Petrology of Inclusion-Rich Lavas at Minna Bluff, Mcmurdo Sound, Antarctica: Implications for Magma Origin, Differentiation, and Eruption Dynamics

Home , Kaersutite, Minna Bluff

PETROLOGY OF INCLUSION-RICH LAVAS AT MINNA BLUFF, MCMURDO SOUND, ANTARCTICA: IMPLICATIONS FOR MAGMA ORIGIN, DIFFERENTIATION, AND ERUPTION DYNAMICS

Mary K. Scanlan

A Thesis

Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of

MASTER OF SCIENCE

August 2008

Committee:

Kurt Panter (Ph.D.), Advisor

John Farver (Ph.D.)

Thom Wilch (Ph.D.)

Mary Scanlan

ABSTRACT

Kurt Panter, Advisor

Xeno Ridge, a newly discovered group of inclusion-rich deposits located at the top of the Minna Bluff stratigraphic section, formed as a result of magmatic mixing/mingling and provides insight into magma origins, mixing and eruption dynamics, and the evolution of Minna Bluff. Phonolite to tephriphonolite lavas are contain abundant inclusions which vary in size, shape, and mineralogy. Five inclusion types are identified at Xeno Ridge. The lavas that host the inclusions are dark-gray and porphyritic with a hypocrystalline, vesicular groundmass. Minerals within the host lavas include feldspar (plagioclase = An27–An84, alkali feldspar =

Ab41Or57−Ab70Or20), amphibole (kaersutite), diopside (~Wo55En35Fs10), titanomagnetite (Ti# 55), olivine (Fo45, Fo81), and apatite. Type I inclusions are highly vesicular with sinuous forms and crenulate margins with the host indicating magmatic mixing/mingling. The mineral

assemblage of Type I includes kaersutite (15-20 vol. %), feldspar (plagioclase = An33−An80, alkali feldspar = ~Ab55Or45), diopside (~Wo55En30Fs6), titanomagnetite (Ti# ~75), olivine (Fo48, Fo85) and apatite. Type II inclusions are kaersutite megacrysts and glomerocrysts dominated by kaersutite with subordinate phenocrysts, microphenocrysts and groundmass composed of

plagioclase (An20 – An76), titanomagnetite (Ti# 84), diopside (~Wo50En35Fs15), and apatite. Type III is a single porphyritic inclusion with phenocrysts of anorthoclase and is similar in texture and mineralogy to lavas found within the Minna Bluff stratigraphic section. Type IV are ‘salt and pepper’ colored inclusions with granular textures consisting of kaersutite with

interstitial plagioclase (An16 – An55), diopside (~Wo50En36Fs4), titanomagnetite, apatite, sodalite, titanite and olivine. Type V inclusions are similar in appearance to Type IV but have a different

mineral assemblage dominated by alkali feldspar (Ab50Or50), nepheline and plagioclase with subordinate, interstitial minerals of Fe-rich clinopyroxene (hedenbergite ~Wo50En17Fs38), titanomagnetite and leucite. Both Types IV and V have sharp contact margins with the host lava indicating that they were fully solidified when entrained by the host magmas, whereas Types I and II were semi-molten. Semi-quantitative geothermobarometric results for kaersutite and clinopyroxene indicate that some crystallized at P-T conditions in the lower crust to upper mantle (5-9 kbars = 15-27 km). High water contents in the magmas induced early crystallization of amphibole and clinopyroxene and suppressed plagioclase, which crystallized along with magnetite at shallow levels within the crust. Four stages are deduced for the mixing and ascent of magma bodies and the incorporation of inclusion types at Xeno Ridge. Stage I: phonolitic magmas that comprise lava compositions prior to mixing with Type I magma ascend into the upper crust. Stage II: replenishing phonotephritic magmas (Type I) ascend from depth within the same conduit system and incorporate partially solidified material (Type II) that originated from sidewall crystallization of previous magmas. Stage III: the mixing event triggered a second episode of magma ascent. Stage IV: the rapid ascent of mixed magmas entrained crystalline selvages of Type IV and V compositions from conduit walls before eruption.

To my mother, who taught me to always challenge myself and that hard work will result in achieving all I could ever hope. Without your constant love and support, I would not be the person I am today.

To my father, who shared a passion for rocks which has inspired and shaped my studies, and will forever influence my life. Thank you for your encouragement, support, and patience. They are and always will be significant, even if you do love soft rocks…

And to my two closest friends, Elle Scanlan and Paul Hogan, who each helped me carry on. Thank you so much for being understanding and always ready to offer inspiring words of motivation. Your advice and loving words will never be forgotten.

ACKNOWLEDGMENTS

The completion of this project would not have been possible without the encouragement and support of my colleagues, peers, friends, and family.

Thank you to my advisor and friend, Kurt Panter, for providing wonderful research and lifetime experiences. I will cherish them all for the rest of my life. I treasure the ability to one day share my Antarctica experience with my children and grandchildren, and for that I am grateful. Thank you for pushing me to think outside of the box, but to keep my feet grounded. I have learned patience and self encouragement during your sabbatical, and the completion of this project was in part driven by my desire to make you proud. Thank you for everything.

Thank you to the Minna Bluff team for welcoming me into the Antarctica community and for helping me through my fear of heights. Without constant encouragement on the ice from Thom Wilch (Albion College) and John Smellie (British Antarctica Survey), I would have been lost. Thank you! Thank you to Bill McIntosh and Nelia Dunbar (New Mexico Institute of Mining and Technology) for welcoming me into your home and your lab. Your hospitality will always be appreciated.

A special thank you to all in the BGSU geology department. In particular, I would like to thank Shelia Roberts for always offering a supportive ear and words of encouragement. You are a wonderful friend. Thank you Pat Wilhelm and Bill Butcher for attending to my every need while Kurt was away. Your help will always be much appreciated. Thank you to John Farver for answering my silly questions and always being available for counsel. A special thank you goes to Jim Evans for sharing a passion for soft rocks, for which my father will be forever grateful. Thank you to my fellow graduate students who always made me feel welcome and at home.

Finally, I would like to thank my family for always being understanding, supportive, and encouraging. Your love and kindness will remain in my heart, and for that I am forever grateful.

TABLE OF CONTENTS

Page

INTRODUCTION ...... 1

Geologic Background...... 2

FIELD RELATIONSHIPS ...... 6

Geology of Minna Bluff...... 6

Xeno-Ridge...... 9

ANALYTICAL TECHNIQUES...... 13

Mineral Chemistry ...... 13

Whole-Rock Chemistry ...... 14

RESULTS ...... 15

Host Lavas...... 15

Inclusions ...... 23

Type I ...... 23

Type II ...... 32

Type III...... 38

Type IV...... 41

Type V...... 46

Comparison of Inclusions and Host Lavas ...... 49

Amphibole...... 52

Clinopyroxene...... 52

Feldspar and Feldspathoid...... 55

Titanomagnetite ...... 59 vii

Olivine ...... 59

Comparison Summary ...... 64

Comparison of Whole Rock Compositions ...... 64

Thermobarometry ...... 65

Clinopyroxene Structural Barometer ...... 66

Amphibole Thermobarometry ...... 67

Relative Ternary Feldspar Thermometry...... 75

DISCUSSION ...... 77

Mineralogical and Textural Diversities ...... 78

Amphibole...... 78

Clinopyroxene...... 79

Feldspar...... 80

Inclusion Origins...... 81

Xeno Ridge Magmatic Progression ...... 87

CONCLUSIONS...... 90

REFERENCES ...... 92

APPENDICES ...... 98

Appendix A, Sample List...... 99

Appendix B, Mineral Chemistry...... 105

Host Compositions...... 106

Type I Compositions...... 151

Type II Compositions...... 178

Type IV Compositions...... 196 viii

Type V Compositions...... 205

Appendix C, Whole-Rock Compositional Data...... 212

Appendix D, Geothermal Barometry...... 215 ix

LIST OF FIGURES

Figure Page

1 Generalized map of Antarctica and satellite image of the Discovery

Volcanic Complex and Ross Island ...... 3

2 Satellite image of Minna Bluff ...... 7

3 TAS diagram of Minna Hook and Xeno-Ridge volcanics...... 8

4 Extent of Xeno-Ridge with sample locations ...... 10

5 Field images of Xeno-Ridge and Big Yellow...... 11

6 Thin section images of host lavas ...... 16

7 Host mineral diagrams of feldspar and feldspathoid minerals...... 20

8 Host mineral diagrams of amphibole, clinopyroxene, and olivine ...... 21

9 Hand sample and thin section images of Type I inclusions...... 25

10 Type I mineral diagrams of amphibole, clinopyroxene, and olivine ...... 30

11 Type I mineral diagrams of feldspar and feldspathoid minerals...... 31

12 Hand sample and thin section images of Type II inclusions ...... 33

13 Type II mineral diagrams of amphibole, clinopyroxene, and olivine...... 36

14 Type II mineral diagrams of feldspar and feldspathoid minerals ...... 37

15 Hand sample and thin section images of Type III inclusions ...... 39

16 Hand sample and thin section images of Type IV inclusions...... 42

17 Type IV mineral diagrams of amphibole, clinopyroxene, and olivine ...... 44

18 Type IV mineral diagrams of feldspar and feldspathoid minerals...... 45

19 Hand sample and thin section images of Type V inclusions ...... 47

20 Type V mineral diagrams of feldspar and feldspathoid minerals...... 50 x

21 Type V mineral diagrams of amphibole, clinopyroxene, and olivine...... 51

22 Comparative mineral diagrams of amphibole, clinopyroxene, and olivine...... 54

23 Comparative plots of clinopyroxene phenocryst and microphenocryst

core compositions ...... 58

24 Comparative mineral diagrams of feldspar and feldspathoid minerals ...... 60

25 Comparative plots of titanomagnetite compositions...... 62

26 Clinopyroxene crystallization pressures ...... 68

27 Variation in amphibole Al- and Ti-Tschermak substitutions ...... 70

28 Variation in amphibole Aliv and Alvi ...... 71

29 Relative amphibole thermobarometry using Ti and Al2O3 contents...... 73

30 Mantle-derived versus shallow crustal amphibole crystallization...... 74

31 Ternary feldspar thermometry diagrams...... 76

33 Schematic cartoon of mineral crystallization sequences ...... 86

33 Schematic cartoon of the evolution of Xeno-Ridge...... 88 xi

LIST OF TABLES

Table Page

1 Host representative mineral chemistry...... 17, 18

2 Host and inclusion sample table ...... 24

3 Type I representative mineral chemistry...... 27, 28

4 Type II representative mineral chemistry ...... 34, 35

5 Type III petrographic summary ...... 40

6 Type IV representative mineral chemistry...... 43

7 Type V representative mineral chemistry...... 48

8 Amphibole compositional span between host and inclusions...... 53

9 Clinopyroxene compositional span between host and inclusions...... 56, 57

10 Feldspar compositional span between host and inclusions...... 61

11 Variation in titanomagnetite compositions ...... 63

12 Variation in olivine compositions...... 63

INTRODUCTION

Inclusions (a.k.a. enclaves, xenoliths) and megacrysts (a.k.a. xenocrysts, antecrysts) in igneous rocks have diverse origins and may or may not be chemically related to their host. If related (i.e. comagmatic, cognate) the inclusions can provide important information regarding (1) melt sources and generation processes (e.g., Wilkinson and Hensel, 1991; Shaw and Eyzaguirre,

2000; Gençalioğlu Kuşcu and Floyd, 2001; Ruebi et al., 2002); (2) temperature and pressure variations (e.g., Bondi et al., 2002; Corsaro et al., 2006; Woodland and Jugo, 2007); and (3) evolution and dynamics of magmatic systems (e.g., Kawabata and Shuto, 2005; Egorova et al.,

2006). Accidental inclusions that are chemically distinct from the host magmas can be used to constrain physical properties, such as heat flow estimates, and composition of the underlying crust and mantle (e.g., McGibbon, 1987; Reay and Sipiera, 1987; Alletti et al., 2005; Martins et al., 2008; Ray et al., 2008).

Inclusions that occur in Cenozoic volcanic rocks from West Antarctica have been used to decipher magma origin and evolution history (e.g., McGibbon, 1987; Wright-Grassham, 1987;

Hornig and Wörner, 1991; Panter et al., 1997). Accidental inclusions of continental crust have been used to determine geothermal gradients and crustal thickness beneath the Transantarctic

Mountains and the Victoria Land Basin (Berg, 1984, 1987; Berg et al., 1989). Mantle inclusions have provided information regarding the composition and P-T conditions of the upper mantle

(Gamble et al., 1988; Hornig and Wörner, 1991; Perinelli et al., 2006).

This study presents petrography, mineral chemistry, and whole-rock compositions of inclusions, megacrysts, and their host lavas from Minna Bluff, which is located in the McMurdo

Sound region of the southern Ross Sea (Fig. 1). The inclusion-rich deposits, hereafter referred to as Xeno Ridge, contain both comagmatic and accidental inclusions. Xeno Ridge consists of

2 grey, vesicular host lava with an abundance of inclusions and inclusion types. Five inclusion types have been identified and range from highly vesicular inclusions with fluidal contacts to crystalline cumulate inclusions which vary between amphibole- and clinopyroxene-dominated mineralogies. The objectives of this study are to (1) characterize the host lavas and inclusions using petrographical, mineralogical, and geochemical methods; (2) determine the compositional and physical (P-T) relationships of the inclusions and host; and (3) to develop and interpretive model to explain their relationships and evolution of the magmatic system.

Geologic Background

Minna Bluff is located the western Ross Sea in south Victoria Land (Fig. 1) and is part of the

McMurdo Volcanic Group (Kyle, 1990). Minna Bluff is near the southern extent of the Victoria

Land Basin, which is one of many extensional basins developed in West Antarctica.

Physiographically, West Antarctica is a broad region of extended and thinned lithosphere bounded to the south and west by the Transantarctic Mountains and to the east and north by the

Pacific Ocean basin. Extension and rifting began in the Late Mesozoic and further developed through the Cenozoic (Wilson, 1999; Wörner, 1999; Sieminski et al., 2003; Watson et al., 2006) and several north-south oriented sedimentary basins are located within the Ross Sea (e.g.,

Victoria Land Basin, Northern Basin). A later stage of extension within the Victoria Land Basin has produced the Terror Rift (Cooper et al., 1987; Kyle et al., 1992; Wilson, 1999; Huerta and

Harry, 2007) which is located to the north of Minna Bluff. Cenozoic alkaline igneous rocks associated with rifting are found throughout West Antarctica (Fitzgerald et al., 1986; LeMasurier and Thomas, 1990) but the fundamental cause of the magmatism is still a subject of considerable debate (Finn et al., 2005).

Figure 1: Generalized map of Antarctica and satellite image of the Discovery Volcanic Complex and Ross Island within South Victoria Land modified from NASA ASTER image. Minna Bluff is a 50 km long peninsula extending south-eastward from Mt. Discovery. Minna Bluff, Brown Peninsula, and Mt. Morning form a three-armed or a ‘Mercedes Benz’ geomorphic pattern of volcanism surrounding Mt. Discovery (shown by the dashed red line), which is replicated by Erebus Volcano on Ross Island. The Terror Rift (shown by the dashed green line) is proposed to hinge at the Discovery Accommodation Zone, representing the region in which the Terror Rift steps at Minna Bluff (Wilson, 1999; Naish et al., 2007). Minna Bluff is divided geomorphically into two segments: ~35 km axis of the peninsula extending ESE from Mt. Discovery; and ~20 km long, NS oriented arm at the eastern end of the peninsula known informally as Minna Hook.

The Royal Society Range located to the west of Minna Bluff is part of the Transantarctic

Mountains in southern Victoria Land (Fig. 1). The Transantarctic Mountains are the highest and most extensive extensionally-related rift-bounded fault block uplift in the world (Van der

Wateren and Cloetingh, 1999; Watson et al., 2006). Crustal thicknesses below the Transantarctic

Mountains estimated from geophysical data vary between 20–45 km thick (tenBrink et al., 1993,

1997; Cooper et al., 1997; Lawrence et al., 2006; Bannister et al., 2003), whereas crust underlying the Victoria Land Basin is estimated to be 19–20 km thick (Trehu, 1989; Cooper et al., 1997; Lawrence et al., 2006). Although the cause of the uplift is still uncertain, a potential mechanism may be related to the thermal buoyancy of the underlying asthenosphere (ten Brink et al., 1997; Studinger et al., 2004; Lawrence et al., 2006). The movement of warm asthenosphere under thin West Antarctic lithosphere (Sieminski et al., 2003; Lawrence et al., 2006; Watson et al., 2006) may be related to upwelling sublithospheric plumes which, in turn, have been used to explain the underlying cause of Cenozoic magmatism in this area (Kyle et al., 1992; Sieminski et al., 2003). Alternatively, passive asthenospheric flow into thinned areas at the base of the lithosphere may be the trigger for volcanism (Wörner, 1999; Huerta and Harry, 2007).

The Discovery Accommodation Zone, as defined by Wilson (1999), is an area of pronounced offset along the Transantarctic Mountain front in the vicinity of Minna Bluff. The zone consists of two isolated structural blocks bounded by transform faults (Fitzgerald, 1992;

Mazzarini et al., 1997). Wilson (1999) suggests that the alkaline volcanism in this region may be controlled by the oblique structures of the accommodation zone and Minna Bluff may reflect an offshore extension of one these transverse structures (Wilson, 1999).

The Erebus Volcanic Province, which includes Minna Bluff, represents the largest area of exposed Late Cenozoic volcanic rocks and potentially the longest and most complete eruptive

5 record in Antarctica (Kyle, 1990; Kyle and Cole, 1974). The terrestrial volcanic rocks range in age from ~19 Ma to the current Strombolian-style activity on Erebus Volcano. Older volcanic material has been recovered from drill cores (CIROS-1, MSSTS-1, Cape Roberts, and AND-2A) and extends the volcanic history of this region back to 24 Ma (Gamble et al., 1986; Barrett, 1987;

McIntosh, 2000; Harwood et al., in review).

Inclusion-rich lavas similarly to the volcanic deposits found at Minna Bluff, are present at many locations within the southern Ross Sea (Berg, 1984, 1987; McGibbon, 1987; Wright-

Grassham, 1987). Upper and lower crustal xenoliths have been identified within lavas erupted on Ross Island (Hut Point Peninsula, Cape Barne and Cape Crozier; Berg, 1984) around Mt.

Discovery (Minna Bluff and Brown Peninsula; Berg, 1984, 1987; Wright-Grassham, 1987) and on White Island (Cooper et al, 2007). Mantle xenoliths have been identified at Foster Crater

(Berg, 1984; Gamble et al., 1988), Mt. Melbourne (Hornig and Wörner, 1991) and Brown

Peninsula (Kyle et al., 1979). Megacrysts of amphibole and pyroxene are also documented at several locations, including Ross Island (Moore and Kyle, 1987), Minna Bluff (Wright-

Grassham, 1987), and White Island (Cooper et al., 2007).

FIELD RELATIONSHIPS

Geology of Minna Bluff

Minna Bluff is a 50 km long peninsula that extends in an eastward direction from Mt. Discovery

(Fig. 1). Minna Bluff along with Brown Peninsula and Mt. Morning form a three-armed pattern of volcanism centered on Mt. Discovery. Ross Island exhibits a similar pattern of volcanism centered on Mt. Erebus (Fig. 1). Minna Bluff is divided geomorphically into two segments. The first segment comprises the long axis (~35 km) of the peninsula extending ESE from Mt.

Discovery and the second segment is delimited by a ~20 km long NS-oriented arm at the eastern end of the peninsula known informally as Minna Hook (Fig. 2). Field studies for the 2006/07 season focused exclusively on Minna Hook. Observations at Minna Hook confirm many of the features that were first described by Wright-Grassham (1987).

Overall, the geology of Minna Bluff is relatively well exposed and consists of volcanic deposits dominated by lavas and breccias with subordinate hydrovolcanic facies (e.g., pillow lavas, hyaloclastite breccias) and minor tephra. The volcanic pile is intruded by numerous domes and small dikes, many of which are well exposed within the east-facing cliffs of Minna

Hook. Deposits that are exposed in the lower cliff face at Minna Hook show alternating layers of subglacially erupted lavas and domes, pillow lavas and hyaloclastite breccias that are interstratified with thin glacial sediments (e.g. till). Along the top of the peninsula are more than

50 monogenetic cones that consist of lavas and interbedded scoria lapilli and agglutinated spatter deposits. Many of these cones contain megacrysts of pyroxene and amphibole and ‘salt and pepper’ colored inclusions composed of feldspar with variable abundances of ferromagnesium phases (amphibole, magnetite, clinopyroxene). The composition of the lavas and domes from

Figure 2: Minna Hook modified from the 15m NASA ASTER image. The location of Minna Hook with respect to Minna Bluff is shown by the dashed black box within the figure inset (from Fig. 1). The dashed red line in Fig. 2 represents the northern extent of Minna Hook volcanic deposits (south of line) from glacial moraine (north of line). The solid black box represents the study area of Xeno-Ridge on the uppermost portion of the Minna Hook stratigraphic section. The approximate camp locations from the 2006/07 Minna Hook season are denoted as well.

the Minna Hook show a full range of alkaline types from basanite to phonolite (Fig. 3;

Appendices A and C).

The volcanic deposits at Minna Bluff are Late Miocene to Early Pliocene in age (7–11

Ma) based on six K–Ar dates (Wright-Grassham, 1987). A detailed geochronology investigation of Minna Bluff samples collected during the 2006/07/08 field seasons is currently being undertaken by other members of the Minna Bluff team. Rocks are being dated using the

40Ar/39Ar method and will provide a complete history of the volcanic development of Minna

Bluff.

Xeno Ridge

Xeno Ridge is an informal name for a newly discovered group of inclusion-rich deposits located

at the top of the Minna Hook stratigraphic section (Figs. 2 and 4). The deposits range from ~5 to

over 20 m in thickness, ~10 to over 200 m in width, and altogether span an area of ~1 km

oriented in a NE-SW direction (Fig. 4). The deposits of Xeno Ridge are primarily dark-gray in

appearance and contain abundant inclusions which vary in size, shape, color, and mineralogy

(Fig. 5 a,b). A unique feature found in all deposits at Xeno Ridge is the occurrence of dark gray

highly vesicular inclusions that show highly sinuous forms and fluidal contacts with the host lava

which suggest mingling of magmas prior to eruption (described below).

The south-western end of Xeno Ridge consists of a volcanic breccia, informally named

Big Yellow (Figs. 4 and 5 c,d). The breccia is yellow to beige in color and contains clasts of

flow banded lava and lava bombs, some of which contain inclusions as well as amphibole

megacrysts. In places the breccia has been intruded by lavas which have baked and oxidized the

Figure 5: Big Yellow and Xeno-Ridge field images as labeled in Figure 4. (A) and (B) are from sample site MS-169 and show the relative abundance and nature of the host and Type I, II, and V. Unfortunately, no field images of Type II and IV are available. (B) and (C) represent the relationship between Big Yellow breccia (Fig. 4 for field location of Big Yellow) and the host lava. The red dashed line in (C) and (D) represents oxidization margin between the Xeno-Ridge host lava and the Big Yellow breccia. The host lava intrudes Big Yellow and in some cases, clasts and bombs of inclusion rich host are present within Big Yellow (as shown in D).

12 breccia on contact (Fig. 5c). The breccia at Big Yellow has a similar lithology to breccias associated with other domes observed in the Minna Hook area.

The lavas that intrude and surround the breccia and make up most of Xeno Ridge are dark to light grey in color, exhibit sub-vertical flow banding, and contain a variety of inclusion types and amphibole megacrysts. Inclusions consist of dark vesicular types, euhedral amphibole megacrysts and glomerocrystic clots, and lighter colored, subrounded to angular, ‘salt and pepper’ types. The details of each inclusion type, including texture, mineralogy, and mineral chemistry, are presented below. At the north-eastern end of Xeno Ridge is a dome, informally named Big Dome (Fig. 4). The lavas of Big Dome have similar textures and mineralogy as the other lavas at Xeno Ridge as well as a similar spectrum of inclusion types. Overall the diversity and abundance of the inclusions is the greatest in the middle portion of Xeno Ridge (near the sample localities for MS-114 and MS-169 in Fig. 4).

ANALYTICAL TECHNIQUES

A total of 176 samples from the Minna Hook area of Xeno Ridge were collected, and of those 41 thin sections from Minna Hook’s stratigraphic sequence and 32 thin sections from Xeno Ridge were examined using standard optical techniques. Nine polished sections were analyzed for mineral chemistry. Particular care was taken in preparing rock sections in order to preserve the contact between the inclusions and host lavas with 30 of the 32 thin and polished sections containing inclusion−lava contacts. The minerals in both inclusions and host lava are subdivided based on the natural distribution in crystal size. Megacrysts are defined as crystals with long axes larger than 2 cm. Crystals with long axes between 1 mm and 2 cm are referred to as phenocrysts and those smaller than 1 mm as microphenocrysts. Smaller crystals (< 1 mm), identifiable by optical properties, are designated as microlites.

Mineral Chemistry

Electron microprobe analyses were conducted at the New Mexico Institute of Mining and

Technology using a three-spectrometer Cameca SX-100 electron microprobe with the assistance of Dr. Nelia Dunbar and Lynn Heizler. The Cameca SX-100 is equipped with one energy- dispersive and three wavelength-dispersive spectrometers as well as a secondary electron and high-speed backscattered electron detectors. A beam current of 19.9 nA and an accelerating voltage of 1 kv were used during analysis. The detection limit of major elements is ~0.2 wt % with an analytical uncertainty of < 1.0 % and trace element uncertainty is < 10 %. Nine sections representing the diversity of inclusions and host lava found at Xeno Ridge were examined and a total of 714 spot analyses were completed. Microprobe analyses of the cores and rims of crystals were used to identify variation in chemical compositions of individual minerals.

Whole Rock Chemistry

Whole rock analysis of major and trace elements of the seven Xeno Ridge samples were obtained using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry

(ICP-MS) at the GeoAnalytical Lab, Washington State University. XRF analyses were performed using a ThermoARL Advant'XP+ sequential XRF spectrometer and ICP-MS analyses were measured using a HP (now Agilent) 4500+ ICP-MS. Prior to analyses, samples were prepared at Bowling Green State University. Samples were cut using a rock saw, then soaked in a ~5.0% HNO3 solution, and placed in an ultrasound bath for 15–25 minutes or until saw marks

were removed. These rock pieces were rinsed with distilled water and allowed to air dry before

further chipping and powdering. Inclusion chips were carefully separated from host with the aid

of a binocular microscope prior to powdering in a tungsten-carbide puck mill. Results from

powdered quartz sand show background concentrations < 0.14 ppm for elements Th, Nb, Y, Hf,

Ta, U, Pb, Rb, Cs, Sc, Zr, and all of the lanthanide series elements (La through Lu). Lead, Ba and Sr in the quartz have slightly higher concentrations at 0.24, 1.0, and 1.0 ppm, respectively.

The highest concentration measured is W at 3027 ppm, which is sourced from the mill itself.

The precisions are <1.0% (2 sigma) for XRF major and trace elements.

RESULTS

The inclusions and host lavas from Xeno Ridge are classified based on petrography and mineral chemistry. In this section, the results for the host lavas are first described followed by the inclusion types. Mineral chemistry and petrology of host lavas and inclusion types are arranged in order of abundance with the most abundant described first. Comparisons between host and inclusion types are then made by discussing each mineral type separately. Finally, mineral chemistry for clinopyroxene, amphibole, and feldspar are used to estimate temperatures and pressures of crystallization.

Host Lavas

The host rock is a dark-gray, porphyritic lava with a hypocrystalline and vesicular groundmass

(Figs. 5 a,b and 6). Irregularly shaped vesicles are abundant throughout the host, comprising ~5–

7 % of total volume and range in size from < 0.01 mm to 0.1 mm in diameter. Larger (up to 5 mm in diameter) elongated and oblong-shaped vesicles are abundant in the host lava within ~1–2 mm of the contact with the inclusions. The minerals within the host include, in order of abundance, feldspar, clinopyroxene, amphibole, titanomagnetite, feldspathoids, olivine, and apatite. Overall, phenocrysts display a seriate texture and feldspars are aligned to produce a pilotaxitic texture (Fig. 6 a,b) which is most obvious near inclusion margins. Generally, the intensity of pilotaxitic textures in the host appears to coincide with the abundance of Type I inclusions. Specifically, strongly aligned textures occur in areas which have a lower abundance of Type I inclusions. Also in these areas, large feldspar phenocrysts show well developed sieved textures (Fig. 6c).

Figure 6: Thin section images from host lavas found at Xeno-Ridge. (A, B) These thin section images represent the trachytic texture (subparallel alignment of tabular plagioclase phenocrysts) within the host. (C) Many plagioclase microphenocrysts have highly sieved cores and are bounded by rims free of melt inclusions. This thin section image is taken using a petrographic microscope. (D) The majority of amphibole phenocrysts and microphenocrysts have sieve textures. This thin section image shows the partial replacement of kaersutite by clinopyroxene, magnetite, and plagioclase. (E) Olivine phenocrysts often occur in glomeroporphyritic clusters surrounded by reaction produced diopside microphenocrysts. Mineral abbreviations: Fel – feldspar; Kers – kaersutite; Mgn – magnetite; Cpx – clinopyroxene; Ol – olivine; Ves – vesicle

Representative mineral chemistry is given in Table 1 and all results for the host lava are provided in Appendix B. The whole-rock composition ranges from tephriphonolite to phonolite

(Fig. 3; Appendix C). Mineralogy and mineral chemistry for host lavas are discussed below in order of abundance.

Feldspar and feldspathoid phenocrysts include plagioclase (An27–An84, 5–8 vol. %) with

lesser amounts (< 1 vol. %) of alkali feldspar (Ab41Or57−Ab70Or20) and nepheline (Fig. 7a; Table

1; Appendix B). Microphenocrysts of feldspar and feldspathoid have a greater compositional

variability (Fig. 7a and Table 1) but consist predominantly of plagioclase (An17−An39, 30–35 vol.

%) with lesser amounts (2–5 vol. %) of alkali feldspar (Ab70Or11), nepheline, and leucite.

Plagioclase and alkali feldspar phenocrysts often display a sieved texture bounded by inclusion- free rims (Fig. 6c). Plagioclase phenocrysts show increases, decreases, and oscillations in An content from core to rim. Similarly, alkali feldspar phenocrysts also show reverse and oscillatory

zoning with respect to An content. Phenocryst and microphenocryst core and rim compositions are shown in Figure 7b. Groundmass compositions include plagioclase (An16–An46) and alkali

feldspar (Ab42Or56–Ab73Or11). Groundmass feldspar are on average more K + Na –rich relative

to phenocryst and microphenocryst compositions (Figs. 7a).

Clinopyroxene crystals are subhedral diopside with minor hedenbergite (< 2 vol. %).

There is no compositional variation with crystal size (Fig. 8a; Table 1; Appendix B). The majority of clinopyroxene phenocryst and microphenocryst compositions plot above the wollastonite 50% line (Fig. 8 a,b).

