Scholars' Mine
Masters Theses Student Theses and Dissertations
1965
Geology, geochemistry and genesis of selected skarn deposits, Northern New Brunswick, Canada
Donald John Bachinski
Follow this and additional works at: https://scholarsmine.mst.edu/masters_theses
Part of the Geology Commons Department:
Recommended Citation Bachinski, Donald John, "Geology, geochemistry and genesis of selected skarn deposits, Northern New Brunswick, Canada" (1965). Masters Theses. 5378. https://scholarsmine.mst.edu/masters_theses/5378
This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. GEOlOGY, GEOCHEHISTRY AND GENESIS OF SELECTED SKARN DEPOSITS, NORTHERN NEW BRUNSWICK CANADA
BY
DONALD J. BACHINSKI
A
THESIS
submitted to the faculty of the
UNIVERSITY OF MISSOURI AT ROLLA in partial fulfillment of the requirements for the Degree of
MASTER OF SCIENCE, GIDLOGY MAJOR
Rolla, Missouri 1965
Approved
{advisor) ABSTRACT
An exhaustive geological and geochemical study is pre sented of magnetite-chalcopyrite skarn deposits occurring within the thermal aureole of the Nicholas Denys quartz monzonite-granodiorite stock. The deposits are crudely lenticular and occur in meta morphosed impure limestone and siliceous, in part limy, argillite-greywacke. These are now represented by andradite epidote-dio?side-calcite Ekarn and calc-silicate to horn felsic rocks respectively. Both deposits are spatially related to the Main fault of the Rocky Brook-Millstream fault system~ late, generally north~-"est trending transverse faults are conspicuous and are deemed of importance in ore localization. Chemical analyses show that the ore deposits represent abnormal concentrations of Fe, Cu and Zn with lesser con- centrations of As, Co, Bi, Mo, Ag and Au. Depletions are evident in sr, Ba, CaO, ao 2 and H2o. Magnetite and chalcopyrite are the predominant ore minerals with lesser pyrite, sphalerite, pyrrhotite, arseno pyrite, marcasite and molybdenite. A thin residual gossan over the Beresford deposit consists largely of limonite and hematite with very minor malachite and rare chalcocite. The skarn deposits are conventional contact metasomatic types with base metals and sulfur genetically related to the Nicholas Denys stock. Iron is probably derived through bleaching of hornfelsic units and in part 1 through the alteration of iron-rich conglomerate. iv TABLE OF CX)NTENTS Page ABST?J-.CT ...... ii TABLE 0 F COl.~TENTS...... iv INTRODUCTION • • • • ...... 1 Location and Access • • • • • • • • • • • • 2 Topography and ~rainage • • • • • • • • • • 3 Acknowledgments • • • • • • • • • • • • • • 3
GENERAL GEOLOGY OF THE BATHURST DISTRICT • 5
GEOI.DGY OF THE NIGADOO RIVER-MILLSTREAM RIVER AREA • 7
General Statement • • • • • • • • • • • • • 7 Description of Rocks. • • • • • • ••• 9 Tetagouche Group • • • • • • • • • 9 Chaleur Bay Group. • • • • • • • • • • • • • • 9 Conglomerate. • • • • • • • • • • • ••• 10 Limestone, Impure Limestone and Derived Skarn • • • • • • • • • • • • • 12 Greywacke-Argillite and Hornfelsic Equivalents. • • • • • • • • 17 Mafic Intrusive Rocks ••••••••••• 19 Serpentinite. • • • • • • • • • • • • 19 Diabase, Diabasic Gabbro ••••• 22 Acid Intrusive Rocks • • • • • • • • • 24 Nicholas Denys Quartz Monzonite Granodiorite •••••••••• 24 Feldspar Porphyry, Quartz Feldspar Porphyry and Aplite. • ••••••• 25 Structural Geology • • • • • • • • • • • 28 Folds ••••••••••• ...... 28 Faults ....•••.•••.••• 28 Longitudinal Faults • . . . . 28 Transverse Faults • • ••••• . . . 29 GOOI.DGY OF THE BERESFDRD AND MILLSTREAM IRON DEPOSITS. • 31 History of Exploration • • • • • • • • • • • 31 Geology of the Deposits • • • • • • • • • • • • 32 Mi.neralogy. . • • . • • • • • . • . . • . . 34 ~1agneti te. • • • • • • • • • • • • 36 Chalcopyrite ••••••••••••• 36 Py-rite . . . . • . • . . . . • • . • • . • . 37 Paragenetic Relations. • • • • • • • • • 38 Mineralization as Related to the Tectonic Cycle 39 GEOCHEl1ISTi-{Y OF <..'OUNTRY AND BJST ROCKS • ...... 40
General Statement ••••• • • • • • • • . . . . . 40 v
C~emical Analyses. • • • • • • • • • ...... £10 Discussion of Statistical Treatment...... 41 Geochemistry of Rocks •••••••• ...... 43 Conglomerate. • • • • • • • • • ...... 43 :::;:ecrystallized Limestone •••• 46 S~carn . . . . • . . . • . • . . . . . <18 Greywacke-Argillite and Hornfelsic Equivalents 51 Bleached Hornfels • • • • • • • • • • • • • • 55 Serpentinite ...... 58 Diabase, 0iabasic Gabbro ••••••••••• 62 Nicholas Denys Quartz Monzonite-Granodiorite. 62 .P.. cid Porphyritic Rocks. • • • • • • • • • • • 65
GEOCH!.'!:1-1IST~{Y Or' THE BERESFORD AND MILLSTREAM IRON SKAR..'I\J Dl!;.?OSITS 67 General Statement...... 67 Sulfur Isotopes •• ...... 67 ORE GENESIS 71
General Statement. • • • • • • • • 71 Source of Iron • • • • • • • • • • 72 Source of Base Metals and Sulfur • • . . . . . 73 Effects of Intrusion • • • • • • • • ...... 74 Origin of the Deposits • • • •• 75
CON\..:LU::il.ONS...... 76 SUGGESTIONS FOR FUTURE WORK . . 78 BIBLIOGRAPHY ...... 80 AP?Ei'l"'DIX 1. Chemical analyses of rocks and ores, Nicholas Denys-Millstream River area. 85
2. Sample locations, Nicholas Denys }tillstream River area • • • • . . . . 90 3. Location of diamond drill hole sections and surface samples, Millstream Iron- Beresford area • • • • • • • • • • • 91
4. Diamond drill hole sections and sample locations . . . 92 VITA ...... 99 TABLE 1. Lithologic units of the Nigadoo River Millstream River area • • • • • • • • 8 II. Paragenesis of the Beresford and Millstream Iron deposits • • • • • • • • • • • • • • • 38 Vi TABLE III. Limits of detection and values for concen trations not found or below the limits of detectability. • • • • • ~2
IV. Statistical analysis of chemical components in conglomerate, Beresford area • • • • 44 V. Statistical analysis of chemical components in conglomerate, ~dllstream Iron area • • 45 VI. Chemical analyses of recrystallized lime- stone • 47 VII. Statistical analysis of chemical components in skarn, Beresford area. • • • • • • 49 VIII. Statistical analysis of chemical components in skarn, !1i.llstream Iron area. • • • • 50 IX. Statistical analysis of chemical components in hornfels, Beresford area • 52 X. Statistical analysis of chemical components in hornfels, Millstream Iron area • 53 XI. Statistical analysis of chemical components in greywacke-argillite. • • • • 54 XII. Statistical analysis of chemical components in calcareous argillite • • • • • • 56 XIII. Statistical analysis of chemical components in bleached hornfels • • • 57 XIV. Chemical analysis of serpentinite breccia. 59
XV. Statistical analysis of chemical components in serpentinite, Beresford area • 60 XVI. Statistical analysis of chemical components in serpentinite, ~llstream Iron area • 61
XVII. Chemical analyses of Devonian mafic igneous rocks • 63 XVIII. Statistical analysis of chemical components in the Nicholas Denys quartzmonzonite- granodiori te • • • • • • • • • 64
XIX. Chemical analyses of porphyritic rocks • 66 XX. Statistical analyses of chemical components in the Beresford deposit • • • • • • • • 68 vii TABLE XXI. Statistical analysis of chemical components in the Millstream Iron deposit. 69 XXII. Sulfur isotope ratios of ore deposits. 70 ILLUSTRATIONS
I1AP 1. Geology of the Nigadoo River-Millstream River area. • • • • • • • • • • • • • in poci~et
2. Ge~logy of the Millstream Iron-Beresford area ...... • in pocket FIGURE 1. Index map of the Bathurst District, New Brunswick. • • • • • • • 2 2. Geology and principal base metal deposits, Bathurst area, showing location of the Nigadoo River-~llstream River area. • • • 6
3. Beresford deposit, section A-A' 33 4. Beresford deposit, section B-B' . . . 35
PLATE I. ~~croboudinage structure in recrystallized limestone • • • • • • • • • • • • • • 14
IIA. Isotropic-anisotropic garnet. Plane polarized light ...... 16 IIB. Isotropic-anisotropic garnet. Crossed nicols. 16 III. Talc alteration of serpentinite . . . . 21" GWLOGY, c.:;l:XJCHBI1IST~Y AND G.t:N.t:SIS O:F ~.I:.:Ll::CTED SKAlW .c:.:::?OsiT.:., NORTHERN NE"w BRUNSWICK, <.;ANADA
l.N'l'RO.l)U<.;TION
Skarn de?Qsits in the Nigadoo River-Millstream ~iver area of northern New Brunswick were studied as part of a more extensive geological and geochemical progra~ in the Bathurst district by the Geological survey of Canada. The geology, petrography, mineralography and geochemis- try of the magnetite-chalcopyrite bearing skarns is presented.
During the summer of 1963, all available diamond drill core from the Beresford and ~llstream Iron deposits was examined and limited detailed mapping and sampling was carried out. Chemical analyses of ores and country rocks were obtain- ed through laboratories of the Geological Survey of Canada~ these include spectrographic analysis for sr, Ba, Cr, ~r, v, Ni, Co, W, Mo, Ag and Bi~ colorimetric determinations of Cu, Pb, ~n, As, Sb and Ni~ Siu2 , Al2o 3 , total iron as Cav, Mgv, KO Ti0 and Mno by X-ray fluorescence 2 I 2 2 analysis and ao by a rapid method. 2 The writer has drawn upon the sulfur isotope data of Tupper (1961) 1 in the discussion of this phase of the geo- chemistry.
1. Dates in parenthesis are those of references listed in the bibliography. 2
A discussion of genesis of the magnetite-chalco?yri~e deposits is also presented.
Location and Access
The deposits are situated near the village of Nicholas
Denys, approximately 10 miles northwest of Bathurst, New
Brunswick, on the Bay of Chaleur (Figures 1 and 2). The area of interest is included in the west half of Nation31
Topographic Survey sheet 21 P/12 and has the co-ordinates
47°42'N, 65°53'W.
INDEX MAP
Access is provided by gravel and paved roads which connect to the provincial highway system.
The region is surveyed and settled, but largely un cleared. Secondary growth covers most parts of the region with travel.adversely affected by windfall locally. 3 Topography and Drainage
Glaci~l and fluvio-glacial outwash covers most of the area with exoosures largely confined to valley walls ann incised stream courses. k£ esker is located to the north west of the Beresford deposit (Map 2) while the presence of kames and terminal or recessional moraines have been sug gested. FaultB in the area. commonly give rise to prominent topographic expressions as, for example, the Main fault which occupies a pronounced depression. Stevens Brook and other streams in the map-area_ are fault controlled. Streams are in a youthful stage of development and drainage is eastward to the Bay of Chaleur.
Acknowledgments
I wish to initially express my gratitude to Professor
P. D. Proctor who acted as the writer's thesis advisor during this study.
The ex~mination in depth of the skarn deposits would not have been possible were it not for the opportunity afforaPd the writer by the Geological Survey of Canada. In this reg~rd, the writer would like to especially thank Dr. R. w_ Boyle of the Survey who acted as co-ordinator of the
Bathurst Project. Discussions with L. Davies, New Brunswick Department of Mines were fruitful.
