 0.003 0.007 0.003 0.003 0.005 0.003 Ni 0.019 0.012 0.016 0.012 0.010 0.010 0.008 Ca 1.709 1.726 1.659 1.804 1.937 1.901 1.977 Na 0.332 0.180 0.113 0.320 0.005 0.003 0.003 K 0.024 0.010 0.006 0.016 0.000 0.000 0.001 Total 15.358 15.164 15.135 15.367 15.060 15.020 15.044 Na+K 0.356 0.190 0.119 0.336 0.005 0.003 0.004 M g# 97.113 96.792 96.787 97.266 96.466 96.535 96.407 C a# 25.756 25.367 23.927 26.718 27.460 27.250 28.233 An# 82.771 90.072 93.303 64.317 99.730 99.645 99.796 Tabel C4.4: Collective analyeee, B. Scorpion (S. Zlkt) Field Microprobe Analyeie & Calculated Formula (baaed on 23 Oxygene) of Amphibole. AB2CST8022(0H.F)2. Mg#=MgMOW(Mg+Fe) Ca » s Ca*10W(Ca+Mg+Fe) An « s Ca'100/(Ca+Na*K) 610 imolite Z9-Sc2, another tren' Z9-Sc2, tremolite Z9-Sc7, circle 1, trem Z9-Sc7, circle 3, trei 9Sc2Am4 9Sc2Am5 9Sc2Am6 9Sc2Am7 9Sc2Am8 9Sc7Am1 9Sc7Ain2 9Sc7Am3 9Sc7Am4 ft% W t% Wt % Wt % Wt% 58.192 58.001 57.532 56.677 57.132 57.867 58.670 58.151 57.617 0.570 0.535 0.929 0.853 0.894 1.056 0.712 0.736 1.209 0.011 0.007 0.002 0.008 0.006 0.011 0.006 0.000 0.000 0.206 0.208 0.281 0.294 0.331 0.375 0.303 0.267 0.323 1.584 1.598 1.702 1.677 1.656 1.420 1.420 1.506 1.573 24.017 24.121 23.926 23.189 23.803 23.851 23.922 24.054 23.619 0.046 0.050 0.023 0.040 0.078 0.052 0.044 0.038 0.051 0.118 0.082 0.094 0.092 0.063 0.103 0.112 0.070 0.071 13.085 13.318 13.084 13.178 12.861 13.260 13.272 13.168 13.132 0.047 0.016 0.051 0.046 0.060 0.118 0.073 0.081 0.157 0.000 0.002 0.000 0.003 0.000 0.007 0.003 0.000 0.003 97.875 97.938 97.625 96.054 96.883 98.121 98.537 98.071 97.755 7.921 7.899 7.862 7.878 7.865 7.863 7.927 7.899 7.860 0.091 0.086 0.150 0.140 0.145 0.169 0.113 0.118 0.194 0.001 0.001 0.000 0.001 0.001 0.001 0.001 0.000 0.000 0.022 0.022 0.030 0.032 0.036 0.040 0.032 0.029 0.035 0.180 0.182 0.195 0.195 0.191 0.161 0.160 0.171 0.179 4.873 4.897 4.874 4.805 4.885 4.832 4.818 4.871 4.803 0.005 0.006 0.003 0.005 0.009 0.006 0.005 0.004 0.006 0.013 0.009 0.010 0.010 0.007 0.011 0.012 0.008 0.008 1.908 1.943 1.916 1.963 1.897 1.931 1.921 1.916 1.919 0.012 0.004 0.014 0.012 0.016 0.031 0.019 0.021 0.042 0.000 0.000 0.000 0.000 0.000 0.001 0.001 0.000 0.001 15.028 15.049 15.054 15.041 15.052 15.047 15.010 15.038 15.047 0.012 0.005 0.014 0.013 0.016 0.032 0.020 0.021 0.042 96.431 96.417 96.162 96.102 96.245 96.768 96.778 98.808 98.399 27.410 27.673 27.428 28.187 27.207 27.884 27.844 27.541 27.808 99.355 99.769 99.295 99.351 99.168 98.345 98.988 98.903 97.851 611 Z9-Sc7,clZ9*Sc7,cirUn 91 ZSUn 93 Z£Z9-Sc7, cirUn 113 ZUn 114 ZUn 116 Z c7Am5 9Sc7Am6 9Sc7Am7 9Sc7Am8 9Sc7Am9 9Sc9Am1 9Sc9Am2 9Sc9Am3 56.569 57.055 57.029 57.166 56.474 52.574 50.455 52.155 1.914 1.327 0.612 1.206 1.336 4.836 7.289 6.454 0.014 0.019 0.021 0.018 0.000 0.078 0.120 0.102 0.839 0.334 0.286 0.428 0.233 1.895 2.412 2.774 1.609 1.546 1.377 1.638 1.551 1.577 1.428 1.390 23.059 23.570 23.500 23.815 23.441 22.686 21.949 22.424 0.037 0.060 0.031 0.046 0.037 0.043 0.051 0.063 0.094 0.106 0.073 0.106 0.085 0.127 0.134 0.149 12.958 13.031 13.436 12.855 13.151 11.087 11.686 11.523 0.132 0.077 0.076 0.046 0.115 1.206 1.888 1.599 0.003 0.005 0.000 0.000 0.000 0.146 0.251 0.312 97.229 97.129 96.442 97.322 96.423 96.254 97.663 98.946 7.773 7.835 7.890 7.835 7.819 7.352 7.015 7.139 0.310 0.215 0.100 0.195 0.218 0.797 