Amphibole crystals range from euhedral to subhedral (phenocrysts 8–10 vol. %, microphenocrysts ~10 vol. %) and commonly display partially resorbed textures with amphibole being replaced by clinopyroxene, magnetite, and plagioclase (Fig. 6a,d). The replacive and sieve

Figure 7: Host lava feldspar and feldspathoid mineral compositions are plotted on the feldspar ternary diagram with end-member compositions of anorthite (An), albite (Ab), and orthoclase (Or). (A) Feldspar phenocryst, microphenocryst, and groundmass, and feldspathoid minerals are plotted. Host plagioclase phenocryst compositions span An27 to An84, microphenocrysts An17 to An39, and groundmass An16 to An46. Alkali feldspar phenocrysts range Ab41Or57 to Ab70Or20, microphenocrysts Ab70Or11, and groundmass Ab42Or56 to Ab73Or11. (B) Feldspar core and rim compositions are plotted. Phenocryst core compositions span An35 to An84 for plagioclase and Ab47Or50 to Ab61Or28 for alkali feldspar.

Figure 8: Host lava amphibole, clinopyroxene, and olivine mineral compositions are plotted on the following diagrams. (A) Phenocryst, microphenocryst, and groundmass compositions are plotted on the clinopyroxene quadrilateral diagram with end-members enstatite (En), ferrosilite (Fs), Wo50 [which is comprised of diopside (Mg:Fe > 50%) and hedenbergite (Mg:Fe < 50%)]. Diopside phenocryst compositions range Wo48En32Fs19 to Wo62En32Fs6, microphenocrysts Wo47En40Fs13 to Wo55En38Fs7, and groundmass Wo47En36Fs17 to Wo57En31Fs12. Hedenbergite phenocryst compositions range Wo51En23Fs26 to Wo62En32Fs7, microphenocrysts Wo51En25Fs24 to Wo53En22Fs25, and groundmass Wo52En19Fs38 to Wo52En25Fs23. Olivine occurs as microphenocrysts, Fo81 to Fo85 and Fo45 to Fo48. (B) Core and rim compositions are plotted on the clinopyroxene quadrilateral diagram. Diopside core compositions range Wo48En32Fs19 to Wo62En32Fs6 for phenocrysts and Wo47En40Fs13 to Wo55En38Fs7 microphenocrysts. Hedenbergite phenocryst compositions range Wo51En23Fs26 to Wo62En32Fs7. Olivine microphenocryst cores range Fo81 to Fo85 and Fo45 to Fo48, and rims Fo81. (C) Amphibole core, rim, and groundmass compositions are plotted on Mg (apfu) vs. octahedral Al. The solid black line represents the core and rim compositions from single phenocrysts and the solid grey line represents single microphenocryst core-rim end-members. Amphiboles were named following the classification of Leake et al (1997) and recalibration schemes of Esawi (2004) and Holland and Blundy (1994). Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

22 textures are a result of devolatilization of amphibole during magma ascent (Rutherford and Hill,

1993; Browne and Gardner, 2006). Compositionally, amphiboles are kaersutite (classification of

Leake et al., 1997) with variable Mg (1.31–2.74 apfu), Fe (Fe3+ 0.02–0.27 apfu, Fe2+ 1.13–2.58 apfu), Ti (0.49–0.77 apfu) and Al (TAl 2.02–2.50 apfu, M1-M3Al 0.06–0.33 apfu) contents (Fig. 8

a,c; Table 1; Appendix B). Like clinopyroxene, there is no difference in composition with

crystal size (phenocryst Mg# [100*Mg/(Mg+Fe2+)] 34–70, microphenocryst Mg# 40–67,

groundmass Mg# 50–63; Fig. 7b), however, analyses of intact (un-resorbed) kaersutite

phenocrysts (Fig. 8c) generally show an overall increase in Mg# between core and rim (Table 1)

with some oscillatory variations noted. A single phenocryst within the host shows a 0.6–9.3 %

increase in Mg# from core to rim (Mg# core = 43–63, rim = 52–69), with two other crystals

showing a 21.9 to 24.8 % increase (Mg# core = 34–39, rim = 56–64). There are also a few

instances of Mg# decrease from core to rim (two phenocrysts both show a 1.2 % decrease; Mg#

core = 37–59, rim = 36–58). Of the nine microphenocryst with core to rim transects, five show a

4.1–11.9 % decrease in Mg# from core to rim (Mg# core = 52–63, rim = 48–57), while the

remaining four show increases of 1.3–3.3 % (Mg# core = 62–64, rim = 63–67) and 11.7–19.5 %

(Mg# core = 40–44, rim = 52–63). In summary, amphibole phenocrysts mostly show an increase

in Mg# between core and rim, while microphenocrysts generally show a decrease in Mg#

between core and rim.

Magnetite is a common phase in the host lava (15–20 vol. %) and typically occurs as

euhedral or lath shaped microphenocrysts (Table 1; Appendix B). Magnetite crystals are

titanomagnetite (Ti# [100*Ti/(Ti+Altotal)] 51–57) and are often associated with clinopyroxene

which surround kaersutite phenocrysts (Fig. 6 a,d).

Less abundant minerals include olivine and apatite. Olivine occurs as microphenocrysts

(total of < 2 vol. %) with a bimodal distribution in forsterite content (Fig. 8 a,b). Olivine is commonly found in glomeroporphyritic clusters with rims consisting of diopside microphenocrysts (Fig. 6e). Representative analyses are provided in Table 1 and all olivine analyses are given in Appendix B. Apatite occurs as euhedral microphenocrysts within the host lava.

Inclusions

Inclusions found within the host lavas at Xeno Ridge are characterized based on color, grain- size, mineralogy, and nature of the contact with the lava and have been subdivided into five types

(I–V). Table 2 summarizes the primary distinguishing features of the five inclusion types discussed below.

Type I

Type I inclusions are dark gray to black and often show teardrop or oblong shapes in outcrop

(Fig. 9a). These inclusions are found in all Xeno Ridge deposits and show diversity in size, shape, crystal, and vesicle contents. Long axes of Type I inclusions range from ~2 cm to > 20 cm and show smooth and fluidal contact relationships with the encapsulating lavas indicating commingling of magmas (Fig. 9a). Apart from one sample (MS169-D), Type I inclusions are highly vesicular (~10–20 vol. %; Fig. 9b). Vesicles are sub-round to round (Fig. 9b) and relatively large with long axis ranging from 0.5 to 3 mm. Larger irregular vesicles are common along inclusion margins (Fig. 9c) and are oriented sub-parallel to their contacts with their host.

Figure 9: Field and petrographic images of Type I inclusions found at Xeno-Ridge. (A) The fluidal nature of Type I inclusions (dark grey) within the host lava (light grey) is seen within this field image. (B) Hand sample image of the highly vesicular nature of Type I inclusions (MS169- N2). (C) Petrographic image (ppl) of a Type I inclusion. The dashed red line denotes the boundary between the host lava and Type I inclusion and each are labeled accordingly. Vesicles within the host are oriented subparallel to inclusion contacts. (D) This petrographic image (ppl) shows vesicles within a Type I inclusion near the host-inclusion contact which is rimmed by host groundmass. The contacts between host groundmass, Type I inclusion, and vesicles are outlined by the dashed red lines and labeled. (E) This hand sample image (MS113A) contains a large amphibole phenocryst in Type I which protrudes into the host lava. (F) Sieve textures within plagioclase microphenocryst, shown within this petrographic image (ppl) are common within Type I inclusions. The core of this microphenocryst is bounded by free of melt inclusion rim. Mineral abbreviations: Fel – feldspar; Kers – kaersutite; Mgn – magnetite; Ves – vesicle

The elongation of vesicles is most likely a consequence of shear stress generated during flow and magma commingling. Vesicles near the outer margin of the inclusions are also occasionally rimmed by groundmass containing finer microphenocrysts and microlites of the host lava (Fig.

9c), again, attesting to their commingled nature. The groundmass within Type I inclusions is easily differentiated from the groundmass of the host lava by the amount of clinopyroxene and amphibole as well as mineral textures and grain-size (inclusion contacts denoted by the red dashed line in Fig. 9 c,d,e); the host lava being finer grained with microlites of kaersutite, clinopyroxene, and magnetite. In some instances, vesicles in the inclusions close to the contact with the host lavas are partially filled by groundmass (Fig. 9d), which can be continuously traced back into the host. Phenocrysts, which comprise ~45% of the total volume of Type I inclusions, tend to be subhedral and are randomly oriented (Fig. 9 c,d).

Representative mineral chemistry is given in Table 3 and all analyses are provided in

Appendix B. The whole-rock composition, determined from a single Type I inclusion separated from the host, is phonotephrite (Fig. 3; Appendix C). Mineralogy and mineral chemistry from

Type I inclusions are discussed below in order of abundance.

The dominate mineral in Type I inclusions is amphibole (phenocrysts 15–20 vol. %, microphenocrysts 20–25 vol. %). The amphibole is kaersutite with variable Mg (1.50–2.72 apfu), Fe (Fe3+ 0.01−0.36 apfu, Fe2+ 1.11−2.36 apfu), Ti (0.39−0.74 apfu), and Al (TAl 2.02–2.43

apfu, M1-M3Al 0.18–0.39 apfu) contents (Fig. 10 a,b,c; Table 3; Appendix B). In some instances

kaersutite phenocrysts penetrate into the host lava (Fig. 9e) and typically show devolatilization

rims composed of titanomagnetite, plagioclase, and diopside and some amphibole

microphenocrysts have been completely replaced – pseudomorphed by fine-grained mixtures of clinopyroxene, plagioclase, and titanomagnetite in the groundmass. Unlike the host, the majority

29 of kaersutite phenocrysts lack sieve textures (Fig. 9 d,e). Kaersutite phenocrysts are typically oscillatory zoned with an overall Mg# increase of 0.6–11.9 % from core to rim (Mg# core = 47–

69, rim = 55–64) and one instance of a 25.2 % increase between core and rim (Mg# core = 40, rim = 65). There is, however, variation in the degree and magnitude of Mg# oscillations and one instance of a 12.9 % decrease in Mg# from core to rim (Mg# core = 63, rim = 50). Of the four transects of amphibole microphenocrysts within Type I inclusions, two show increases in Mg# from core to rim of 1.4–5.3 % (core Mg# = 57–60, rim = ~62) with one instance of a 29.1 % increase (Mg# core = 39, rim = 68), and one decrease of 3.8 % between core and rim (Mg# core

= 64, rim = 60). Amphibole transects are shown in Figure 10c. The compositions of amphibole in the groundmass have Mg# that range from 53 to 67.

Feldspar and feldspathoid phenocrysts compositions (Fig. 11a) include plagioclase

(An33−An80; 2–5 vol. %) and alkali feldspar (Ab55Or45−Ab60Or40; < 1 vol. %). Plagioclase

phenocrysts often show sieved cores with relatively clean inclusion-free rims (Fig. 9f) and typically show a decrease in An content (normally zoned) from core to rim (Fig. 11b).

Microphenocrysts (~25 vol. %) include plagioclase (An36−An69), alkali feldspar

(Ab60Or40−Ab70Or14), and nepheline (Fig. 11a; Table 3; Appendix B). Groundmass

compositions (Fig. 11a) include plagioclase (An22–An59) and alkali feldspar (Ab51Or48–

Ab70Or14).

Clinopyroxene microphenocrysts often occur along with magnetite and plagioclase as

reaction rims on kaersutite phenocrysts. Clinopyroxene phenocrysts (~1–2 vol. %; Fig. 10a;

Table 3) occur as diopside (Wo55En30Fs6) and hedenbergite (Wo63En39Fs7). Diopside

microphenocrysts (Wo48En29Fs23–Wo58En35Fs8; < 3 vol. %) are slightly less enriched in Ca as

compared to phenocrysts (Fig. 10a; Table 3; Appendix B). The majority of Type I

Figure 10: Amphibole, clinopyroxene, and olivine mineral compositions from Type I inclusions are plotted on the following diagrams. (A) Phenocryst, microphenocryst, and groundmass compositions are plotted on the clinopyroxene quadrilateral diagram. Diopside phenocryst compositions are Wo55En30Fs6, microphenocrysts Wo48En29Fs23–Wo58En35Fs8, and groundmass Wo45En42Fs13–Wo56En37Fs6. Hedenbergite phenocryst compositions are Wo63En39Fs7. Olivine occurs as phenocrysts, Fo85, and microphenocrysts, Fo80 and Fo48. (B) Type I core and rim compositions are plotted. Diopside core compositions are Wo48En29Fs23–Wo58En35Fs8 for microphenocrysts. Hedenbergite phenocryst core compositions are Wo63En39Fs7. (C) Amphibole core, rim, and groundmass compositions are plotted on Mg (apfu) vs. octahedral Al. The solid black line represents the core and rim compositions from single phenocrysts and the solid grey line represents single microphenocryst core-rim end-members. Amphiboles were named following the classification of Leake et al (1997) and recalibration schemes of Esawi (2004) and Holland and Blundy (1994). Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

Figure 11: Type I feldspar and feldspathoid mineral compositions are plotted on ternary diagrams. (A) Type I plagioclase phenocryst compositions span An33 to An80, microphenocrysts An36 to An69, and groundmass An22 to An59. Alkali feldspar phenocrysts range Ab55Or45 to Ab60Or40, microphenocrysts Ab60Or40 to Ab70Or14, and groundmass Ab51Or48 to Ab70Or11. (B) Feldspar core and rim compositions are plotted. Phenocryst core compositions range from An44 to An78 for plagioclase and Ab55Or45 to Ab60Or40 for alkali feldspar.

32 clinopyroxenes plot above the quadrilateral and are similar to those in the host lava.

Groundmass compositions are diopside (Wo45En42Fs13–Wo56En37Fs6) shown graphically in

Figure 10a.

Accessory minerals within Type I inclusions include magnetite, olivine and apatite.

Magnetite microphenocrysts have Ti# 79 and groundmass Ti# 74 (combined volume of 15–20

%; Table 3; Appendix B) and are classified as titanomagnetite. Olivine (Fig 10a,b; Table 3)

include high-Mg phenocrysts (core = Fo85) and microphenocrysts (core = Fo80) with lower-Mg

rims (rim = Fo48). Apatite is present as microphenocrysts.

Type II

Type II inclusions consist of single black amphibole megacrysts (2−4 cm long axis; Fig. 12a) and

dark-colored heteromineralogic clots composed of megacrysts of amphibole and plagioclase, and

phenocrysts, microphenocrysts and groundmass composed of plagioclase, magnetite, diopside,

nepheline, and apatite (Fig. 12b). Glomerocrysts range in size from ~7 mm to 9 cm in diameter.

The contacts between single amphibole megacrysts and the host lava are sharp along crystal

boundaries but in some cases also display rims of fine-grained clinopyroxene, magnetite, and

plagioclase formed by devolatilization during magma ascent (Fig. 12a). In contrast, the contacts

between the groundmass of Type II inclusions are similar to Type I, being highly irregular and

fluidal (Fig. 12b). Within the glomerocrysts, plagioclase megacrysts are blocky and subhedral

whereas plagioclase phenocrysts tend to be more subhedral and elongated, or lath-like, in shape.

In some cases, Type II glomerocrysts are present within some Type I inclusions.

Figure 12: Hand sample images of Type II inclusions found at Xeno-Ridge. Type II inclusions are found as (A) single kaersutite megacrysts and (B) dark-colored heteromineralogic clots (‘glomerocrysts’) composed of megacrysts of amphibole within a finer groundmass consisting of phenocryst and microphenocryst that are similar in composition to Type I inclusions. Abbreviations: Kers – kaersutite; Ves – vesicle; Gm – groundmass

Figure 13: Type II amphibole and clinopyroxene mineral compositions are plotted on the following diagrams. (A) Phenocryst, microphenocryst, and groundmass compositions are plotted on the clinopyroxene quadrilateral diagram. Diopside microphenocryst compositions are Wo49En38Fs13 to Wo55En28Fs18 and groundmass Wo48En39Fs13 to Wo54En30Fs16. (B) Type II core and rim compositions are plotted. Diopside core compositions are Wo49En38Fs13 to Wo58En35Fs8 for microphenocrysts. (C) Amphibole core, rim, and groundmass compositions are plotted on Mg (apfu) vs. octahedral Al. The solid black line represents the core and rim compositions from single phenocrysts and the solid grey line represents single microphenocryst core-rim end- members. Amphiboles were named following the classification of Leake et al (1997) and recalibration schemes of Esawi (2004) and Holland and Blundy (1994). Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

Figure 14: Type II feldspar and feldspathoid mineral compositions are plotted on ternary diagrams. (A) Feldspar phenocryst, microphenocryst, and groundmass and feldspathoid compositions are plotted. Type II plagioclase phenocryst compositions span An46 to An66, microphenocrysts An38 to An58, and groundmass An20 to An76. (B) Feldspar core and rim and feldspathoid compositions are plotted. Phenocryst core compositions span An54 to An66 for plagioclase.

Type II megacrysts are kaersutite. Kaersutite is also the most common amphibole composition within the Type II glomerocrysts (phenocrysts = ~65 vol. %, microphenocrysts =

~15 vol. %; Fig. 13a). All kaersutite within Type II inclusions show an increase in Mg# from core to rim of 6.0 – 12.4 % (Mg# cores = 47–55, rims = 59–64; Fig. 13c; Table 4; Appendix B).

Plagioclase (An46−A66) is present as megacrysts and phenocrysts (1–2 vol. %) within

Type II glomerocrysts along with microphenocrysts (~10 vol. %) of plagioclase (An38−An58) and nepheline (Fig. 14a). Overall, there is no variation in composition with grain size. Plagioclase shows an overall increase in An content between core and rim (Fig. 14b). There are, however, many instances of normal and oscillatory zoning (Table 4; Appendix B). Groundmass compositions of plagioclase range from An20 to An76.

Microphenocrysts of titanomagnetite (Ti# 84; 6–10 vol. %) and diopside (Wo49En38Fs13–

Wo55En28Fs18; < 2 vol. %; Fig. 13a) are present in devolatilization reaction rims on kaersutite

megacrysts and phenocrysts (Table 4; Appendix B). Diopside in the groundmass

(Wo48En39Fs13–Wo54En30Fs16) is very similar in composition to diopside microphenocrysts (Fig.

13 a,b). The majority plot above the pyroxene quadrilateral, similar to host lava and Type I

clinopyroxenes. Type II clinopyroxene compositions show a slight increase in Ca and non-

quadrilateral components (e.g., Ca-Tschermak) with decrease in Mg (Fig. 13 a,b). This is

opposite of trends observed in clinopyroxenes in the host lavas and Type I inclusions. Subhedral

microphenocryst-sized apatite is also present within Type II glomerocrysts.

Type III

Only one inclusion of Type III was identified at Xeno Ridge. The inclusion is reddish-brown in

color and porphyritic with crystals of anorthoclase in a hypocrystalline, feldspar and magnetite-

Figure 15: Petrographic and hand sample images of the Type III inclusion found at Xeno-Ridge. (A) The Type III inclusion is reddish-brown in color, as seen in this hand sample, vesicular, and porphyritic with crystals of anorthoclase in a hypocrystalline, feldspar and magnetite-dominated groundmass. The host-inclusion contact is smooth and denoted by the dashed red line. There are radial cracks within the inclusion trending from the contact into the inclusion center. Vesicles are circular to slightly elliptical in shape and are < 1 mm in diameter. (B) This thin section image represents the nature of the radial cracks within inclusion. The cracks are comprised of vesicles. Mineral abbreviations: An – anorthoclase; Mgn – magnetite; Ves – vesicle

Table 5. Type III summary

Mineralogy Phenocryst and microphenocryst vol. % Description Size Anorthoclase < 7 Euhedral to subhedral, 2-3 mm blocky to stumpy Groundmass Plagioclase 45-50 Blocky, highly abundant Magnetite 20-25 Absent along the inclusion margin Texture Reddish-brown in color; porphyritic; hypocrystalline groundmass

Contact with host Rounded with radial, vesicle-filled cracks into the center of the inclusion

Vesiculation Close to contact - elliptical, 1-5 mm diameter

Within inclusion - 20- 25 vol. %

41 dominated groundmass (Fig. 15 a,b). Vesicles within the inclusion have a circular to slightly elliptical shape and are < 1 mm in diameter. The contact margin between the inclusion and the host lava is gradational and difficult to identify due to their similarity in color and grain size (Fig.

15a). The inclusion is highly vesicular and has cracks that radiate from the rim to the center

(Fig. 15b). Vesicles near the margin are more elliptical in shape and range from 1 to 5 mm in length.

Phenocrysts in Type III are identified as anorthoclase (using standard petrographic techniques) and comprise < 7 vol. % of the inclusion. The anorthoclase are typically euhedral to subhedral, blocky to stumpy in shape, and average 2–3 mm in length (Fig. 15a). Blocky microphenocrysts include plagioclase and magnetite. Magnetite microphenocrysts (20–25 vol.

%) are found throughout the inclusion but are notably absent along the inclusion margin with the host lava.

A summary of mineralogical data based on petrographic characteristics and textures is provided in Table 5. Mineral chemistry was not determined for this inclusion Type. The whole- rock composition of the Type III inclusion is trachyte (Fig. 3; Appendix C).

Type IV

Type IV inclusions have a ‘salt and pepper’ colored appearance and are non-vesicular with intergranular textures consisting of amphibole laths and anhedral interstitial plagioclase, clinopyroxene, and magnetite (Fig. 16 a,b). The contact margin between the inclusion and the host is sharp and microphenocrysts within the host lava are oriented semi-parallel to inclusion contacts, all of which suggests that the inclusions were solid when incorporated into the host magma.

Figure 16: Petrographic and hand sample images of Type IV inclusions found at Xeno-Ridge. (A) Type IV inclusions have sharp and angular contact relationships with the host lava indicating the inclusion was solid upon entrainment within the host. (B) This thin section image represents the dominate mineralogy of the inclusion type with medium grain amphibole and plagioclase comprising the majority of inclusion mineralogy, with subordinate magnetite and clinopyroxene as fine grain material. Abbreviations: Fel – feldspar; Kers – kaersutite; Mgn – magnetite; Cpx – clinopyroxene

Figure 17: Type IV amphibole and clinopyroxene mineral compositions are plotted on the following diagrams. (A) Medium and fine grain compositions are plotted on the clinopyroxene quadrilateral diagram. Diopside fine grain compositions are Wo50En36Fs4 to Wo54En39Fs7. (B) Core and rim compositions of medium grains are plotted on the clinopyroxene quadrilateral diagram. (C) Amphibole core, rim, and groundmass compositions are plotted on Mg (apfu) vs. octahedral Al. No single crystal core-rim pairs are available for Type IV medium grain amphibole compositions. Amphiboles were named following the classification of Leake et al (1997) and recalibration schemes of Esawi (2004) and Holland and Blundy (1994). Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

Figure 18: Type IV feldspar and feldspathoid mineral compositions are plotted on ternary diagrams. (A) Feldspar and feldspathoid medium grain compositions are plotted. Type IV plagioclase medium grain compositions range from An16 to An55. (B) Feldspar core and rim and feldspathoid compositions are plotted. Medium grain core compositions range from An22 to An55 for plagioclase.

The minerals in Type IV inclusions have an overall medium grain size (1–7 mm) and amphibole is the most abundant mineral (~55 vol. %). The amphibole is classified as kaersutite with variable Mg (1.97–2.50 apfu), Fe (Fe3+ 0.01–0.21 apfu, Fe2+ 1.48–2.08 apfu), and Al (TAl

2.17–2.23 apfu, M1-M3Al 0.09–0.25 apfu) contents. Chemical transects of amphibole crystals

show that the Mg# decreases from core to rim (Mg# core = 63, rim = 49–53; Fig. 17 a,b,c; Table

6; Appendix B). Amphibole is lath shaped with thick (~1–2 mm) reaction rims composed

dominantly of magnetite with minor amounts of clinopyroxene and plagioclase. Plagioclase is

the next most abundant mineral in Type IV inclusions (~25 vol. %) with a compositional range

from An16 to An55 (Fig. 18 a,b; Table 6; Appendix B). The finer grained (< 1 mm; ~15 vol. %)

interstitial assemblage includes plagioclase, titanomagnetite, diopside (Wo50En36Fs4–

Wo54En39Fs7; Figure 17 a,b; Table 6), sodalite, apatite, titanite, and olivine (Appendix B). Based

on the mineralogy and mineral abundances, Type IV inclusions are classified as kaersutite-rich

diorite.

Type V

In hand sample, Type V inclusions are similar in appearance to Type IV inclusions, being ‘salt

and pepper’ colored and granular, but they are distinct mineralogically. A major difference is

that the dark colored mafic mineral in Type V inclusions is pyroxene rather than amphibole.

Furthermore, felsic minerals (feldspars and feldspathoids) dominate over mafic minerals. Type

V inclusions are considered to be more abundant in Xeno Ridge deposits relative to Type IV

inclusions (based on field observations from the 2006/07/08 seasons and in collected hand

samples) and are larger, ranging in size from ~7 cm to > 25 cm in diameter (Fig. 5 a,b).

Figure 19: Petrographic and hand sample images of Type V inclusions found at Xeno-Ridge. (A) This hand sample image of the host and Type V inclusion contact is sharp and irregular, similar to that observed for Type IV inclusions. (B) This thin section image represents the subhedral granular texture of Type V inclusions. Medium grain crystals of clinopyroxene are partially to fully replaced by titanomagnetite, as shown in (C). Abbreviations: Fel – feldspar; Mgn – magnetite; Cpx – clinopyroxene

Type V inclusions are subhedral granular and have a range in crystal size from fine to medium grained (Fig. 19). The contact margin between the inclusion and the host lava is sharp and microphenocrysts within the host lava are oriented semi-parallel to inclusion contacts, similar to what is observed between the host lava and Type IV inclusions, suggesting that it was incorporated into the lava in a solid state.

The mineral assemblage in Type V inclusions (Table 7; Appendix B) consist of, in order of abundance, alkali feldspar (Ab47Or52−Ab59Or40; Fig. 20), nepheline, plagioclase, magnetite,

pyroxene, and leucite. Feldspar and feldspathoid minerals comprise ~75–90 vol. % and

pyroxene and magnetite comprise the remaining volume. Pyroxene compositions are provided in

Table 7 and Appendix B and graphically shown in Figure 21 a,b. Pyroxene compositions range

from diopside (Wo48En28Fs19–Wo50En31Fs23) to hedenbergite (Wo48En15Fs38–Wo53En13Fs34) and consist of 0–10 vol. % of the inclusion. Typically, 80–85 % of the clinopyroxene crystals are replaced by titanomagnetite, or other Ti-Fe oxide, leaving only a small core of the original crystal intact (Fig. 19c). In some cases, the clinopyroxene crystals are entirely replaced by magnetite. Apatite and titanite are also identified in thin section (< 1 vol. %; Table 7; Appendix

B). Based on mineralogy and mineral abundances the Type V inclusions are classified as a plagioclase-nepheline syenite and chemically equivalent to tephriphonolite (Fig. 3; Appendix C).

Comparison of Inclusions and Host Lavas

The physical relationships between the inclusions and the host lava have already been established based on textures: Types I and II were semi-molten when they were incorporated into the host magma, while Types III, IV, and V were fully solidified. The minerals in the inclusions are compared to the host lava and to each other in order to assess their compositional

Figure 20: Type V feldspar and feldspathoid mineral compositions are plotted on the following diagrams. Feldspar and feldspathoid medium-grain core compositions are plotted on the feldspar ternary diagram. Type V medium grain alkali feldspar range Ab47Or52 to Ab59Or40.

Figure 21: Type V clinopyroxene mineral compositions are plotted on the following diagrams. Medium-grain core compositions are plotted on the clinopyroxene quadrilateral diagram. Diopside medium grain compositions range Wo48En28Fs19 to Wo50En31Fs23 and hedenbergite medium grain compositions Wo48En15Fs38 to Wo53En13Fs34.

52 relationships. The mineral chemistry of all crystal size fractions for each inclusion type (except for Type III which was not analyzed) are compared with minerals in the host lava in Figures 22 and 24.

Amphibole

The host lava and all inclusions, with the exception of Types III and V, contain kaersutite.

Texturally, the kaersutite in the host lavas differ from those in the inclusions in that they show higher degrees of sieving caused by devolatilization reactions. Kaersutite phenocrysts within the host lava have the greatest compositional range (Mg# 34–70), exceeding the compositional span of all inclusion types (Fig. 22) and host microphenocrysts and groundmass (Table 8). Core compositions of amphiboles from inclusion Types I, II, and IV plot within the compositional range of amphiboles from the host (Fig. 22a).

The zoning in amphibole phenocrysts in the host and Type I inclusions show an overall increase in Mg# from core to rim. Similar zoning is found in Type I microphenocrysts (Table 8) and Type II (Type II = 6.0–12.4 % increase in Mg# between core and rim). However, zoning in medium grain amphiboles within Type IV inclusions show a decrease in Mg# from core to rim

(8.8–17.6 %).

Amphiboles within the groundmass of Type I inclusions plot within the field defined by groundmass amphiboles in the host lavas (Fig. 22b). Finer grained amphiboles in Type IV inclusions plot within the Fe-enriched portion of the host groundmass field (Fig. 22b).

Clinopyroxene

Clinopyroxene is the most abundant, volumetrically, in host lavas and show the greatest range in

55 compositions relative to clinopyroxene in the inclusions (Fig. 22 a,b). The clinopyroxene in

Types I and II inclusions have a similar range in composition but show opposite trends with respect to Ca and Mg contents. That is, low-Mg diopside in Type II inclusions have higher Ca contents relative to the low Mg diopside in Type I inclusions (Fig. 22 a,b).

Fine grained clinopyroxene in Type IV inclusions are plotted as groundmass for means of comparison in Figure 22b. Although Type IV inclusions have a limited number of mineral analyses, their compositions appear to be similar to host lavas. Type V clinopyroxene compositions plot mostly outside of the host compositional field being more Fe-rich (Fig. 22b).

Clinopyroxene core compositions in the host lavas show a range in TAl (phenocryst =

0.09–0.50 apfu; microphenocryst = 0.04–0.41 apfu) that is similar to the TAl content of Type I

cores (phenocryst = 0.092 apfu, microphenocryst = 0.025–0.513 apfu; Fig. 23a). Type II core

TAl values are similar to host and Type I cores, but tend to have lower Mg# at equivalent TAl values.

A strong positive correlation between TAl and Ti contents are shown in Figure 23b.

Increases in Ti + TAl represent increases in pressure during crystallization. Roughly equivalent clinopyroxene Ti and TAl ranges are seen in host and Type I compositions. Type II

clinopyroxene compositions fall within the span of the host and Type I. Type V clinopyroxene

plot at lower Ti + TAl values suggesting relatively lower pressure conditions crystallization.

Feldspar and Feldspathoid

The range of phenocryst and microphenocryst feldspar compositions in the host lava exceeds that

of all inclusion types (Figs. 8 a,b and 24a). Plagioclase feldspar in Type I inclusions have a

similar range in composition (Fig. 24a) but Type II phenocrysts and microphenocrysts are more

Figure 23: The mineral chemistry of host and Type I, II, and V inclusion clinopyroxene phenocrysts and microphenocryst cores are plotted in this figure. Type V compositions are of medium grain clinopyroxene. (A) This plot shows the relationships between Mg# and TAl (apfu), showing a roughly positive correlation. Clinopyroxene core compositions within the host and Type I have the greatest compositional range. Type V compositions are isolated at low amounts of TAl. (B) This plot shows the relationships between Ti and TAl (apfu). Xeno Ridge clinopyroxene fall along the 3.5:1 ratio line of TAl:Ti. This ratio is held constant throughout Xeno Ridge clinopyroxene, but the total abundance of TAl and Ti vary. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

59 restricted (Fig. 24a). Medium grained feldspars in Type IV inclusions are more similar to groundmass feldspar compositions within the host (Fig. 24a).