The Noranoa exploration Company Limited, specifically
Mr. Paul Sawyer, are to be commended for their release of 4 all available data on the Beresford Mines Limited deposit.
A. B. Baldwin of M. J. Boylen Engineering Offices is thanked for information used in this study.
Chemical analyses were provided by the &nalytical laboratories of the Geological Survey of Canada under the direction of Dr. J. Maxwell.and J. Lynch.
Statistical analysis of chemical parameters were under taken under the auspices of the Computer Division, Department of Mines and Technical Surveys, Ottawa.
Lastly, the writer must acknowledge discussions with fellow graduate students of the University of Missouri at
Rolla which served to prod the writer to succinctly state his findings. 5 GENERAL GEOLOGY OF THE BATHURST DISTRICT
The rocks of the Bathurst district have been divided by Smith and Skinner {1958) into three regional geological units: the Orcovician folded belt, the Silurian-Devonian folded belt, and the Pennsylvanian cover (Figure 2). Ordovician rocks underlie the central part of the dis trict and include sedimentary and volcanic units that are intruded by Ordovician and Devonian gabbro and diorite sills and dikes and by granitic intrusions of Devonian age. The sedimentary and volcanic rocks have undergone moderate regional and intense dynamic meta~orphism being subjected to both the Taconic and Acadian orogenies. Massive Pb-Zn Cu sulfide deposits occur in these rocks. The Silurian-Devonian folded belt occurs to the north of the above unit and has involved volcanic and sedimentary rocks of I~ddle to Late Silurian and Early to ~ddle Devonian age. Deformation is not as intense in these rocks which were involved only in the Acadian orogeny. Silurian rockR have been intruded by gabbro and diorite masses, granitic stocks and quartz and/or feldspar porphyry sills, dikes and plugs, all of Devonian age. The Silurian rocks are host to numerous small, commonly discordant sulfide veins and lenses, in addition to the skarn deposits under consideration. Flat-lying Pennsylvanian conglomerate and sandstone occur in the eastern part of the district~ _ the presence of scattered outliers suggests an original more extensive cover. 6 Pennsylvanian strata rest unconformably on the older rocks.
LEGEND MINING PROPERTIES
PENNSYLVANIAN (Undivided) G) Nigadoo Mines Ltd. 0 Sandstone, shale, coog/omerote @ Sturgeon River Mines DEVONIAN (D New Calumet r--:J Medic intrusive rocks; gabbro, ~ d1orite. diabase <3) Anaconda Co. (Caribou) r--:J Felsic intrusive rocks- granite. gneissic ® Anaconda Co. L:..._j granite, quartz diorite ® Brunswick No. 12 DEVONIAN- SILURIAN (Undivided) (J) Brunswick No. 6 0 Sedimentary and volcanic rocks ® Consolidated Mining and Smelting Co. ORDOVICIAN ® Consolidated Mining and Smeltina: Co. llltiODLE ORDOVICIAN TIETAGOUCHE QROU,_ (1-&J @ Anacon lead Mines(New Lerder.. U'") r:-l Slota division: slate, phyllite, ~ orgiltile, greywocl
Figure 2. Geology unJ principal base' metn I deposits, Buthur•st area, showing locution of the :-..1 i gaJoo i~ i ver-~l i I 1st- ream River area. 7 GillLOGY OF THE NIGAOOO RIVER - MILLSTREAM RIVE.:{ AREA
General Statement
Middle Silurian gre~;ackes, argillites, conglomerates, calcareous slates and phyllites, and subgreywacke of the Chaleur Bay Group ( Ta.ble 1) are intruded by diabase, dia basic gabbro, diorite, serpentinized peridotite, feldspar and quartz feldspar porphyry dikes, sills and plugs and by a quartz monzonite-granodiorite stock (Martin, 1963, personal communication). Petrographic and geochemical studies are largely con fined to the lowermost Cnaleur Bay Group which is host to the skarn deposits. This steeply dipping, east-northeast trending sequence consists of intercalated conglomerate argillite, impure, siliceous limestone and interbedded grey
wacke-argillite. The chlorite-albite-muscovite-calcite subfacies of the greenschist facies of regional metamorphism is complicated
in the immediate area of interest -.::_.:z the superposition of contact metamorphic assemblages within the thermal aureole of the Nicholas Denys stock. The Chaleur Bay Group forms a broad, northeast trending
synclinoriUm (Map l) with folds of lesser wavelength con spicuous along the southern part of the map-area. Faults are prominent in the region with the Main fault being the principal one in a complex wrench fault system. 8 TABLE I
LITHOLOGIC UNITS OF THE NIGADOO RIVER - i1ILLSTREAJ1 RIVER ARE.'\
Period or Era Group Epoch Lithology
Cenozoic Recent, Soil, till, sand and Pleistocene gravel.
Paleozoic Devonian Quartz monzonite-grana- I diorite, quartz and/or l feldspar porphyry, aplite.j r--?------~------4------~, Diabase, diabasic gabbro, , diorite. Serpentinized peridotite, serpen~inite .. Intrusive Contact i:1iddle Chaleur Green-grey slate, phyl Silurian Bay lite, argillite and sand stone, minor red argil lite, phyllite and sand stone. Conglomerate, grit, grey wacke and argillite. GreYwacke-argillite and hornfelsic equivalents. Siliceous, impure lime stone and derived skarn. Conglomerate-argillite, greywacke.
u/c--~------; Ordovician Diabase, diabasic gabbro, diorite. Intrusive Contact Middle Teta Dark grey phyllite, Ordovician gouche graphitic schist, and quartzose subgreywacke. The i'1ain fat..:.lt is developed along a tight overturred C'.nti cline on t~e south limb of the synclinorium. Late, ge~e~ally northwesterly trending faults are common and of importance in ore localization.
Description of Rocks
~0tngouc0P Groun Rocks of the Middle Ordovician Tetagouche Group und8r lj_e. the southern and extreme northwest parts of the Nigadoo
River - Millstream River area (Map 1). Davies (1965) briefly describes these units which con~ist of ohyllite, argillite (locally graphitic) with lesser lenses of quartz ose subgre;,,acke. The rocks have suffered intense mechanical deforr.ation and lie in a series of tight, isoclinal folds. The Teta- gouche rocks are in fault contact with the overlying Chaleur
Bay Grouo but as Davies (op. cit.) emphasizes, the difference in degree of metamorphism between them suggests the existP.nce of an unconformity. Cavies (1958) noted the probable pres ence of an unconformity between the groups to the west but conclusive evidence to support its extension into the map area is lacking.
Chaleur Bay Grou>J
The northern portion of tr.e Nigadoo River - Millstream
River area is underlain by rocks of the Middle Silurian Chaleur Bay Group. A lower greywacke-argillite unit passes 10 U?ward into a conglomerate-greywacke sequence which is overlain in turn by a limy argilli te-slate-phylli te-sand~.:;tocJ.e series.
The lovrermost portion of the C"i'1aleu~ Bay Grouo will be described in con~iderable detail in that it is host to the skarn deposits under investigation. About 2000 feet of interbedded, dark grey to greenish greywacke and argillite are oresent in the map-area. A conglomeritic facies is developed locally such as in proximity to the Beresford and Millstream Iron deposits (Ma? 2). The skarn horizon, pre
sumably an imoure, in part argillaceous limestone, can be traced westwards from Stevens Brook to the mouth of AnnPs
Creek. It is interlayered with the greywacke-argillite unit and occurs on both sides of the Main fault.
Conglomerate A polymictic conglomerate, intercalated with argillite and/or greywacke, averaging 50 feet in thickness occurs between seroentinite and skarn (Map 2). Individual con glomerate lenses thicken and thin and, as in the Millstream
Iron area, may im~erceptibly grade into fractured, carbona tized and serpentinized rocks occupied by the Main fault.
In the Beresford area, the unit is grey to brownish green whereas a dark greenish black coloration is more typical westwards. Crudely developed bedding is exhibited by indi vidual conglomeritic layers.
Poorly sorted, closely packed, subrounded to disk- 11 sha?ed pebbles, oriented parallel to the bedding character- ize the conglomerate. Pebbles consist of grey-green argil lite, siliceous argillite, matic volcanic rock, feldspar oo:c~hyry, quartz fragments and rr:,rely, iron format~_on. The matr:l.x is commonly argillaceous, locally consti- tuting a greywacke: an appreciable carbonate content is present in places. Magnetite is an important matrix con stituent exceot in proximity to the Beresford deposit. Individual maqnetite grains are euhedral to subhedral and exhibit a tendency to form lenses which follow the bedding.
Magnetite is considered a primary, detrital constituent of the rock. In general, the conglomerate is markedly hetero geneous ,..,i th quartz, chlorite, biotite, plageoclase and carbonaceous material prominent matrix constituents, in addition to magnetite. Slip surfaces in melanocratic variants in the Mill stream Iron area are filmed with serpentine, lesser calcite, hematite and pyrite. In general, sulfides are restricted to late fractures. Calcite and quartz-calcite macro and micro-fracture fillings are ubiquitous, with a pronounced tendency to be perpendicular to the Pe~ding. These late fractures offset primary magnetite lenses in the Millstream
Iron area and in most instances are free of iron oxides and sulfides. Greenish black andalusite porphyroblasts, up to 2 rnm. in diameter, occur in both conglomerate and intercalated ar~illite in the western part of the area of interest, 12 nearer the thermal center. These andalusite met~crysts con- tain abundant inclusions of magnetite, carbonaceous ~aterial, chlorite and quartz. Inconclusive X-ray powder diffract.ion patterns were obtained dt:e to masl<:ing by inclusions of quartz and chlorite. Epidote and anthophyllite have also been recognized in areas affected by the Nicholas Denys stock.