1.195 1.041 0.001 0.002 0.002 0.002 0.000 0.008 0.013 0.011 0.091 0.036 0.031 0.046 0.025 0.209 0.265 0.300 0.185 0.178 0.159 0.188 0.180 0.184 0.166 0.159 4.724 4.825 4.847 4.866 4.838 4.729 4.550 4.576 0.004 0.007 0.004 0.005 0.004 0.005 0.006 0.007 0.010 0.012 0.008 0.012 0.009 0.014 0.015 0.016 1.908 1.917 1.992 1.888 1.951 1.661 1.741 1.690 0.035 0.021 0.020 0.012 0.031 0.327 0.509 0.425 0.001 0.001 0.000 0.000 0.000 0.026 0.045 0.055 15.043 15.048 15.053 15.049 15.075 15.313 15.519 15.419 0.036 0.021 0.020 0.012 0.031 0.353 0.554 0.479 96.233 96.452 96.817 98.288 96.421 98.248 98.479 98.839 27.988 27.707 28.460 27.196 27.995 25.264 26.964 26.302 98.167 98.899 98.983 99.359 98.445 82.473 75.874 77.915 612 others H9-I2, pyroxenes & 2 Un 260 H9-I2, tremclite (955); chlorite (956); hombiend Label 9l2Am1 9l2Am2 9l2Am3 9l2Am4 9l2Am5 9l2Am6 9l2Am7 O xides SI02 53.012 57.177 55.130 49.019 46.650 46.659 44.836 AI203 4.192 1.632 2.883 7.292 10.077 11.314 11.003 TI02 0.353 0.218 0.265 1.190 1.539 1.669 1.691 Cr203 0.510 0.227 0.263 0.761 0.633 0.603 0.864 FeO tot 6.260 4.315 4.390 4.196 4.623 4.682 4.612 MgO 19.133 22.330 20.947 19.284 18.311 18.206 17.879 MnO 0.117 0.194 0.158 0.041 0.082 0.089 0.078 NIG 0.026 0.073 0.047 0.029 0.065 0.092 0.094 CaO 12.270 11.795 11.971 12.673 12.275 12.227 12.385 N a20 0.486 0.320 0.409 1.178 1.531 2.075 2.059 K20 0.012 0.000 0.013 0.084 0.124 0.144 0.129 Total 96.371 98.280 96.476 95.748 95.910 97.758 95.629 Cations Si 7.523 7.832 7.714 7.015 6.698 6.586 6.498 AI 0.701 0.264 0.475 1.230 1.705 1.882 1.879 Ti 0.038 0.022 0.028 0.128 0.166 0.177 0.184 Cr 0.057 0.025 0.029 0.086 0.072 0.067 0.099 Fe 0.743 0.494 0.514 0.502 0.555 0.553 0.559 Mg 4.048 4.560 4.370 4.114 3.920 3.831 3.863 Mn 0.014 0.023 0.019 0.005 0.010 0.011 0.010 NI 0.003 0.008 0.005 0.003 0.008 0.010 0.011 Ca 1.866 1.731 1.795 1.943 1.888 1.849 1.923 Na 0.134 0.085 0.111 0.327 0.426 0.568 0.579 K 0.002 0.000 0.002 0.015 0.023 0.026 0.024 Total 15.128 15.044 15.062 15.368 15.471 15.560 15.629 Na+K 0.136 0.085 0.113 0.342 0.449 0.594 0.603 M g# 84.493 90.220 89.476 89.125 87.598 87.388 87.359 C a* 28.027 25.512 26.875 29.623 29.672 29.665 30.307 An# 93.215 95.319 94.078 85.033 80.787 75.888 78.128 Tabel C4.5: Collective analysée. Different places In the mantle section Microprobe Analyele & Calculated Formula (based on 23 Oxygens) of Amphibole. AB2C5T8022(0H,F)2. Mg#sMg*100/(Mg+Fe) C a# = Ca'100/(Ca+Mg+Fe) An#sCa*100/(Ca4Na+K) 613 Un 431 H9-l2,trenfK)lite (1489): pyx (1490,1491.1494), hornblende (1492,1493) 9l2Am8 9l2Am9 9l2Am10 54.328 45.559 44.665 3.225 10.523 11.578 0.244 2.064 2.248 0.247 1.013 1.007 4.434 5.430 5.032 21.466 17.555 17.202 0.324 0.041 0.091 0.087 0.070 0.064 12.086 12.216 12.257 0.502 1.999 1.907 0.010 0.153 0.142 96.952 96.622 96.193 7.595 6.551 6.444 0.531 1.783 1.969 0.026 0.223 0.244 0.027 0.115 0.115 0.518 0.653 0.607 4.474 3.763 3.700 0.038 0.005 0.011 0.010 0.008 0.007 1.810 1.882 1.895 0.136 0.557 0.534 0.002 0.028 0.026 15.168 15.569 15.551 0.138 0.585 0.560 89.616 65.214 65.903 26.613 29.882 30.552 92.925 76.275 77.196 614 BIBLIOGRAPHY Alabaster, T., and Pearce, J. A., 1985. The interrelationship between magmatic and ore- forming hydrothermal processes in the Oman ophiolite.Econ. 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