Groundmass compositions from Type I inclusions plot within the compositional range of host feldspar groundmass (Fig. 24b), with exception of one crystal (MS113A-52). Type II groundmass plagioclase are more Ca-rich relative to the host groundmass, but fall within the field defined by host phenocryst and microphenocryst compositions (Fig. 24b; Table 10).

Feldspathoid minerals in the host lava and Type I, II, and V inclusions are similar in composition. Nepheline and rare leucite are identified within the host. Type I, II, and V inclusions also contain nepheline, whereas Type IV inclusions contain sodalite.

Titanomagnetite

Titanomagnetite compositions vary distinctly between the host and Type I and II inclusions (Fig.

25; Table 11). The Ti# of titanomagnetite is greatest in Type II samples and lowest within the host. Titanomagnetite compositions from Type IV and V inclusions were not determined and thus cannot be compared.

Olivine

In hand sample, olivine phenocrysts in the host are visible to the naked eye and range in size up to 1.5 mm in diameter whereas olivine in all inclusions is rare and mostly microscopic. Type I inclusions contain olivine phenocrysts (< 1 vol. %; Fig. 10 a,b; Table 12), which are smaller but show both Mg-rich and Fe-rich compositions that are identical to the host (Fig. 22).

Figure 25: The mineral chemistry of host and Type I and II titanomagnetite compositions are plotted in this figure, showing the relationship between Ti# and Fe2+ (apfu). Host compositions have the lowest Ti# while the Type II titanomagnetite compositions are highest. These relationships show the relative amounts of Altotal to Ti [Ti# = 100*Ti/(Ti+Altotal)]. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %.

Table 11. Titanomagnetite compositional comparison between host lava and inclusions

Titanomagnetite: Ti# Microphenocryst Groundmass Core Rim

Hos t 57 - 51 - -

Type I 79 - 74

Type II 84 - -

Type IV -- -

Type V -- - Ti# = 100Ti/(Ti+Altotal)

Table 12. Olivine compositional comparison between host lava and inclusions

Olivine Phenocryst Microphenocryst Core Rim Core Rim

Hos t --Fo85 - Fo81; Fo48 - Fo45 Fo81

Type I Fo85 -Fo80 Fo48

Type II -- - -

Type IV -- - -

Type V -- - -

Comparison Summary

Overall, the range in chemistry of the minerals within the host lava exceeds those in any inclusion type. This may, in part, reflect a sampling bias related to the limited number of each inclusion type analyzed and/or, particularly in the case of Types IV and V inclusions, the limited number of spots analyses taken, relative to the host lava. It is very important to note, however, that except for Fe-rich clinopyroxene in Type V, all mineral compositions within the inclusions fall within the range of minerals measured in the host lava. Type I inclusions and the host are compositionally the most similar. Type I inclusions also contain the same bimodal distribution of olivine compositions that are present within the host (Fig. 22). Type I and II inclusions are texturally similar, with similarities in composition. However, Type II inclusions are slightly less compositionally diverse than Type I, which again may be due to sampling bias. Type IV and V are texturally distinct but mineralogically Type IV inclusions resemble the host and Type I and II inclusions.

Comparison of Whole-Rock Compositions

The whole-rock compositions of Xeno Ridge host lavas and inclusion Types I, III, and V are plotted on a total alkali versus silica ratio diagram shown in Figure 3. The Xeno Ridge samples are plotted in comparison with other samples from Minna Hook as well as with other alkaline volcanic rocks from the McMurdo Sound area (White Island, Cooper et al., 2007; Erebus

Volcano, Kyle et al., 1992).

Overall the Xeno Ridge whole-rock compositions fall within the evolved range of samples from the rest of Minna Hook and are comparable to other alkaline rocks from the area

(Fig. 3). Whole-rock compositions of the host lava were determined on four separate samples

65 from different locations on Xeno Ridge (Fig. 4 - MS-113 near Big Yellow, MS-114, MS-169, and MS-115 from Big Dome). The compositions of the host lava form a continuum from tephriphonolite to phonolite with the most evolved compositions (phonolite) collected near the ends of Xeno Ridge (samples MS-113 and MS-115) and less evolved compositions

(tephriphonolite) closer to the center of the ridge (samples MS-114 and MS-169). The whole rock compositions of the inclusions analyzed consist of Type I = phonotephrite, Type III = trachyte and Type IV = tephriphonolite (Fig. 3). Type I inclusions are less evolved than host, and may extend the compositional continuum to relate compositions of less evolved host (MS-

114 and MS-169) to more evolved host (MS-113 and MS-115). The composition of Type III is more silica enriched as compared to the host and other inclusion compositions. All samples from

Xeno Ridge are silica-undersaturated with between 8 and 22 wt. % normative nepheline.

Thermobarometry

Techniques for estimating temperatures and pressures of crystallization are based on theoretical and experimental studies. Application of these methods in determining P-T conditions for crystallization of minerals in natural samples requires careful consideration. For rocks from

Xeno Ridge several independent methods are employed. Pressures are estimated for clinopyroxene using a quantitative approach of Nimis and Ulmer (1998) and Nimis (1999), amphibole temperatures and pressures are estimated following the work of Ernst and Liu (1998) and temperatures for ternary feldspars are estimated by comparison with the findings of Fuhrman and Lindsley (1988).

Clinopyroxene Barometry

Pressures of crystallization for clinopyroxene are estimated using the structural barometer of

Nimis and Ulmer (1998) and Nimis (1999), which calculates the response of the clinopyroxene crystal structure to changes in pressure. Increases in pressure result in decreases of site sizes.

The structural barometer does not require knowledge of the exact composition of the equilibrium melt and therefore is ideal for Xeno Ridge samples which show clear evidence of magma mixing. Experiments used by Nimis (1999) extended the compositional range of magmatic liquids used by Nimis and Ulmer (1998) to include alkaline magma types. Although the experimental compositions are less alkaline than the Xeno Ridge samples, the barometer is still applicable. The Nimis and Ulmer (1998) and Nimis (1999) structural barometer calculates both anhydrous and hydrous pressures. The anhydrous model is temperature independent with an uncertainty of ± 1.75 kbar (Nimis and Ulmer, 1998; Nimis, 1999) and underestimates crystallization pressures for hydrous systems by ~ 1 kbar per wt. % H2O in the melt (Nimis,

1999; Bondi et al, 2000). A barometric model for hydrous magmas is appropriate fro Xeno

Ridge samples.

The ubiquity of amphibole megacrysts and phenocrysts within most Xeno Ridge

inclusion types and the host lavas indicate that the magmas were water-rich. However, in order

to use the Nimis (1999) model to estimate hydrous pressures, temperatures must be known.

Because slight temperature differences (± 20°C) can have a significant impact on hydrous pressure calculations (± 1 kbar) only reliable estimates of temperature should be used (Nimis and

Ulmer, 1998; Nimis, 1999). An independent and quantitative estimate of temperature for Xeno

Ridge samples cannot be made because of the absence of appropriate equilibrium mineral

assemblages and or equilibrium melt (glass) mineral pairs.

Anhydrous pressures are estimated using the compositions of clinopyroxene phenocrysts and microphenocrysts cores and rims. The minerals were carefully selected in order to avoid reacted and corroded grains. The quality of each mineral analysis and its reliability for determining pressure by the anhydrous model was assessed using the CpxBar Excel version of

Nimis (2000; http://dmp.unipd.it). Calculated anhydrous pressures for clinopyroxenes in the host

lavas vary from -5.6 to 6.0 kbar, Type I = -0.8 to 4.2 kbar, Type II = -4.0 to 3.25, and Type IV =

-6.36 to 1.43 kbar (Fig 26a; Appendix D). Type V clinopyroxene were not suitable for pressure

calculations, most likely due to the replacement of clinopyroxene by Fe-Ti oxides. Because

these calculations are for anhydrous compositions they represent minimum pressures. In order to

provide a rough estimate for hydrous pressures a value of 3 wt. % H2O is assigned as a

reasonable average value for Xeno Ridge magmas (cf. Whittington et al., 2001; Ferise et al.,

2003; Holness and Bunbury, 2006). This correction shifts all of the analyses to higher pressures by 3 kbar (Fig. 26b).

Amphibole Thermobarometry

Temperature and pressure estimates for Ti-rich amphiboles have proven to be problematic

because of the susceptibility of Ti to substitute into tetrahedrally coordinated sites (Holland and

Blundy, 1994). Quantitative Al-in-hornblende barometers (e.g., Hammarstrom and Zen, 1986)

and thermometers (e.g., Blundy and Holland, 1990; Holland and Blundy, 1994) do not provide

reliable estimates for Ti-rich varieties (e.g., kaersutite) and thus cannot be applied at Xeno Ridge.

However, qualitative estimates can be made based on: (1) Al- and Ti-Tschermak substitutions;

(2) the relative proportions of tetrahedrally coordinated (TAl) and octahedrally coordinated (M1-

M3 Al) aluminum; and (3) a comparison of total Al2O3 and TiO2 concentrations to natural and

Figure 26: Pressure estimates for clinopyroxene in Xeno Ridge lavas and inclusions are plotted as follows. (A) Pressure estimates of Xeno-Ridge lavas and inclusions are determined using the structural geobarometer of Nimis and Ulmer (1998) and Nimis (1999). Xeno-Ridge anhydrous pressures (minimum hydrous pressures). The crust-mantle boundary resides at 19-20 km (Lawrence et al., 2006) and is plotted using 2.9 to 3.3 kbar per km with respect to anhydrous conditions. (B) Assuming ~3 wt. % H2O clinopyroxene calculations underestimate crystallization pressures by 3 kbar (1 kbar increase per 1 wt. % H2O; Nimis and Ulmer, 1998; Nimis, 1999) with an uncertainty of ±1.75 kbar.

69 synthetic amphibole with experimentally constrained P-T equilibrium conditions.

Al-Tschermak substitution (TSi + M1-M3Mg = TAl + M1-M3Al) in the amphibole structure is

controlled by variations in pressure, where atoms with smaller ionic radii replace larger atoms

(TSiÆTAl and M1-M3MgÆM1-M3Al) with increasing pressure (Johnson and Rutherford, 1989;

Schmidt, 1992; Bachmann and Dungan, 2002). Ti-Tschermak substitution (TSi + M1-M3Mn = TAl

+ M1-M3Ti), on the other hand, is sensitive to changes in temperature (Spear, 1981; Bachmann and

Dungan, 2002), where atoms with larger ionic radii replace smaller atoms at higher temperatures.

That is, with increases in temperature, there are more Ti substitutions. No correlation exists between total Al (TAl + M1-M3Al) and Si + Mg (Fig. 27a), which indicates that pressure did not

play a significant role in the overall compositional variations shown by amphibole from Xeno

Ridge rocks. However, a dominate temperature control is clearly indicated by the strong

negative correlation that exists between Si + Mn and TAl + Ti (Fig. 27b).

The amount of TAl versus M1-M3Al in amphibole can relay important information

regarding the relative influences of temperature and pressure on crystallization within a

magmatic system. Increases in M1-M3Al have been attributed to pressure increases (Schmidt,

1992, Ernst and Liu, 1998) whereas increases in TAl are attributed to temperature increases

(Blundy and Holland, 1990; Anderson and Smith, 1995). Xeno Ridge amphibole phenocryst TAl

and M1-M3Al contents are plotted in Figure 28a and show a broad negative correlation. Core to

rim transects in amphibole from host lavas and Type I, II, and IV inclusions mostly show rims

with higher amounts of TAl relative to cores, and in Type I amphibole, oscillatory zoning with

respect to M1-M3Al content is observed (Fig. 28b).

Figure 27: Amphibole pressure and temperature controls on composition can be interpreted using various Tschermak substitutions. (A) Relative increases in pressure conditions can be determined with Al-Tschermak substitutions in amphibole. Xeno-Ridge amphibole compositions show no correlation of Al-Tschermak components and thus no systematic changes with pressure. This however does not exclude amphibole crystallization at a range of pressures. (B) Amphibole Ti- Tschermak substitutions are related to changes in temperature. Xeno-Ridge amphiboles show a distinct correlation suggests amphibole compositions are strongly controlled by temperature. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %. The regression value is 0.937.

Figure 28: Variation between TAl and M1-M3Al (apfu) in amphibole can be correlated to relative changes in temperature and pressure. (A) Xeno-Ridge TAl and M1-M3Al contents of the host and Type I, II, and IV amphibole phenocrysts show an overall negatively trending relationship. (B) Amphibole core-rim transects (some of which also contain crystal mantle compositions) from the host and Type I, II, and IV show oscillations and in some cases show opposite variations in relative proportions. Amphibole in the host lava transects tend to slope negatively from core to rim, with some variation in oscillation and one core-rim transect which is reversely zoned from core to rim. Type I core-rim transects also show an overall negative slope however mantle compositions tend to be more enriched in TAl and less in M1-M3Al than rim compositions. Type II core-rim transects show similar trends to that of the host in addition to positively sloping trends from core to rim. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %. Abbreviations: C – core, M – mantle, and R – rim.

The strong correlation between Ti-Tschermak substitutions (Fig. 27b) within Xeno Ridge amphibole suggest composition was temperature controlled. This is supported by the relationships between TAl and M1-M3Al shown in Figure 28.

An experimental study of natural and synthetic coarse-grained Ca-amphibole in mid- ocean ridge basalt by Ernst and Liu (1998) reveal TiO2 concentration varies with pressure. As

previously discussed, changes in total Al (or Al2O3 wt. %) can be a function of both pressure and

temperature. These relationships allow the measured Al2O3 and TiO2 contents of amphiboles to

be used as a semi-quantitative thermobarometer (Ernst and Liu, 1998).

Ernst and Liu (1998) plot Ca-amphibole Al2O3 and TiO2 isopleths as a function of P and

T (Figure 29). The composition of amphibole in the host lavas and inclusions from Xeno Ridge

plot outside the field of experimental data in Figure 29 (red-hatched field) at temperatures that

exceed 1000ºC and pressures between 3 and 9 kbar. The pressures are equivalent to middle crust

to upper mantle depths (~9 to 30 km, assuming 2.9 to 3.3 km per kbar).

Finally, amphibole compositions from the host and Type I, II, and IV are plotted in

Figure 30a and compared to both mantle- and shallow crustal-derived kaersutitic amphiboles

(Vinx and Jung, 1977; Alletti et al., 2005) and kaersutite from Foster Crater (Gamble et al.,

1988), which is located in the foothills of the Royal Society Range (Fig. 1). Gamble et al. (1988) determined that kaersutite from Foster Crater equilibrated at middle to lower crustal depths from mantle derived mafic alkaline melts. Kaersutite from Xeno Ridge plot within the field for mantle-derived compositions (Vinx and Jung, 1977) and overlaps with Gamble’s Group II xenoliths. There is a strong positive correlation between total Al and Ti in Xeno Ridge amphiboles (Fig. 30a), which also corresponds with variations between cores and rims of zoned crystals (Fig. 30b).

Figure 29: Isopleths of Al2O3 and TiO2 (wt. %) modified from Ernst and Liu (1998) have been determined using stabilities of natural and synthetic Ca-rich amphibole. Al2O3 has been determined to be influenced by both temperature and pressure, whereas TiO2 can be correlated to changes in temperature. The red region within the plot represents the compositional range of Xeno-Ridge lavas with respect to TiO2 and Al2O3 wt.% contents. These compositions are slightly outside the range of than those used by Ernst and Liu (1998), however an approximate pressure range of 3 to 9 kbar and a minimum temperature value of > 1000 ºC can be interpreted.

Figure 30: Amphibole compositions can be compared to that of other amphibole originating from mantle melts and shallow crustal magmas. Compositionally ranges for shallow crystal versus deep crystal origins have been determined by Vinx and Jung (1977) and references therein and are shown as grey fields within the diagram. Gamble et al. (1988) mantle-derived kaersutite xenolith compositions are shown in two compositional fields, the upper representing kaersutite from Group II xenoliths, and the lower representing kaersutite from HCPS xenoliths (K-metasomatized spinel- clinopyroxenites, wehrlites, and dunites). Synthetic amphibole compositions are also plotted from Irving and Green (2008). Amphibole compositions of the host and Type I, II, and IV are shown with respect to varying Altotal and Ti contents and plot within the range of mantle amphiboles. Similarly, Xeno-Ridge compositions coincide with Group II amphibole xenoliths compositions from Foster Crater (Gamble et al., 1988). Gamble et al. (1988) determined the kaersutite from Foster Crater to have upper mantle origins and crystallized from mafic alkaline melts. Error range: 1.0% uncertainty for > 0.2 wt. %, 10% error for < 0.2 wt. %. Abbreviations: C – core, M – mantle, and R – rim.

The result of qualitative thermobarometry of kaersutite within the host and Type I, II, and

IV inclusions suggest they are from mantle-derived melt and the variation in composition is temperature controlled with little influence from changes in pressure. The relatively high pressure and temperatures of crystallization support crystallization at depth, most likely within a pooling region at the crust-upper mantle interface.

Relative Ternary Feldspar Thermometry

Equilibrium temperatures of feldspars can be determined using the ternary feldspar model and thermometer of Fuhrman and Lindsley (1988). This thermometer is based on synthetic ternary feldspar compositions and experimentally-derived thermodynamic data, and is not limited to compositions near the feldspar binaries (Fuhrman and Lindsley, 1988). To adequately use this thermometer, two feldspars which represent equilibrium conditions must be used and will yield three congruous temperatures (one temperature for each An, Ab, Or compositions; ± 40°C). The thermometry program initially calculates the three equilibrium temperatures and then determines a set of feldspar compositions roughly equivalent to the calculated values with the least amount of variation between projected temperatures (Fuhrman and Lindsley, 1988). These sets of temperatures produce tie lines, which in turn are interpreted as feldspar equilibrium isotherms.

Unfortunately crystallization conditions within Xeno Ridge do not unanimously represent equilibrium conditions due to varying degrees of magma evolution, magmatic mixing, and crystal resorption. This being said, the usability of this ternary feldspar thermometer regarding

Xeno Ridge is impractical. However approximate genetic relationships between feldspar compositions, not necessarily equilibrium P-T conditions, can be determined by plotting ternary feldspar compositions in conjunction with experimentally derived isotherms (Fuhrman and

Figure 31: Isotherms for 750, 900, and 1000°C, with pressures of 1.0, 0.5, and 1.0 kbar respectively are plotted [modified from Deer et al. (1992) using the ternary feldspar model and thermometer of Fuhrman and Lindsley (1988)] representing equilibrium condition of feldspars. The majority of Xeno-Ridge feldspars fall within a single isotherm, with some deviation within the groundmass and host phenocryst compositions. This suggests feldspar compositions crystallized prior to or post-mixing, with some crystallization occurring during mixing. Based on textural evidence and the lack of disequilibrium features within the majority of host plagioclase, this supports crystallization under isothermal conditions post-mixing. Type IV feldspar compositions fall within multiple isotherm conditions and thus represent disequilibrium conditions during crystallization.

Lindsley, 1988). Isotherms (750, 900, and 1000°C at 1.0, 0.5, and 1.0 kbar respectively; modified from Deer et al., 1992, pg. 394) are shown in Figure 31 and plotted with Xeno Ridge ternary feldspar compositions. Surprisingly the majority of Xeno Ridge phenocryst and microphenocryst feldspars in the host lavas and inclusions fall along isotherms suggesting feldspar compositions crystallized during equivocal conditions before or after mixing. There are instances in which feldspar phenocryst compositions (within the host and Type IV) and groundmass compositions (within the host and Type I, II, and IV) cross isotherms. This may be interpreted as a consequence of mixing and is supported by the occurrence of strong disequilibrium textures of host lava feldspar that is in close proximity to Type I inclusions.

DISCUSSION

The results clearly demonstrate the host lava and majority of inclusions from Xeno Ridge are petrogenetically related. Estimated P-T conditions show similar ranges for clinopyroxene and amphibole crystallization, suggesting similar origins. Overall, Type I, II, and IV show comagmatic relationships with the host lava. The term comagmatic refers to magmas and or cumulate material which show geochemical relationships signifying equivalent genetic origins, including parental melts and evolutionary pathways. Type V inclusions are broadly similar to other inclusions and the host but have mineralogical dissimilarities, including the lack of amphibole and higher abundance of clinopyroxene that is more Fe-rich (hedenbergite). Type V inclusions may also be comagmatic, but evolved under slightly different physiochemical conditions (e.g., different water content and or fO2 conditions). The Type III inclusion is

compositionally and texturally dissimilar to the host and other inclusion types and thus is not

78 comagmatic but similar to other Minna Hook lavas and is regarded as accidental. It was entrained during the ascent of the host magmas through the Minna Hook sequence.

Mineralogical and Textural Diversities

Although the mineral assemblages of the host and Type I, II, and IV suggest comagmatic relationships, there are variations within phenocryst populations and mineral abundances.

Variation in the degree of amphibole devolatilization observed between the host and the inclusions has significant implications regarding processes of inclusion entrainment and magma ascent. The recognized variations in the extent of resorption of host plagioclase phenocrysts as a function of the proximity to Type I inclusions may denote the intensity of magmatic hybridization.

Amphibole

Amphibole is the primary mineral phase in Xeno Ridge rocks and is present within the host lava and Type I, II, and IV inclusions (Table 2). Amphibole phenocrysts are more abundant in Type I, II, and IV inclusions relative to the host lava. The groundmass in host lava has higher abundances of clinopyroxene, plagioclase, and titanomagnetite relative to Type I and II inclusions. This may be a result of the devolatilization breakdown reaction of amphibole.

Devolatilization of amphibole is a result of decompression and out-gassing of magmas during ascent (Rutherford and Hill, 1993; Rutherford and Devine, 2003; Browne and Gardner, 2006).

Most of the remaining amphibole phenocrysts and microphenocryst within the host are strongly sieved with thick reacted margins composed of clinopyroxene, plagioclase, and titanomagnetite.

However there is some variability in the degree of amphibole breakdown. Amphibole from

79 sample sites near the center of Xeno Ridge (e.g., MS-169; Fig. 4) are more strongly sieved relative to amphibole from lavas sampled near the ends of Xeno Ridge (e.g., MS-113; Fig. 4).

Groundmass amphibole in the host lava is rare and the intensity of the devolatilization varies. In contrast, devolatilization textures in amphibole within Type II and IV inclusions are rare and not as well developed.

Variation in the thickness of devolatilized rims on amphibole crystals in host lavas and inclusions may be due to several factors. The degree of amphibole breakdown in host lava and inclusions is a result of the level of inclusion entrainment within the host and the rate of magma ascent. Type I and II entrainment occurring after most of the host magma has been degassed could explain the difference in devolatilization textures. The relative rates of ascent are also significant and the host magma may have ascended at a faster rate and to a shallower level within the crust relative to the magmas which formed the inclusions. Fast ascent rates result in the rapid degassing of a magma and thus high degrees of amphibole decompression. It is important to note that amphibole present within fully solidified inclusions during the time of entrainment will not breakdown significantly.

Variation in the degree of amphibole devolatilization cannot be easily explained if inclusions are entrained within the host at depth. If inclusions, particularly Type I and II, are entrained at depth, the host and inclusions would ascend at the same rate, not allowing for variation in degree of amphibole devolatilization (Rutherford and Hill, 1993; Rutherford and

Devine, 2003).

Clinopyroxene

Variations in the composition of clinopyroxene reveal changes in P-T conditions that may

80 help resolve crystallization histories between the host and the different inclusion types.

Clinopyroxene with lower relative concentrations of Ti + TAl indicate higher pressures of

crystallization (Thompson, 1974; Wass, 1979; Adam and Green, 1994). The range of Ti + TAl in clinopyroxene cores within host lavas and Type I and II suggests both low and high crystallization pressures (Fig. 26b). Lower pressure crystallization is apparent for clinopyroxene resulting from amphibole breakdown by devolatilization. Clinopyroxene that show an increase in the concentration of Ca from core to rim (reverse zoning) indicate crystallization at progressively lower temperatures (Adam and Green, 1994) or an overall change in magma composition due to mixing with a more mafic magma. Clinopyroxene crystallized as a result of amphibole breakdown is high in Ca, supporting a lower temperature origin. The relatively low

Ti + TAl values for clinopyroxene in Type V inclusions and their relatively low Ca content

supports crystallization at higher pressures and temperatures.

Feldspar

Within the host lava there is significant variation in the nature of feldspar habit ranging from tabular, elongated, and aligned plagioclase phenocrysts to irregular, blocky, sieved phenocrysts. Although there is no significant variation between host plagioclase compositions and sample collect sites at within Xeno Ridge, differences in the phenocryst habits and textural variation can be correlated to proximity of Type I inclusions. Host lava containing tabular, elongated phenocrysts occur away from Type I inclusions, whereas irregularly shaped phenocrysts occur in close proximity to Type I inclusions. This suggests that the degree of mixing/mingling is a controlling factor in plagioclase crystallization. Based on feldspar habits, the highest degree of magmatic hybridization occurred near sample sites MS-169 (Fig.4). Some

81 plagioclase crystallization occurred during or prior to mixing, as is suggested by the resorbed and sieved plagioclase phenocrysts and the other after as indicated by homogeneous, unreacted textures.

Inclusion Origins

Texturally, Type II, IV, and V show cumulate relationships to the host lava and Type I.

Determining the origins of these inclusions is crucial for interpreting the petrogenesis of the magmatic system and the evolution of Xeno Ridge. Cumulate inclusions within igneous rocks form by the accumulation of crystals within a magma and may originate from (1) quenching of less evolved replenishing magma injected into the system (e.g., Bacon and Metz, 1984; Bacon,

1986; Coombs et al., 2002; Holness and Bundbury, 2006) or (2) solidification fronts along the margins of magma chambers (e.g., Tait et al., 1989; Mattioli et al., 2003; Holness et al., 2005;

Holness and Bunbury, 2006).

Textures of inclusions formed from the quenching of replenishing magma are controlled by differences in composition, temperature, and volatile contents of the interacting magmas. The composition of replenishing magmas are often more mafic and inclusions typically have sharp chilled margins and are ellipsoidal in shape (Bacon, 1986; Coombs et al., 2006). These features indicate that the inclusions formed by rapid crystallization upon contact with a more evolved and cooler magma (Bacon, 1986). None of the Type I and II inclusions (i.e. inclusions that show fluidal contacts with host lavas) displays quenched margins suggesting that the magma temperatures were similar prior to injection and mingling.

Inclusions derived from solidification fronts - crystal mush or casings along magma chamber margins, vary with respect to composition and texture, ranging from partially

82 disintegrated mush (individual crystals and glomerocrysts) to fully solidified granular fragments.

This textural variability can be attributed to original state of the material incorporated (solidified or partially solidified) as well as mechanisms of entrainment and its transport prior to solidification of the entire mixture. Overall, the presence of inclusions derived from a pre-mix crystal mush requires that the dislodgement of the material and its transport does not destroy the original textures (Snyder, 2000; Holness and Bunbury, 2006). Their preservation during ascent is largely controlled by the size and geometry of the magma conduit system (Holness and

Bunbury, 2006). Their preservation also depends on the durability of the inclusion itself. Those inclusions that are unable to withstand vesicle expansion and other physical processes associated with entrainment and ascent of magmas are unlikely to be preserved as isolated bodies but are more likely dispersed as smaller crystal clots or as individual crystals within the host liquid.

Xeno Ridge cumulate inclusion Type II, IV, and V most likely originated as solidification fronts with varying degrees of crystallization in magma chambers/conduits. As noted by the nature of the host-inclusion contacts, Types I and II were not fully crystalline upon entrainment whereas Type IV and V were solidified and most likely remnants of frozen casing on pre- existing conduit systems.

The incorporation of Type II crystalline mush within the magmatic system from chamber/conduit walls was induced by a separate pulse of magma. The occurrence of Type II megacrysts within Type I inclusions suggests that the replenishing liquid was the Type I magma.

If significant temperature and compositional differences between the mush and the replenishing magma exist, then the interaction should result in the resorption of pre-mix materials and inclusion margins (e.g., Bacon, 1986; Coomb et al., 2002). However the mineralogical similarities between Type I and II paired with similar thermobaromic approximations and the

83 lack of quench textures suggest roughly equivalent compositions and temperatures. Physical and mechanical means of crystal mush and the incorporation into Type I liquid, as well as later mixing with host magmas, caused the disaggregation of this material to form both single amphibole megacrysts and heterogeneous glomerocrysts.

It is unlikely that Type II inclusions originated from Type I liquid. Although this simplification would explain the occurrence of Type II inclusions within Type I, the oscillatory variations in Mg#, TAl, and M1-M3Al, and the difference in the degree and nature of amphibole

devolatilization seen between Type I and II do not support crystallization from the same magma.

Type I and II inclusions, however, most likely are derived from similar magmas with some

variation in P-T conditions.

Type IV and V were fully solidified as denoted by the nature of inclusion contacts within

the host lava. The lack of resorption and dissolution textures along the margins of these

inclusions suggest a limited time of entrainment prior to eruption. The mineralogical distinction

between amphibole- and clinopyroxene-dominated inclusions is significant. This mineralogical

difference between Type IV and V inclusions suggests that at the time of crystallization, Type IV

magmas contained more water than Type V by virtue of the occurrence of amphibole. Time

spans between when Type IV and V inclusions solidified and when they were incorporation into

the host magma cannot be determined and are not necessarily equivalent. However, both Type

IV and V solidified prior to their entrainment and thus can provide a first order sequence of

events.

Many inclusion-bearing alkaline lavas erupted in areas of extended lithosphere (i.e. rifts)

contain both clinopyroxene- and amphibole-dominated cumulate inclusions (e.g., Bondi et al.,

2002; Wagner et al., 2003; Alletti et al., 2005; Holness and Bunbury, 2006). The clinopyroxene-

84 bearing Type V inclusions may represent magmas that crystallized from water-poor magmas. By the same reasoning, amphibole-rich magmas represented by the host lavas and the majority of inclusion types present at Xeno Ridge (Type I, II, and IV) were generated from water-rich magmas. Although amphibole is a common phase in lavas from the upper portion of the Minna

Hook sequence and along the length of Minna Bluff, few sites other than Xeno Ridge contain

Type I inclusions and the majority of ‘salt and pepper’ inclusions appear to be dominated by pyroxene-bearing types. The abundance of amphibole at Xeno Ridge as well as elsewhere on

Minna Bluff requires the crystallizing magmas to have relatively high water contents. This may be the result of melting of an original ‘wet’ upper mantle source or amphibole may have crystallized from differentiated magmas that experienced significant fractional crystallization of anhydrous minerals to promote the generation of hydrous residual liquids (Merrill and Wyllie,

1974; Irving and Green, 2008). In either case, it is likely that the amphiboles crystallized at high pressures as indicated by comparisons with natural and experimental data (Figs. 29 and 30a). In a recent study of phase relationships in alkaline magmas at high pressures Irving and Green

(2008) determined that kaersutite and olivine are in equilibrium with a hydrous (H2O ~ 4 wt. %)

nepheline mugearite liquid (~= Type I) at 14 ± 1 kbar (~42 km depth). Furthermore, hydrous

pressure estimates for some clinopyroxene phenocrysts within host and Type I inclusions also

support high pressure crystallization near the base of the crust or within the upper mantle (Fig.

26b).

The occurrence of Type V inclusions in amphibole-bearing lavas within the uppermost

portion of Minna Bluff stratigraphic sequence and along the length of the peninsula suggests an

earlier widespread emplacement and crystallization of relatively ‘dry’ phase of magmatism.