Limestone, Impure Limestone and Derived Skarn
Grey, thin-bedded recrystallized limestone has been intersected in drilling in J::oth the 1'1illstream Iron and
Beresford deposits. Transitions to skarn are characterized by an increase in number and thickness of beige porcellaneous to granular skarn bands which alternate with marble. Finely intercalated, limy argillaceous beds commonly occur and pre sumably it is these areas that are more receptive to sl Recrystallized limestones consist almost entirely of alternating layers of fine to medium-grained granular cal cite and carbonaceous/argillaceous material. Pyrite is a common accessory confined to the latter and occurs with cal cite in late fractures as well. Beige to yellow aphanitic bands typical of transitional variants are characteristically pyritic, yellowish-brown and cryptocrystalline. X-ray powder diffraction patterns reveal 1.3 the o~ese~ce of olagioclasA. These layers are more c0::1::>c ter. t than the intervening s~ccharoidal calca=uous bands wit~ th2 result that, locally, where the rcc~-cs have been under st:.css, microboudinage structures are procuced (?late I) 7 te:1:2i.or. fractures in the cryptocrystalline, in pa=t isotro~ic layer, have been filled by coarse calcite and locally, minor pyrite. These micro-dilatant zones servec as loci of low pressure and low c~emical potential resulting in ~he 9re~ipitation of cal- cite and lesser pyrite. Introduction involved a migration of com90nents from immediately adjacent limestone. Fi~ely granular beige skarn layers consist of garnet, lesser epidote, calcite, chlorite and rarely, scapolite. The chalcopyrite-magnetite daposits are essentially localized within a relatively thin skarn band which attains a thickness of 80 feet in the Millstream Iron area and 40 feet at the Beresford deposit. The unit is exposed on either side of the-anticlinal axis in the Beres=ord area but has not been observed south of the Millstream deposit. Skarn largely represents an original impure limestone, nresuma~ly siljceous and argillac£~us in 9art. The Pxtreme variability of the skarn, both texturally and mineralogi cally, attests to an inherent sedimentological heteroqeneity. Fine-grained, porcellaneous a~d co~pact vari~nts contrcst m3.:--kedly Nith thos~ of a r.lediurn-grc...ined granular fabric~ the former represent originally more argillaceous units and might better be termed calc-silicate rocks. Beige, yellow, greenish brown to green colorations have been noted~ massive, 14 Plate I Microboudinage structure displayed by more competent argillaceous layer in granular, saccharoidal recrystallized limestone. Coarse calcite fills the dilatant zone which acted as a site of low chemical potential. X 20. 15 finely bedded or crudely banded structures exist. Granular skarns are characterized by pale orange andra dite which, when intergrown with sulfides and oxides, ex hibits excellent dodecahedral forms (Plate II). Crystals have been observed up to 5 mm. in diameter, though averaging 1 - 2 mm. Garnet commonly predominates with varying pro portions of diopside, epidote, calcite, magnetite, and chalcopyrite. Hornblende, actinolite, muscovite and rarely green to dark brown-green biotite in addition to poikilitic albite containing grains of epidote are locally present. A mosaic of colorless to pale brown equidirnensional, anisotro?ic-isotropic zoned garnet with sulfides and oxides occupying interstitial positions is common. Euhedral andra dite may be completely embedded in chalcopyriteormagnetite~ unequivocal textures indicative of replacement are rare. Fine granular aggregates of epidote, calcite and hematite locally corrode garnet. Elsewhere these same minerals fill fractures in garnet and occupy intergranular spaces. Quartz and tourmaline occur associated with and as inclusions with in magnetite. Garne~erous areas in places are extremely fine-grained and the rocks are essentially isotropic in these instances. Variable concentrations of magnetite, chalcopyrite and pyrite characterize the unit. Magnetite and chalcopyrite, though generally independent of each other, commonly exhibit a crude banding with silicates and calcite. As mentioned earlier, where associated with garnet, both ore minerals 16 Plate II 1\ • B. Alternating isotropic and anisotropic layers in garnet. A. Plane polarized light. B. Crossed nicols. X 20. l7 occur interstitially. Pyrite, and to a lesser extent, chalcopyrite, form irregular veinlets, blebs, disseminations or fill late fractures. Late calcite fracture fillings are ubiquitous. Greywacke-Argillite and Hornfelsic Equivalents In the Beresford area a considerable thickness of inter calated greywacke-argillite outcrops to the north of the skarn zone and south of the serpentinite (Map 2). A vari able thickness of thermally altered argillite-greywacke also occurs between the conglomerate-argillite and skarn. In the area of interest, rocks of this unit are alter nately dark greyish brown and pale greenish or bluish grey, invariably compact and hornfelsic. Where removed from the thermal aureole, as to the southeast of the Beresford deposit, the sedimentary rocks reflect only a low grade of regional metamorphism. Graded bedding is conspicuously developed in these rocks and is commonly preserved within the contact metamorphic aureole. Interbeds of grit con taining 1/8 inch feldspar grains and smaller quartz eyes are observed locally. Individual bands within this unit commonly exhibit a bleached, cherty appearance, hence the field designation of cherty argillite. In general, the hornfels.isdark brown to greyish brown whereas bleached zones associated with frac tures and presumably, in part at least, with sedimentologi cal variations, are pale grey. Typically, the bleached 18 bands are parallel, or nearly so, to the bedding, but whPre cross fractures occur, bleached selvages are apparent. To the immediate east and south of the Beresford deposit, localized, intense bleaching has given rise to a pale g=ey to white hornfe1sic rock. Erratically distributed discontinuous layers of sul fides, principally pyrite, and in the ~llstream Iron area, magnetite, occur within these rocks in proximity to the deposits. Chalcopyrite occurs capriciously as blebs, minute disseminations, or less commonly, as fracture fillings. Late transverse fractures are largely pyritic. Disseminated specks of pyrrhotite are confined to bleached bands. In places, the distinction between a hornfels and skarn or calc-silicate rock may be arbitrary, as for example, in proximity to the Millstream Iron deposit, where the former contains garnetiferous bands. These increase in number and thickness, grading imperceptibly into more typical skarn. Hornfelsic rocks are microcrystalline to cryptocrystal line with portions being essentially isotropic. Brownish variants are characterized by very fine brown biotite and locally, finely divided iron oxides~ pale bleached portions are generally finer grained, lack biotite and commonly con tain appreciable diopside. Coarse knots in bleached zones consist of granular, euhedral diopside extending from the walls into a plagioclase core. Slightly sericitized sub hedral plagioclase grains are relatively common in altered greywacke. Chlorite, quartz and sericite are ubiquitous 1) when grain size permits identification~ muscovite, antho phyllite and actinoli~e have also been recognized. The latter mineral was determined by X-ray powder diffraction from fracture fillings in hornfelsic rocks in proximity to the Millstream Iron deposit. Calcite is a habitual vein mineral: carbonaceous material is only rarely preserved. Mafic Intrusive Rocks Mafic intrusions of two or more ages occur in the Niga doo River - Millstream River area. Diorite, diabase and diabasic gabbro sills intrude the rocks of the Tetagouche Group (Map 1) and appear to have been emplaced prior to the folding of these sediments. (Davies, 1965). The Chaleur Bay Group is intruded by sills of diorite, diabase, dia basic gabbro and serpentinite of Devonian age~ these latter will be described in more detail. Serpentinite An extremely altered, sheared pale bluish-grey weather ing serpentinite sill extends from Stevens Brook in the east, westward to the ~llstrearn Iron deposit, terminating near Bradley Brook, northwest of the Sturgeon River deposit (Map 1). Mottled, bluish to greenish black serpentinized perido tite in part occupies the axial portion of a very tight anti cline. It appears to be bounded by fault planes associated with the Main fault which has given rise to extensive sheared, brecciated and carbonatized zones. A mesh of anastomising calcite stringers, ubiquitous hematitic staining and green seroentine accentuate such zones. MacKenzie (1950) believed the ultramafic body was injecteG along a thrust fault associated with the formation of the Mc.i n fault:- Davies ( 1965) ,.,as unable to find conclusive evidence to support this contention. Along Stevens Brook, serpentinite has been brecciated by late north-south faulting. Elsewhere the sill is soft, somewhat friable and moderately sheared in a direction parallel to the Main fault. Grain size varies from rela tively coarse to extremely fine. Imperfectly developed chrysotile veinlets are erratic in occurrence. Slip sur faces are invariably coated with greenish serpentine and less commonly pyrrhotite and/or pyrite films and blebs. Pyrite is commonly associated with late calcite stringer~. In the examination of drill core from the Millstream Iron area, a serpentinized rock type was observed to display a diffuse fragmental and bedded appearance, suggestive of a sedimentary, in part rudaceous ancestry. Subsequent geo chemical studies by the writer have established that this rock type represents a serpentinized conglomerate. Antigorite, magnetite, lesser talc, minor calcite and magnesite and rare serpohite are the principal mineralogic constituents though showing some variation in their rela tive proportions. Magnetite constitutes about 5% of most samples and where the rock is relatively undisturbed, forms discontinuous rims which presumably outline original ferro- 21 Plate III Talc alteration of serpentine with attendant removal of iron oxides. Residual clots of serpentine are crudely veined with magnetite. Crossed nicols . X 20. 