The mineralogical similarities between Type IV and Types I and II most likely represent a comagmatic origin within the same system. However, textural relationships support the emplacement and crystallization of Type IV prior to their dislodgment by the host magma and the entrainment of fluidal inclusion Types I and II. The lack of thick devolatilization rims on amphibole phenocrysts in Type II inclusions (as seen in the host and Type I inclusions) may be explained by rapid ascent, undercooling and solidification of Type IV magmas at shallower levels in the crust.

Based on textures and mineral compositions a crystallization sequence is deduced (Fig.

32). Host and Type I inclusions contain olivine crystals that are anhedral with reaction rims of clinopyroxene (Fig. 6e), while clinopyroxene is subhedral to euhedral. This supports a paragenesis of olivine before clinopyroxene. Amphibole-dominated compositions may indicate the melting of an original ‘wet’ mantle source. Elevated water contents can induce early amphibole crystallization at relatively high pressures (Eggler, 1972; Merrill and Wyllie, 1974;

Irving and Green, 2008). Kaersutite is stable at pressures less than 25 kbar, temperatures less than 1100 °C, and water contents between 3.5 and 5 wt. % within the melt (Merrill and Wyllie,

1974; Irving and Green, 2008). The inferred abundance of water within the Xeno Ridge system resulted in early crystallization of amphibole with clinopyroxene and the suppression of plagioclase (Cashman and Blundy, 2000; Blatter et al., 2007). It is possible that the amphibole and clinopyroxene crystallized in equilibrium within the upper mantle at the base of the crust as indicated by P-T estimates. Apatite occurs as phenocrysts as well as inclusions in amphibole.

Both high and low crystallization pressures have been determined for apatite crystallization

(Thompson et al., 2001; Busà et al., 2002). The latest stage of solidification of Xeno Ridge

87 magmas appears to be dominated by lower pressure and temperature crystallization of titanomagnetite and plagioclase.

Xeno Ridge Magmatic Progression

A schematic cartoon showing the mixing and ascent of magma bodies and the incorporation of inclusion types of Xeno Ridge is shown in Figure 33.

Stage 1: phonolitic magmas that comprise lava compositions prior to hybridization with

Type I magma (see Stage 2) ascend into the upper crust. The conduit system through which the magma is rising represents a path of weakness that may have experienced periodic reactivation controlled by regional stresses and may have channeled earlier magmas (Type IV). The magmas, rising to shallow levels, decompressed and lost volatiles which promoted devolatilization of amphibole. Amphibole breakdown produced some of the clinopyroxene, plagioclase, and titanomagnetite observed in the groundmass.

Stage 2: replenishing phonotephritic magmas (Type I) ascend from depth within the same conduit system. The walls of the conduit through which the magmas are ascending contain partially solidified material that most likely originated from sidewall crystallization of previous magmas. The crystalline mush (Type II) was not fully solidified allowing the material to be easily dislodged and entrained within the rising magmas.

Stage 3: Type I magma continued to ascend the conduit entraining Type II material before being injected into the mostly devolatilized and evolved host liquid. During this stage, rapid mixing and hybridization of the host and Types I and II inclusions occurs. Significant crystallization of plagioclase feldspar occurred within the hybridized magmas based on textural

89 variations observed with respect to the proximity of Type I inclusions in the host lava. The highest degree of hybridization, based on field, petrographic and compositional information, occurs near the center of Xeno Ridge, although Type I liquid inclusions are dispersed throughout the host.

Stage 4: the mixing event triggered a second episode of magma ascent leading to eruption

(cf. Sparks et al., 1977; Snyder, 2000; Perugini et al., 2007). Upon ascent, the mixed magmas entrained crystalline selvages of Type IV and V compositions from conduit walls. Based on the compositional similarity of Type IV to the other amphibole-dominated inclusions and the host lava, Type IV inclusions may have crystallized within the same conduit system (Mid-Stage 4).

Type V on the other hand, most likely did not crystallized within the same system but represents cumulate material from an earlier, more widespread, magma injection(s) (Late Stage 4).

CONCLUSION

Overall, variation in the host lava and the five inclusion types identified at Xeno Ridge using petrographical, mineralogical, and geochemical methods provides insight into magma evolution, crystallization sequences, and eruption within the latest stage of Minna Bluff’s history.

• Xeno Ridge deposits represent magmas that underwent high degrees of hybridization and

mixing.

• Inclusions present within the host lavas represent a spectrum of comagmatic and accidental

types.

• The role of water within this alkaline system is significant, suppressing plagioclase

crystallization and inducing relatively early amphibole growth.

Questions to be addressed by future work on Xeno Ridge host lavas and inclusions include unraveling the origin and fractionational crystallization history of the phonolitic host magmas.

Did they fractionate in the upper mantle or evolve at shallower levels within the crust, or could they have been derived as direct partial melts from an enriched upper mantle source? Is the composition of Type I inclusions appropriate for being parental to the phonolitic compositions?

Another puzzle is the unusual occurrence of kaersutite in phonolite. Is the kaersutite in equilibrium with phonolitic compositions? If not where and how did it form? Did kaersutite play a critical role in the evolution of mantle derived melts to produce phonolite magmas?

Determining the compositional spectrum of Type I and IV inclusions is critical in interpreting the overall chemical diversity of Xeno Ridge inclusions; only one of each type was analyzed. More inclusions of both types were collected during the 2007/08 field season and will be analyzed. The origin of Type V inclusions may provide significant insight on the origin of

Minna Bluff. The change from clinopyroxene- to amphibole-dominated mineralogies may represent an overall shift from ‘dry’ and ‘wet’ magmatism, which may have regional implications for volcanism and tectonism.

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APPENDICES 99

APPENDIX A 100

Xeno-Ridge host sample collection locations: GPS coordinates and elevations

Sample GPS Coordinate Elevation Whole-Rock Composition zone N E PT TP P T MS-113 58 c 544627 1276125 N/A - - X - MS-114 58 c 545351 1277093 661 m - X - - MS-115 58 c 545877 1277697 560 m - - X - MS-169 N/A N/A - X - -

Xeno-Ridge host sample description

Sample Description MS-113 Light grey, frothy; few inclusions (all Type I) MS-114 Light grey, abundant small Type I, II inclusions MS-115 Crystal-poor medium grey lava; rare feld crystals MS-169 Dark grey; denser than MS-113, MS-114; all inclusions types present 101

Minna Hook sample collection locations: GPS coordinates and elevations

Sample GPS Coordinate Elevation Sample Location zone N E MS-3 58 c 548580 1266616 N/A Gully 4

MS-4 58 c 548446 1267179 N/A Gully 13 MS-5 58 c 548554 1267179 N/A Gully 13

MS-31 58 c 545670 1265155 N/A W from Camp Cliff MS-32 Approx. same as MS-31 302 m W from Camp Cliff MS-33 Approx. same as MS-32 228 m W from Camp Cliff MS-27 58 c 545707 1265371 154 m W from Camp Cliff MS-24 58 c 545726 1265116 68.9 m W from Camp Cliff

MS-39 58 c 548463 1267746 39 m Gully 22 MS-38 58 c 548500 1267813 33 m Gully 22 MS-37 58 c 548521 1267869 1 m Gully 22

MS-49 Approx. same as MS-45 ~200 m Gully 69 MS-48 Approx. same as MS-46 ~200 m Gully 69 MS-46 58 c 548278 1271812 121 m Gully 69 MS-44 Approx. same as MS-43 ~10 m above MS-43, < 121 m Btwn Gullies 69+70 MS-43 58 c 548442 1261806 N/A Btwn Gullies 69+70

MS-51 58 c 547992 1266609 329.2 m MB Corner MS-51-2 58 c 548041 1266606 317 m MB Corner MS-52 58 c 548087 1266523 274.3 m MB Corner MS-53 58 c 548121 1266523 243.8 m MB Corner MS-54 58 c 548138 1266488 207.3 m MB Corner MS-55 58 c 548166 1266384 128 m MB Corner MS-56 58 c 548810 1266372 91.4 m MB Corner 102

Minna Hook sample collection locations, continued

Sample GPS Coordinate Elevation Sample Location zone N E MS-81 58 c 547464 1271086 N/A Gully 73 MS-82 58 c 547392 1271188 ~820 m Gully 73 MS-83 58 c 547483 1271389 768 m Gully 73 MS-90 58 c 547779 1274929 243 m Gully 100 MS-88 58 c 547796 1274815 231 m Gully 100 MS-91 58 c 547843 1274843 197 m Gully 100 MS-86 58 c 547847 1274825 161 m Gully 100 MS-85 58 c 547993 1274836 75 m Gully 100

MS-159 58 c 547025 1273866 914 m Gully 105 MS-160 58 c 547033 1273974 ~900 m Gully 105 MS-161 58 c 547059 1274028 847 m Gully 105 MS-162 58c 547173 1274120 735 m Gully 105 MS-167 58 c 547386 1274678 620 m Gully 105 MS-166 58 c 547386 1274678 616 m Gully 105 MS-168 506 m Gully 105

MS-108 58 c 544105 1275595 876 m Above Camp 2 MS-112 58 c 545863 1276267 N/A Camp Dome

103

Minna Hook sample collection summary: compositions and descriptions

Sample Whole-Rock CompositionDescription T/B PT TP TA P MS-3- ---XFresh lava, sheety; crystaline lava/dome

MS-4 - X - - - Green platey lava; overlying unconformity MS-5 - X - - - Grey brown platey lava; banded vesiculated units; under unconformity

MS-31X----Dark grey lava MS-32X----Subaerial dark grey lava with few kaer and some ol MS-33X----Massive grey ol rich lava; subaerial flow MS-27X----Lava overlying dike; glassy margins and large ol MS-24X----Wet lava above pillow HC

MS-39X----Lobe HC, darkk grey lava lobe; above unconformity MS-38 - - X - - Finely jointed light grey lava; below unconformity; GPS slightly off MS-37 - - X - - Massive lava lobe in pillow HC

MS-49 - - - X - Subaerial non-vesicular lava body 5 m below unconformity; Plag, kaer rich MS-48X----Lava lobe within pillow HC; dense black lava containing oxidized ol, plag, kaer MS-46 - - - X - Massive crystal poor lava MS-44 - X - - - Lava above unconformity, platey dark, fine grained lava. MS-43 - - X - - Basal lava below unconformity, dark grey fine grained rock, lots of alteration

MS-51X----20+ m thick dark grey lava; collected at bottom of cliff prow MS-51-2 - - X - - Grey green clastogenic lava; xenolith rich MS-52 - - X - - Grey green lava; clean flow, microvesicular MS-53X----30 m thick dry. Dark grey lava MS-54X----Dark grey lava lobe within HC; just below dry lava MS-55X----Dry dark grey lava; small crystals and some quenching MS-56X----Dark grey lava lobe in HC

104

Minna Hook sample collection summary, continued

Sample Whole-Rock CompositionDescription T/B PT TP TA P MS-81 - - - X Platey, grey green lava flow with abundant feldspar crystals MS-82 - - X - - Lava lobe within HC, with oxidized ol and kaer.; upper of two lavas in contact MS-83X----Dark grey lava, ol rich; lower of two lavas in contact MS-90 - - X - - Lowest lava flow in subaerial sequence above wet-dry transition; grey green lava MS-88 - - X - - Platey green grey lava lobe in HC; above unconformity MS-91X----Interior of lava pillow from unit below unconformity MS-86X----Feldspar-rich dry lava flow, contains kaer. May contain fspthoids MS-85 - - X - - Greenish lava lobe in HC; 10% feld, discolored; contains kaer; tabular ol

MS-159 - X - - - Dark grey platey lava; associated with red scoria and is flow banded MS-160 - - X - - Green grey flow banded lava; felds have mafic inclusions MS-161 - - X - - Dark grey lava; part of a set of thin flows MS-162 - X - 20+ m yellowish lava unit; contains large feld crystals MS-167 - - X - - Crystal poor greenish lava MS-166 - - X - - Coarse crystal rich green lava MS-168 X - - - - Olivine bearing dike

MS-108 - - X - - Grey pumice from PC fall/flow from surge deposit near top of ridge MS-112 - - - - X Dark grey light grey lava

105

APPENDIX B 106

HOST COMPOSITIONS 107

Feldspars and Feldspathoids

108

109

110

111

112

113

114

115

116

117

118

119

Amphibole 120

Electron analysis: Host Amphibole

ppp MS113A-33 MS113A-34 MS113A-35 MS113A-36 MS113A-38 MS113A-39 MS113A-40 core mantle rim core core mantle rim Titano-Potassian Potassian Kaersutite Potassian Kaersutite Potassian Potassian Ferrokaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.43 38.65 37.98 38.13 37.98 38.61 38.29

TiO2 4.97 5.68 5.77 6.00 5.97 5.45 6.03

Al2O3 12.92 13.93 14.40 14.01 14.09 13.75 13.94

Cr2O3 MgO 6.76 10.96 11.07 10.37 10.72 9.90 11.01 CaO 11.29 11.73 11.74 11.72 11.56 11.52 11.68 MnO 0.38 0.19 0.15 0.20 0.19 0.24 0.19 FeO* 18.97 12.55 12.29 13.06 13.08 14.19 12.43

Na2O 2.51 2.32 2.34 2.32 2.42 2.38 2.31

K2O 1.40 1.31 1.28 1.31 1.28 1.34 1.33 NiO F 0.14 0.16 0.23 0.14 0.22 0.17 0.18 Cl 0.03 0.03 0.03 0.02 0.02 0.04 0.02 Total 97.80 97.50 97.28 97.28 97.54 97.60 97.39

Structural formulae on the basis of 24 O Si 5.937 5.806 5.722 5.761 5.729 5.840 5.762 Ti 0.577 0.642 0.654 0.681 0.677 0.620 0.682 Aliv 2.069 2.210 2.297 2.250 2.293 2.176 2.254 Alvi 0.281 0.251 0.251 0.241 0.204 0.270 0.211 Cr 0.000 0.000 0.000 Mg 1.558 2.454 2.487 2.334 2.410 2.233 2.470 Ca 1.869 1.888 1.896 1.897 1.868 1.866 1.883 Mn 0.050 0.024 0.019 0.025 0.025 0.031 0.024 Fe3+ 0.047 0.121 0.152 0.084 0.169 0.122 0.128 Fe2+ 2.402 1.452 1.391 1.564 1.475 1.667 1.431 Na 0.750 0.675 0.683 0.679 0.708 0.699 0.674 K 0.276 0.251 0.245 0.253 0.246 0.259 0.256 Ni

Mg# 39.3 62.8 64.1 59.9 62.0 57.2 63.3

p – phenocryst, mp – microphenocryst, gm – groundmass 121

Electron analysis: Host Amphibole

p pp p MS113A-37 MS114A-23 MS114A-24 MS114A-27 MS114A-28 MS114A-49 MS114A-50 core core rim core rim core rim Titano- Kaersutite Titano- Kaersutite Kaersutite Potassian Titanian Kaersutite Ferrokaersutite Ferrokaersutite Ferroparagasite

SiO2 38.69 38.03 38.72 39.07 39.02 38.77 39.04

TiO2 5.51 6.09 5.07 5.49 4.96 4.20 5.18

Al2O3 13.15 13.95 13.25 13.63 13.09 12.85 13.56

Cr2O3 MgO 8.07 10.18 8.90 11.13 8.91 5.68 9.69 CaO 11.36 11.51 11.42 11.67 11.40 10.79 11.38 MnO 0.29 0.20 0.35 0.15 0.30 0.57 0.22 FeO* 16.89 13.14 15.92 12.20 15.84 21.39 14.67

Na2O 2.42 2.64 2.54 2.76 2.75 2.71 2.72

K2O 1.27 1.20 1.27 1.14 1.24 1.33 1.13 NiO F 0.19 0.15 0.09 0.17 0.15 0.07 0.16 Cl 0.04 0.02 0.02 0.02 0.04 0.09 0.03 Total 97.87 97.09 97.55 97.43 97.70 98.45 97.77

Structural formulae on the basis of 24 O Si 5.908 5.760 5.903 5.861 5.939 6.007 5.896 Ti 0.633 0.694 0.581 0.619 0.568 0.489 0.588 Aliv 2.100 2.248 2.111 2.145 2.068 2.017 2.118 Alvi 0.263 0.240 0.264 0.262 0.278 0.321 0.291 Cr 0.000 0.000 0.000 0.000 Mg 1.837 2.299 2.022 2.489 2.022 1.313 2.182 Ca 1.858 1.868 1.866 1.876 1.859 1.791 1.841 Mn 0.037 0.026 0.045 0.019 0.039 0.074 0.028 Fe3+ 0.065 0.055 0.107 0.050 0.058 0.179 0.107 Fe2+ 2.089 1.607 1.917 1.479 1.956 2.582 1.741 Na 0.716 0.774 0.752 0.804 0.812 0.813 0.798 K 0.247 0.232 0.247 0.218 0.240 0.264 0.217 Ni

Mg# 46.8 58.9 51.3 62.7 50.8 33.7 55.6

p – phenocryst, mp – microphenocryst, gm – groundmass 122

Electron analysis: Host Amphibole

ppp MS114A-64 MS114A-63 MS114A-65 MS114A-66 MS114A-68 MS114A-67 core rim core rim core rim Titano-Potassian Kaersutite Titano- Kaersutite Titano-Potassian Kaersutite Ferrokaersutite Ferrokaersutite Ferrokaersutite

SiO2 39.20 39.20 38.21 38.69 39.07 39.08

TiO2 4.72 5.01 4.85 5.54 4.54 5.15

Al2O3 12.58 13.18 13.65 13.85 13.13 13.27

Cr2O3 MgO 8.35 9.01 6.59 9.91 7.32 9.15 CaO 11.33 11.39 11.23 11.60 11.09 11.52 MnO 0.39 0.30 0.45 0.25 0.42 0.32 FeO* 17.27 16.00 19.40 14.19 19.07 15.96

Na2O 2.61 2.55 2.59 2.63 2.61 2.65

K2O 1.30 1.23 1.16 1.17 1.29 1.29 NiO F 0.09 0.21 0.15 0.19 0.07 0.17 Cl 0.04 0.04 0.04 0.03 0.06 0.04 Total 97.87 98.11 98.31 98.04 98.66 98.60

Structural formulae on the basis of 24 O Si 5.992 5.942 5.876 5.825 5.967 5.899 Ti 0.543 0.571 0.561 0.628 0.521 0.585 Aliv 2.023 2.074 2.141 2.186 2.058 2.114 Alvi 0.239 0.275 0.326 0.266 0.295 0.242 Cr 0.000 0.000 Mg 1.904 2.036 1.511 2.223 1.667 2.060 Ca 1.856 1.849 1.851 1.871 1.814 1.863 Mn 0.051 0.039 0.059 0.032 0.054 0.041 Fe3+ 0.111 0.122 0.134 0.092 0.187 0.106 Fe2+ 2.091 1.900 2.354 1.691 2.238 1.904 Na 0.772 0.748 0.771 0.767 0.772 0.776 K 0.254 0.237 0.228 0.224 0.251 0.247 Ni

Mg# 47.7 51.7 39.1 56.8 42.7 52.0

p – phenocryst, mp – microphenocryst, gm – groundmass 123

Electron analysis: Host Amphibole

ppp MS169A-22 MS169A-23 MS169A-24 MS169A-66 MS169A-67 MS169A-68 MS169B1-66 MS169B1-67 core mantle rim core mantle rim core rim Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.25 38.07 38.32 38.66 38.45 38.47 38.79 39.41

TiO2 6.05 6.51 5.92 6.04 6.16 6.12 6.22 5.52

Al2O3 14.47 15.33 14.25 14.57 14.45 14.28 14.33 13.89

Cr2O3 0.01 0.00 MgO 9.72 12.06 10.08 10.93 10.84 11.08 9.79 10.85 CaO 11.71 12.05 11.46 11.88 11.92 11.58 11.95 11.79 MnO 0.21 0.12 0.22 0.15 0.17 0.17 0.24 0.22 FeO* 13.57 10.12 13.61 12.19 12.32 12.36 14.14 13.27

Na2O 2.39 2.21 2.41 2.38 2.43 2.64 2.59 2.55

K2O 1.18 1.10 1.19 1.16 1.13 1.23 1.18 1.27 NiO 0.00 0.02 F 0.19 0.22 0.26 0.28 0.28 0.34 0.45 0.50 Cl 0.01 0.00 0.04 0.02 0.02 0.03 0.03 0.04 Total 97.74 97.80 97.78 98.26 98.18 98.29 99.72 99.31

Structural formulae on the basis of 24 O Si 5.757 5.636 5.772 5.754 5.736 5.741 5.757 5.846 Ti 0.685 0.725 0.670 0.676 0.692 0.687 0.695 0.616 Aliv 2.248 2.379 2.246 2.257 2.272 2.274 2.245 2.169 Alvi 0.317 0.291 0.277 0.296 0.266 0.232 0.261 0.254 Cr 0.001 0.000 Mg 2.180 2.663 2.263 2.424 2.411 2.464 2.167 2.399 Ca 1.888 1.912 1.850 1.893 1.906 1.851 1.900 1.874 Mn 0.027 0.015 0.028 0.019 0.021 0.021 0.030 0.028 Fe3+ 0.044 0.120 0.136 0.081 0.065 0.118 0.019 0.112 Fe2+ 1.663 1.130 1.574 1.434 1.469 1.421 1.736 1.530 Na 0.699 0.635 0.705 0.687 0.703 0.764 0.744 0.732 K 0.226 0.208 0.229 0.220 0.215 0.234 0.223 0.241 Ni 0.000 0.002

Mg# 56.7 70.2 59.0 62.8 62.1 63.4 55.5 61.1

p – phenocryst, mp – microphenocryst, gm – groundmass 124

Electron analysis: Host Amphibole

pp MS169B1-41 MS169B1-42 MS169B1-40 MS169B1-50 MS169B1-51 MS169B1-52 MS169B1-49 core mantle rim core mantle mantle rim Titano-Potassian Titano-Potassian Titano-Potassian Kaersutite Kaersutite Kaersutite Potassian Ferrokaersutite Ferrokaersutite Ferrokaersutite Kaersutite

SiO2 38.95 39.07 38.57 38.92 37.36 38.95 39.55

TiO2 5.02 4.92 4.93 5.88 6.90 5.93 5.40

Al2O3 12.92 12.98 12.79 14.18 15.51 14.07 14.28

Cr2O3 0.02 0.01 0.00 0.00 0.02 0.03 0.00 MgO 6.52 6.53 6.19 10.55 11.56 10.70 10.32 CaO 11.47 11.47 11.11 12.08 12.26 11.88 11.75 MnO 0.44 0.39 0.45 0.23 0.10 0.20 0.26 FeO* 20.46 20.21 20.99 13.65 11.56 13.44 14.15

Na2O 2.78 2.75 2.76 2.43 2.33 2.56 2.61

K2O 1.33 1.34 1.29 1.25 1.13 1.26 1.39 NiO 0.00 0.02 0.00 0.00 0.03 0.00 0.00 F 0.25 0.49 0.44 0.42 0.35 0.36 0.33 Cl 0.05 0.05 0.05 0.03 0.01 0.03 0.03 Total 100.22 100.22 99.56 99.62 99.11 99.42 100.06

Structural formulae on the basis of 24 O Si 5.918 5.940 5.925 5.769 5.519 5.775 5.835 Ti 0.574 0.562 0.570 0.655 0.767 0.662 0.599 Aliv 2.090 2.066 2.094 2.243 2.496 2.236 2.180 Alvi 0.221 0.259 0.215 0.230 0.199 0.219 0.298 Cr 0.002 0.001 0.000 0.000 0.002 0.003 0.000 Mg 1.477 1.479 1.417 2.331 2.547 2.366 2.269 Ca 1.868 1.869 1.828 1.918 1.941 1.887 1.857 Mn 0.056 0.050 0.058 0.029 0.013 0.025 0.032 Fe3+ 0.074 0.051 0.145 0.092 0.139 0.100 0.112 Fe2+ 2.522 2.516 2.542 1.596 1.284 1.563 1.630 Na 0.820 0.811 0.821 0.698 0.668 0.737 0.747 K 0.258 0.259 0.253 0.237 0.212 0.239 0.261 Ni 0.000 0.002 0.000 0.000 0.003 0.000 0.000

Mg# 36.9 37.0 35.8 59.4 66.5 60.2 58.2

p – phenocryst, mp – microphenocryst, gm – groundmass 125

Electron analysis: Host Amphibole

pppp MS169C-02 MS169C-03 MS169C-04 MS169C-36 MS169D-04 MS169D-05 MS169N2-18 core mantle rim core core rim core Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.35 38.43 39.04 38.51 38.10 38.89 39.14

TiO2 5.84 5.77 5.61 6.12 6.40 6.52 6.29

Al2O3 14.16 14.11 13.82 14.29 15.04 14.28 14.97

Cr2O3 0.02 0.03 0.00 0.05 MgO 9.51 9.38 11.31 11.32 11.10 12.51 12.45 CaO 11.83 11.79 11.94 12.09 12.30 12.35 12.24 MnO 0.21 0.23 0.22 0.19 0.16 0.13 0.12 FeO* 15.10 15.19 13.00 12.56 12.16 10.33 10.24

Na2O 2.51 2.53 2.70 2.45 2.62 2.60 2.26

K2O 1.17 1.13 1.31 1.26 1.24 1.03 1.27 NiO 0.01 0.00 0.00 0.00 F 0.26 0.33 0.18 0.31 1.15 0.98 0.29 Cl 0.02 0.02 0.03 0.02 0.01 0.02 0.01 Total 98.99 98.93 99.14 99.17 100.27 99.64 99.27

Structural formulae on the basis of 24 O Si 5.750 5.769 5.790 5.706 5.625 5.711 5.714 Ti 0.658 0.652 0.625 0.682 0.711 0.720 0.690 Aliv 2.262 2.242 2.226 2.307 2.379 2.295 2.298 Alvi 0.236 0.250 0.183 0.184 0.238 0.175 0.273 Cr 0.003 0.003 0.000 0.006 0.000 0.000 0.000 Mg 2.127 2.100 2.500 2.500 2.443 2.739 2.711 Ca 1.900 1.895 1.897 1.918 1.946 1.943 1.915 Mn 0.027 0.030 0.028 0.024 0.020 0.016 0.014 Fe3+ 0.108 0.101 0.124 0.124 0.031 0.043 0.097 Fe2+ 1.782 1.803 1.485 1.428 1.469 1.224 1.151 Na 0.729 0.738 0.775 0.703 0.751 0.741 0.639 K 0.224 0.215 0.247 0.238 0.233 0.192 0.237 Ni 0.002 0.000 0.000 0.000

Mg# 54.4 53.8 62.7 63.6 62.5 69.1 70.2

p – phenocryst, mp – microphenocryst, gm – groundmass 126

Electron analysis: Host Amphibole

mp mp mp mp mp mp MS114A-06 MS114A-15 MS114A-16 MS114A-17 MS114A-25 MS114A-51 MS169B1-09 mantle core core rim core core rim Titano-Potassian Kaersutite Kaersutite Potassian Kaersutite Kaersutite Potassian Ferrokaersutite Kaersutite Kaersutite

SiO2 38.96 38.88 38.17 38.81 38.84 38.73 37.62

TiO2 4.91 5.16 5.69 5.16 5.17 5.03 6.21

Al2O3 13.00 13.53 14.22 13.25 13.70 13.96 14.34

Cr2O3 0.03 MgO 8.72 9.76 10.25 8.93 10.03 10.05 10.80 CaO 11.49 11.55 11.61 11.49 11.56 11.60 11.85 MnO 0.41 0.26 0.21 0.33 0.24 0.20 0.17 FeO* 16.53 14.20 13.50 15.59 13.99 13.96 13.46

Na2O 2.62 2.59 2.57 2.65 2.68 2.49 2.50

K2O 1.32 1.15 1.25 1.30 1.14 1.20 1.34 NiO 0.00 F 0.19 0.21 0.23 0.24 0.15 0.24 0.15 Cl 0.02 0.04 0.02 0.04 0.05 0.05 0.02 Total 98.17 97.32 97.70 97.78 97.55 97.52 98.48

Structural formulae on the basis of 24 O Si 5.928 5.895 5.757 5.906 5.868 5.855 5.640 Ti 0.562 0.589 0.645 0.590 0.587 0.572 0.700 Aliv 2.085 2.114 2.257 2.100 2.143 2.161 2.380 Alvi 0.243 0.300 0.264 0.275 0.292 0.320 0.144 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.003 Mg 1.978 2.206 2.305 2.025 2.259 2.266 2.414 Ca 1.874 1.876 1.875 1.874 1.871 1.879 1.902 Mn 0.052 0.033 0.027 0.043 0.031 0.026 0.022 Fe3+ 0.098 0.071 0.112 0.044 0.091 0.125 0.172 Fe2+ 2.001 1.727 1.586 1.939 1.673 1.636 1.509 Na 0.774 0.760 0.752 0.781 0.783 0.731 0.728 K 0.256 0.222 0.240 0.253 0.220 0.231 0.256 Ni 0.000

Mg# 49.7 56.1 59.2 51.1 57.5 58.1 61.5

p – phenocryst, mp – microphenocryst, gm – groundmass 127

Electron analysis: Host Amphibole

mp mp mp mp MS114A-61 MS114A-62 MS169A-04 MS169A-05 MS169A-07 MS169A-06 MS169A-17 core rim core rim core rim mantle Titano-Potassian Potassian Kaersutite Titano- Titano- Kaersutite Kaersutite Ferrokaersutite Ferrokaersutite Ferrokaersutite Ferrokaersutite

SiO2 38.49 38.87 38.32 38.96 38.21 38.55 38.42

TiO2 4.77 5.14 5.97 5.64 5.40 5.61 5.79

Al2O3 13.19 13.40 14.32 14.21 13.94 14.32 14.19

Cr2O3 MgO 6.85 9.09 9.07 8.39 7.43 11.10 10.77 CaO 11.09 11.39 11.79 11.54 11.42 11.91 11.67 MnO 0.42 0.29 0.24 0.28 0.37 0.14 0.18 FeO* 19.23 15.73 15.05 16.97 18.20 12.73 12.81

Na2O 2.62 2.76 2.63 2.79 2.60 2.67 2.50

K2O 1.30 1.30 1.16 1.19 1.16 0.95 1.24 NiO F 0.19 0.17 0.17 0.17 0.20 0.25 0.26 Cl 0.05 0.04 0.02 0.02 0.03 0.03 0.03 Total 98.19 98.17 98.74 100.17 98.97 98.25 97.86

Structural formulae on the basis of 24 O Si 5.927 5.889 5.754 5.808 5.809 5.753 5.765 Ti 0.552 0.585 0.674 0.633 0.618 0.630 0.653 Aliv 2.091 2.122 2.249 2.204 2.207 2.264 2.250 Alvi 0.297 0.267 0.285 0.288 0.285 0.248 0.254 Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Mg 1.572 2.052 2.031 1.864 1.683 2.469 2.408 Ca 1.829 1.849 1.896 1.844 1.860 1.905 1.876 Mn 0.055 0.037 0.030 0.036 0.048 0.018 0.023 Fe3+ 0.135 0.087 0.025 0.092 0.122 0.136 0.119 Fe2+ 2.334 1.902 1.865 2.020 2.186 1.447 1.485 Na 0.783 0.811 0.765 0.806 0.767 0.771 0.728 K 0.255 0.252 0.223 0.226 0.225 0.180 0.237 Ni