22 magnesian grains. Their shape is suggestive of olivine and it is surmised, in any event, that exsolved iron oxides have undergone a process of accretion along grain boundaries in the orthodox manner. In places, magnetite and associated hematite are localized along distinctive partings in ser pentinized grains suggestive of former diallage. Crudely oriented massive magnetite veinlets commonly occur in areas which are otherwise devoid of iron oxides, yet serpentinized as elsewhere. Silicification is of local importance and has given rise to irregular quartz aggregates. Late talc and lesser carbonate alteration effectively obliterates all vestiges of the original rock save residual. clots of serpentine. These altered areas are lacking in iron oxides though the residual clots of serpentine are crudely veined with magne- tite (Plate III). Pyrite stringers cut magnetite veinlets and serpentine and may, in part, be related to the period of alteration. Late calcite veinlets are of capricious distribution and commonly bear pyrite and lesser hematite. Diabase, Diabasic Gabbro Exposures of.diabasic gabbro are located about 1000 feet east of the Beresford deposit and an altered, in part mineralized, diabase outcrops to the immediate west of the ore zone. Diabase has also been intersected in drill holes. The sill of greyish brown weathering diabasic gabbro exhibits sharp contacts with adjacent .intercalated greywacke- 23 argillite. The medium-grained, greenish grey rock contains up to 45% subhedral to euhedral plagioclase lathes up to 2 mm. in length. Plagioclase has the composition of labrado rite (An 57)~ the lathes are intensely altered to sericite, calcite and lesser epidote, though albite twinning remains conspicuous. Ferrornagnesian minerals are represented in the main by large, poikilitic grains of hypersthene con stituting 40% of the rockr lathes of plagioclase extending into these grains give rise to an ophitic texture. Minute anhedral to euhedral pyrite, and epidote may occur associ ated with pyroxene. Veins and disseminated grains of chlorite are common~ small magnetite grains are also present. The metamorphosed, locally sheared, intensely altered diabasic rock, to the west of the Beresford deposit, carries localized irregular concentrations of pyrite, pyrrhotite and specks of galena and sphalerite in fractured, silicified portions. Mineralization is restricted to a few square feet though overburden obscures its areal extent. These fractures trend north-northwest. A sub-ophitic to ophitic texture in which bent or fractured lathes and stubby plagioclase crystals, generally 1 mm. in length, extend into pyroxene, characterizes the rock. Scattered plagioclase phenocrysts up to 3 mm. in length occur embedded in a decussate-textured matrix. Albite and Carlsbad twinning, continuous and discontinuous zoning are apparent in plagioclase which makes up 50% of the rock. Cores of plagioclase are both sericitized and kaolinized. 24 Pale green to colorles~ pigeoni'te,, augite and dark green to greenish brown pleochroic hornblende are all to some extent chloritized and epidotized. Chloritized biotite constitutes 5% of the rock while pyroxenes and hornblende constitute 30 and 10% respectively. Accessories include apatite, potash feldspar, iron oxides, pyrite and leucoxene. Acid Intrusive Rocks Nicholas Denys Quartz Monzonite - Granodiorite A massive, medium to coarse-grained, grey to pink bio tite quartz monzonite with granodioritic phases, intrudes Middle Silurian rocks of the Chaleur Bay Group. Tupper and Hart (1961) report a K/Ar ratio giving a Devonian age of 392 ± 12 million years. The stock is poorly exposed in general though a sharp contact is situated about 200 feet north of the Millstream Iron deposit (Maps 1 and 2). Accord ing to Buddington•s criteria (1959), the pluton is assigned to the epizonal level of intrusion. A thermal aureole has developed in Chaleur Bay Group rocks but unfortunately lack of relevant exposures and the effect of movements associ ated with the Rocky Brook-Millstream fault system renders a facies delineation difficult. Hornfelsic rocks are charac teristically developed within the aureole and have been described earlier in the paper. The stock is fractured where crossed by northwest trending faults. Martin (personal communication) is presently studying the petrogeochemistry of the stock in conjunction with a regional study of granitic 25 rocks in northern New Brunswick. Material examined by the writer is characterized by a 9an-hypidiomorphic granular texture and consists of 45% plagioclase (An28 to An12 ), 20% potash feldspar and 20% qua~tz. Albite twinning and zoning of a normal ty?e are conspicuously developed in plagioclase. Alteration of cores of zoned plagioclase crystals consists of predominant seri cite, epidote and carbonate with lesser chlorite. POtash feldspar is largely represented by orthoclase although minor microcline is indicated by diffuse polysynthetic twin ning. Anhedral quartz commonly displays sutured grain boundaries. Mafics are represented by partly chloritized, pleochroic brown biotite and locally, by hornblende~ together these may constitute 10% of the rock. Accessories include apatite, sphene, euhedral magnetite, and pyrite. Feldspar Porphyry, Quartz Feldspar Porphyry and Aplite Numerous, generally northwest trending feldspar porphyry and quartz feldspar porphyry dikes cut the Ordovician and Silurian rocks of the district. They occur in greatest profusion within the thermal aureole of the granitic stock between the Beresford and Sturgeon River deposits. A9litic sills and dikes, commonly only a few inches in thickness, occur within hornfelsic sedimentary rocks in the Millstream Iron area. Davies (1965) mentions that recent drilling suggests the aplite dikes also cut the Nicholas Denys stock. It is presumed that these dikes and sills are chronologically 26 and genetically related to the quartz monzonite-granodiorite period of intrusion. Pinkish grey weathering feldspar porphyry outcrops along the Millstream River and in proximity to the Mill- stream Iron deposit. Euhedral phenocrysts of creamy-orange feldspar, up to 8 mm. in long dimension occur embedded in a microcrystalline matrix. A glomeroporphyritic tendency ex hibited by plagioclase (An to An ) gives rise to clots 30 32 u~ to 2 mm. in diameter~ individual grains display albite twinning and are commonly zoned. Phenocrysts and individual grains within the aggregates are euhedral to subhedral and freauently poikilitic. The rock is characterized by the variable alteration of most constituents. Plagioclase com- prises up to 70% of some porphyries and locally is intensely altered to complex aggregates of sericite, calcite, chlorite, hematite and a diffuse creamy brown alteration product of indeterminate origin, possibly argillic material or finely divided iron oxides. Potash feldspar, constituting up to 20% of some porphyries is less altered and infrequently dis plays diffuse polysynthetic twinning. Anhedral quartz (10%) is confined to the matrix. Original mafic phenocrysts, 2-4 mrn. in diameter are almost totally altered to calcite, minor epidote and euhedral to subhedral pyrite. The existence of brown, pleochroic haloes suggests the original mafic was biotite. A few grains of hornblende are also preserved. A distinctive, mineralized grey feldspar quartz porphyry outcrops to the north of the Millstream River, a'few·hun- 27 dred feet west of the Nicholas Denys-Sormany cross-road. The porphyry is host to capriciously distributed pyrite, pyrrhotite, arsenopyrite pods a few feet in diameter, re lated to late transverse fractures. Creamy plagioclase phenocrysts, up to 2 mm. in dia meter, display albite and Carlsbad twinning, in addition to continuous zoning. Partially resorbed, anhedral quartz ?henocrysts 2 rnrn. in diameter serve to differentiate this porphyry1 embayment and inclusion material is identical with the cryptocrystalline to microcrystalline matrix. Such resorption phenomenon are characteristic of volcanic rocks and hypabyssal intrusions and ~t is of interest that this tendency is also expressed in the Nigadoo quartz feld spar porphyry. Both potash feldspar present in the matrix and plagioclase phenocrysts have undergone minor sericiti zation. Reddish brown to pale beige pleochroic biotite phenocrysts average 1 mm. in diameter. Pyrite and arseno pyrite are commonly euhedral and if fractured are veined by quartz and lesser potash feldspar. Apatite, zircon and calcite are minor constituents. Pink aplitic sills which are confined to hornfelsic rocks within the thermal aureole are comm:>nly finely granu lar but locally may contain a few creamy albite phenocrysts. These subhedral to euhedral grains occur in a fine-grained allotriomorphic granular matrix of quartz, orthoclase, albite, partly chloritized brown biotite· (5%) and accessory minute grains of magnetite and hematite. Biotite may also 28 occur as rare phenocrysts up to 1.5 mm. in diameter. Structural Geology Folds The Silurian Chaleur Bay Group rocks form a broad, northeast plunging synclinorium whose axial trace trends northeast. Minor folds developed on the limbs of this large structure include tight isoclinal folds within the Ordovi cian rocks and folds of a more open type in the Silurian sequence. The synclinorium has a wavelength of 4 miles whereas that of the minor folds is in the order of 400 feet. The Ivlain fault appears to coincide with an anticlinal axis in the lowermost Silurian roCks. Davies (1965) describes the nature of folding in the Nigadoo River - Millstream River area in some detail. Faults Davies (op. cit.) also presents an account of faulting in the district. Faulting is considered by most students of the area as one of the most important factors in locali zing mineral deposits. Faults in the region may be grouped on the basis of their trends~ namely, a longitudinal system trending N 60° E to N 80° E and a transverse group vrhich Davies (op. cit.) has further subdivided into three systems. Longitudinal Faults· The Rocky Brook - Millstream fault system is the most 29 prominent structural feature in the region and appears to consist of a series of en echelon faults associated with tight folding in the lowermost Silurian. The system probably represents a dextral wrench fault {Davies, oo. cit.). The Main fault or "break" as it 1& locally known, is the principal fault in this system with the Rocky Brook fault being a subsidiary, related to movement along the Main fault. The Main fault occurs entirely within the lower Chaleur Bay Group greywacke-argillite sequence, its trace being, in part, coincident with a tight overturned isoclinal anti cline. The fault zone dips steeply·south, displays a width of 200-400 feet and in part, is occupied by serpentinite. The Rocky Brook fault, in part at least, separates the Ordovician and Silurian rocks: a dextral strike-slip move ment similar to the Hain fault is indicated {Davies, op. cit.). The fault trends N80° E, dips steeply south and seems to be equivalent to the Main fault in terms of width and complexity. Transverse Faults Three distinctive transverse systems have been recog nized in the districts a system restricted largely to the area south of the Main fault which trends N 75° E to east west in the competent Silurian greywacke-argillite and is warped to N70° E in proximity to the Ordovician-Silurian contact: a northwest trending system of faults, predominant 30 north-of the Main fault exhibiting apparent dextral move ment; a north-south system is represented by only a few faults in the map-area, the most notable being that occupied by Stevens Brook. Several of the northwest trending faults may be dis tinctly later in that they appear to offset the Main fault. Davies (op. cit.) has considered the possibility of normal faulting accompanying the intrusion of the Nicholas Denys stock and suggests that normal faulting was guided by pre existing northwest trending wrench faults. The northwest trending system is considered of economic significance in that several mineral deposits are related to them, eg. Nigadoo, Keyrnet, Beresford. The concept of re activation of these faults during emplacement of the Nicho las Denys stock would obviously facilitate the problem of relating mineralization to this phase of igneous activity. Additionally, geochemical studies indicate in the majority of instances the presence of significant amounts of As, Zn, Cu, and locally Sb and Pb in late fault or fracture zones. 