Mg# 40.3 51.9 52.1 48.0 43.5 63.0 61.9

p – phenocryst, mp – microphenocryst, gm – groundmass 128

Electron analysis: Host Amphibole

mp mp mp mp mp MS169B1-09 MS169B1-20 MS169B1-19 MS169C-08 MS169C-09 MS169D-06 MS169D-39 rim core rim core rim core core Potassian Kaersutite Kaersutite Kaersutite Kaersutite Potassian Potassian Kaersutite Kaersutite Kaersutite

SiO2 37.62 38.25 38.70 37.56 37.91 38.28 38.44

TiO2 6.21 6.11 6.18 6.30 6.07 6.09 5.08

Al2O3 14.34 14.72 14.31 15.28 14.63 14.33 13.81

Cr2O3 0.03 0.00 0.02 0.01 0.01 MgO 10.80 11.01 12.22 10.67 9.70 11.24 10.90 CaO 11.85 11.85 12.11 12.13 11.66 12.21 11.76 MnO 0.17 0.18 0.18 0.17 0.22 0.19 0.20 FeO* 13.46 12.06 12.98 13.04 14.44 12.22 13.36

Na2O 2.50 2.45 2.72 2.43 2.41 2.60 2.62

K2O 1.34 1.06 1.22 1.20 1.12 1.34 1.45 NiO 0.00 0.01 0.01 0.00 0.00 F 0.15 0.35 0.42 0.37 0.46 0.91 2.70 Cl 0.02 0.03 0.03 0.02 0.04 0.02 0.04 Total 98.48 98.08 101.09 99.19 98.66 99.41 100.35

Structural formulae on the basis of 24 O Si 5.640 5.708 5.647 5.584 5.696 5.693 5.795 Ti 0.700 0.686 0.678 0.705 0.686 0.681 0.576 Aliv 2.380 2.305 2.385 2.432 2.323 2.312 2.224 Alvi 0.144 0.278 0.062 0.240 0.259 0.198 0.223 Cr 0.003 0.000 0.002 0.002 0.001 Mg 2.414 2.450 2.657 2.364 2.172 2.492 2.448 Ca 1.902 1.895 1.892 1.932 1.877 1.945 1.900 Mn 0.022 0.022 0.023 0.021 0.029 0.023 0.026 Fe3+ 0.172 0.108 0.268 0.133 0.155 0.039 0.144 Fe2+ 1.509 1.394 1.307 1.484 1.654 1.480 1.534 Na 0.728 0.709 0.769 0.700 0.701 0.749 0.765 K 0.256 0.201 0.227 0.228 0.215 0.255 0.279 Ni 0.000 0.001 0.001 0.000 0.000

Mg# 61.5 63.7 67.0 61.4 56.8 62.7 61.5

p – phenocryst, mp – microphenocryst, gm – groundmass 129

Electron analysis: Host Amphibole

mp mp mp mp mp gm gm MS169D-40 MS169N2-09 MS169N2-10 MS169N2-11 MS169N2-26 MS114A-02 MS114A-07 core mantle core core core Potassian Kaersutite Kaersutite Kaersutite Kaersutite Titano- Kaersutite Kaersutite Ferrokaersutite

SiO2 37.93 39.66 39.69 40.12 39.70 38.83 39.10

TiO2 6.00 5.83 5.51 5.80 5.55 4.94 5.48

Al2O3 13.86 13.83 13.57 13.73 13.85 13.26 12.95

Cr2O3 MgO 11.01 11.28 11.32 11.56 11.54 8.62 9.95 CaO 12.27 11.90 11.86 11.95 11.84 11.30 11.44 MnO 0.20 0.18 0.21 0.18 0.20 0.34 0.28 FeO* 12.89 12.65 12.72 12.38 12.27 16.19 14.09

Na2O 2.52 2.50 2.57 2.63 2.47 2.55 2.95

K2O 1.34 1.31 1.28 1.31 1.21 1.23 1.03 NiO F 0.29 0.24 0.19 0.19 0.21 0.18 0.19 Cl 0.03 0.02 0.02 0.04 0.01 0.05 0.03 Total 98.36 99.41 98.92 99.89 98.84 97.49 97.48

Structural formulae on the basis of 24 O Si 5.695 5.843 5.877 5.872 5.865 5.931 5.918 Ti 0.678 0.646 0.614 0.638 0.617 0.568 0.623 Aliv 2.313 2.168 2.136 2.137 2.152 2.083 2.086 Alvi 0.137 0.229 0.227 0.229 0.253 0.299 0.223 Cr 0.000 0.000 Mg 2.465 2.478 2.498 2.522 2.541 1.964 2.246 Ca 1.973 1.879 1.881 1.873 1.873 1.849 1.854 Mn 0.025 0.023 0.026 0.022 0.024 0.043 0.036 Fe3+ 0.058 0.089 0.098 0.066 0.129 0.108 0.030 Fe2+ 1.558 1.467 1.473 1.447 1.383 1.955 1.753 Na 0.733 0.714 0.736 0.747 0.707 0.756 0.865 K 0.257 0.247 0.242 0.244 0.228 0.239 0.199 Ni

Mg# 61.3 62.8 62.9 63.5 64.8 50.1 56.2

p – phenocryst, mp – microphenocryst, gm – groundmass 130

Electron analysis: Host Amphibole

gm gm gm gm MS114A-08 MS114A-18 MS169B1-36 MS169N2-07

Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.24 37.03 38.88 37.50

TiO2 5.52 6.27 5.77 6.66

Al2O3 13.74 14.88 14.06 14.77

Cr2O3 0.00 MgO 10.06 10.70 11.13 10.94 CaO 11.37 11.28 11.89 11.81 MnO 0.27 0.19 0.21 0.18 FeO* 14.05 12.42 13.16 12.66

Na2O 2.83 2.69 2.76 2.63

K2O 1.11 1.23 1.29 1.31 NiO 0.00 F 0.19 0.23 0.55 0.18 Cl 0.04 0.01 0.02 0.02 Total 97.42 96.94 99.72 98.65

Structural formulae on the basis of 24 O Si 5.799 5.612 5.758 5.593 Ti 0.630 0.715 0.642 0.747 Aliv 2.218 2.409 2.258 2.422 Alvi 0.231 0.238 0.191 0.168 Cr 0.000 0.000 0.000 Mg 2.275 2.417 2.458 2.432 Ca 1.846 1.832 1.887 1.887 Mn 0.034 0.024 0.027 0.023 Fe3+ 0.131 0.175 0.121 0.123 Fe2+ 1.645 1.393 1.505 1.452 Na 0.832 0.790 0.791 0.761 K 0.215 0.237 0.244 0.249 Ni 0.000

Mg# 58.0 63.4 62.0 62.6

p – phenocryst, mp – microphenocryst, gm – groundmass 131

Clinopyroxene 132

Electron analysis: Host Diopside

pp MS113A-08 MS113A-09 MS113A-10 MS113A-11 MS113A-12 MS113A-13 MS114A-01MS114A-04 core core core mantle rim rim core rim

SiO2 40.56 47.13 45.37 48.07 47.62 47.65 44.90 48.88

TiO2 4.62 2.15 2.70 1.67 1.74 1.91 3.20 1.26

Al2O3 12.57 6.56 7.66 5.45 5.45 5.52 9.11 4.38

Cr2O3 MgO 10.05 13.20 11.49 12.02 11.02 12.03 11.40 10.52 CaO 21.63 21.70 21.10 21.73 21.78 22.19 21.75 21.96 MnO 0.13 0.14 0.18 0.25 0.34 0.20 0.13 0.36 FeO* 8.07 7.16 9.17 8.90 10.14 8.35 7.10 10.54

Na2O 0.58 0.49 0.51 0.51 0.53 0.54 0.69 0.73

K2O 0.02 0.02 0.01 0.03 0.01 0.02 0.00 0.00 NiO F 0.06 0.20 0.07 0.00 0.00 0.07 0.06 0.03 Cl 0.00 0.00 0.02 0.00 0.01 0.00 0.00 0.00 Total 98.27 98.73 98.27 98.61 98.62 98.49 98.33 98.65

Structural formulae on the basis of 6 O Si 1.545 1.771 1.729 1.821 1.816 1.806 1.699 1.867 Ti 0.132 0.061 0.077 0.047 0.050 0.055 0.091 0.036 Aliv 0.455 0.229 0.271 0.179 0.184 0.193 0.301 0.133 Alvi 0.110 0.061 0.073 0.064 0.061 0.053 0.105 0.064 Cr Mg 0.571 0.739 0.653 0.679 0.626 0.680 0.643 0.599 Ca 0.883 0.873 0.861 0.882 0.890 0.901 0.882 0.899 Mn 0.004 0.005 0.006 0.008 0.011 0.007 0.004 0.012 Fe3+ 0.123 0.082 0.081 0.057 0.063 0.071 0.065 0.051 Fe2+ 0.134 0.143 0.211 0.225 0.260 0.194 0.160 0.286 Na 0.043 0.036 0.038 0.038 0.039 0.039 0.050 0.054 K 0.001 0.001 0.000 0.001 0.000 0.001 0.000 0.000 Ni

End-members Quad 54.5 77.1 72.9 82.1 81.6 80.7 69.9 84.9 Wo 55.6 49.8 49.9 49.4 50.1 50.8 52.4 50.4 En 35.9 42.1 37.8 38.0 35.3 38.3 38.2 33.6 Fs 8.5 8.1 12.2 12.6 14.7 10.9 9.5 16.0 Mg# 81.0 83.8 75.6 75.1 70.6 77.8 80.1 67.7

p – phenocryst, mp – microphenocryst, gm – groundmass 133

Electron analysis: Host Diopside

pp MS113A-14 MS113A-15 MS113A-17 MS113A-18 MS113A-19 MS169C-11 MS169C-12 MS169C-13 core core mantle mantle rim core core rim

SiO2 49.03 47.93 43.48 40.48 42.58 42.52 45.20 46.73

TiO2 1.01 1.69 3.47 4.91 3.68 4.21 2.83 2.21

Al2O3 3.75 5.30 9.96 12.47 10.86 10.48 8.36 6.68

Cr2O3 0.03 0.01 0.00 MgO 10.16 10.80 10.71 9.90 10.56 10.07 10.92 10.06 CaO 21.34 21.66 21.84 21.64 21.48 21.53 22.22 22.23 MnO 0.41 0.36 0.17 0.13 0.13 0.21 0.23 0.40 FeO* 12.60 10.63 8.28 8.60 8.30 9.40 9.18 11.06

Na2O 0.66 0.61 0.64 0.59 0.61 0.75 0.67 0.75

K2O 0.00 0.00 0.01 0.00 0.01 0.01 0.02 0.03 NiO 0.02 0.01 0.01 F 0.02 0.13 0.02 0.00 0.00 0.34 0.13 0.13 Cl 0.01 0.01 0.00 0.01 0.01 0.02 0.00 0.01 Total 98.98 99.11 98.58 98.73 98.21 99.58 99.77 100.31

Structural formulae on the basis of 6 O Si 1.879 1.824 1.649 1.538 1.620 1.610 1.698 1.761 Ti 0.029 0.048 0.099 0.140 0.105 0.120 0.080 0.063 Aliv 0.121 0.176 0.352 0.462 0.380 0.390 0.302 0.239 Alvi 0.048 0.061 0.094 0.097 0.107 0.078 0.069 0.058 Cr 0.001 0.000 0.000 Mg 0.580 0.613 0.605 0.561 0.599 0.568 0.612 0.565 Ca 0.876 0.883 0.887 0.881 0.876 0.873 0.894 0.897 Mn 0.013 0.012 0.005 0.004 0.004 0.007 0.007 0.013 Fe3+ 0.064 0.063 0.107 0.128 0.107 0.126 0.121 0.110 Fe2+ 0.340 0.275 0.155 0.146 0.157 0.171 0.167 0.239 Na 0.049 0.045 0.047 0.044 0.045 0.055 0.049 0.055 K 0.000 0.000 0.001 0.000 0.000 0.000 0.001 0.001 Ni 0.000 0.000 0.000

End-members Quad 86 82 65 54 62 61.0 69.9 76.1 Wo 49 50 54 56 54 54.2 53.5 52.8 En 32 35 37 35 37 35.2 36.5 33.2 Fs 19 16 9 9 10 10.6 10.0 14.0 Mg# 63.1 69.0 79.6 79.4 79.3 76.8 78.5 70.3

p – phenocryst, mp – microphenocryst, gm – groundmass 134

Electron analysis: Host Diopside

p MS169A-52 MS169A-53 MS169A-54 MS169A-55 MS169A-56 MS169A-57 core core mantle rim rim rim

SiO2 47.22 49.83 46.03 48.24 45.03 48.30

TiO2 2.30 0.96 2.71 1.91 2.58 1.72

Al2O3 6.09 3.15 7.30 5.54 8.16 5.18

Cr2O3 0.02 0.00 0.00 0.00 0.00 0.01 MgO 11.20 10.37 10.80 11.79 8.84 12.23 CaO 22.15 21.67 22.07 22.16 21.72 21.97 MnO 0.23 0.42 0.21 0.22 0.33 0.27 FeO* 9.52 12.26 8.89 8.93 11.45 8.93

Na2O 0.66 0.57 0.65 0.57 0.78 0.56

K2O NiO 0.01 0.00 0.00 0.00 0.00 0.00 F Cl Total 99.39 99.22 98.66 99.36 98.88 99.16

Structural formulae on the basis of 6 O Si 1.782 1.905 1.749 1.816 1.725 1.818 Ti 0.065 0.028 0.077 0.054 0.074 0.049 Aliv 0.218 0.095 0.251 0.184 0.275 0.182 Alvi 0.053 0.046 0.076 0.061 0.094 0.048 Cr 0.001 0.000 0.000 0.000 0.000 0.000 Mg 0.630 0.591 0.612 0.662 0.505 0.687 Ca 0.895 0.887 0.898 0.894 0.892 0.886 Mn 0.007 0.013 0.007 0.007 0.011 0.008 Fe3+ 0.083 0.036 0.069 0.057 0.090 0.077 Fe2+ 0.218 0.356 0.214 0.224 0.276 0.204 Na 0.048 0.043 0.048 0.041 0.058 0.041 K Ni 0.000 0.000 0.000 0.000 0.000 0.000

End-members Quad 78.2 89.0 74.9 81.6 72.5 81.8 Wo 51.4 48.4 52.1 50.2 53.3 49.9 En 36.1 32.2 35.5 37.2 30.2 38.6 Fs 12.5 19.4 12.4 12.6 16.5 11.5 Mg# 74.3 62.4 74.1 74.7 64.6 77.1

p – phenocryst, mp – microphenocryst, gm – groundmass 135

Electron analysis: Host Diopside

p gm MS169B1-58a MS169B1-58b MS169B1-58c MS169B1-58d MS169B1-58e MS169C-05 core mantle mantle rim rim

SiO2 41.63 41.57 41.43 41.37 41.19 45.21

TiO2 4.57 4.56 4.56 4.58 4.58 2.74

Al2O3 12.89 12.79 12.85 12.69 12.72 8.45

Cr2O3 0.24 0.22 0.22 0.20 0.17 0.00 MgO 10.57 10.40 10.43 10.99 10.60 10.66 CaO 22.39 22.07 22.11 21.89 22.03 21.81 MnO 0.12 0.11 0.10 0.11 0.10 0.27 FeO* 7.96 8.04 8.09 7.92 8.10 9.85

Na2O 0.54 0.53 0.57 0.55 0.56 0.76

K2O 0.00 0.03 0.00 0.00 0.01 0.06 NiO 0.01 0.03 0.01 0.02 0.01 0.01 F 0.16 0.15 0.00 0.33 0.09 0.32 Cl 0.00 0.00 0.00 0.00 0.00 0.01 Total 101.09 100.49 100.36 100.63 100.15 100.14

Structural formulae on the basis of 6 O Si 1.551 1.550 1.543 1.538 1.537 1.699 Ti 0.128 0.128 0.128 0.128 0.129 0.077 Aliv 0.458 0.449 0.457 0.461 0.462 0.301 Alvi 0.105 0.113 0.108 0.095 0.098 0.073 Cr 0.007 0.006 0.007 0.006 0.005 0.000 Mg 0.587 0.578 0.579 0.609 0.590 0.597 Ca 0.894 0.881 0.882 0.872 0.881 0.878 Mn 0.004 0.004 0.003 0.004 0.003 0.009 Fe3+ 0.056 0.112 0.128 0.144 0.142 0.128 Fe2+ 0.192 0.138 0.124 0.102 0.111 0.182 Na 0.039 0.038 0.041 0.039 0.041 0.056 K 0.000 0.001 0.000 0.000 0.000 0.003 Ni 0.000 0.001 0.000 0.001 0.000 0.000

End-members Quad 54.2 55.1 54.3 53.9 53.8 69.9 Wo 56.0 55.2 55.7 55.1 55.7 53.0 En 36.7 36.2 36.5 38.5 37.3 36.0 Fs 7.3 8.6 7.8 6.5 7.0 11.0 Mg# 83.4 80.7 82.4 85.6 84.2 76.7

p – phenocryst, mp – microphenocryst, gm – groundmass 136

Electron analysis: Host Diopside

pp MS169C-15 MS169C-16 MS169C-17 MS169C-18 MS169C-31 MS169C-32 MS169C-33 core mantle mantle rim rim rim rim

SiO2 42.30 48.93 49.91 50.48 43.46 42.91 45.35

TiO2 4.36 1.58 1.04 0.70 3.93 4.10 3.08

Al2O3 10.69 4.93 3.49 2.63 9.98 10.24 7.99

Cr2O3 0.01 0.00 0.00 0.00 0.21 0.17 0.02 MgO 9.78 12.73 11.23 11.20 11.30 11.08 10.63 CaO 22.00 22.18 22.41 21.69 22.52 22.49 22.05 MnO 0.22 0.26 0.46 0.56 0.12 0.11 0.29 FeO* 9.88 8.71 10.85 10.46 7.62 7.60 9.64

Na2O 0.74 0.55 0.60 1.06 0.52 0.54 0.73

K2O 0.03 0.00 0.01 0.04 NiO 0.00 0.00 0.00 0.00 0.00 0.04 0.01 F 0.09 0.08 0.00 0.32 Cl 0.01 0.00 0.00 0.00 Total 100.10 99.94 99.98 99.14 99.67 99.27 99.79

Structural formulae on the basis of 6 O Si 1.593 1.825 1.881 1.917 1.627 1.615 1.700 Ti 0.123 0.044 0.029 0.020 0.111 0.116 0.087 Aliv 0.407 0.175 0.120 0.083 0.372 0.385 0.293 Alvi 0.067 0.042 0.035 0.035 0.068 0.069 0.061 Cr 0.000 0.000 0.000 0.000 0.006 0.005 0.001 Mg 0.549 0.708 0.631 0.634 0.631 0.621 0.594 Ca 0.887 0.886 0.904 0.882 0.903 0.907 0.885 Mn 0.007 0.008 0.015 0.018 0.004 0.004 0.009 Fe3+ 0.146 0.084 0.069 0.086 0.112 0.108 0.173 Fe2+ 0.165 0.187 0.272 0.246 0.127 0.132 0.123 Na 0.054 0.039 0.044 0.078 0.038 0.039 0.053 K 0.001 0.000 0.000 0.002 Ni 0.000 0.000 0.000 0.000 0.000 0.001 0.000

End-members Quad 59.3 82.5 86.6 85.9 62.8 61.5 70.7 Wo 55.4 49.8 50.1 50.1 54.5 55.0 53.0 En 34.3 39.7 34.9 36.0 38.0 37.7 35.5 Fs 10.3 10.5 15.1 14.0 7.5 7.3 11.5 Mg# 76.9 79.1 69.8 72.0 83.5 83.8 75.6

p – phenocryst, mp – microphenocryst, gm – groundmass 137

Electron analysis: Host Diopside

pp MS169D-01 MS169D-02 MS169D-03 MS169D-11 MS169D-12 MS169D-13 MS169D-14 core rim rim core core mantle rim

SiO2 43.85 46.57 50.39 46.53 40.32 39.83 44.03

TiO2 3.51 2.14 0.93 2.39 4.49 5.00 2.83

Al2O3 10.49 6.60 3.28 6.87 12.77 12.91 9.05

Cr2O3 MgO 11.76 13.76 11.43 13.08 10.46 9.51 10.98 CaO 22.63 22.47 22.87 22.33 22.51 22.13 22.20 MnO 0.14 0.14 0.48 0.16 0.11 0.17 0.23 FeO* 7.00 6.77 10.57 7.44 7.92 9.15 9.07

Na2O 0.63 0.47 0.51 0.45 0.58 0.74 0.68

K2O 0.00 0.00 0.04 0.00 0.00 0.01 0.01 NiO F 0.01 1.18 0.04 0.00 0.17 0.07 0.08 Cl 0.02 0.02 0.00 0.01 0.00 0.00 0.01 Total 100.03 100.11 100.54 99.25 99.34 99.53 99.15

Structural formulae on the basis of 6 O Si 1.627 1.737 1.888 1.738 1.517 1.504 1.660 Ti 0.098 0.060 0.026 0.067 0.127 0.142 0.080 Aliv 0.373 0.263 0.112 0.262 0.483 0.496 0.340 Alvi 0.085 0.027 0.033 0.041 0.084 0.079 0.063 Cr Mg 0.650 0.765 0.639 0.729 0.587 0.535 0.617 Ca 0.899 0.898 0.918 0.894 0.907 0.895 0.897 Mn 0.004 0.004 0.015 0.005 0.004 0.005 0.007 Fe3+ 0.137 0.150 0.063 0.119 0.187 0.187 0.166 Fe2+ 0.080 0.062 0.269 0.113 0.062 0.102 0.120 Na 0.045 0.034 0.037 0.033 0.043 0.054 0.049 K 0.000 0.000 0.002 0.000 0.000 0.000 0.001 Ni

End-members Quad 62.7 73.7 87.8 73.8 51.7 50.4 66.0 Wo 55.2 52.1 50.3 51.5 58.3 58.4 54.9 En 39.9 44.4 35.0 42.0 37.7 34.9 37.8 Fs 4.9 3.6 14.7 6.5 4.0 6.6 7.3 Mg# 89.1 92.5 70.4 86.6 90.5 84.0 83.8

p – phenocryst, mp – microphenocryst, gm – groundmass 138

Electron analysis: Host Diopside

pmmp pmp mp MS169D-17 MS169D-18 MS113A-24 MS113A-45 MS113A-46 MS114A-26 MS114A-52 core rim core core rim core core

SiO2 46.90 47.00 41.46 45.97 50.15 48.25 45.61

TiO2 2.33 1.78 4.83 2.70 0.78 1.50 1.96

Al2O3 6.70 6.08 11.12 7.41 2.25 4.94 7.11

Cr2O3 MgO 13.50 12.43 9.75 11.89 10.07 10.43 8.81 CaO 22.57 22.69 21.43 21.56 21.63 22.08 21.59 MnO 0.17 0.27 0.15 0.21 0.65 0.38 0.46 FeO* 7.03 8.63 8.88 8.65 12.32 10.45 12.89

Na2O 0.45 0.61 0.66 0.50 0.91 0.71 0.75

K2O 0.00 0.01 0.01 0.00 0.04 0.01 0.00 NiO F 0.00 0.07 0.01 0.19 0.02 0.12 0.02 Cl 0.02 0.01 0.00 0.00 0.01 0.01 0.00 Total 99.65 99.57 98.29 99.08 98.83 98.88 99.21

Structural formulae on the basis of 6 O Si 1.741 1.757 1.587 1.734 1.925 1.841 1.748 Ti 0.065 0.050 0.139 0.077 0.023 0.043 0.057 Aliv 0.259 0.243 0.413 0.270 0.075 0.159 0.252 Alvi 0.034 0.025 0.088 0.059 0.027 0.063 0.070 Cr Mg 0.747 0.693 0.556 0.669 0.576 0.593 0.503 Ca 0.898 0.909 0.879 0.871 0.890 0.903 0.887 Mn 0.005 0.009 0.005 0.007 0.021 0.012 0.015 Fe3+ 0.127 0.161 0.096 0.095 0.070 0.063 0.125 Fe2+ 0.091 0.109 0.188 0.178 0.325 0.271 0.288 Na 0.033 0.044 0.049 0.036 0.068 0.052 0.056 K 0.000 0.000 0.001 0.000 0.002 0.000 0.000 Ni

End-members Quad 74.1 75.8 58.7 73.0 88.0 83.1 74.8 Wo 51.7 53.2 54.2 51.1 49.7 51.1 52.8 En 43.0 40.5 34.3 38.6 32.2 33.6 30.0 Fs 5.3 6.4 11.6 10.3 18.2 15.3 17.2 Mg# 89.1 86.4 74.7 79.0 63.9 68.7 63.6

p – phenocryst, mp – microphenocryst, gm – groundmass 139

Electron analysis: Host Diopside

mp mp mp MS114A-53 MS114A-70 MS169B1-04 MS169B1-05 MS169B1-06 MS169B1-07 MS169B1-08 core core core core mantle mantle rim

SiO2 49.80 47.10 47.92 47.95 44.75 46.15 49.30

TiO2 0.99 1.80 1.81 1.68 2.73 2.35 0.73

Al2O3 3.37 6.39 5.60 5.29 8.13 7.24 2.28

Cr2O3 0.00 0.00 0.00 0.00 0.01 MgO 10.17 9.48 12.49 12.68 10.27 11.71 10.46 CaO 22.07 21.87 22.23 22.39 21.65 22.28 22.45 MnO 0.44 0.37 0.25 0.22 0.30 0.24 0.69 FeO* 11.63 11.89 8.96 8.55 10.55 8.96 12.30

Na2O 0.66 0.83 0.58 0.53 0.62 0.62 0.57

K2O 0.00 0.01 0.01 0.00 0.01 0.00 0.02 NiO 0.01 0.00 0.00 0.01 0.01 F 0.03 0.15 0.14 0.18 0.30 0.06 0.15 Cl 0.00 0.00 0.01 0.00 0.00 0.00 0.00 Total 99.15 99.89 100.01 99.47 99.31 99.62 98.96

Structural formulae on the basis of 6 O Si 1.903 1.787 1.789 1.798 1.702 1.730 1.894 Ti 0.028 0.051 0.051 0.047 0.078 0.066 0.021 Aliv 0.097 0.213 0.211 0.202 0.298 0.270 0.103 Alvi 0.054 0.073 0.035 0.031 0.066 0.051 0.000 Cr 0.000 0.000 0.000 0.000 0.000 Mg 0.579 0.536 0.695 0.709 0.582 0.655 0.599 Ca 0.903 0.889 0.889 0.899 0.882 0.895 0.924 Mn 0.014 0.012 0.008 0.007 0.010 0.008 0.022 Fe3+ 0.035 0.098 0.116 0.115 0.121 0.131 0.103 Fe2+ 0.336 0.279 0.164 0.153 0.214 0.149 0.292 Na 0.049 0.061 0.042 0.038 0.045 0.045 0.042 K 0.000 0.001 0.001 0.000 0.001 0.000 0.001 Ni 0.000 0.000 0.000 0.000 0.000

End-members Quad 88.2 77.8 78.9 79.8 70.2 73.1 87.5 Wo 49.7 52.2 50.9 51.1 52.6 52.7 50.9 En 31.8 31.5 39.8 40.2 34.7 38.5 33.0 Fs 18.5 16.4 9.4 8.7 12.8 8.8 16.1 Mg# 63.3 65.8 80.9 82.2 73.1 81.4 67.3

p – phenocryst, mp – microphenocryst, gm – groundmass 140

Electron analysis: Host Diopside

mp mp mp mp MS169A-65 MS169B1-13 MS169B1-17 MS169B1-18 MS169B1-23 MS169B1-22 rim core core rim core rim

SiO2 42.00 47.91 52.36 51.50 53.07 49.34

TiO2 4.45 1.74 0.88 1.04 0.42 1.26

Al2O3 10.82 5.48 2.59 3.80 1.06 4.07

Cr2O3 0.00 0.00 0.00 0.02 0.01 MgO 9.57 12.78 14.88 12.25 13.85 10.09 CaO 21.34 22.46 22.57 21.36 22.21 22.32 MnO 0.21 0.23 0.35 0.49 0.35 0.53 FeO* 9.77 8.38 6.36 9.47 9.24 12.14

Na2O 0.69 0.61 0.67 1.39 0.51 0.77

K2O 0.00 0.01 0.04 0.06 0.01 0.04 NiO 0.00 0.00 0.00 0.01 0.02 F 0.18 0.00 0.61 0.20 0.18 0.32 Cl 0.00 0.00 0.00 0.00 0.01 0.01 Total 99.03 99.58 101.31 101.55 100.95 100.90

Structural formulae on the basis of 6 O Si 1.602 1.788 1.915 1.891 1.963 1.859 Ti 0.127 0.049 0.024 0.029 0.012 0.036 Aliv 0.399 0.212 0.085 0.109 0.036 0.140 Alvi 0.088 0.029 0.027 0.056 0.010 0.040 Cr 0.000 0.000 0.000 0.000 0.000 Mg 0.544 0.711 0.811 0.670 0.764 0.567 Ca 0.872 0.898 0.884 0.840 0.880 0.901 Mn 0.007 0.007 0.011 0.015 0.011 0.017 Fe3+ 0.107 0.129 0.057 0.095 0.039 0.085 Fe2+ 0.204 0.132 0.138 0.196 0.247 0.298 Na 0.051 0.044 0.048 0.099 0.037 0.056 K 0.000 0.000 0.002 0.003 0.001 0.002 Ni 0.000 0.000 0.000 0.000 0.001

End-members Quad 60.1 78.8 89.2 82.1 93.9 83.9 Wo 53.8 51.6 48.3 49.2 46.6 51.1 En 33.6 40.8 44.2 39.3 40.4 32.1 Fs 12.6 7.6 7.5 11.5 13.1 16.9 Mg# 72.7 84.3 85.5 77.4 75.6 65.6

p – phenocryst, mp – microphenocryst, gm – groundmass 141

Electron analysis: Host Diopside

mp mp mp mp mp mp mp MS169B1-56 MS169C-35 MS169C-37 MS169D-22 MS169D-38 MS169N2-12 MS169N2-13 core mantle core core rim core rim

SiO2 45.61 45.42 45.37 44.80 46.31 49.41 42.31

TiO2 2.96 2.56 2.81 2.57 2.06 1.70 4.48

Al2O3 8.45 8.45 8.32 8.39 6.41 5.23 11.39

Cr2O3 0.00 0.01 0.00 MgO 10.96 10.81 11.08 11.08 11.72 12.56 9.72 CaO 22.53 22.24 22.47 22.58 22.62 21.93 21.36 MnO 0.23 0.23 0.21 0.22 0.26 0.25 0.20 FeO* 9.54 9.53 8.98 8.94 8.81 8.77 9.51

Na2O 0.67 0.65 0.65 0.73 0.56 0.56 0.71

K2O 0.00 0.01 0.02 0.03 0.00 0.02 0.00 NiO 0.01 0.00 0.02 F 0.11 0.10 0.10 0.11 0.01 0.08 0.08 Cl 0.02 0.00 0.01 0.01 0.00 0.00 0.01 Total 101.07 100.02 100.04 99.45 98.79 100.50 99.77