31 GECI.OGY OF THE BERESFORD AND MILLSTREAM IRON DEPOSITS History of Exploration The Millstream Iron deposits were discovered about 1890 and have been subjected to intermittent examination since that time. The property was known as the Ellis Iron Mines during the period 1900-1913. The deposits are described briefly by Lindeman (1908) and by Young (1911), who presented a more detailed description of the deposit and includes a map outlining the ore zone. A limited amount of mapping and trenching was carried out by Goodwin in 1928. More recently, drilling has been carried out in 1949 and 1952. In 1952, the Noranda Exploration Company, Limited out lined their Beresford chalcopyrite-magnetite skarn deposit in the Lavigne Brook area during a detailed diamond drill program. Considerable drilling has also been performed in 1956, 1957 and 1962. The property has been subjected to magnetometer, electromagnetic and self-potential surveys. Geochemical surveys for readily extractible copper in soils and stream sediments were carried out in the summer of 1962. Geological mapping of the Beresford property has been com pleted by J. Kruse of the Noranda Exploration Company Limited. Reports indicate that approximately 200,000 tons of about 2% Cu have been outlined. 32 Geology of the Deposits The chalcopyrite-magnetite skarn deposits under inves tigation are essentially similar and thus will be discussed jointly. The contact of the Nicholas Denys quartz mon zonite-granodiorite is situated about 200 feet north of the Millstream Iron deposit and approximately ~ mile northwest of the Beresford deposit. This difference in distance from the thermal center is reflected in the grade of contact metamor~hism of the rocks associated with the deposits. In the MillRtream Iron area, biotite and andalusite are con spicuous. Both deposits are stratigraphically controlled in that they occur in a skarn band derived from impure siliceous limestone (Figures 3 and 4) and to a lesser ex tent in hornfelsic,calc~silicate bands derived from original limy, argillaceous beds. Recrystallized limestone is essen tially unmineralized adjacent to magnetite-sulfide bearing skarns. Complications regarding genesis arise from the additional spatial relation of both deposits to the Main fault of the Rocky Brook - Millstream fault system~ whether this relationship is merely fortuitous is a matter of con jecture. Of possible greater significance is the existence, in close proximity to the deposits, of northwest trending transverse faults which presumably, in part at least, post date final movements associated with the Main fault. As has been mentioned, elsewhere in the district these faults assume importance in sulfide localization. 33 Fiaur-e 3 I I l EG END I I I=:::J Fcl dsp<:~ r- por-phyJy ~ Se r-pent i nite / c:::=!J Ilorn Fe I s ms& ~ccr-ysta I I i zed I i mestone c::::E:!J Sknr-n ~ Co ng l ome rate- a r g i I I i te ~Ore "r Br ecci a BERE~ F ORD DE~OS IT SECT I O~ A-A' Sca l e 1"=50 ' 34 Both deoosits are crudely lenticular and conform in a general fashion with the strike and dip of the enclosinq rocks, striking east-northeast, dipping steeply north to vertically while plunging to the east at about 50 degrees. Sulfide and oxide concentrations in the Beresford deposit extend to a depth of at least 450 feet and extend for approx imately 300 feet along strike. These are limits established by drilling and do not necessarily reflect ore-grade materi al. There are distinct chalcopyrite-magnetite lenses in both deposits. The ore minerals commonly exhibit a crude banding, alternating with the host skarn mineral assemblage. Chalco pyrite and magnetite, appear, to some extent, independent of each other thus giving rise to the possibility of different sources of sulfide and oxide components. Mineralogy In order of decreasing abundance, the following pri mary ore minerals have been observed megascopically and/or in polished section: magnetite, chalcopyrite, pyrite, sphalerite, pyrrhotite, arsenopyrite, marcasite and moly bdenite. Both skarn deposits are very similar mineralogi- cally. A recent thin residual g~ssan caps the Beresford deposit with predominant limonite and hematite, minor mala chite and rare chalcocite being the secondary minerals. 3 .) LEGEND ~ !'> i Rbase c:::::::::J S<'rpcntinite c:::==J Hornfe ls c::::::::J 1<' cry~ tn I I i zed I i mcston<' c::=:::J ~karn c::::::::J Conglomcrate - ar~i I I ite ~ Ore .... Grecci a / Fuu lt zone :·· ·::·: .: . ... ':· . ... Finure 4 BEf~ESFORD DEPOSI T SECT ION B- B' Sca l e 1"=50 ' 36 Magnetite and ch~loopyrite most commonly occur in crude lenses paralleling silicate bands in skarn and layer ing in greenish-grey hornfelsic sedimentary rocks. Both minerals are generally medium-grained and invariably occur interstitially in granular qarnet~erous skarns. Dissemina tions and blebs of chalcopyrite may occur in magnetite but characteristically, concentrations of the two are not cor- relative. Irregularity of tenor over limited distances a~pears to be an inherent property of this type of deposit. ·Gangue minerals largely consist of garnet, diopside, epidote, calcite and lesser hornblende, actinolite and infrequently, quartz. Magnetite Hypidiomorphic to allotriomorphic granular aggregates of magnetite occur in massive lenses or interstitially among euhedral calc-silicate skarn minerals. Individual grains of magnetite seldom exceed 1 mm. in diameter. Tex tures suggest magnetite formed later than calc-silicate minerals~ textures indicative of replacement of garnet are only rarely observed. Magnetite grains are locally frac tured~ vein fillings consist of pyrite, pyrrhotite, chalcopyrite, marcasite and.calcite. Magnetite embedded in chalcopyrite is generally ragged or anhedral. Chalcooyrite Chalcopyrite, generally ranging from .1 to 1 rnm. in grain size, is the predominant sulfide and most important 37 ore mineral in both deposits under consideration. Locally, pyrite, pyrrhotite or more rarely, sphalerite, are more abundant. In granular skarns, massive chalcopyrite occurs interstitial to euhedral calc-silicate grains, analogous to magnetite. Growth rings in garnet porphyroblasts locally contain introduced chalcopyrite fillings. Crude, essenti ally massive chalcopyrite bands may occur bearing no obvious relationship to magnetiter fractures in gangue silicates and magnetite are commonly filled with chalcopyrite indica ting that the former crystalline phases were subjected to stress prior to the deposition of chalcopyrite. Sphalerite and chalcopyrite are commonly closely associated, and in general, exhibit mutual boundaries texturesr minute, oriented blebs of sphalerite in chalcopyrite, suggestive of exsolution, are locally observed. Chalcopyrite also occurs as inclusions or fissure fillings in pyrrhotite. A low and spurious content of arsenopyrite is present, embedded in chalcopyrite. Pyrite Cubes of pyrite from .OS to .2 mm. in diameter have been observed in chalcopyrite and rarely, pyrite stringers cut chalcopyrite, indicative of at least two generations of pyrite. Pyrite samples from surface workings exhibit crude colloform banding1 secondary limonite, 'hematite Zl.nd chal cocite are associated with pyrite in this environment. 38 Paragenetic Relations Mineralogic studies suggest the following sequence of formation (Table II). Table :n: Paragenesis of the Beresford· and Millstream Iron deposits. calc-silicates magnetite pyrite chalcopyrite sphalerite ------pyrrhotite calcite hematite, chalcocite, limonite, malachite arsenopyrite, marcasite, molybdenite - douptful paragene tic sequence. The significance of the above series has been questioned by numerous workers: according to orthodox hypothesis, the series is believed to represent a sequence of deposition from a fluid medium. However, the possibility that it represents a crystalloblastic series analogous to that enter- tained by metamorphic petrologists must be considered. In this context, calc-silicates such as garnet would have the strongest form energy, followed by magnetite with chalco- pyrite and associated sulfides exhibiting little tendency to form crystal faces. Whether this process was operative 39 in an essentially solid state is open for debate. Geo chemical considerations indicate the probable presence of a p~rvasive fluid medium, in large part 00 , during skarni 2 fication. It would appear, however, that the conventional crysta~~ob~astic concept is inapp~icab~e to the present system, especially with reference to sulfide formation. Mineralization as Related to the Tectonic Cycle McCartney and Potter (1962) presented a general out line of mineralization as related to the development of the Appalachian folded belt1 this scheme is a modification of proposals made by the Russians (Bilibin, 1955, Sermenov and Serpckhov, 1957), correlating structura~ deformation, igneous activity and sedimentation in geosync~ines with rnetallogenetic concepts. The Beresford and ~llstream Iron deposits occur in Middle Silurian rocks associated with a quartz monzonite- granodiorite of Devonian age (392 ± 12 m.y.). The deposits are anomalous in regard to the above metallogenetic scheme in that the magnetite-chalcopyrite skarns were depicted as being associated with plagiogranite of Ordovician-Si~urian age. More recent work by McCartney (personal communication) indicates that the magnetite-chalcopyrite skarn type minerali zation is included in the middle or Devonian orogenic stage. 