Structural formulae on the basis of 6 O Si 1.693 1.703 1.699 1.684 1.751 1.835 1.597 Ti 0.083 0.072 0.079 0.073 0.059 0.047 0.127 Aliv 0.307 0.297 0.301 0.316 0.249 0.165 0.403 Alvi 0.063 0.077 0.066 0.056 0.036 0.064 0.104 Cr 0.000 0.000 0.000 Mg 0.607 0.604 0.618 0.621 0.661 0.695 0.547 Ca 0.896 0.893 0.901 0.909 0.916 0.872 0.864 Mn 0.007 0.007 0.007 0.007 0.008 0.008 0.007 Fe3+ 0.127 0.123 0.124 0.168 0.137 0.046 0.097 Fe2+ 0.170 0.176 0.157 0.113 0.141 0.226 0.203 Na 0.048 0.047 0.047 0.053 0.041 0.040 0.052 K 0.000 0.001 0.001 0.001 0.000 0.001 0.000 Ni 0.000 0.000 0.001

End-members Quad 69.3 70.3 69.9 68.4 75.1 83.5 59.7 Wo 53.6 54.4 53.8 55.4 53.3 48.7 53.5 En 36.3 36.1 36.9 37.8 38.4 38.8 33.9 Fs 10.1 10.5 9.4 6.9 8.2 12.6 12.6 Mg# 78.2 77.5 79.7 84.6 82.4 75.5 72.9

p – phenocryst, mp – microphenocryst, gm – groundmass 142

Electron analysis: Host Diopside

mp mp mp mp gm gm gm MS169N2-19 MS169N2-20 MS169N2-27 MS169N2-28 MS169A-18 MS169A-61 MS169A-64 core rim core core

SiO2 45.93 47.14 48.38 46.50 50.49 52.11 47.07

TiO2 2.89 2.53 1.90 2.46 0.74 0.65 2.06

Al2O3 8.52 7.11 5.65 7.88 2.66 1.43 6.55

Cr2O3 MgO 11.09 12.35 11.99 11.20 10.99 12.02 10.41 CaO 22.07 21.41 21.94 22.21 21.91 21.60 22.01 MnO 0.20 0.25 0.28 0.24 0.49 0.51 0.36 FeO* 9.01 8.96 9.39 8.93 10.94 9.90 10.81

Na2O 0.66 0.49 0.56 0.66 0.54 0.75 0.67

K2O 0.01 0.03 0.01 0.00 0.03 0.01 0.05 NiO F 0.03 0.00 0.02 0.08 0.00 0.10 0.00 Cl 0.00 0.01 0.00 0.00 0.00 0.00 0.03 Total 100.40 100.27 100.12 100.16 98.79 99.06 100.00

Structural formulae on the basis of 6 O Si 1.712 1.755 1.808 1.737 1.930 1.976 1.775 Ti 0.081 0.071 0.053 0.069 0.021 0.018 0.058 Aliv 0.288 0.245 0.192 0.263 0.070 0.024 0.225 Alvi 0.086 0.067 0.057 0.084 0.050 0.039 0.066 Cr Mg 0.616 0.686 0.668 0.624 0.626 0.679 0.585 Ca 0.881 0.854 0.878 0.889 0.897 0.877 0.889 Mn 0.006 0.008 0.009 0.008 0.016 0.016 0.011 Fe3+ 0.087 0.071 0.068 0.089 0.018 0.003 0.091 Fe2+ 0.194 0.208 0.225 0.191 0.332 0.311 0.249 Na 0.048 0.035 0.041 0.048 0.040 0.055 0.049 K 0.000 0.001 0.000 0.000 0.001 0.000 0.002 Ni

End-members Quad 71.2 75.5 80.8 73.7 91.1 93.9 77.5 Wo 52.1 48.9 49.6 52.2 48.4 47.0 51.6 En 36.4 39.2 37.7 36.6 33.7 36.4 33.9 Fs 11.5 11.9 12.7 11.2 17.9 16.7 14.5 Mg# 76.1 76.7 74.8 76.6 65.4 68.6 70.1

p – phenocryst, mp – microphenocryst, gm – groundmass 143

Electron analysis: Host Diopside

gm gm gm gm gm gm gm MS169B1-14 MS169B1-15 MS169B1-26 MS169B1-48 MS169C-40 MS169D-26 MS169D-29

SiO2 45.75 49.26 46.13 45.05 50.04 43.24 42.38

TiO2 2.80 1.70 3.00 3.13 1.00 3.19 3.90

Al2O3 8.27 5.21 7.19 8.94 2.92 9.60 9.77

Cr2O3 0.00 0.01 0.04 0.01 0.00 MgO 11.10 12.54 11.66 10.83 11.95 10.39 10.57 CaO 22.37 22.46 21.30 22.08 22.52 22.09 22.13 MnO 0.22 0.27 0.21 0.26 0.42 0.19 0.16 FeO* 9.10 8.46 9.30 9.37 10.51 9.25 9.11

Na2O 0.68 0.54 0.44 0.71 0.46 0.69 0.63

K2O 0.00 0.01 0.02 0.01 0.03 0.05 0.04 NiO 0.00 0.01 0.00 0.02 0.00 F 0.08 0.26 0.27 0.10 0.31 0.01 0.07 Cl 0.00 0.01 0.01 0.00 0.00 0.00 0.00 Total 100.37 100.73 99.56 100.50 100.14 98.71 98.75

Structural formulae on the basis of 6 O Si 1.707 1.828 1.742 1.681 1.885 1.642 1.610 Ti 0.079 0.047 0.085 0.088 0.028 0.091 0.111 Aliv 0.293 0.172 0.257 0.319 0.115 0.358 0.390 Alvi 0.070 0.056 0.063 0.075 0.014 0.072 0.048 Cr 0.000 0.000 0.001 0.000 0.000 Mg 0.617 0.693 0.656 0.602 0.671 0.588 0.599 Ca 0.894 0.893 0.862 0.883 0.908 0.898 0.901 Mn 0.007 0.008 0.007 0.008 0.013 0.006 0.005 Fe3+ 0.115 0.060 0.056 0.120 0.078 0.155 0.165 Fe2+ 0.168 0.203 0.238 0.173 0.253 0.138 0.124 Na 0.049 0.039 0.032 0.051 0.034 0.051 0.046 K 0.000 0.000 0.001 0.000 0.001 0.002 0.002 Ni 0.000 0.000 0.000 0.000 0.000

End-members Quad 70.7 82.8 74.3 68.1 87.9 64.2 61.0 Wo 53.2 49.9 49.1 53.3 49.6 55.3 55.5 En 36.7 38.8 37.4 36.3 36.6 36.2 36.9 Fs 10.0 11.3 13.6 10.4 13.8 8.5 7.7 Mg# 78.5 77.4 73.4 77.7 72.6 80.9 82.8

p – phenocryst, mp – microphenocryst, gm – groundmass 144

Electron analysis: Host Diopside

gm gm gm gm gm gm MS169D-30 MS169D-31 MS169D-32 MS169N2-08 MS169N2-14 MS169N2-24

SiO2 42.96 44.47 48.50 48.54 40.71 38.40

TiO2 3.54 2.67 1.12 2.00 5.09 6.51

Al2O3 9.51 7.49 3.47 6.45 12.93 14.10

Cr2O3 MgO 10.79 12.06 11.70 13.53 9.66 8.40 CaO 22.30 22.38 22.54 21.73 21.59 21.34 MnO 0.19 0.19 0.36 0.15 0.15 0.18 FeO* 8.75 8.57 9.90 7.18 8.98 10.06

Na2O 0.68 0.54 0.52 0.46 0.67 0.81

K2O 0.03 0.01 0.00 0.00 0.00 0.02 NiO F 0.00 0.29 0.07 0.08 0.06 0.06 Cl 0.02 0.01 0.02 0.00 0.00 0.00 Total 98.77 98.68 98.19 100.11 99.83 99.88

Structural formulae on the basis of 6 O Si 1.627 1.684 1.855 1.796 1.533 1.457 Ti 0.101 0.076 0.032 0.056 0.144 0.186 Aliv 0.373 0.316 0.146 0.204 0.467 0.543 Alvi 0.052 0.018 0.011 0.077 0.107 0.087 Cr Mg 0.609 0.681 0.667 0.746 0.542 0.475 Ca 0.905 0.908 0.924 0.861 0.871 0.867 Mn 0.006 0.006 0.012 0.005 0.005 0.006 Fe3+ 0.169 0.185 0.109 0.049 0.122 0.144 Fe2+ 0.108 0.086 0.208 0.173 0.161 0.175 Na 0.050 0.039 0.039 0.033 0.049 0.060 K 0.001 0.001 0.000 0.000 0.000 0.001 Ni

End-members Quad 62.7 68.4 84.8 79.6 53.3 45.7 Wo 55.8 54.2 51.4 48.4 55.3 57.2 En 37.6 40.6 37.1 41.9 34.4 31.3 Fs 6.7 5.1 11.6 9.7 10.2 11.5 Mg# 85.0 88.8 76.3 81.2 77.1 73.1

p – phenocryst, mp – microphenocryst, gm – groundmass 145

Electron analysis: Host Diopside—rimming olivine clusters

MS169A-10 MS169A-60 MS169C-28

SiO2 46.70 43.12 41.44

TiO2 2.08 3.80 5.00

Al2O3 7.20 10.66 11.18

Cr2O3 0.04 MgO 11.24 10.90 10.00 CaO 22.02 22.18 21.95 MnO 0.21 0.13 0.12 FeO* 8.80 7.46 9.37

Na2O 0.72 0.52

K2O 0.00 0.00 NiO 0.00 F 0.06 0.02 Cl 0.00 0.00 Total 99.03 98.79 99.11

Structural formulae on the basis of 6 O Si 1.762 1.628 1.582 Ti 0.059 0.108 0.144 Aliv 0.238 0.371 0.418 Alvi 0.082 0.103 0.085 Cr 0.001 Mg 0.632 0.614 0.569 Ca 0.890 0.898 0.898 Mn 0.007 0.004 0.004 Fe3+ 0.091 0.091 0.044 Fe2+ 0.187 0.145 0.255 Na 0.053 0.038 K 0.000 0.000 Ni 0.000

End-members Quad 76 3 58 Wo 52 54 52 En 37 37 33 Fs 11 9 15 Mg# 77.2 80.9 69.1

p – phenocryst, mp – microphenocryst, gm – groundmass 146

Electron analysis: Host Hedenbergite

p pmpmpgmgm MS169C-29 MS169C-30 MS169D-37 MS114A-03 MS114A-69 MS169D-25 MS169N2-29 core mantle core core core

SiO2 49.20 49.64 48.01 49.32 44.86 48.07 48.71

TiO2 0.69 0.52 0.57 0.85 2.86 0.60 0.52

Al2O3 2.98 2.62 2.40 2.65 7.24 2.24 2.57

Cr2O3 0.03 0.00 MgO 8.13 7.92 6.75 7.39 6.42 7.56 5.37 CaO 21.38 21.67 21.87 20.77 21.10 22.20 20.85 MnO 0.59 0.64 0.72 0.83 0.58 0.90 1.26 FeO* 16.31 16.86 17.70 15.33 15.36 16.04 19.46

Na2O 0.67 0.64 0.62 1.38 0.96 0.67 1.22

K2O 0.00 0.01 0.08 0.03 0.06 NiO 0.00 0.01 F 0.05 0.03 0.00 0.03 0.05 Cl 0.00 0.01 0.00 0.00 0.00 Total 99.96 100.52 98.70 98.57 99.46 98.32 100.07

Structural formulae on the basis of 6 O Si 1.859 1.868 1.894 1.924 1.743 1.892 1.906 Ti 0.020 0.015 0.017 0.025 0.084 0.018 0.015 Aliv 0.103 0.091 0.106 0.076 0.257 0.104 0.093 Alvi 0.033 0.028 0.006 0.046 0.075 0.000 0.025 Cr 0.001 0.000 Mg 0.458 0.444 0.397 0.429 0.372 0.444 0.313 Ca 0.865 0.874 0.924 0.868 0.878 0.937 0.874 Mn 0.019 0.020 0.024 0.027 0.019 0.030 0.042 Fe3+ 0.394 0.406 0.113 0.085 0.087 0.120 0.130 Fe2+ 0.086 0.088 0.471 0.415 0.413 0.409 0.507 Na 0.049 0.047 0.048 0.104 0.072 0.051 0.092 K 0.000 0.000 0.000 0.000 0.004 0.001 0.003 Ni 0.000 0.000

End-members Quad 87 88 86 84 74 86 83 Wo 49 49 52 51 53 52 52 En 26 25 22 25 22 25 18 Fs 25 25 26 24 25 23 30 Mg# 51.1 49.6 45.8 50.9 47.4 52.1 38.2

p – phenocryst, mp – microphenocryst, gm – groundmass

147

Magnetite 148

Electron analysis: Host Magnetite

mp mp MS113A-48 MS169N2-02 mantle core

SiO2 0.10 0.07

TiO2 16.69 16.46

Al2O3 8.06 9.93

Cr2O3 0.05 0.04 MgO 4.36 6.46 CaO 0.03 0.04 MnO 0.65 0.40 FeO* 63.69 62.82 Total 93.62 96.22

Structural formulae on the basis of 4 O Si 0.004 0.003 Ti 0.457 0.429 Al 0.346 0.405 Cr 0.001 0.001 Mg 0.236 0.334 Ca 0.001 0.002 Mn 0.020 0.012 Fe3+ 0.739 0.736 Fe2+ 1.201 1.084 sum 3.006 3.006

Ti # 56.9 51.4

p – phenocryst, mp – microphenocryst, gm – groundmass 149

Olivine 150

Electron analysis: Host Olivine

mp mp mp mp mp mp mp MS169A-09 MS169A-58 MS169A-59 MS169B1-37 MS169C-19 MS169C-27 MS169C-38 core core core core rim core core

SiO2 40.27 39.77 39.40 33.64 39.77 40.26 34.33

TiO2 0.02 0.04 0.06 0.05 0.04 0.03 0.24

Al2O3 0.05 0.05 0.00 0.02 0.06 0.06 0.05

Cr2O3 0.00 0.01 0.01 0.00 MgO 44.53 41.65 41.90 19.54 43.17 44.81 21.30 CaO 0.33 0.31 0.33 0.52 0.32 0.30 0.48 MnO 0.15 0.23 0.25 2.59 0.22 0.11 2.08 FeO* 13.95 17.02 16.99 43.09 17.24 14.64 41.25

CoO 0.02 0.02

Na2O 0.03 0.03

K2O 0.02 0.03 NiO 0.18 0.11 0.11 0.01 0.13 0.17 0.02 F 0.03 0.11 Cl 0.00 0.00 Total 99.47 99.17 99.04 99.53 100.96 100.40 99.91

Structural formulae on the basis of 4 O Si 1.011 1.016 1.009 0.994 1.000 1.005 0.997 Ti 0.000 0.001 0.001 0.001 0.001 0.001 0.005 Al 0.001 0.001 0.000 0.001 0.002 0.002 0.002 Cr 0.000 0.000 0.000 0.000 Mg 1.667 1.586 1.599 0.861 1.618 1.667 0.922 Ca 0.009 0.008 0.009 0.017 0.008 0.008 0.015 Mn 0.003 0.005 0.005 0.065 0.005 0.002 0.051 Fe 0.293 0.364 0.364 1.065 0.362 0.306 1.002 Co 0.000 0.000 Na 0.002 0.001 K 0.001 0.001 Ni 0.004 0.002 0.002 0.000 0.003 0.003 0.000 sum 2.988 2.983 2.990 3.005 2.999 2.994 2.998

End-member Fo% 85.1 81.4 81.5 44.7 81.7 84.5 47.9

p – phenocryst, mp – microphenocryst, gm – groundmass 151

TYPE I COMPOSITIONS 152

Feldspars and Feldspathoids 153

154

155

156

157

Electron analysis: Type I Feldspathoids

Nepheline Nepheline Nepheline Nepheline pmpgmgm MS169D-42 MS169A-50 MS169D-73 MS169D-77 core core

SiO2 44.89 52.86 47.59 44.66

Al2O3 34.70 29.96 32.82 34.63 CaO 1.03 0.33 0.29 0.90 FeO 0.31 0.78 0.92 0.44

Na2O 16.82 16.20 16.75 16.80

K2O 3.73 1.97 3.77 4.20 SrO 0.02 0.01 0.00 0.03 BaO 0.04 0.02 0.02 0.01 Total 101.55 102.12 102.15 101.67

Structural formulae on the basis of 16 O Si 4.196 4.788 4.403 4.182 Al 3.821 3.198 3.579 3.822 Ca 0.104 0.032 0.029 0.090 Fe 0.024 0.059 0.071 0.035 Na 3.048 2.844 3.004 3.051 K 0.444 0.227 0.445 0.501 Sr 0.001 0.000 0.000 0.002 Ba 0.001 0.001 0.001 0.000 Sum 11.640 11.149 11.532 11.683

p – phenocryst, mp – microphenocryst, gm – groundmass 158

Amphibole 159

Electron analysis: Type I Amphibole

p MS113A-61 MS113A-62 MS113A-63 MS113A-64 MS113A-65 core core core rim rim Kaersutite Kaersutite Kaersutite Kaersutite Potassian Kaersutite

SiO2 38.46 38.37 37.89 38.07 38.68

TiO2 5.73 6.09 6.62 6.09 5.87

Al2O3 13.51 14.19 14.89 14.09 13.80 MgO 9.16 10.77 11.29 10.64 10.66 CaO 11.59 11.82 12.06 11.85 11.74 MnO 0.23 0.19 0.15 0.19 0.19 FeO* 15.27 12.34 11.18 12.51 12.99

Na2O 2.48 2.40 2.33 2.37 2.34

K2O 1.28 1.16 1.15 1.25 1.32 NiO F 0.17 0.26 0.18 0.18 0.29 Cl 0.03 0.02 0.03 0.02 0.02 Total 97.89 97.60 97.78 97.27 97.89

Structural formulae on the basis of 24 O Si 5.832 5.759 5.649 5.742 5.808 Ti 0.654 0.687 0.742 0.691 0.663 Aliv 2.176 2.250 2.358 2.265 2.205 Alvi 0.235 0.257 0.256 0.236 0.234 Mg 2.071 2.411 2.510 2.393 2.386 Ca 1.883 1.901 1.927 1.915 1.888 Mn 0.029 0.024 0.019 0.024 0.024 Fe3+ 0.065 0.067 0.050 0.057 0.095 Fe2+ 1.869 1.479 1.342 1.519 1.533 Na 0.728 0.699 0.674 0.692 0.680 K 0.247 0.221 0.218 0.241 0.253 Ni

Mg# 52.6 62.0 65.2 61.2 60.9

p – phenocryst, mp – microphenocryst, gm – groundmass 160

Electron analysis: Type I Amphibole

pp MS113A-56 MS113A-57 MS113A-58 MS113A-66 MS113A-67 MS113A-68 MS113A-69 core mantle rim core core rim rim Titano Potassian Kaersutite Kaersutite Kaersutite Kaersutite Potassian Kaersutite Ferrokaersutite Kaersutite

SiO2 38.20 38.43 37.69 38.56 37.37 38.23 37.97

TiO2 5.02 5.60 6.23 5.61 6.60 5.79 5.99

Al2O3 12.99 13.99 14.77 13.63 15.23 14.15 14.11 MgO 6.88 9.47 11.25 9.29 11.67 9.91 10.67 CaO 11.38 11.70 11.88 11.67 11.99 11.66 11.55 MnO 0.37 0.23 0.13 0.26 0.10 0.21 0.23 FeO* 18.86 14.42 11.33 14.79 10.86 13.67 12.67

Na2O 2.41 2.52 2.35 2.43 2.27 2.35 2.43

K2O 1.34 1.17 1.20 1.17 1.13 1.36 1.26 NiO F 0.05 0.29 0.14 0.13 0.19 0.23 0.25 Cl 0.03 0.02 0.01 0.03 0.04 0.03 0.02 Total 97.54 97.83 96.98 97.55 97.44 97.59 97.15

Structural formulae on the basis of 24 O Si 5.910 5.811 5.666 5.847 5.584 5.777 5.742 Ti 0.584 0.636 0.705 0.639 0.742 0.658 0.681 Aliv 2.099 2.195 2.345 2.160 2.433 2.233 2.274 Alvi 0.267 0.296 0.267 0.274 0.242 0.285 0.233 Mg 1.588 2.136 2.522 2.099 2.600 2.231 2.405 Ca 1.887 1.895 1.913 1.896 1.919 1.888 1.870 Mn 0.049 0.029 0.017 0.034 0.013 0.027 0.029 Fe3+ 0.072 0.050 0.087 0.052 0.135 0.072 0.127 Fe2+ 2.365 1.771 1.334 1.821 1.217 1.653 1.470 Na 0.723 0.739 0.685 0.715 0.659 0.689 0.713 K 0.265 0.226 0.230 0.226 0.215 0.262 0.244 Ni

Mg# 40.2 54.7 65.4 53.5 68.1 57.5 62.1

p – phenocryst, mp – microphenocryst, gm – groundmass 161

Electron analysis: Type I Amphibole

pp MS169A-39 MS169A-46 MS169A-40 MS169A-41 MS169A-45 MS169N2-43 MS169N2-42 core core mantle rim rim core rim Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Titano- Ferriokaersutite

SiO2 38.82 38.80 37.89 38.34 38.44 39.57 39.17

TiO2 5.80 5.88 6.22 5.89 6.13 5.86 5.76

Al2O3 13.51 13.78 14.75 14.12 14.06 13.80 13.73 MgO 9.07 10.51 11.16 9.62 10.52 11.29 8.71 CaO 11.67 11.62 12.02 11.66 11.71 12.02 11.59 MnO 0.23 0.20 0.17 0.27 0.18 0.15 0.26 FeO* 15.08 13.32 11.62 14.41 13.09 12.46 16.40

Na2O 2.48 2.55 2.45 2.65 2.57 2.52 2.53

K2O 1.21 1.23 1.15 1.14 1.19 1.30 1.27 NiO F 0.26 0.19 0.20 0.18 0.22 0.21 0.12 Cl 0.02 0.03 0.02 0.02 0.02 0.02 0.02 Total 98.13 98.09 97.64 98.28 98.11 99.21 99.55

Structural formulae on the basis of 24 O Si 5.865 5.815 5.670 5.767 5.759 5.838 5.855 Ti 0.659 0.662 0.701 0.667 0.691 0.651 0.648 Aliv 2.137 2.197 2.338 2.243 2.251 2.168 2.155 Alvi 0.268 0.232 0.260 0.257 0.228 0.230 0.260 Mg 2.043 2.349 2.489 2.158 2.349 2.484 1.940 Ca 1.888 1.865 1.927 1.878 1.880 1.900 1.857 Mn 0.029 0.025 0.021 0.034 0.022 0.019 0.033 Fe3+ 0.010 0.095 0.064 0.073 0.076 0.050 0.079 Fe2+ 1.895 1.570 1.389 1.737 1.560 1.486 1.968 Na 0.727 0.739 0.710 0.772 0.745 0.722 0.732 K 0.233 0.234 0.220 0.218 0.227 0.244 0.242 Ni

Mg# 51.9 59.9 64.2 55.4 60.1 62.6 49.6

p – phenocryst, mp – microphenocryst, gm – groundmass 162

Electron analysis: Type I Amphibole

pp MS169A-36 MS169A-37 MS169A-38 MS169A-44 MS169N2-55MS169N2-56 core mantle rim rim core rim Titano- Kaersutite Kaersutite Potassian Kaersutite Kaersutite Ferrokaersutite Kaersutite

SiO2 38.92 37.46 37.99 38.78 38.74 39.49

TiO2 5.66 5.92 6.21 5.88 6.25 5.88

Al2O3 13.38 13.50 14.74 13.98 14.74 14.16 MgO 8.14 9.01 11.05 10.32 11.12 11.33 CaO 11.39 11.94 12.06 11.67 12.16 11.93 MnO 0.30 0.25 0.14 0.22 0.18 0.16 FeO* 16.60 15.12 11.66 13.65 12.07 12.52

Na2O 2.46 2.43 2.31 2.41 2.40 2.41

K2O 1.22 1.24 1.09 1.34 1.28 1.30 NiO F 0.22 0.13 0.18 0.37 0.31 0.28 Cl 0.04 0.01 0.02 0.01 0.02 0.01 Total 98.31 97.01 97.45 98.62 99.27 99.47

Structural formulae on the basis of 24 O Si 5.904 5.748 5.690 5.800 5.714 5.812 Ti 0.645 0.683 0.699 0.661 0.693 0.651 Aliv 2.102 2.253 2.318 2.214 2.292 2.203 Alvi 0.288 0.188 0.281 0.245 0.268 0.247 Mg 1.840 2.060 2.467 2.302 2.446 2.486 Ca 1.851 1.963 1.935 1.869 1.921 1.881 Mn 0.038 0.032 0.018 0.028 0.022 0.020 Fe3+ 0.042 0.005 0.061 0.108 0.047 0.112 Fe2+ 2.062 1.935 1.396 1.595 1.441 1.425 Na 0.725 0.723 0.671 0.697 0.687 0.689 K 0.236 0.242 0.209 0.256 0.240 0.244 Ni

Mg# 47.2 51.6 63.9 59.1 62.9 63.6

p – phenocryst, mp – microphenocryst, gm – groundmass 163

Electron analysis: Type I Amphibole

pp MS169N2-46 MS169N2-47 MS169N2-48 MS169N2-49 MS169N2-61 MS169N2-62 MS169N2-63 core core mantle rim core mantle rim Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.34 39.02 39.00 39.21 38.14 38.91 38.72

TiO2 6.49 6.19 6.04 6.01 6.34 6.24 6.28

Al2O3 15.40 14.65 14.27 14.19 14.47 14.49 14.59 MgO 12.47 10.68 10.71 10.99 9.80 10.90 10.92 CaO 12.33 12.06 11.95 11.99 11.58 11.95 11.88 MnO 0.13 0.14 0.20 0.20 0.25 0.17 0.18 FeO* 10.27 13.06 13.17 12.63 14.37 12.85 13.11

Na2O 2.27 2.39 2.43 2.45 2.52 2.43 2.42

K2O 1.14 1.23 1.20 1.26 1.21 1.24 1.25 NiO F 0.20 0.14 0.21 0.17 0.10 0.25 0.23 Cl 0.01 0.02 0.02 0.02 0.03 0.03 0.01 Total 99.06 99.57 99.20 99.12 98.80 99.43 99.57

Structural formulae on the basis of 24 O Si 5.613 5.744 5.773 5.793 5.702 5.741 5.712 Ti 0.715 0.685 0.672 0.668 0.713 0.693 0.697 Aliv 2.404 2.265 2.239 2.215 2.315 2.272 2.307 Alvi 0.246 0.274 0.246 0.252 0.227 0.243 0.222 Mg 2.721 2.343 2.364 2.419 2.184 2.397 2.401 Ca 1.935 1.902 1.895 1.898 1.855 1.889 1.877 Mn 0.016 0.017 0.025 0.025 0.031 0.021 0.022 Fe3+ 0.141 0.072 0.094 0.064 0.134 0.097 0.149 Fe2+ 1.113 1.534 1.533 1.494 1.657 1.485 1.464 Na 0.645 0.683 0.696 0.701 0.729 0.694 0.691 K 0.213 0.230 0.227 0.237 0.231 0.232 0.235 Ni

Mg# 71.0 60.4 60.7 61.8 56.9 61.7 62.1

p – phenocryst, mp – microphenocryst, gm – groundmass 164

Electron analysis: Type I Amphibole

pp mp MS169N2-64 MS169N2-65 MS169N2-74 MS169N2-72 MS169N2-73 MS114A-42 MS114A-43 core rim core rim rim core rim Titanian Kaersutite Kaersutite Kaersutite Kaersutite Potassian Titanian Kaersutite Pargasite Ferropargasite

SiO2 39.32 38.80 39.07 39.12 39.14 38.42 37.90

TiO2 4.07 6.00 6.15 6.23 5.97 4.02 6.22

Al2O3 14.24 14.29 14.37 14.60 14.27 12.86 14.92 MgO 9.57 10.70 10.59 11.52 10.74 6.46 11.74 CaO 11.61 11.89 12.02 12.39 11.92 10.66 11.64 MnO 0.27 0.20 0.20 0.15 0.19 0.55 0.15 FeO* 15.91 13.30 13.64 11.68 13.30 20.33 11.10

Na2O 2.56 2.43 2.48 2.44 2.51 2.49 2.60

K2O 1.24 1.31 1.23 1.21 1.28 1.30 1.15 NiO F 0.40 0.25 0.27 0.13 0.19 0.17 0.20 Cl 0.03 0.02 0.02 0.03 0.02 0.04 0.01 Total 99.21 99.19 100.03 99.49 99.51 97.28 97.63

Structural formulae on the basis of 24 O Si 5.894 5.756 5.753 5.735 5.778 5.996 5.655 Ti 0.459 0.669 0.681 0.687 0.663 0.471 0.698 Aliv 2.136 2.259 2.260 2.267 2.233 2.042 2.365 Alvi 0.367 0.233 0.228 0.254 0.244 0.311 0.249 Mg 2.138 2.367 2.324 2.518 2.363 1.503 2.610 Ca 1.865 1.889 1.895 1.945 1.885 1.782 1.860 Mn 0.034 0.025 0.025 0.019 0.024 0.072 0.019 Fe3+ 0.237 0.114 0.098 0.020 0.093 0.284 0.159 Fe2+ 1.748 1.532 1.578 1.411 1.546 2.353 1.222 Na 0.744 0.697 0.707 0.693 0.719 0.755 0.752 K 0.237 0.248 0.231 0.227 0.240 0.259 0.219 Ni

Mg# 55.0 60.7 59.6 64.1 60.5 39.0 68.1

p – phenocryst, mp – microphenocryst, gm – groundmass 165

Electron analysis: Type I Amphibole

mp mp mp mp MS114A-40 MS114A-41 MS114A-42 MS114A-43 MS169D-44 MS169D-53 core rim core rim mantle core Kaersutite Kaersutite Potassian Titanian Kaersutite Kaersutite Kaersutite Ferropargasite

SiO2 38.20 37.94 38.42 37.90 37.85 37.43

TiO2 6.22 6.25 4.02 6.22 5.76 6.17

Al2O3 14.63 14.37 12.86 14.92 14.30 14.71 MgO 11.08 10.42 6.46 11.74 10.11 9.68 CaO 11.59 11.67 10.66 11.64 11.97 12.22 MnO 0.16 0.23 0.55 0.15 0.22 0.26 FeO* 11.65 12.78 20.33 11.10 14.39 14.51

Na2O 2.79 2.73 2.49 2.60 2.54 2.45

K2O 1.13 1.14 1.30 1.15 1.26 1.24 NiO F 0.22 0.22 0.17 0.20 0.17 0.16 Cl 0.03 0.02 0.04 0.01 0.03 0.02 Total 97.69 97.76 97.28 97.63 98.59 98.84

Structural formulae on the basis of 24 O Si 5.710 5.705 5.996 5.655 5.690 5.620 Ti 0.700 0.707 0.471 0.698 0.651 0.697 Aliv 2.297 2.302 2.042 2.365 2.327 2.389 Alvi 0.277 0.241 0.311 0.249 0.199 0.211 Mg 2.470 2.336 1.503 2.610 2.265 2.166 Ca 1.856 1.879 1.782 1.860 1.927 1.965 Mn 0.021 0.030 0.072 0.019 0.028 0.033 Fe3+ 0.059 0.052 0.284 0.159 0.133 0.073 Fe2+ 1.396 1.554 2.353 1.222 1.671 1.746 Na 0.809 0.795 0.755 0.752 0.740 0.713 K 0.215 0.219 0.259 0.219 0.241 0.237 Ni

Mg# 63.9 60.1 39.0 68.1 57.5 55.4

p – phenocryst, mp – microphenocryst, gm – groundmass 166

Electron analysis: Type I Amphibole

mp mp mp gm gm gm gm MS169N2-44 MS169N2-75 MS169N2-76 MS113A-60 MS114A-44 MS169D-58 MS169D-72 mantle rim rim Kaersutite Kaersutite Potassian Potassian Titanian Kaersutite Kaersutite Kaersutite Kaersutite Pargasite

SiO2 39.21 39.67 39.26 38.14 37.41 38.29 37.89

TiO2 5.87 5.83 6.09 3.33 6.13 5.19 6.44

Al2O3 14.35 14.09 14.31 14.26 14.33 14.01 14.62 MgO 11.09 11.76 11.17 8.94 9.95 11.74 10.96 CaO 12.00 11.88 11.88 11.09 11.23 11.79 12.31 MnO 0.17 0.19 0.20 0.28 0.21 0.19 0.19 FeO* 12.56 12.45 12.55 16.98 13.50 11.95 12.28

Na2O 2.65 2.55 2.49 2.50 2.63 2.53 2.42

K2O 1.28 1.20 1.33 1.48 1.26 1.29 1.18 NiO F 0.14 0.31 0.32 0.29 0.32 0.32 0.21 Cl 0.02 0.04 0.03 0.04 0.03 0.03 0.02 Total 99.33 99.96 99.63 97.32 97.00 97.32 98.52

Structural formulae on the basis of 24 O Si 5.780 5.808 5.778 5.868 5.696 5.767 5.645 Ti 0.650 0.642 0.674 0.385 0.702 0.588 0.722 Aliv 2.227 2.213 2.235 2.179 2.321 2.256 2.360 Alvi 0.264 0.210 0.243 0.386 0.244 0.221 0.206 Mg 2.437 2.566 2.451 2.049 2.259 2.635 2.435 Ca 1.894 1.864 1.872 1.827 1.831 1.902 1.964 Mn 0.021 0.024 0.025 0.036 0.027 0.024 0.023 Fe3+ 0.052 0.169 0.098 0.364 0.132 0.187 0.041 Fe2+ 1.495 1.350 1.444 1.799 1.582 1.312 1.488 Na 0.757 0.724 0.709 0.747 0.776 0.739 0.698 K 0.241 0.224 0.250 0.290 0.244 0.248 0.225 Ni

Mg# 62.0 65.5 62.9 53.3 58.8 66.8 62.1

p – phenocryst, mp – microphenocryst, gm – groundmass 167

Clinopyroxene 168

Electron analysis: Type I Diopside

pmpmpmpmpmpmp MS169D-62 MS113A-49 MS113A-50 MS 113A-59 MS113A-70 MS169A-31 MS169A-49 rim mantle core core rim core core

SiO2 44.07 45.39 45.14 44.46 42.00 50.93 43.78

TiO2 3.16 2.71 2.76 2.61 4.12 0.68 3.41

Al2O3 10.20 8.21 8.25 8.46 10.99 1.50 9.89 MgO 11.66 10.93 10.53 10.61 10.66 8.70 10.64 CaO 22.75 21.94 21.74 21.77 20.71 19.98 21.40 MnO 0.16 0.25 0.26 0.25 0.18 0.62 0.19 FeO* 7.23 8.95 9.32 9.25 9.21 14.40 8.66

Na2O 0.55 0.64 0.67 0.63 0.63 1.55 0.71

K2O 0.00 0.01 0.01 0.02 0.00 0.02 0.00 F 0.00 0.05 0.00 0.10 0.14 0.04 0.07 Cl 0.01 0.01 0.00 0.01 0.00 0.00 0.00 Total 99.78 99.07 98.68 98.17 98.64 98.40 98.75

Structural formulae on the basis of 6 O Si 1.640 1.715 1.716 1.698 1.597 1.975 1.659 Ti 0.088 0.077 0.079 0.075 0.118 0.020 0.097 Aliv 0.360 0.285 0.284 0.302 0.403 0.025 0.341 Alvi 0.088 0.081 0.085 0.080 0.089 0.043 0.101 Mg 0.647 0.616 0.597 0.604 0.604 0.503 0.601 Ca 0.907 0.888 0.885 0.891 0.844 0.830 0.869 Mn 0.005 0.008 0.008 0.008 0.006 0.020 0.006 Fe3+ 0.135 0.186 0.091 0.119 0.125 0.059 0.098 Fe2+ 0.090 0.096 0.206 0.177 0.168 0.408 0.176 Na 0.040 0.047 0.049 0.047 0.046 0.116 0.052 K 0.000 0.000 0.000 0.001 0.000 0.001 0.000

End-members Quad 64.0 71.5 71.6 69.9 59.7 87.8 65.9 Wo 55.2 52.6 52.5 53.3 52.2 47.7 52.8 En 39.3 36.4 35.4 36.1 37.4 28.9 36.5 Fs 5.5 11.0 12.2 10.6 10.4 23.5 10.7 Mg# 87.8 76.8 74.4 77.4 78.2 55.2 77.4

p – phenocryst, mp – microphenocryst, gm – groundmass 169

Electron analysis: Type I Diopside

mp mp mp mp mp mp mp MS169D-43 MS169D-52 MS169D-67 MS169D-68 MS169D-75 MS169N2-45 MS169N2-57 core core core core rim core rim

SiO2 43.54 46.72 46.63 39.52 44.37 44.54 49.04

TiO2 3.13 2.11 2.24 5.63 3.10 3.19 1.72

Al2O3 8.79 6.20 6.76 13.48 8.75 8.95 5.20 MgO 9.98 13.96 13.38 9.59 10.46 10.42 12.29 CaO 22.14 21.80 22.24 22.15 22.23 22.11 22.30 MnO 0.29 0.14 0.10 0.14 0.22 0.23 0.25 FeO* 9.74 7.07 6.84 8.66 9.01 9.66 8.85

Na2O 0.72 0.47 0.46 0.64 0.66 0.70 0.55

K2O 0.00 0.03 0.00 0.01 0.00 0.01 0.00 F 0.00 0.08 0.01 0.00 0.00 0.00 0.12 Cl 0.01 0.01 0.00 0.00 0.01 0.00 0.01 Total 98.34 98.59 98.65 99.81 98.80 99.81 100.33

Structural formulae on the basis of 6 O Si 1.664 1.751 1.747 1.488 1.683 1.675 1.827 Ti 0.090 0.060 0.063 0.159 0.089 0.090 0.048 Aliv 0.336 0.249 0.251 0.513 0.317 0.325 0.173 Alvi 0.060 0.025 0.044 0.086 0.075 0.072 0.056 Mg 0.569 0.780 0.747 0.538 0.591 0.584 0.683 Ca 0.907 0.875 0.893 0.893 0.904 0.891 0.890 Mn 0.009 0.005 0.003 0.004 0.007 0.007 0.008 Fe3+ 0.148 0.139 0.114 0.155 0.113 0.123 0.061 Fe2+ 0.163 0.082 0.100 0.118 0.173 0.181 0.215 Na 0.053 0.034 0.033 0.046 0.049 0.051 0.040 K 0.000 0.001 0.000 0.001 0.000 0.000 0.000

End-members Quad 66.4 75.1 74.9 48.8 68.3 67.5 82.7 Wo 55.4 50.4 51.3 57.7 54.2 53.8 49.8 En 34.7 44.9 42.9 34.7 35.5 35.3 38.2 Fs 9.9 4.8 5.8 7.6 10.4 10.9 12.0 Mg# 77.8 90.4 88.2 82.0 77.4 76.4 76.0

p – phenocryst, mp – microphenocryst, gm – groundmass 170

Electron analysis: Type I Diopside

mp mp gm gm gm gm gm MS169N2-68 MS169N2-71 MS113A-71 MS114A-48 MS169A-32 MS169A-34 MS169A-47 core core

SiO2 45.64 47.87 45.79 47.85 50.76 46.81 51.51

TiO2 2.86 2.05 2.40 1.73 0.73 2.32 1.33

Al2O3 8.54 5.62 6.78 5.50 1.52 6.51 2.90 MgO 10.70 11.33 10.77 10.34 8.74 11.87 13.84 CaO 22.05 21.70 21.28 22.04 20.08 21.20 20.62 MnO 0.20 0.27 0.33 0.37 0.65 0.23 0.26 FeO* 9.35 10.72 10.57 10.54 14.32 9.02 7.74

Na2O 0.69 0.47 0.61 0.77 1.55 0.53 0.83

K2O 0.00 0.00 0.02 0.00 0.05 0.02 0.02 F 0.00 0.03 0.00 0.00 0.19 0.06 0.00 Cl 0.00 0.00 0.01 0.00 0.00 0.02 0.00 Total 100.03 100.05 98.55 99.13 98.57 98.58 99.04

Structural formulae on the basis of 6 O Si 1.710 1.802 1.749 1.818 1.968 1.776 1.926 Ti 0.081 0.058 0.069 0.050 0.021 0.066 0.037 Aliv 0.290 0.198 0.251 0.182 0.032 0.224 0.074 Alvi 0.087 0.051 0.054 0.064 0.037 0.068 0.054 Mg 0.598 0.636 0.613 0.586 0.505 0.672 0.772 Ca 0.885 0.875 0.871 0.897 0.834 0.862 0.826 Mn 0.006 0.009 0.011 0.012 0.021 0.007 0.008 Fe3+ 0.092 0.065 0.105 0.075 0.069 0.063 0.005 Fe2+ 0.201 0.272 0.233 0.259 0.396 0.224 0.237 Na 0.050 0.034 0.045 0.057 0.117 0.039 0.060 K 0.000 0.000 0.001 0.000 0.002 0.001 0.001

End-members Quad 71.0 80.2 74.9 81.1 87.3 77.6 90.4 Wo 52.6 49.1 50.7 51.5 48.1 49.1 45.0 En 35.5 35.7 35.7 33.6 29.1 38.2 42.0 Fs 12.0 15.3 13.6 14.9 22.8 12.7 12.9 Mg# 74.8 70.0 72.5 69.3 56.1 75.0 76.5

p – phenocryst, mp – microphenocryst, gm – groundmass 171

Electron analysis: Type I Diopside

gm gm gm gm MS169D-45 MS169D-46 MS169D-54 MS169N2-58

SiO2 41.20 43.36 46.56 48.25

TiO2 4.40 3.28 2.01 2.29

Al2O3 11.28 10.38 6.51 6.61 MgO 10.55 11.48 12.50 13.52 CaO 22.13 22.49 22.20 21.45 MnO 0.16 0.14 0.25 0.18 FeO* 8.47 7.65 8.76 7.86

Na2O 0.61 0.55 0.59 0.46

K2O 0.01 0.02 0.01 0.01 F 0.00 0.00 0.02 0.12 Cl 0.00 0.01 0.00 0.00 Total 98.79 99.36 99.39 100.74

Structural formulae on the basis of 6 O Si 1.560 1.623 1.743 1.779 Ti 0.125 0.092 0.057 0.063 Aliv 0.440 0.377 0.257 0.221 Alvi 0.063 0.081 0.030 0.066 Mg 0.595 0.641 0.698 0.743 Ca 0.898 0.902 0.890 0.847 Mn 0.005 0.004 0.008 0.006 Fe3+ 0.171 0.151 0.156 0.062 Fe2+ 0.098 0.089 0.118 0.181 Na 0.045 0.040 0.043 0.033 K 0.000 0.001 0.001 0.000

End-members Quad 56.0 62.3 74.3 77.9 Wo 56.5 55.3 52.2 47.9 En 37.4 39.3 40.9 42.0 Fs 6.1 5.4 6.9 10.2 Mg# 85.9 87.9 85.5 80.4

p – phenocryst, mp – microphenocryst, gm – groundmass 172

Electron analysis: Type I Diopside—rimming olivine clusters

gm gm MS169A-30 MS169D-60

SiO2 48.64 48.18

TiO2 1.59 1.55

Al2O3 5.27 5.19 MgO 12.33 12.74 CaO 21.87 22.40 MnO 0.24 0.26 FeO* 8.88 8.23

Na2O 0.52 0.57

K2O 0.00 0.01 F 0.11 0.06 Cl 0.00 0.00 Total 99.44 99.19

Structural formulae on the basis of 6 O Si 1.827 1.807 Ti 0.045 0.044 Aliv 0.173 0.193 Alvi 0.060 0.036 Mg 0.690 0.712 Ca 0.880 0.900 Mn 0.007 0.008 Fe3+ 0.061 0.111 Fe2+ 0.218 0.147 Na 0.038 0.041 K 0.000 0.001

End-members Quad 82.7 80.7 Wo 49.2 51.2 En 38.6 40.5 Fs 12.2 8.4 Mg# 76.0 82.9

p – phenocryst, mp – microphenocryst, gm – groundmass 173

Electron analysis: Type I Hedenbergite

p MS169D-61 core

SiO2 48.95

TiO2 0.53

Al2O3 2.48 MgO 7.36 CaO 21.59 MnO 0.78 FeO* 17.00

Na2O0.71

K2O0.01 F0.03 Cl 0.01 Total 99.44

Structural formulae on the basis o Si 1.908 Ti 0.016 Aliv 0.092 Alvi 0.022 Mg 0.428 Ca 0.902 Mn 0.026 Fe3+ 0.461 Fe2+ 0.093 Na 0.054 K 0.000

End-members Quad 87.0 Wo 50.4 En 23.9 Fs 25.8 Mg# 48.1

p – phenocryst, mp – microphenocryst, gm – groundmass 174

Magnetite 175

Electron analysis: Type I Magnetite

mp gm MS169D-70 MS169D-66 core

SiO2 1.81 0.10

TiO2 19.21 18.55

Al2O3 3.28 4.18 MgO 2.99 2.30 CaO 0.79 0.01 MnO 0.95 1.24 FeO* 66.25 68.68 Total 95.29 95.06

Structural formulae on the basis of 4 O Si 0.072 0.004 Ti 0.549 0.518 Al 0.147 0.183 Mg 0.169 0.127 Ca 0.034 0.001 Mn 0.031 0.039 Fe3+ 0.756 0.781 Fe2+ 1.349 1.352 sum 3.107 3.005

Ti # 78.9 73.9

p – phenocryst, mp – microphenocryst, gm – groundmass 176

Olivine 177

Electron analysis: Type I Olivine

ppmpmp MS169D-56 MS169D-57 MS169A-29 MS169D-78 core core core rim SiO2 39.44 39.11 39.143 3.65

TiO2 0.00 0.00 0.03 0.12

Al2O3 0.05 0.05 0.05 0.03 MgO 45.16 45.28 40.852 0.70 CaO0.320.330.330.56 MnO0.240.200.272.17 FeO* 14.15 14.10 18.354 0.82 Na2O 0.020.020.010.01

K2O 0.010.000.00 F 0.020.140.04 Cl 0.01 0.00 0.00 Total 99.40 99.22 99.089 8.06

Structural formulae on the basis of 4 O Si 0.994 0.989 1.0080 .997 Ti 0.000 0.000 0.0010 .003 Al 0.002 0.001 0.0020 .001 Mg 1.697 1.707 1.5690 .915 Ca 0.009 0.009 0.009 0.018 Mn 0.005 0.004 0.006 0.054 Fe 0.298 0.298 0.395 1.012 Na 0.001 0.001 0.001 0.000 K 0.000 0.000 0.000 sum 3.006 3.010 2.991 3.000

End-member Fo% 85.1 85.1 79.9 47.5

178

TYPE II COMPOSITIONS 179

Feldspars and Feldspathoids

180

181

182

183

184

Electron analysis: Type II Feldspathoids

Nepheline gm MS169B2-67

SiO2 52.14

Al2O3 30.65 CaO 0.14 FeO 0.55

Na2O 16.33

K2O2.11 SrO 0.03 BaO 0.02 Total 101.97

Structural formulae on the basis of 16 O Si 4.733 Al 3.279 Ca 0.014 Fe 0.041 Na 2.874 K 0.244 Sr 0.002 Ba 0.001 Sum 11.187

p – phenocryst, mp – microphenocryst, gm – groundmass 185

Amphibole 186

Electron analysis: Type II Amphibole

pppp p MS169B2-56 MS169B2-57 MS169B2-58 MS169K-01 MS169K-02 MS169K-21 mantle rim core core rim rim Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.32 38.28 38.41 38.35 39.41 38.61

TiO2 5.86 6.53 5.60 5.77 6.06 5.83

Al2O3 14.17 14.44 14.10 13.99 13.65 14.00 MgO 10.76 12.79 9.92 9.44 11.24 9.29 CaO 11.87 12.43 12.03 11.80 12.01 11.84 MnO 0.20 0.12 0.23 0.27 0.20 0.23 FeO* 12.73 9.45 14.59 14.71 12.37 15.20

Na2O 2.54 2.32 2.52 2.58 2.43 2.51

K2O 1.16 1.19 1.13 1.25 1.20 1.19 F 0.34 0.12 0.12 0.09 0.32 0.18 Cl 0.02 0.00 0.02 0.02 0.02 0.02 Total 97.96 97.68 98.67 98.27 98.92 98.91

Structural formulae on the basis of 24 O Si 5.750 5.669 5.759 5.779 5.836 5.789 Ti 0.661 0.728 0.631 0.654 0.675 0.658 Aliv 2.260 2.337 2.254 2.227 2.171 2.219 Alvi 0.242 0.182 0.233 0.255 0.209 0.253 Mg 2.406 2.823 2.217 2.120 2.481 2.078 Ca 1.909 1.973 1.932 1.905 1.906 1.902 Mn 0.025 0.015 0.029 0.035 0.025 0.029 Fe3+ 0.082 0.044 0.102 0.042 0.054 0.061 Fe2+ 1.513 1.126 1.723 1.810 1.476 1.843 Na 0.739 0.667 0.732 0.754 0.696 0.731 K 0.222 0.225 0.215 0.240 0.227 0.227

Mg# 61.4 71.5 56.3 53.9 62.7 53.0

p – phenocryst, mp – microphenocryst, gm – groundmass 187

Electron analysis: Type II Amphibole

ppp MS169K-03 MS169K-04 MS169K-42 MS169K-43 MS169K-44 MS169K-45 core rim core rim core rim Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite Kaersutite

SiO2 38.69 39.18 38.56 38.57 37.95 38.62

TiO2 5.83 5.87 5.75 6.16 5.92 6.08

Al2O3 14.15 13.68 13.88 14.10 14.03 14.00 MgO 9.59 11.51 9.17 10.93 9.41 10.68 CaO 12.01 12.01 11.79 12.20 11.75 12.18 MnO 0.24 0.18 0.28 0.20 0.23 0.25 FeO* 14.52 12.01 15.59 12.41 15.12 13.02

Na2O 2.50 2.54 2.54 2.53 2.59 2.52

K2O 1.18 1.14 1.28 1.16 1.22 1.18 F 0.19 0.34 0.17 0.15 0.36 0.16 Cl 0.02 0.02 0.03 0.02 0.02 0.03 Total 98.92 98.48 99.03 98.41 98.59 98.72

Structural formulae on the basis of 24 O Si 5.784 5.822 5.791 5.745 5.729 5.753 Ti 0.655 0.656 0.650 0.690 0.672 0.681 Aliv 2.219 2.187 2.219 2.257 2.283 2.252 Alvi 0.273 0.205 0.234 0.218 0.209 0.206 Mg 2.137 2.550 2.053 2.427 2.117 2.372 Ca 1.923 1.912 1.897 1.946 1.901 1.943 Mn 0.030 0.023 0.035 0.025 0.030 0.031 Fe3+ 0.027 0.068 0.074 0.011 0.094 0.031 Fe2+ 1.788 1.422 1.881 1.533 1.811 1.590 Na 0.725 0.732 0.741 0.730 0.759 0.728 K 0.226 0.216 0.245 0.220 0.234 0.224

Mg# 54.5 64.2 52.2 61.3 53.9 59.9

p – phenocryst, mp – microphenocryst, gm – groundmass 188

Electron analysis: Type II Amphibole

pppmp MS169K-64 MS169K-65 MS169K-71 MS169K-78 MS169K-79 MS169B2-63 core rim core rim core Titano- Kaersutite Titano- Titano- Kaersutite Kaersutite Ferrokaersutite Ferrokaersutite Ferrokaersutite

SiO2 38.86 38.48 38.46 38.75 38.76 37.16

TiO2 5.48 5.93 5.49 5.56 5.79 5.90

Al2O3 13.85 14.27 13.96 13.62 13.70 14.95 MgO 8.76 10.93 8.55 8.28 10.44 10.64 CaO 12.04 12.03 11.80 11.61 11.88 12.03 MnO 0.28 0.19 0.26 0.25 0.24 0.18 FeO* 15.68 12.38 16.25 16.64 13.79 12.95

Na2O 2.48 2.50 2.73 2.57 2.60 2.49

K2O 1.23 1.14 1.23 1.28 1.26 1.15 F 0.26 0.18 0.26 0.22 0.22 0.21 Cl 0.01 0.02 0.04 0.03 0.01 0.04 Total 98.93 98.04 99.02 98.82 98.70 97.69

Structural formulae on the basis of 24 O Si 5.844 5.749 5.801 5.857 5.796 5.605 Ti 0.620 0.667 0.623 0.632 0.652 0.669 Aliv 2.155 2.258 2.202 2.147 2.214 2.412 Alvi 0.302 0.251 0.279 0.279 0.197 0.237 Mg 1.964 2.434 1.923 1.866 2.328 2.393 Ca 1.939 1.926 1.907 1.880 1.903 1.944 Mn 0.035 0.024 0.033 0.032 0.031 0.022 Fe3+ 0.000 0.057 0.019 0.032 0.080 0.140 Fe2+ 1.991 1.488 2.030 2.071 1.641 1.489 Na 0.723 0.724 0.799 0.752 0.753 0.729 K 0.235 0.217 0.236 0.247 0.240 0.221

Mg# 49.7 62.0 48.6 47.4 58.7 61.7

p – phenocryst, mp – microphenocryst, gm – groundmass 189

Clinopyroxene 190

Electron analysis: Type II Diopside

mp mp mp mp mp mp mp MS169B2-62 MS169K-11 MS169K-14 MS169K-15 MS169K-32 MS169K-33 MS169K-35 MS169K-36 core rim core core rim rim core rim

SiO2 49.45 44.57 44.36 46.16 44.37 46.93 42.72 44.37

TiO2 1.44 2.42 2.35 1.78 2.73 1.41 3.89 2.81

Al2O3 3.75 6.82 6.28 5.05 7.69 4.90 8.07 7.76 MgO 11.92 8.28 7.79 8.54 8.17 7.92 7.13 8.10 CaO 21.83 22.05 21.82 21.53 22.09 21.86 21.51 22.11 MnO 0.28 0.46 0.54 0.58 0.41 0.59 0.40 0.44 FeO* 9.08 13.13 14.16 13.97 13.42 14.74 14.81 13.32

Na2O 0.74 0.61 0.64 0.69 0.68 0.71 0.76 0.61

K2O 0.05 0.01 0.01 0.00 0.01 0.01 0.01 0.01 F 0.15 0.00 0.19 0.03 0.08 0.26 0.00 0.03 Cl 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 Total 98.70 98.34 98.14 98.33 99.66 99.34 99.30 99.55

Structural formulae on the basis of 6 O Si 1.877 1.732 1.739 1.797 1.703 1.819 1.658 1.705 Ti 0.041 0.071 0.069 0.052 0.079 0.041 0.113 0.081 Aliv 0.123 0.268 0.260 0.203 0.297 0.181 0.341 0.295 Alvi 0.045 0.044 0.029 0.029 0.051 0.043 0.028 0.057 Mg 0.675 0.480 0.455 0.495 0.468 0.458 0.413 0.464 Ca 0.888 0.918 0.916 0.898 0.908 0.908 0.895 0.910 Mn 0.009 0.015 0.018 0.019 0.013 0.019 0.013 0.014 Fe3+ 0.050 0.129 0.143 0.122 0.139 0.109 0.144 0.121 Fe2+ 0.238 0.298 0.321 0.332 0.291 0.369 0.337 0.307 Na 0.054 0.046 0.048 0.052 0.051 0.053 0.057 0.046 K 0.002 0.000 0.000 0.000 0.001 0.001 0.001 0.000

End-members Quad 86.4 73.2 73.9 79.7 70.3 80.7 65.9 70.5 Wo 49.3 54.2 54.1 52.0 54.5 52.4 54.4 54.2 En 37.5 28.3 26.9 28.7 28.0 26.4 25.1 27.6 Fs 13.2 17.6 19.0 19.3 17.5 21.3 20.5 18.3 Mg# 73.9 61.7 58.6 59.9 61.6 55.4 55.0 60.2

p – phenocryst, mp – microphenocryst, gm – groundmass 191

Electron analysis: Type II Diopside

mp mp mp mp mp mp MS169K-52 MS169K-53 MS169K-54 MS169K-74 MS169K-76 MS169K-81 MS169K-82 MS169K-83 core rim rim core rim core rim rim

SiO2 48.31 44.93 48.80 47.02 44.12 46.22 46.93 49.02

TiO2 1.76 2.64 1.62 2.19 2.87 2.32 1.72 0.97

Al2O3 5.01 8.00 4.73 6.54 9.30 6.02 5.83 3.47 MgO 11.73 9.57 11.93 12.93 11.24 10.20 9.20 9.27 CaO 22.00 21.71 22.17 21.94 21.80 21.85 22.35 22.08 MnO 0.27 0.36 0.29 0.17 0.18 0.32 0.44 0.62 FeO* 9.60 11.52 9.52 7.68 8.46 11.70 12.49 13.37

Na2O 0.44 0.61 0.51 0.51 0.57 0.55 0.62 0.67

K2O 0.00 0.00 0.00 0.01 0.00 0.02 0.00 0.00 F 0.01 0.04 0.05 0.02 0.09 0.05 0.12 0.13 Cl 0.00 0.00 0.01 0.00 0.00 0.00 0.02 0.00 Total 99.14 99.39 99.63 99.02 98.64 99.24 99.72 99.59

Structural formulae on the basis of 6 O Si 1.828 1.712 1.836 1.762 1.670 1.764 1.792 1.880 Ti 0.050 0.076 0.046 0.062 0.082 0.067 0.049 0.028 Aliv 0.172 0.288 0.164 0.237 0.330 0.236 0.208 0.120 Alvi 0.052 0.071 0.046 0.052 0.085 0.035 0.054 0.036 Mg 0.661 0.543 0.669 0.722 0.634 0.580 0.524 0.530 Ca 0.892 0.886 0.894 0.881 0.884 0.893 0.914 0.907 Mn 0.009 0.012 0.009 0.005 0.006 0.010 0.014 0.020 Fe3+ 0.052 0.111 0.064 0.100 0.124 0.108 0.101 0.078 Fe2+ 0.251 0.256 0.236 0.141 0.144 0.265 0.297 0.351 Na 0.032 0.045 0.037 0.037 0.042 0.041 0.046 0.049 K 0.000 0.000 0.000 0.001 0.000 0.001 0.000 0.000

End-members Quad 82.8 71.2 83.6 76.3 67.0 76.4 79.2 85.8 Wo 49.4 52.6 49.7 50.5 53.2 51.4 52.7 50.7 En 36.7 32.2 37.2 41.4 38.1 33.4 30.2 29.6 Fs 13.9 15.2 13.1 8.1 8.7 15.3 17.1 19.6 Mg# 72.5 68.0 74.0 83.7 81.5 68.6 63.8 60.2

p – phenocryst, mp – microphenocryst, gm – groundmass 192

Electron analysis: Type II Diopside

gm gm gm gm gm gm gm gm MS169K-16 MS169K-17 MS169K-20 MS169K-25 MS169K-26 MS169K-34 MS169K-39 MS169K-40

SiO2 48.87 49.16 47.17 44.94 46.52 47.88 48.31 47.70

TiO2 1.01 0.99 1.34 2.47 2.06 1.38 1.14 1.28

Al2O3 3.17 3.28 4.17 6.96 6.32 3.99 3.74 4.34 MgO 9.51 10.16 7.17 8.79 9.34 9.00 9.06 8.79 CaO 22.23 22.19 21.49 22.13 22.18 21.75 22.30 21.66 MnO 0.59 0.49 0.69 0.40 0.43 0.69 0.60 0.65 FeO* 13.54 12.83 16.36 12.13 12.21 13.75 13.81 14.28

Na2O 0.43 0.47 0.79 0.66 0.62 0.68 0.61 0.74

K2O 0.00 0.01 0.00 0.02 0.02 0.04 0.01 0.02 F 0.06 0.09 0.06 0.24 0.08 0.05 0.00 0.11 Cl 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00 Total 99.40 99.66 99.25 98.75 99.77 99.21 99.57 99.56

Structural formulae on the basis of 6 O Si 1.879 1.877 1.839 1.735 1.772 1.846 1.854 1.834 Ti 0.029 0.028 0.039 0.072 0.059 0.040 0.033 0.037 Aliv 0.121 0.123 0.161 0.265 0.228 0.154 0.146 0.166 Alvi 0.023 0.025 0.031 0.052 0.056 0.027 0.023 0.031 Mg 0.545 0.579 0.417 0.506 0.531 0.517 0.518 0.504 Ca 0.916 0.908 0.898 0.915 0.905 0.898 0.917 0.892 Mn 0.019 0.016 0.023 0.013 0.014 0.023 0.020 0.021 Fe3+ 0.071 0.076 0.112 0.118 0.099 0.097 0.102 0.116 Fe2+ 0.364 0.334 0.421 0.273 0.290 0.346 0.342 0.343 Na 0.032 0.035 0.060 0.050 0.046 0.051 0.045 0.055 K 0.000 0.000 0.000 0.001 0.001 0.002 0.001 0.001

End-members Quad 87.7 87.1 81.9 73.6 77.3 83.5 84.2 81.6 Wo 50.2 49.9 51.7 54.0 52.5 51.0 51.6 51.3 En 29.9 31.8 24.0 29.8 30.7 29.4 29.2 29.0 Fs 20.0 18.4 24.3 16.1 16.8 19.7 19.2 19.8 Mg# 60.0 63.4 49.7 64.9 64.6 59.9 60.3 59.5

p – phenocryst, mp – microphenocryst, gm – groundmass 193

Electron analysis: Type II Diopside

gm gm gm gm gm gm gm MS169K-58 MS169K-60 MS169K-61 MS169K-63 MS169K-67 MS169K-68 MS169K-77

SiO2 48.28 51.34 46.37 51.64 44.30 45.54 47.63

TiO2 1.24 0.62 1.76 0.70 3.58 2.87 2.20

Al2O3 4.73 1.95 5.35 1.94 8.59 7.64 6.57 MgO 8.74 12.61 8.09 12.08 10.50 10.58 13.15 CaO 21.76 21.97 21.84 22.02 21.64 21.85 21.99 MnO 0.60 0.49 0.67 0.46 0.23 0.31 0.16 FeO* 13.59 9.11 13.57 9.50 9.02 9.98 7.15

Na2O 0.68 0.68 0.68 0.88 0.65 0.71 0.50

K2O 0.01 0.01 0.03 0.03 0.01 0.01 0.02 F 0.12 0.00 0.10 0.05 0.02 0.06 0.11 Cl 0.01 0.01 0.00 0.00 0.01 0.00 0.01 Total 99.76 98.79 98.45 99.29 98.54 99.54 99.49

Structural formulae on the basis of 6 O Si 1.851 1.941 1.806 1.947 1.688 1.721 1.776 Ti 0.036 0.018 0.052 0.020 0.103 0.082 0.062 Aliv 0.149 0.059 0.194 0.053 0.312 0.279 0.224 Alvi 0.065 0.028 0.052 0.033 0.074 0.061 0.065 Mg 0.499 0.711 0.470 0.679 0.597 0.596 0.731 Ca 0.894 0.890 0.911 0.889 0.884 0.884 0.878 Mn 0.019 0.016 0.022 0.015 0.007 0.010 0.005 Fe3+ 0.063 0.045 0.090 0.045 0.080 0.107 0.072 Fe2+ 0.373 0.243 0.352 0.255 0.207 0.208 0.151 Na 0.051 0.050 0.051 0.064 0.048 0.052 0.036 K 0.000 0.001 0.001 0.001 0.000 0.000 0.001

End-members Quad 83.6 90.9 80.2 90.3 68.8 72.1 77.6 Wo 50.6 48.3 52.6 48.8 52.4 52.4 49.9 En 28.3 38.6 27.1 37.2 35.3 35.3 41.5 Fs 21.1 13.2 20.3 14.0 12.3 12.3 8.6 Mg# 57.3 74.5 57.2 72.7 74.2 74.1 82.9

p – phenocryst, mp – microphenocryst, gm – groundmass 194

Magnetite 195

Electron analysis: Type II Magnetite

mp MS169K-69 core

SiO2 0.08

TiO2 23.87

Al2O3 2.93 MgO 2.50 CaO 0.00 MnO 0.79 FeO* 63.83 Total 94.039

Structural formulae on the basis of 4 O Si 0.003 Ti 0.680 Al 0.131 Mg 0.141 Ca 0.000 Mn 0.025 Fe3+ 0.509 Fe2+ 1.514 sum 3.003

Ti # 83.8

p – phenocryst, mp – microphenocryst, gm – groundmass 196

TYPE IV COMPOSITIONS 197

Feldspars and Feldspathoids 198

199

Electron analysis: Type IV Plagioclase

MS169C-87 MS169C-88 rim rim

SiO2 60.94 54.91

Al2O3 24.01 28.19 CaO 4.76 8.84 FeO 0.42 0.77

Na2O 7.57 5.87

K2O 1.69 0.46 SrO 0.31 0.53 BaO 0.14 0.13 Total 99.82 99.68

Structural formulae on the basis of 8 O Si 2.733 2.495 Al 1.269 1.509 Ca 0.229 0.430 Fe 0.016 0.029 Na 0.658 0.517 K 0.097 0.027 Sr 0.008 0.014 Ba 0.002 0.002 Sum 5.010 5.022

End-members %An 23.3 44.2 %Ab 66.9 53.1 %Or 9.8 2.7

Minerals are medium grain size unless otherwise specified. 200

Electron analysis: Type IV Feldspathoids

Sodalite

MS169C-55 core

SiO2 39.63

Al2O3 33.96 CaO 0.24 FeO 0.06

Na2O 25.33

K2O0.36 SrO 0.00 BaO 0.03 Total 99.62

Structural formulae on the basis of 16 O Si 5.786 Al 5.842 Ca 0.037 Fe 0.007 Na 7.170 K 0.068 Sr 0.000 Ba 0.002 Sum 18.912

Minerals are medium grain size unless otherwise specified.