40 GEOCHEMISTRY OF COUNTRY AND HOST ROCKS General Statement A com9rehensive geochemical study of skarn d~?Qsits within the thermal aureole of the Nicholas Denys stock has been undertaken. All rock types in the area have been sampled in addition to exhaustive sampling of the deposits themselves and rocks in proximity to them. Major, minor and. trace constituents have been obtained. Whole rock analyses ~ere undertaken in this initial phase of the study since it is believed that an understanding of the gener~l distribution of components is of prime importance in the evaluation of such an hypothesis as lateral secretion. The ~riter constructed 14 diamond drill hole sections together ~ith constituent distributions in the Beresford area and a in the Millstream Iron area in like fashion. In addition, the results of extensive surface sampling were evaluated. This information is included .in Appendices 2, 3 and 4. Chemical Analyses M~jor, minor and selected trace constituents were ob tained on 246 samples from the Beresford - ~llstream Iron area. Oxide concentrations obtained by X-ray fluorescence and rapid methods are given in percentages throughout. Spectrographic results for sr, Ba, Cr, Zr, V, Ni, Co, Mo, 41 Ag and Bi, and colorimetric determinations of Zn, Cu, Pb, As, Sb and Ni are given in ppm. Where pertinent, limits of detection of these constituents are given in Table III. Arbitrary values for concentrations given as less than the limit of detectability (i.e., constituent present in sample but not in measureable quantities) and for constituents not found, are also tabulated; these values were utilized in the statistical treatment and hence appear in various tables derived from computer print-outs (Appendix 1). Discussion of Statistical Treatment Observations have been grouped on the basis of area and rock type so as to establish if differences exist with reference to the genesis of the skarn deposits under inves- tigation. Statistical tests to establish the significance of variations between rock types from different portions within the thermal aureole have not been undertaken. Though observations are, of necessity, concentrated in the Beresford area r.elati ve to the Millstream Iron region, an attempt wi 11 be made at a later date to apply significance tests to estab- lish the influence of temperature on the concentrations of several components. Mean values, both arithmetic ( ~ =~x) and geometric (G. M. = '\ ~------:r x .... xn) have been obtained for each consti tu- yx 2 ent in the various sample groupings. The geometric mean is less sensitive to extreme values and has been used as more •J.•able .III Limits of detection and arbitrary values for concentrations not found or below the limits of detectability. A=bitrary J Arbitrary value value for ' Lirni t of for< lirni t of constituent Constituent Detection detection not found Cu 4 2 1 ~b 5 1 As 2 1 Sb 1 .s .1 Ni 5 1 ~r 10 5 1 Ba 10 5 1 Cr 30 15 1 :.c:r 40 20 1 v 70 35 1 Ni 30 15 1 Co 20 10 1 M:::> 100 0 Ag 5 0 Bi 80 0 w "=' 3000 nf. in all samples <0.5 0.3 <0.1 o.os <.0.02 0.01 < 0.01 0.01 <0.1 o.os Note: cu, Pb, As, Sb and Ni-colorirnetric analyses, ppm. Sr, Ba, Cr, Zr, V, Ni, Co, Mo, Ag, Bi, and W-spectrographic analyses~ ppm. uxides in per cent. 43 representative where appropriate. Standard deviations, (S =1/~(x- x) 2 ), a measure of n-1 dispersion, have been obtained in like manner. The standard deviation is dependent on each analysis and is sensitive to extreme valuesr it has been utilized in this study since it can be more readily applied to statistical calculations contemplated by the writer at a later stage. In general, the range in composition is as useful as the mean, which is equivalent to stating that the standard deviation is of as much interest as the mean. The coefficient of variation, V or C, is the ratio of the standard deviation to the mean Citx 100) and is an ex pression of the tendency of the standard deviation to be small for a small mean, large for a large mean. The co- efficient of variation is an expression, then, of relative dispersion. Geochemistry of Rocks Conglomerate The intercalated conglomerate-argillite unit in the map-area is of considerable interest in any consideration of genesis in view of its appreciable iron content (Tables IV and V). An examination of the distribution of all chemical parameters has been made with particular reference to the ore deposits. In general, the distributions are of 44 Table IV 3tatistical analysis of 12 conglomerates sampled from the Beresford area. Trace const~tuents in ppm., oxides in per cent. Coefficient Constit- Aver- Geometric Standard of varia- uent Range age Mean Deviation tion X 100 L;n 40-210 78 71 44.3 56.5 Cu nf-240 63 19 75.3 120.1 Pb nf- 5 ' 2 1 1.8 90.5 As nf-170 33 11 48.0 145.1 Sb <1-2.6 0.9 0.8 o. 7. 76.1 . N"l. 40-260 191 176 60.7 31.8 Sr 83-300 196 183 69.4 35.4 Ba 26-110 61 55 27.0 44.5 Cr 220-960 375 340 208.3 55.5 Zr 110-320 164 157 57.1 34.8 v 170-360 281 275 56.0 19.9 Co nf- 82 31 8 32.7 105.6 Mo nf- 50 8 - 19.4 233.6 Ag nf - - -- Bi nf - - - - Si0 48.0 47.9. 3.1 6.5 2 43.0-51.5 Al o 14.2 14.0 2.0 14.0 2 3 8.5-15.8 Total Fe 12.4 1.8 14.6 as Fe 10.1-15.1 12.5 2o 3 CaO 2.4-28.6 7.5 5.9 7.1 94.6 Mgo 1.3-12.2 6.4 5.8 2.6 41.2 :(20 4.2 1.5 1.4 93.6 l <.1- - Tio 2.4 2.3 0.5 21.5 2 1.2- 3.3 I"lnO .12-.38 0.21 :0~19 .08 41.0 C02 <.1- 3.4 o.s 0.2 .96 208.0 45 Table V Statistical analysis of 6 conglomerates from the Millstream Iron area. Trace constituents in ppm., oxides in per cent. ~ I Coefficient ' · Consti t- Aver- !Geometric Standard of varia- uent Range age Mean Deviation tion X 100 Zn 40-120 83 77 32.0 38.4 Cu nf-100 38 12 43.4 113.2 Pb nf- 90 55 24 I 41.2 74.7 As nf - - - - Sb <1 - - - - Ni 140-270 202 196 51.2 25.4 sr 180-440 250 238 96.7 38.7 Ba 63-200 100 92 50.6 50.5 Cr 290-560 398 387 106.8 26.8 zr 130-170 158 158 16.0 10.1 v 270-360 308 307 31.9 10.3 Co nf- 64 21 4 30.3 148.0 fu nf - - - - Ag nf - - - - Bi nf - - - - Si0 47.7 47.5 4.8 10.0 2 39.9-51.7 Al o 15.0 15.0 0.6 3.8 2 3 14.3-15.8 Total Fe 11.8-14.6 13.1 13.1 1.0 7.5 as Fe o 2 3 Cao 1.6-4.0 3.0 2.9 0.8 26.0 MgO 5.8-11.5 7.3 7.1 2.2 30.4 0.2 18.6 K2 o o.5- 1.0 0.7 0.7 Ti0 2.5 2.4 0.6 22.6 2 1.5- 3.2 Hno .03-.21 .10 .08 .07 70.4 58.6 C02 <.1- .2 .1 .1 .07 46 ~uestionable significance: a composite profile, for example of total Fe as Fe2o 3 against distance from the Millstream Iron deposit tends to suggest depletion in iron near the deposit. However, inherent sedimentological variations may exp~ain the distribution pattern as wel~. Similar studies in the Beresford area were negative or as was the case in one section, total Fe2o 3 exhibited a continuous decrease away from the deposit. The latter distribution pattern tends to support the view that iron may have been introduced during skarn mineralization: this is not supported by petro graphic observations. A comparison of Tables IV and V for conglomerates shows a significant difference in Cao. Inclu- sion of a sample abnormally high in calcite is responsible for the enhanced content of lime in the Beresford conglomer- ate. Part of the variation apparent in Mg0 is due to local ~~rpentinization. ~llstream conglomerates are relatively, though erra,tically, enriched in Pb. Most other components appear more or less consistent or do not vary in a syste rnatic fashion: Zr for example, largely or wholly present as detrital zircon, is markedly consistent throughout, indica tive of original sedimentation conditions. Recrvstallized Limestone Marbles from both the Millstream Iron and Beresford areas exhibit considerable variation in most constituents (Table VI). Interbedded argillaceous material which is invariably present and minor amounts of admixed skarn, Sample Srec. No. t.rea Rock Zn Cu Pb As Sb Ni Sr Ba Cr Zr v Ni Co ~ I -- . . .. . - ~--·- .. f------7654 1 9 700 96 .1 120 4,4 30 450 1 . 74 82 12') 51 '+5 . 7655 1 9 30 12 10 7 2,2 25 920 67 15 530 1 ----1 ---28 7665 1 9 400 380 10 30 ,5 50 1100 190 43 87 75 40 1 7542 1 9 30 28 5 67 1,9 40 1 '•00 130 60 1 35 1 1 7544 1 9 30 24 10 55 ,5 90 1400 78 44 - 1 1 .1 1 7710 1 9 8000 230 5 240 15.4 130 410 45 15 1 35 130 1 . . 7624 2 9 240 60 10 6 ,5 30 2000 5 15 1 35 . 15 20 I 7626 2 9 240 80 5 1 .5 20 1400 29 15 45 35 1 33 I Sump~t Spec. Spec. Total 'ire~ l1g No. :Reel< L:c Bi Ti l:n SiC,. Al2. 03 ~ ... Fep" CaO KcC Ka.O TiOz. J.~no cot. I . . I ' I ! 7710 9 50 0 0 3000 2900 14.3 5.2 ,9 i 1 6.5 39.2 .3 .53 .45 30e0 I ------1----:------1------· --~------. ------7665 1 9 0 0 0 26,7 6,2 3,5 35.4 ,3 ,9 ,48 elO 21.2 ------I------·------~ 7654 1 9 0 0 0 27,6 8,3 4,4 42,3 2,6 ,05 • 74 t'?.7 12,2 ------1------·------. ·- ··----- f----C...... ----- 7655 1 9 0 0 0 9 .2. 3,0 1.3 50e8 .3 .a e15 .07 32e9 . ------1----· --- 1----··· ------.. ------. ~----~-- 7542 1 9 0 0 0 14,9 4.8 3.0 42.7 1.3 1.5 ,43 ,09 29,0 - - ---· -· -- ---~-- r-:------·-- ... -~ ... - ·--· •7544 1 9 0 0 0 12,5 4,1 1.5 46,7 ,3 1.1 ,25 ,os 31,4 . . ------1-·· -·----1------· ------·- ----1------~---- 7624 2 9 0 0 0 8.9 3.1 3.3 50.0 .5 .6 .21 .18 33.9 .. ------·------·------· ··--· ·--·--·-- ·------·-· ------,------1------·- 1------1------.!.. 7626 2 9 200 0 0 7,8 2.8 2.2 51.9 .5 .3 .13 .14 35.9 '-.) TublcVI~'·l.iOi',nlinot• <:Hl-1 tl·occ c~~~stitucnts in lir.JCstones(Y) ft·om the Gcr·csFor,l anu ~ illstr·c,1m lt•on <1t'cas(l <1n.l ~ Pcspcctivcly).Tr,occ constituents in pprn.,o.xidcs 1n f'<'t' cent. ~~pee. i•,.1icotes Sf'~"'Ct:·oq.•npl,jc. 48 unavoidably included, are responsible for the observed vari- ations in Si0 , Al o , Cao and, in part, total Fe o • 2 2 3 2 3 Epigenetic mineralization has given rise to erratically distributed concentrations of Cu, Zn, As, Sb and Mo. The recrystallized limestones are characterized by an ap9reciable sr content in accord with investigations by various workers (Graf, 1960) on the distribution of sr in sedimentary rocks. Skarn Skarn removed from the Millstream Iron and Beresford ore zones has been analyzed for major, minor and trace con- stituents (Tables VII and VIII). The extreme variability of concentration of most constituents is reflected in the standard deviation and coefficient of variation. Geometric means are more significant than the average in such cases. The extreme heterogeneity of skarn and calc-silicate rocks is evident in the range of concentration of Si02 , Variations in total Fe2o 3 are in part a reflection of introduced magnetite and, to a lesser extent, iron sulfides. The concentration of CaO is markedly lower than that observed in recrystallized limestones and the Writer feels that, locally at least, a marked decrease in lime has occurred. Wide fluctuations in base metal constituents such as Zn, Cu, As, Sb, Ni, Co, Mo, Ag and Bi are undoubtedly related to epigenetic additions. 49 Table VII Statistical analysis of selected constituents in 29 samples of skarn from the Beresford area. Trace constituents in ppm., oxides in per cent.· co e f.c.J.. ~ c ~(;.:X:. ._.... t Consti t- Aver- Geometric Standard of var~a- , uent Range age Mean Deviation tion X 100 Zn 20-1700 271 170 317.0 117.1 Cu 4-8800 1747 424 2327.4 133.2 Pb nf- 35 11 7 8.2 76.7 As nf- 240 47 19 63.7 134.2 Sb <1- 23 3.9 1.7 6.1 157.8 Ni 5- 620 69 36 144.5 - 166.8 Sr nf- 280 87 64 60.4 69.5 Ba nf- 320 67 16 220.3 330.5 Cr nf- 220 100 78 51.4 51.3 Zr nf- 200 102 51.3 50.2 v nf- 230 127 72 60.2 47.4 Co nf- 270 38 6 65.9 173.1 Mo nf-5100 252 - 951.0 377.3 Ag· nf- 26 2 - 6 296.7 Bi nf-1300 82 - 256.8 311.6 SiC 37.9 37.6 4.6 12.1 2 24.0-45.1 Al o 10.3 10.1 2.2 20.9 2 3 6.0-14.4 Total Fe 12.9 11.3 8.2 63.3 as Fe o 4.5-37.6 2 3 cao 10.0-32.9 27.8 26.9 6.0 21.5 MgQ < .5- 6.1 2.1 1.5 1.6 73.1 K o .5 237.7 2 <.1- 2.5 • 2 - Tio .92 .87 .30 33.1 2 .38- 1.5 MnO .34- 1.0 • 62 .60 .17 26.8 1.5 113.3 C02 <.1- 7.2 1.4 .7 50 Table VIII Statistical analysis of selected constituents in 14 sa~ples of skarn from the Millstream Iron area. Trace constituents in ppm., oxides in per cent. Coefficie:-:t .. Constit- Aver- Geometric Standard of varia- uent Range age .He an Deviation tion X 100 Zn 10-6000 526 89 1582.2 300.6 Cu 8-1400 292 135 365.5 125.3 ?b nf- 380 41 12 98.6 243.5 As 2- 70 23 14 21.3 94.6 Sb nf-13.2 2.7 1.4 3.4 125.8 Ni 10- 80 2S 22 21.4 76.7 Sr nf- 430 101 55 111.3 110.6 Ba 5- 77 21 16 18.7 88.7 Cr <30- 160 73 57 46.1 63.6 Zr nf- 240 127 92 54.6 43.1 v 76- 190 117 113 32.9 28.0 Co nf- 83 20 7 24.6 120.4 J'b nf-9900 725 - 2641.1 364.3 Ag nf - - - - Bi nf- 500 36 - 133.6 374.2 Si0 37.5 37.2 4.4 11.9 2 23.6-41.2 Al o 10.3 10.1 2.1 20.5 2 3 7.0-14.7 Total Fe 11.1 10.3 4.6 41.2 as Fe o 3.S-22.6 2 3 CaO 13.2-46.0 30.5 29.4 7.S 25.6 MgO <.5- 6.5 2.1 1.5 l.S 84.5 K .2 194.3 2o <.1- .a .1 - Ti0 .so .75 • 29 36.0 . 