201

Amphibole 202

Electron analysis: Type IV Amphibole

fine grain fine grain fine grain MS169C-42 MS169C-50 MS169C-74 MS169C-62 MS169C-64 MS169C-86 rim rim core Titano- Kaersutite Kaersutite Kaersutite Kaersutite Titano- Ferrokaersutite Ferrokaersutite

SiO2 37.85 38.59 38.97 38.77 38.09 37.98

TiO2 6.38 5.46 5.83 5.10 4.68 5.17

Al2O3 12.68 13.66 13.59 13.72 13.37 12.95 MgO 8.73 9.49 11.21 10.47 9.06 8.64 CaO 11.24 11.99 11.72 11.92 11.65 11.61 MnO 0.37 0.26 0.2 2 0.25 0.32 0.33 FeO* 18.02 15.66 11.98 13.88 15.80 18.02

Na2O 2.87 2.97 2.9 0 3.03 3.01 2.87

K2O 1.14 1.14 1.1 3 1.11 1.23 1.12 NiO 0.00 0.01 0.0 0 0.00 0.02 0.01 F 0.25 0.21 0.2 7 0.25 0.27 0.38 Cl 0.02 0.03 0.01 0.03 0.05 0.04 Total 99.59 99.49 97.82 98.59 97.55 99.14

Structural formulae on the basis of 24 O Si 5.741 5.784 5.831 5.816 5.839 5.793 Ti 0.728 0.615 0.656 0.576 0.539 0.593 Aliv 2.262 2.222 2.171 2.192 2.168 2.233 Alvi 0.004 0.189 0.225 0.232 0.245 0.085 Mg 1.973 2.121 2.500 2.342 2.070 1.965 Ca 1.826 1.926 1.879 1.915 1.913 1.897 Mn 0.047 0.033 0.028 0.031 0.042 0.042 Fe3+ 0.020 0.050 0.014 0.057 0.058 0.211 Fe2+ 2.230 1.910 1.484 1.682 1.966 2.077 Na 0.843 0.863 0.840 0.882 0.893 0.847 K 0.220 0.217 0.215 0.213 0.241 0.218 Ni 0.000 0.001 0.000 0.000 0.003 0.001

Mg# 46.9 52.6 62.7 58.2 51.3 48.6

Minerals are medium grain size unless otherwise specified. 203

Clinopyroxene 204

Electron analysis: Type IV Diopside

fine grain fine grain fine grain MS169C-44 MS169C-58 MS169C-65

P2O5 0.019

SiO2 53.145 51.838 46.312

TiO2 0.001

SO2 0.373 0.462 3.118

Al2O3 1.539 1.512 7.52 MgO 12.238 12.229 11.866 CaO 23.407 23.56 22.922 MnO 0.275 0.316 0.145 FeO* 9.343 9.771 7.163

Na2O 0.696 0.717 0.858

K2O 0.036 0.044 0.026 NiO 0.02 0.007 F 0.098 0.1 Cl 0.003 0.004 Total 101.072 100.596 100.063

Structural formulae on the basis of 6 O P 0.001 Si 1.968 1.933 1.722 S 0.000 Ti 0.010 0.013 0.087 Aliv 0.031 0.066 0.278 Alvi 0.036 0.000 0.052 Mg 0.676 0.680 0.658 Ca 0.929 0.941 0.913 Mn 0.009 0.010 0.005 Fe3+ 0.025 0.093 0.113 Fe2+ 0.265 0.212 0.109 Na 0.050 0.052 0.062 K 0.002 0.002 0.001 Ni 0.001 0.000

End-members Quad 92.9 89.5 72.2 Wo 49.7 51.4 54.3 En 36.1 37.1 39.1 Fs 14.2 11.6 6.5 Mg# 71.8 76.2 85.7

Minerals are medium grain size unless otherwise specified.

205

TYPE V COMPOSITIONS 206

Feldspars and Feldspathoids 207

Electron analysis: Type V Alkali Feldspar

MS169B1-65 MS169B2-73 MS169B2-80 core core core

SiO2 66.08 66.97 67.65

Al2O3 20.03 19.73 19.89 CaO 0.11 0.03 0.21 FeO 0.06 0.17 0.08

Na2O 5.42 6.20 6.86

K2O 9.11 8.33 7.15 SrO 0.06 0.02 0.03 BaO 0.46 0.09 0.09 Total 101.33 101.54 101.96

Structural formulae on the basis of 8 O Si 2.953 2.970 2.973 Al 1.055 1.031 1.030 Ca 0.005 0.001 0.010 Fe 0.002 0.006 0.003 Na 0.469 0.533 0.585 K 0.519 0.471 0.401 Sr 0.002 0.001 0.001 Ba 0.008 0.002 0.002 Sum 5.014 5.016 5.004

End-members %An 0.5 0.1 1.0 %Ab 47.2 53.0 58.7 %Or 52.3 46.9 40.3

Minerals are medium grain size unless otherwise specified. 208

Electron analysis: Type V Feldspathoids

Nepheline Nepheline

MS169B2-70 MS169B2-71 core core

SiO2 45.43 45.36

Al2O3 33.96 34.29 CaO 0.30 0.81 FeO 0.38 0.43

Na2O 17.21 16.80

K2O 4.12 3.89 SrO 0.00 0.00 BaO 0.02 0.00 Total 101.42 101.59

Structural formulae on the basis of 16 O Si 4.255 4.235 Al 3.747 3.774 Ca 0.031 0.081 Fe 0.029 0.034 Na 3.125 3.042 K 0.492 0.464 Sr 0.000 0.000 Ba 0.001 0.000 Sum 11.680 11.630

Minerals are medium grain size unless otherwise specified. 209

Clinopyroxene 210

Electron analysis: Type V Diopside

MS169B1-60 MS169B2-81 core core

SiO2 51.72 49.54

TiO2 0.40 0.68

Al2O3 1.33 2.16 MgO 9.92 8.97 CaO 22.38 20.98 MnO 0.59 1.31 FeO* 13.24 15.01

Na2O 1.02 0.63

K2O 0.00 0.01 NiO 0.02 F 0.00 0.15 Cl 0.03 0.00 Total 100.65 99.44

Structural formulae on the basis of 6 O Si 1.953 1.918 Ti 0.011 0.020 Aliv 0.047 0.082 Alvi 0.013 0.016 Mg 0.559 0.518 Ca 0.906 0.870 Mn 0.019 0.043 Fe3+ 0.086 0.074 Fe2+ 0.332 0.412 Na 0.075 0.047 K 0.000 0.001 Ni 0.001

End-members Quad 89.0 89.0 Wo 50.4 48.4 En 31.1 28.8 Fs 18.5 22.9 Mg# 62.7 55.7

Minerals are medium grain size unless otherwise specified. 211

Electron analysis: Type V Hedenbergite

MS169B2-74 MS169B2-75 MS169B2-76 MS169B2-78 core core core core

SiO2 49.61 48.77 50.28 49.64

TiO2 0.19 0.40 0.37 0.47

Al2O3 0.77 1.52 2.85 1.29 MgO 2.94 3.97 2.93 3.48 CaO 16.84 15.98 15.23 15.53 MnO 2.01 1.76 1.98 1.67 FeO* 22.80 21.51 20.24 23.33

Na2O 3.61 3.35 3.98 3.53

K2O 0.01 0.05 0.18 0.05

F 0.13 0.06 0.07 0.00 Cl 0.00 0.03 0.00 0.00 Total 98.90 97.40 98.11 99.00

Structural formulae on the basis of 6 O Si 1.968 1.953 1.991 1.963 Ti 0.006 0.012 0.011 0.014 Aliv 0.032 0.047 0.007 0.036 Alvi 0.004 0.025 0.126 0.024 Mg 0.174 0.237 0.173 0.205 Ca 0.716 0.686 0.646 0.658 Mn 0.068 0.060 0.066 0.056 Fe3+ 0.295 0.258 0.165 0.255 Fe2+ 0.461 0.462 0.505 0.517 Na 0.277 0.260 0.305 0.271 K 0.000 0.002 0.009 0.002 Ni

End-members Quad 70 70 69 71 Wo 53 50 49 48 En 13 17 13 15 Fs 34 33 38 37 Mg# 27.4 33.9 25.5 28.4

Minerals are medium grain size unless otherwise specified. 212

APPENDIX C 213

Whole rock compositions from XRF

Host Type I Type III Type V wt % oxide MS-113 MS-114 MS-169 Bh MS-169 N MS-169 Bi MS-169 I

SiO2 54.85 53.97 52.52 50.6 7 59.55 56.02 TiO2 0.899 1.232 1.521 2.08 7 0.300 1.037 Al2O3 19.79 19.86 18.89 18.4 6 21.96 18.98 FeO 6.16 6.41 7.69 9.23 4.08 7.33 MnO 0.214 0.205 0.220 0.22 4 0.183 0.281 MgO 1.28 1.48 2.33 3.06 0.27 1.02 CaO 3.50 4.38 5.34 6.88 1.77 3.47 Na2O 8.09 7.81 7.19 6.1 0 8.62 7.14 K2O 4.97 4.31 3.91 2.72 3.20 4.43 P2O5 0.246 0.359 0.388 0.55 9 0.071 0.297 NiO 5.5 5.5 13.4 15.4 0.5 2.3 Cr2O3 11.7 9.8 25.4 30.4 5.4 3.9 Sc2O3 5.8 6.7 13.3 14.1 1.1 2.6 V2O3 76.6 80.3 148 195.4 8.1 8.5 BaO 473.5 966.7 638.2 780.3 268.4 5726.2 Rb2O 137.1 134.5 112.4 47.1 51.7 74.8 SrO 425 967.7 662.6 888.3 528.6 1092.5 ZrO2 860.8 790.0 725.1 601.1 1159.5 539.7 Y2O3 36.2 37.1 36.3 38.4 38.7 40.9 Nb2O5 170.7 198.0 164.8 162.5 201.6 280.2 Ga2O3 31.1 30.9 32.1 28.0 39.8 25.1 CuO 10.0 12.1 19.3 28.3 12.9 13.3 ZnO 144.8 125.9 142.2 147.2 184.5 125.7 PbO 9.4 6.6 7.0 4.3 23.3 5.2 La2O3 105.5 108.7 92.4 89.7 124.4 111.5 CeO2 175.9 181.9 160.4 173.2 201.7 217.8 ThO2 20.4 19.1 14.2 10.6 29.0 8.6 Nd2O3 50.7 59.1 51.3 63.7 49.7 74.8 U2O3 4.5 4.2 5.0 5.3 7.0 3.7 Bi2O5 0.0 0.0 0.0 0.0 0.0 0.0 Cs2O 0.0 0.0 0.0 0.0 0.0 0.0 As2O5 0.0 0.0 0.0 0.0 0.0 0.0 W2O3 0.0 0.0 0.0 0.0 0.0 0.0 214

Whole rock compositions from ICP-MS

Host Type I Type III Type V ppm MS-113 MS-114 MS-169 Bh MS-169 N MS-169 Bi MS-169 I

La 87.96 92.48 79.85 76.02 106.99 97.06 Ce 145.27 155.52 138.23 139.51 165.83 180.19 Pr 14.30 15.77 14.31 15.30 15.08 19.90 Nd 45.01 51.69 47.87 54.36 43.36 67.53 Sm 7.29 8.48 8.19 9.61 6.29 10.88 Eu 1.77 2.60 2.39 2.96 1.48 4.54 Gd 5.90 6.63 6.57 7.86 4.97 8.29 Tb 0.92 0.99 1.01 1.14 0.80 1.20 Dy 5.38 5.81 5.79 6.42 5.04 6.82 Ho 1.11 1.15 1.14 1.24 1.07 1.30 Er 3.06 3.09 3.08 3.16 3.12 3.31 Tm 0.49 0.47 0.47 0.45 0.51 0.47 Yb 3.16 3.07 2.99 2.74 3.39 2.97 Lu 0.51 0.49 0.46 0.43 0.54 0.48 Ba 427 871 569 698 244 5431 Th 18.79 18.01 14.48 10.85 25.30 8.11 Nb 120.88 140.54 117.43 114.78 142.39 199.17 Y 29.01 29.68 29.59 31.06 29.07 31.78 Hf 11.23 10.63 9.87 8.46 14.33 8.07 Ta 9.11 9.80 8.19 7.16 11.22 11.86 U 4.47 4.33 4.31 3.58 7.28 2.47 Pb 8.32 7.68 6.78 4.53 20.45 5.16 Rb 121.8 118.9 100.3 41.1 46.8 66.2 Cs 1.35 1.55 1.16 0.24 0.08 0.59 Sr 356 807 555 742 438 914 Sc 4.3 4.2 8.0 9.8 1.2 1.8 Zr 599 550 503 413 803 375 W 183 323 194 122 169 402

215

APPENDIX D 216

Host Clinopyroxene Structural Pressures from Nimis and Ulmer (1998) and Nimis (1999)

P (kbar) 3 AN Min Depth Max Depth Sample Xl wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Mg# Oxide total MS113A-08 p c OK OK OK OK OK OK 5.73 8.73 25.32 28.81 MS113A-09 p c OK OK OK OK OK OK 1.84 4.84 14.04 15.97 MS113A-10 p c OK OK OK OK OK OK 1.38 4.38 12.71 14.46 MS113A-11 p c OK OK OK OK OK OK -0.55 2.45 7.11 8.10 MS114A-01 p c OK OK OK OK OK OK 4.33 7.33 21.26 24.20 MS169A-54 p c OK OK OK OK OK OK 0.33 3.33 9.67 11.00 MS169C-05 p c OK OK OK OK OK OK 1.66 4.66 13.52 15.38 MS169C-11 p c OK OK OK OK OK OK 2.93 5.93 17.19 19.56 MS169C-12 p c OK OK OK OK OK OK 1.31 4.31 12.50 14.22 MS169C-15 p c OK OK OK OK OK OK 2.04 5.04 14.62 16.64 MS169C-16 p c OK OK OK OK OK OK -1.12 1.88 5.44 6.19 MS169D-01 p c OK OK OK OK OK OK 4.72 7.72 22.39 25.48 MS169D-11 p c OK OK OK OK OK OK 0.81 3.81 11.04 12.57 MS169D-12 p c OK OK OK OK OK OK 5.19 8.19 23.74 27.02 MS169D-13 p c OK OK OK OK OK OK 4.43 7.43 21.53 24.50 MS113A-17 p c OK OK OK OK OK OK 3.64 6.64 19.25 21.91 MS113A-18 p c OK OK OK OK OK OK 4.79 7.79 22.59 25.70 MS169B1-58a p c OK OK OK OK OK OK 5.78 8.78 25.46 28.97 MS169B1-58b p c OK OK OK OK OK OK 5.91 8.91 25.85 29.42 MS169B1-58c p c OK OK OK OK OK OK 5.95 8.95 25.95 29.53 MS169D-17 p c OK OK OK OK OK OK 0.81 3.81 11.05 12.58 MS113A-12 p r OK OK OK OK OK OK -2.00 1.00 2.90 3.30 MS113A-13 p r OK OK OK OK OK OK -0.89 2.11 6.12 6.97 MS113A-19 p r OK OK OK OK OK OK 4.87 7.87 22.83 25.98 MS169A-55 p r OK OK OK OK OK OK -0.98 2.02 5.85 6.66 MS169A-57 p r OK OK OK OK OK OK -1.12 1.88 5.46 6.21 MS169B1-58d p r OK OK OK OK OK OK 5.93 8.93 25.89 29.46 MS169B1-58e p r OK OK OK OK OK OK 5.68 8.68 25.16 28.63 MS169C-13 p r OK OK OK OK OK OK -1.72 1.28 3.71 4.22 MS169C-18 p r OK OK OK OK OK OK -3.50 -0.50 MS169C-31 p r OK OK OK OK OK OK 2.66 5.66 16.40 18.66 MS169C-32 p r OK OK OK OK OK OK 2.76 5.76 16.71 19.02 MS169C-33 p r OK OK OK OK OK OK 0.38 3.38 9.80 11.16 MS169D-02 p r OK OK OK OK OK OK 1.04 4.04 11.73 13.35 MS169D-03 p r OK OK OK OK OK OK -5.23 -2.23 MS169D-14 p r OK OK OK OK OK OK 2.11 5.11 14.83 16.88 MS169D-18 p r OK OK OK OK OK OK -0.64 2.36 6.84 7.78 MS169D-38 p rOK OK OK OK OK OK -0.96 2.04 5.90 6.72

217

Host Clinopyroxene Structural Pressures, continued

P (kbar) 3 AN Min Depth Max Depth Sample Xl wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Mg# Oxide total MS113A-24 mp c OK OK OK OK OK OK 3.21 6.21 17.99 20.48 MS113A-45 mp c OK OK OK OK OK OK 1.09 4.09 11.86 13.49 MS169A-52 mp c OK OK OK OK OK OK -1.26 1.74 5.06 5.75 MS169B1-04 mp c OK OK OK OK OK OK -0.89 2.11 6.11 6.95 MS169B1-05 mp c OK OK OK OK OK OK -1.20 1.80 5.21 5.93 MS169B1-06 mp c OK OK OK OK OK OK 0.21 3.21 9.30 10.59 MS169B1-07 mp c OK OK OK OK OK OK 0.45 3.45 10.00 11.38 MS169B1-13 mp c OK OK OK OK OK OK -0.72 2.28 6.61 7.52 MS169B1-17 mp c OK OK OK OK OK OK -0.94 2.06 5.97 6.79 MS169B1-23 mp c OK OK OK OK OK OK -4.95 -1.95 MS169B1-56 mp c OK OK OK OK OK OK 0.87 3.87 11.22 12.77 MS169C-35 mp c OK OK OK OK OK OK 1.50 4.50 13.05 14.85 MS169C-37 mp c OK OK OK OK OK OK 1.19 4.19 12.16 13.84 MS169D-22 mp c OK OK OK OK OK OK 1.44 4.44 12.88 14.65 MS169N2-12 mp c OK OK OK OK OK OK -0.30 2.70 7.82 8.90 MS169N2-19 mp c OK OK OK OK OK OK 2.13 5.13 14.87 16.92 MS169N2-27 mp c OK OK OK OK OK OK -0.83 2.17 6.29 7.16 MS169N2-28 mp c OK OK OK OK OK OK 1.67 4.67 13.54 15.41 MS169A-65 mp r OK OK OK OK OK OK 2.78 5.78 16.75 19.06 MS169B1-18 mp r OK OK OK OK OK OK 0.70 3.70 10.72 12.19 MS169B1-35 mp r OK OK OK OK OK OK 1.58 4.58 13.28 15.11 MS169N2-13 mp r OK OK OK OK OK OK 4.07 7.07 20.49 23.32 MS169N2-20 mp r OK OK OK OK OK OK 1.21 4.21 12.21 13.89 MS169A-64 gm gm OK OK OK OK OK OK -1.28 1.72 5.00 5.68 MS169B1-14 gm gm OK OK OK OK OK OK 1.36 4.36 12.66 14.40 MS169B1-15 gm gm OK OK OK OK OK OK -0.82 2.18 6.32 7.20 MS169B1-26 gm gm OK OK OK OK OK OK 0.11 3.11 9.02 10.26 MS169B1-48 gm gm OK OK OK OK OK OK 1.96 4.96 14.38 16.37 MS169C-40 gm gm OK OK OK OK OK OK -5.61 -2.61 MS169D-26 gm gm OK OK OK OK OK OK 2.27 5.27 15.29 17.40 MS169D-29 gm gm OK OK OK OK OK OK 1.37 4.37 12.66 14.41 MS169D-30 gm gm OK OK OK OK OK OK 1.79 4.79 13.90 15.82 MS169D-31 gm gm OK OK OK OK OK OK -0.15 2.85 8.26 9.40 MS169D-32 gm gm OK OK OK OK OK OK -4.96 -1.96 MS169N2-08 gm gm OK OK OK OK OK OK 2.33 5.33 15.45 17.58 MS169N2-14 gm gm OK OK OK OK OK OK 5.34 8.34 24.19 27.53 MS169N2-24 gm gm OK OK OK OK OK OK 4.41 7.41 21.49 24.45

218

Host Clinopyroxene Structural Pressures, continued

P (kbar) 3 AN Min Depth Max Depth Sample Xl wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Oxide total MS113A-24 mp c OK OK OK OK OK OK 3.21 6.21 17.99 20.48 MS113A-45 mp c OK OK OK OK OK OK 1.09 4.09 11.86 13.49 MS169A-52 mp c OK OK OK OK OK OK -1.26 1.74 5.06 5.75 MS169B1-04 mp c OK OK OK OK OK OK -0.89 2.11 6.11 6.95 MS169B1-05 mp c OK OK OK OK OK OK -1.20 1.80 5.21 5.93 MS169B1-06 mp c OK OK OK OK OK OK 0.21 3.21 9.30 10.59 MS169B1-07 mp c OK OK OK OK OK OK 0.45 3.45 10.00 11.38 MS169B1-13 mp c OK OK OK OK OK OK -0.72 2.28 6.61 7.52 MS169B1-17 mp c OK OK OK OK OK OK -0.94 2.06 5.97 6.79 MS169B1-23 mp c OK OK OK OK OK OK -4.95 -1.95 MS169B1-56 mp c OK OK OK OK OK OK 0.87 3.87 11.22 12.77 MS169C-35 mp c OK OK OK OK OK OK 1.50 4.50 13.05 14.85 MS169C-37 mp c OK OK OK OK OK OK 1.19 4.19 12.16 13.84 MS169D-22 mp c OK OK OK OK OK OK 1.44 4.44 12.88 14.65 MS169N2-12 mp c OK OK OK OK OK OK -0.30 2.70 7.82 8.90 MS169N2-19 mp c OK OK OK OK OK OK 2.13 5.13 14.87 16.92 MS169N2-27 mp c OK OK OK OK OK OK -0.83 2.17 6.29 7.16 MS169N2-28 mp c OK OK OK OK OK OK 1.67 4.67 13.54 15.41 MS169A-65 mp r OK OK OK OK OK OK 2.78 5.78 16.75 19.06 MS169B1-18 mp r OK OK OK OK OK OK 0.70 3.70 10.72 12.19 MS169B1-35 mp r OK OK OK OK OK OK 1.58 4.58 13.28 15.11 MS169N2-13 mp r OK OK OK OK OK OK 4.07 7.07 20.49 23.32

219

Type I Clinopyroxene Structural Pressures from Nimis and Ulmer (1998) and Nimis (1999)

P (kbar) AN Min Depth Max Depth Sample Xl 3 wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Mg# Oxide total MS169D-62 p r OK OK OK OK OK OK 4.25 7.25 21.01 23.91 MS113A-49 mp r OK OK OK OK OK OK 1.70 4.70 13.62 15.50 MS113A-50 mp r OK OK OK OK OK OK 1.56 4.56 13.22 15.04 MS113A-59 mp r OK OK OK OK OK OK 1.74 4.74 13.75 15.65 MS113A-70 mp r OK OK OK OK OK OK 4.54 7.54 21.85 24.87 MS169A-49 mp r OK OK OK OK OK OK 4.07 7.07 20.49 23.32 MS169D-43 mp r OK OK OK OK OK OK 0.62 3.62 10.50 11.95 MS169D-52 mp r OK OK OK OK OK OK 0.95 3.95 11.46 13.04 MS169D-67 mp r OK OK OK OK OK OK 1.44 4.44 12.89 14.67 MS169D-68 mp r OK OK OK OK OK OK 4.69 7.69 22.30 25.38 MS169D-75 mp r OK OK OK OK OK OK 1.36 4.36 12.65 14.40 MS169N2-45 mp r OK OK OK OK OK OK 1.39 4.39 12.72 14.47 MS169N2-57 mp r OK OK OK OK OK OK -1.07 1.93 5.59 6.36 MS169N2-68 mp r OK OK OK OK OK OK 1.86 4.86 14.08 16.02 MS169N2-71 mp r OK OK OK OK OK OK -2.29 0.71 2.05 2.33 MS113A-71 gm gm OK OK OK OK OK OK -0.83 2.17 6.28 7.15 MS169A-34 gm gm OK OK OK OK OK OK 0.55 3.55 10.28 11.70 MS169A-47 gm gm OK OK OK OK OK OK 0.11 3.11 9.02 10.26 MS169D-45 gm gm OK OK OK OK OK OK 3.27 6.27 18.19 20.70 MS169D-46 gm gm OK OK OK OK OK OK 4.07 7.07 20.50 23.33 MS169D-54 gm gm OK OK OK OK OK OK 0.01 3.01 8.74 9.94 MS169N2-58 gm gm OK OK OK OK OK OK 1.92 4.92 14.27 16.24 MS169D-61 p c OK OK OK OK OK No MS169A-31 gm r OK OK OK OK OK No MS114A-48 gm gm OK OK OK OK OK No MS169A-32 gm gm OK OK OK OK OK No MS169A-51 gm gm OK Bad Bad OK OK No

220

Type II Clinopyroxene Structural Pressures from Nimis and Ulmer (1998) and Nimis (1999)

P (kbar) 3 AN Min Depth Max Depth Sample Xl wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Oxide total MS169B2-62 mp c OK OK OK OK OK OK -2.38 0.62 1.79 2.04 MS169K-52 mp c OK OK OK OK OK OK -2.35 0.65 1.89 2.15 MS169K-74 mp c OK OK OK OK OK OK 1.07 4.07 11.80 13.43 MS169K-54 mp r OK OK OK OK OK OK -2.40 0.60 1.74 1.98 MS169K-76 mp r OK OK OK OK OK OK 3.25 6.25 18.12 20.62 MS169K-60 gm gm OK OK OK OK OK OK -4.03 -1.03 MS169K-63 gm gm OK OK OK OK OK OK -4.00 -1.00 MS169K-67 gm gm OK OK OK OK OK OK 1.18 4.18 12.12 13.80 MS169K-68 gm gm OK OK OK OK OK OK 0.01 3.01 8.72 9.92 MS169K-77 gm gm OK OK OK OK OK OK 1.72 4.72 13.69 15.58 MS169K-14 mp c OK OK OK OK OK No MS169K-15 mp c OK OK OK OK OK No MS169K-35 mp c OK OK OK OK OK No MS169K-81 mp c OK OK OK OK OK No MS169K-11 mp r OK OK OK OK OK No MS169K-32 mp r OK OK OK OK OK No MS169K-33 mp r OK OK OK OK OK No MS169K-36 mp r OK OK OK OK OK No MS169K-53 mp r OK OK OK OK OK No MS169K-82 mp r OK OK OK OK OK No MS169K-83 mp r OK OK OK OK OK No MS169K-16 gm gm OK OK OK OK OK No MS169K-17 gm gm OK OK OK OK OK No MS169K-20 gm gm OK OK OK OK OK No MS169K-25 gm gm OK OK OK OK OK No MS169K-26 gm gm OK OK OK OK OK No MS169K-34 gm gm OK OK OK OK OK No MS169K-39 gm gm OK OK OK OK OK No MS169K-40 gm gm OK OK OK OK OK No MS169K-58 gm gm OK OK OK OK OK No MS169K-61 gm gm OK OK OK OK OK No

221

Type IV Clinopyroxene Structural Pressures from Nimis and Ulmer (1998) and Nimis (1999)

P (kbar) AN Min Depth Max Depth Sample Xl 3 wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Oxide total MS169C-44 fg OK OK OK OK OK OK -5.41 -2.41 MS169C-58 fg OK OK OK OK OK OK -6.36 -3.36 MS169C-65 fg OK OK OK OK OK OK 1.43 4.43 12.85 14.62

Type V Clinopyroxene Structural Pressures from Nimis and Ulmer (1998) and Nimis (1999)

P (kbar) AN Min Depth Max Depth Sample Xl 3 wt.% Fe3+

T-site (kbar) (km) (km) Ca+Na M-sites Checks H2O Mg# > 0.7 Oxide total MS169B1-60 mg OK OK OK OK OK No MS169B2-81 mg OK OK OK OK OK No MS169B2-75 mg OK OK OK OK OK No MS169B2-74 mg OK OK OK OK OK No MS169B2-76 mg OK OK OK OK OK No MS169B2-78 mg OK OK OK OK OK No