2 .35- 1.5 33.3 rmo .23- .sa .55 .52 .18 5.0 181.2 C02 .1-19.0 2.8 .9 51 Greyw~c~e-Arqillite and Hornfelsic Eauivalents Statements of relative depletion and enrichment im?lY an original equivalence to a suitable standard: this equivalence has not been established with certainty and caution is suggested in evaluation of the chemical data. Hornfels from the Millstream Iron and Beresford areas are tentatively related to graywacke-argillite outside the sphere of influence of the Nicholas Denys pluton. To illus- trate the uncertainties involved, the appreciably higher Cao content of certain hornfels {Table IX and X) may suggest that the non-hornfelsic equivalent was originally a more limy sedimentary rock or, on the other hand, one might infer that Cao has been introduced into hornfelsic rocks. Hornfels from the Beresford (Table IX) and Millstream Iron (Table X) areas show slight increases in total Fe2o 3 and CaO with depletions in Si02 relative to greywacke argillite (Table XI). Beresford hornfels are also relatively depleted in MgO with Al o , K 0, Ti0 , MnO and co remaining 2 3 2 2 2 essentially equivalent. Millstream hornfels are depleted in K o, display slight increases in Ti0 and MnO with Al 2o 3 2 2 and MgO consistent. Trace constituents such as Cu, As, and sr are enriched whereas depletions are evidenced by Ba and Zr in rocks from sourious concentrations of Co and Mo the Beresford area. ~ also occur~ the distribution of Cu, As,·Co, and Mo are markedly variable and deemed to be related to the period of mineralization. zr, however, may reflect inherent 52 Table IX Statistical analysis of selected constituents in 36 hornfels from the Beresford area. Trace constituents in p9m. 7 oxi~es in ner cent. Coefi'icient Constit- Aver- Geometric Standard of varia- uent Range age Mean Deviation tion :X. 100 Zn 30- 850 110 86 134.5 122.0 Cu 4-1700 248 99 393.3 158.3 Pb nf- 55 10 5 13.7 134.1 As nf-6300 287 30 1067.5 371.9 Sb nf- 9.3 1.3 0.9 0.8 67.9 Ni 10-2600 145 69 423.1 291.9 sr 70- 810 331 276 200.7 60.7 Ba 5-1300 473 340 302.3 64.0 Cr nf- 340 123 88 75.0 60.9 Zr nf- 600 161 131 96.5 60.0 v nf- 280 164 138 63.2 38.6 Co nf- 200 23 6 37.6 160.8 f'1o nf- 50 2 - 8.3 600.0 ! Ag nf - - - - Bi nf - - - - Si0 54.4 53.8 8.2 15.1 2 42.4-69.7 A1 o 14.3 14.1 2.1 14.9 2 3 7.5-18.0 Total Fe 8.1 7.4 4.8 58.7 as Fe o 4.1-32.6 2 3 cao 1.5-24.5 8.6 6.6 6.6 76.1 HgO 0.3- 9.1 3.5 2.6 2.2 63.1 K 2.1 1.5 57.2 2o 0.2- 8.0 2.7 Ti0 1.4 1.2 0.6 46.1 2 0.1- 2.8 73.7 MnO .03- .71 .20 .16 .15 .2 .8 152.5 C02 ~.1- 2.8 .5 53 Table X Statistical analysis of selected constituents in 8 hor~fels from the Millstream area. Trace constituents in ppm., oxides in per cent. Coc;,fficie"-tt Constit- I Aver- Geometric Standard of variz:.- uent Range age Mean Deviation tion ./. 100 Zn 30- 90 55 49 28.3 51.4 l · Cu 20-450 98 56 145.1 148.8 Pb nf- 60 11 4 20.1 181.0 .Z\s <2- 44 14 4 18.4 129.3 Sb <.5-1.3 .6 .5 .3 60.7 Ni 30-230 89 71 69.2 77.4 Sr 170-590 321 283 176.0 54.8 Ba 37-300 166 135 98.3 59.4 Cr nf-640 234 111 204.5 87.4 Zr 20-230 144 123 58.0 40.4 v <70-280 189 165 78.1 41.3 Co nf- 76 23 5 32.8 140.9 r-'f..o nf - - - - Ag nf - - - - Bi nf - - - - ' Si0 48.9 48.8 3.4 7.0 . 2 42.7-55.1 A1 o 14.9 14.9 1.6 10.5 2 3 12.0-17.4 Total lte 10.0 9.8 2.1 20.9 as Fe o 7.3-12.9 2 3 Cao 3.6-27.0 13.5 10.3. 9.2 68.2 .MgO 1.0- 7.2 4.9 4.2 2.1 43.9 , K o 0.1- 2.5 1.2 0.8 0.9 74.8 I 2 Tio 2.6 1.7 1.6 I 0.7 39.0 2 1.0- MnO .15- .46 • 27 .25 .12 45.0 65.3 C02 <.1- .2 .1 .1 .05 Table XI Statistical analysis of major, minor and trace constituents in 8 non-hornfelsic greywacke-argillites from the Nicholas Denys area. Trace constituents in ppm., oxides in per cent. Coeffici.::r.t Consti t- Aver- Geometric Standard of Varia- uent .xange age Mean Devi.e;.. tion ti.on ....:. 100 'l ..::;;n 60-100 80 79 13 16.37 cu 16-140 49 40 39 79.24 Pb nf- 50 15 10 15 100.61 As nf- 76 20 11 25 122.99 Sb nf- 14 2.2 0.7 4.8 212.94 Ni 50- 90 65 63 16 25.35 Sr 55-530 208 172 146 69.91 Ba 160-850 500 458 197 39.45 Cr 56-340 172 148 96 55.93 Zr 130-320 201 193 64 31.92 v < 70-220 125 104 67 53.99 Co nf- 10 2 1 3 149.74 }1o nf - - - - .'A.g nf - - - - Bi nf - - - - Si0 58.9 58.7 4.8 8.20 2 51.9-66.1 Al o 14.7 14.6 1.0 6.61 2 3 13.6-16.9 Total Fe 6.3 6.2 0.7 10.80 as Fe o 5.3- 7.4 2 3 Cao 1.0- 5.4 3.1 2.8 1.3 41.18 MgO 3.2- 5.8 4.2 4.2 0.8 18.84 ' K o 2.3 0.4 16.42 2 1.7- 2.8 2.3 Tio 1.0 1.0 0.4 34.58 2 .74- 1.8 32.49 MnO .06- .17 0.12 0.11 0.04 1.9 145.56 C02 <.1- 5.5 1.3 0.4 sedimentological variations. .P.ornf2ls from t~e Nillstrcn:n Iron area are enriched in Cu, Cr, Co and sr, depleted in As • I Ba and Zr with other trace constituents remaining more or less equivalent. Calcareous argi~~ites, ~ocated to the east of the Beres- ford area, are appreciably higher in Si0 and lower in 2 Al o and total Fe o (Table XII) than hornfels from both 2 3 2 3 the Beresford and Millstream Iron areas. Lime, however, is equivalent to hornfels from the Beresford area though appre- ciably lower than I1illstream hornfels. It is quite possible that a ?Qrtion, at least, of hornfelsic rocks within the aureole, are equivalent to units termed calcareous argillites to the east. The writer expects to pursue at a later date the corre- lation of mineralogical variations with chemical data on hand:- variations in iron content of hornfels are locally the result, for example, of the introduction of magnetite. Brownish, hornfelsic variants are characterized further by abundant biotite which accounts for considerable iron. I"'·le t a 1 s sueh as z· n, Cu , Pb , As , Mo, Ag and Bi occur in low concentrations in non-hornfelsic argillaceous rocks analyzed~ there is no evidence to suggest that these rocks supplied the base metals of interest. Bleached Hornfels A corn9 arison of the chemical composition of normal and bleached hornfels (Tables IX and XIII) indicates bleaching Table XII Statistical analysis of major, minor and trace ele~cnt con stituEnts in 4 calcareous arg::..lli tes, ··Nicholas l:enys area. Trace constituents in ppm., oxides in per cent. Coefficienti Constit- Aver- Geometric Standard of Varia- uent Range age Mean Deviation tion X 100 ' Zn 40-120 78 71 35 45.16 Cu 4-180 52 17 85 164.38 Pb 5- 35 16 12 14 88.38 As 10- 85 30 19 37 122.29 Sb nf-1.8 0.9 0.6 o.a 82.98 Ni 25- 90 61 55 30 48.24 .Sr 120-220 183 177 48 26.23 Ba 190-460 330 31.3 119 36.11 Cr 66-200 122 110 61 50.53 :.C.::r 1.00-390 185 156 139 74.96 v 79-240 137 125 72 52.41 Co nf - - - - 1'-b nf - - - - ~~g nf - -··· - - Bi nf - - - - Si0 58.7 3.9 6.58 2 55.1-62.6 58.8 Al o 13.1 13.0 1.4 10.88 2 3 ll.l-14.4 Total Fe 7.1 6.6 3.2 45.1.5 as Fe o 4.1-11.3 2 3 Cao 3.3- 8.4 5.4 5.1 2.2 40.45 1'1g0 .5- 7.9 3.1 2.0 3.3 106.95 K 1.8 0.6 31.51 2o 1..4- 2.7 1.9 Tio 1.2 1.1 0.5 43.32 2 • 66- 1..8 27.38 !'1nO .08- .16 0.14 0.13 0.04 99.78 C02 .l- 6.7 2.9 1.3 2.9 Table XIII Statistical analysis of selected constituents in 5 samples of bleached hornfels from the Beresford area. Trace con stituents in ppm., oxides in per cent. Coefficien'..:.' Consti t- Aver--~Geometric Standard of Varia- I uent Range age Mean Deviation tion X 100 I Zn 30-1000 252 98 491.6 166.5 Cu 28-1400 410 146 583.9 142.4 Pb nf- 600 121 4 267.9 221.8 As 16-4000 828 78 1773.4 214.2 Sb <1- 7.0 2.0 1.0 2.8 143.1 Ni 40- 110 67 62 29.1 43.4 Sr 180- 640 462 42.5 173.0 37.4 Ba 130- 630 356 29S 232.7 65.4 Cr 61- 180 115 108 43.6 37.8 Zr 81- 150 118 116 27.4 23.2 v 130- 210 172 169 36.3 21.1 Co nf- 110 31 8 46.1 146.8 Mo nf- so 20 - 27.4 136.9 Ag nf - - - - Bi nf - - - - Si0 52.3 52.1 6.0 11.5 2 46.5-61.2 Al o 15.3 1S.2 1.2 7.6 2 3 13.7-16.6 Total Fe 5.6 S.5 0.9 16.7 as Fe o 4.2- 6.4 2 3 Cao 5.4-21.9 15.7 14.1 6.8 43.2 40.4 MgO 1.0- 4.2 3.1 2.8 1.2 K 1.8 1.1 1.8 100.4 2o 0.4- 4.6 Tio 1.0 1.0 0.23 21.7 2 .71- 1.3 52.47 ·-MnO .12- .so 0.31 0.27 0.16 0.2 89.1 C02 <.1- .4 0.2 0.1 1... 58 is associated with a loss in total iron expressed as ~c ~G L. .j and a gai:.! in CaO. The remaining major and minor const::.tu- e~ts do not a~oear to vary systematically. Conclusions ar2 of necessity tentative in view of the high degree of dis- persian as evidenced by standard d~viations and coefficients of variation. Mineralogical expressions of these chemical variatio~s are found in the elimination of biotite and iron oxides and in the formation of diopside. Diffuse material, presumably carbonaceous in nature, is also eliminated. Removal of biotite reflects dehydration~ eliminatj_on of iron oxides is a function of variations in the partial ?ressures of oxygen and sulfur w~ich control the concorr~i- tant formation of pyrrhotite in bleached portions. ;(emoval of carbonaceous material involves expulsion of during co 2 oxidation. Trace element constituents are characterized by their extreme variability~ geometric means are thus more aopro- priate in considerations of average concentrations. Among metals, ~n and Cu are present in rrDderate amounts with ex- treme values the result of epigenetic mineralization. Aopreciable concentrations of As, Sr and Ba also occur. Seroentinite In vievl of the ap?reciable iron content (Tables XV and XVI) of serpentinite and its spati~l relationship to the skarn deposits, attention was focuse'-, on establishing 59 whether significant variations exist in the intrusive both laterally and in cepth. Though variations do occur in the concentrations of most constituents, systematic gradients were not disclosed in the present study. Serpentinite con- tains substantial amounts of Ni, Cr, and Co, and is undoubt- edly derived from the alteration of ul tramatic rocks \ i''aust, 1963). It has been possible to differentiate intensely altered, serpentinized conglomerate from serpentinite proper in the Millstream Iron area on the basis of selected cheMic?l co~- stituents. Within the M~in fault zone, these rocks are very similar in ?.ppearance though widely divergent in their con- centrations of Ni and Cr, especially, and most other consti- tuents as well. IL1 the St~vens Brook area, it has been possible to establish the effects of late north-south transverse fault- ing on the composition of serpentinite (Table XIV). Table XIV. M;;~jor, minor and trace constituents in serpentinite brecci'3 fro~ the Steve~s Brook area. Trace constituents in ppm., oxides in oer cent. Sample I } Area Rock Zn Cu!PbiAs Sb Ni sr Ba Cr Zr v No. 7672 Stevens Serpen- ! Brook tinite ~;o nflnf 12 nf 1400 76 20 1500 nf nf BrPccia : Total Spec. Fe as Ni Co Mo Ag Bi SiO.., Al~0 Fe o CaO I"l;JO K 0 TiO l'·bO .... , L. 3 2 3 2 2 1400 78 nf nf nf 29.1 2.9 5.8 13.5 22.8 .1 .01 .19 60 Table XV Statistical Analysis of Selected Constituents in 21 Serpen tinites, Beresford Area. Trace constituents in ppm., oxides in per cent. Coefficient Consti t- Aver- Geometric Standard of Varia- uent Range age Mean Deviation tion X 100 Zn 50-220 80 74 38.9 48.6 Cu nf-320 36 10 69.9 196.1 Pb nf- 10 3 2 3.3 131.9 As 5-330 56 37 68.6 122.3 Sb nf-5.6 1.3 0.9 1.2 97.5 N.i 90-2700 2247 .2008 537.4 23.9 Sr nf- 64 33 :.20 18.5 56.0 Ba nf-110 23 16 22.1 96.9 Cr 200-2800 2024 1853 587.3 29.0 Zr nf - - - - v nf-730 53 5 157.5 299.6 Co 10-340 119 104 59.2 49.9 Mo nf- 50 - - - - Ag nf - - - - Bi nf - - - - Sio 40.9 1.9 4.6 2 36.9-43.7 41.0 Al o 1.7 0.3 16.0 2 3 1.0- 2.5 1.8 Total Fe 7.0 1.3 17.8 as Fe o 4.9-10.1 7.1 2 3 Cao <. • 5- 6.2 1.7 1.2 1.6 93.3 I1gO 29.9-41.8 36.7 36.6 2.9 7.9 .• 02 458.3 1<20 ~ .1- .1 .OS - Tio .10 .17 .06 58.3 2 < .02- .15 26.9 Hno .07- .22 .13 .12 .03 .6 125.9 C02 < .1- 2.7 .s .3 Gl Table XVI Statistical analysis of se:'..ect2d constituents in 3 ser-ocn tinites from the Millstream Iron area. Trace constituents in ppm. 1 oxides in per cent. \C-:>efficicnt Constit Aver Geomc;:tric Standard · .::.>f varic..- uent ~ange age !1ean Deviation tion X 100 Zn 70-190 123 114 38.9 ·~8. 6 Cu nf-200 83 21 104.0 125.3 Pb nf- 5 4 3 2.3 63.0 As 2 2 2 oo.o oo.o Sb • 5 • 5 .5 oo.o oo.o Ni 2100-2400 2267 2263 152.8 6.7 Sr 36-55 44 43 9.8 22.4 Ba 14-25 20 19 5.6 27.8 Cr 1500-1900 1667 1658 208.2 12.5 Zr nf - v nf-35 12 19.6 159.2 Co 91-150 120 118 29.5 24.5 .Mo nf Ag nf Bi nf i 5102 39.3-43.5 40.9 40.9 2.3 5.5 I Al203 1.3- 2.2 1.6 1.6 o.s 30.2 : Total Fe ) 9.4 9.2 2.1 22.1 as Fe o 7.0-10.7 2 3 CaO 1.6-12.6 5.3 3.2 6.3 119.3 r1g0 23.8-32.2 29.3 29.0 4.8 16.3 <'.1- .2 .1 0.1 173.2 <.02 MnO .16- .20 .18 .18 .02 11.4 .3-1.3 .a .7 .s 62.5 It 1s ?.ODarent that a considerable, relative loss in SiO?.' t1g0 and Ni has occurred with lesser decreases in tot2l Additions of CaO, Al o , Sr and co h~ve 2 3 2 occurred with the remaining constituents unchanged or not disolaying significant variations. Diabase, Diabasic Gabbro Diabasic rocks of Middle Ordovician age located to the south of the Main fault have been analyzed but do not aooear to bear any significant relationship to the metal content of the skarn deposits. Devonian mafic intrusions in the Beresford area, how- ever, cont~in aporeciable Cu and Zn (Table XVII)~ the significance of these concentrations is obscure. In genern.l, the very limited areal extent of these diabasic rocks tends to negate a generic relationship. Nicholas DF>nys Quartz 1'-bnzonite-Granodiorite Major, minor and trace constituents of the Nichola~ Denys pluton ar~ presented in Table XVIII. The range in Cu values is of interest; this dispersion is reflected in the standard deviation and coefficient of variation. The s.:=tmple of granitic rock containing 280 ppm. Cu is located along the Nicholas Denys - Sormany crossroad in close proximity to the Millstream Iron deposit. This abnormally high concentration may be si~nificant in terms of providing a source for copper in the skarn deposits. The remaining constituents do not appear to be anomalous. sw:~ple Spec, ~·. ro. iJ'8i.< Jcck L:n Cu rb ~.s ~;b J.•;l Sr Bu Cr Zr v Ni Co I 7583 1 18 70 68 1 44 1.8 75 400 190 94 73 220 81 45 .. ~ . . . ·- . -·-··,-~. ~ ~ ~--- 1------···· .• -. ... ' --· •• c '" •• -~-----~ -~ ... ~--~--~ '"•' .. '• ~. u• " • - ---~ -~- ~ -- . ---- . ..,._. ·-- .. ------···· -----~~-- - . - -·· 7645 1 18 110 48 10 7 1.3 80 530 150 1 RO 5l• 230 79 1 -----·-·-· -- -- -·------·-······ ------f------7646 1 18 40 20 10 3 1.3 30 1000 75 120 67 220 54 44 ------.. ------·------f------1------f----.------ 7688 1 18 60 56 ,.___ 1.. ____ 16 .s 45 300 1200 1 220 35 1 1 ~- __ ...... ,...... ~- ---~ ...... ·---~ M•------· -- ---~k------··•<>• --~------~-- - -·------~ ------r>··---~- --~------.------~--~--~- -~---...-----~ ---- 7557 1 18 850 136 20 23 .5 80 61 290 76 79 190 69 50 -~------· ... ------···------···------f------7713 1 18 120 180 1 16 2,3 110 370 320 100 110 230 90 59 b<:.;i~:plc I S:rec. Spec. 'Iotal ;.;n l\c. .. ..re<; hoc:~ ko 1>£ Bi 'l'i SiOz. Al2. 03 ~.rrezo3 CaO L:,CC K-z.O Ti02 ~no coz ----- 7557 1 18 0 0 0 44.3 16.0 10.6 7.5 6.0 .9 2.1 .38 .4 .. _, ____ ~ ---··· ------. -- -- - ... ------· ------~------· ------·-··· - ·------· ------·--- ... -- -~------·------7713 1 18 0 0 0 12 f)00 1400 46.3 14,9 9.3 7.0 8.5 2.1 1.8 .25 .z ------··------. ---. 7688 1 18 0 0 0 560\J 520 62.7 15.6 5.9 2.2 3.3 4.4 .98 .oa .os ------. ------. ------.. ------7645 1 18 0 0 0 45,7 15.5 9.5 9,8 9,2 3,2 1,6 ,16 .1 -· ...... ·•n •' - -~ -~-. ------·- . ---- ···------· ------·------·-· --- .... - ... ----- . ---- - ... . ---- -~------~~ 7646 1 18 0 0 I) 49.5 13.3 6.2 16.9 6.6 .a .87 .22 .1 - -- -··· -·------7583 1 18 0 0 0 45.2 15.7 9.8 A.5 6.2 2.6 1.8 .20 • 05 L1hlc XVII. ·:~.i,w,rninot• .:1n,l tr·,,ce constitue!Yts in Dcvoniun mufic i~Jnco~rs i'ocks( l.q) f1•om ~ :-J i: h c G~ I' c:; f o r• d ., I' c <~ ( I ) • T !' o c c con~ t i t ur' n t s i n r! Hn •. ox i .lc s i n per c c n t . ~-:-f"CC .= sp,·ctt·o~l'<'lf"h i c. 64 Table XVIII Statistical analysis of selected constituents in 5 samples of the Nicholas :C·enys stock. Trace constituents in p;?m., oxides in per cent. I Coeff :Lci .= n t j Constit- Aver- Georr..~tric Standard of Varia- uent Range age Mean Deviation tion X 100 Zn 20-50 32 30 13.0 <10.7 I Cu nf-280 65 9 121.2 185.9 ' Pb nf-35 10 3 14.7 153.4 As nf-9 4 3 3.6 93.8 Sb nf-<1 - - - - Ni nf-5 3 2 2.2 84.3 Sr 300-400 360 358 43.0 11.9 Ba 350-850 580 556 185.2 31.9 Cr nf - - - - Zr nf-120 48 21 49.5 104.0 v nf-<70 - - - - Co nf - - - - .M:::l nf - - - - Ag nf - -- - Bi nf - - - - Si0 2 68.0-71.3 69.9 69.9 1.3 1.9 Al o 15.7 2 3 15.0-16.3 15.7 0.5 3.3 Total Fe as Fe 1.5- 2.9 2.5 2.4 0.6 23.3 2o 3 CaO 1.8- 2.9 2.4 2.3 0.5 20.5 MgO .(.5- 2.5 1.1 0.9 0.9 77.4 K2o 2.0- 2.7 2.3 2.3 0.3 13.7 Ti0 1.2 0.72 1.6 135.6 2 .34- 4.1 MnO .04- .12 0.07 0.06 .03 45.2 C02 <.1 - - - - 65 1'12rtin (J.963, oersonal cornmunication) is present.ly se?arating various minerals and will be analyzing these fractions for selected trace constituents. His results are not available at present. Acjd Porphyritic Roc~s Late, generally, northwesterly trending feldsoar and auartz feldspar porphyry dikes, associated with the NichoJas Denys stock have been analyzed (Table XIX). Comparison with the grani t_j_c pluton (Table XVIII) indicates an essential equi vale>nce in Al , K HnO, Zn and Sr. Porphyritic 2o 3 2o, rocks oontain relatively more Cu, As, Zr and MgO. Slight enrichments are a?parent in 00 2 , Ni and CaO~ the latter is present in appreciable quantity in a feldspar porphyry dike in the Millstream Iron area. Pb is erratic in behavior as is total Fe with the latter showing a tendency to be 2o 3 enriched in porphyritic rocks, especially in the aplitic sill in proximity to the Millstream Iron deposit. The latter is also anomalous in that it is markedly higher in Sio2 than the granitic stock, in contrast to the remaining porphyritic rocks sRmpled which are distinctly lower in Si02 • This variance m3y reflect differentiation trends in that those porphyritic rocks distinctly low in Si0 2 may have formed from initial differentiates whereas the aplite re9resents the injection of a much later, more acidic differentiate. c,.. f:.c:x;r 1e 1-;o .I .2:e:.:.l Reel. I Zn Cu Fb .!...s .Sb r'i '-'· Ba Cr I Zr I 'V I.Sy.e:c. Cc I --+--+ --+- -+- I I +-- Ni __ _2?_3_8_ . , __ -~-' _!: 1___ j___~_?_- L__ ?_~___ j_ __ _?_O_ _J __ _!_L• 5 1 1 51 o 1 s6 ~-lJ-c~~~~---~-l---_!- L_ _!_ __ ___ l~~-l---~L~~--J-}_~U-J __ l __ J____ 4_J_~~-.J __ !_q__j_48~J 6ao 1 11 l9ol 1 1 1 1 1 --~6_8_l ___ L_ ___ ?L2J_ L. ___zg______20 . _. J __ L_19J ___ ~~J-~?--l-22Qjl_40_j_l3_Q!___~_?J~ 7o_J __! !Q.J .. ~?. _ __l613l __ L, ____2L2l __j ___1Q_J ___~--L-l_J_L2_L~2-L?. _ 1a 1 29o j 11 20 !--Ll-_LL__ L ___ 76 ?.t_J ______~L?~--~--- zv 1 6a_ _J __s_J_l_zo 11.1 114o~o 14oo-1--ll-~-1o 0-~-J __1j_!_ __ _ 4017 3\ 21 I 180 - 24_j___2_~-'~--.L--1_0__ L_-.!: ... L--~_9_j_2~-+_0 I 430.J _ _!_l_23~l!~ 1 1 4844 31 21 50 8 5 1 I 1. 8 1 o I 390 I 370 11 250 1 1 1 S~L;lel I S;.ec ·1Spec. 'Ioto.l r:c.. r.!'e~li.\ockl ~c .H.( Bi I 'Ii kn I Si02 Al2 0~ I Fe 2 ~ I C&(; r~c 11~1.0 TiC:t. roo C02. 768911121 0 "v --~-1~~~~-L~-o~L~~~~-~-~-·6J_~·.?.L.~~~-1---~~~L~·sJ_. 791+------+---- .os 1. .3 753811121 0 0 0 62.5117.3 • 9 I '+ • 4 I 1 • 51 4 • 4 .731 .03 .9 - --- I - •· ..... ------·------t------t------1-·· ---· ---1------1------1------~------1------··-' ------1----1------21 .z :+~~118JI :::-*::~+~-::! ~;t-"j~~: 1-!~:lr.:: • 05 -::::1-:t;:-- -···- -- --··------•·---- __ .. _ ----.- t- ____ , ____ - -- +:+-H -~------+------·--·-- --~--1------4J1713121 0 c o I 35.:;;.; I 21:;166.8117.11 3.11 1.4 I 3.212.0 .481 .o3 .os ____ 4?_44_1 3J2_~_ -'-~----'-~l~-L~_3_o?J_~~~l6 3 ~!j_ls. 1_~ .!-~~J~~.?-l-~ ~.Zl~-~ -1--~~~J_-_:~_J_·!_ 767313121 0 0 c 65ell16e1l 3e5l 2e4l ~.011.8 .561 .Q6 I 1·0 -,. tr•<1ce const:ituent-.s fcl,lsk1 General Statement The magnetite-chalcopyrite skarn deposits represent abnormal concentrations of Fe, Cu, Zn and lesser concentra tions of As, Co, Bi, Mo, Ag, Au (Tables XX and XXI). Deple tions are evident in Sr, Ba, CaO, and presumably H ao 2 2o. Substantial dispersion indicates geometric means are more realistic estimates of the average concentrations. Molybdenum was only found in measureable quantities in 10 percent of the samples from the Beresford deposit and 15 percent of samples from the ~llstrearn Iron deposit. Ag and Bi were found in about 50 percent of the samples analyzed for in the Beresford ores~ 20 and 30 percent of those sam ples from the Millstream Iron deposit contained measureable concentrations of Ag and Bi respectively. Major and minor oxide components behave similarly to the skarns discussed previously. Sulfur Isotopes In a comprehensive study of the Bathurst - Newcastle sulfide deposits, Tupper (1959) presents sulfur isotope ratios of chalco9 yrite and pyrite from the Beresford deposit among others. Pertinent ratios from several deposits in the Nigadoo River - Millstream River area are included in the 68 Table XX Statistical analysis of selected constituents in samples from Beresford skarn deposit. Trace constituents in ppm., oxides in per cent. Coeffi- No. of Geo- Standard cient of Constit- Obser- Aver- metric Devia- Varia- uent vations Range age Mean tion tion Zn 30 180-10,000+ 1946 921 2925.9 150.3 Cu 30 8-10,000+ 6119 - 2898.5 47.4 Pb 30 nf-160 40 19 45.3 113.9 As 30 5-3000 172 39 544.8 316.8 Sb 30 <: 1-105 9.7 3.8 19.1 197.1 Ni 30 10-250 85 68 51.5 60.6 sr 29 nf-330 64 30 77.4 120.1 Ba 29 nf-1200 67 16 220.3 330.5 Cr 29 nf-230 56 40 40.7 72.8 ~r 29 nf-210 66 16 60.6 91.8 v 29 nf-190 . 79 so 47.0 59.4 Co 29 nf-470 141 58 134.9 95.6 M:> 29 nf-480 21 - 91.5 435.0 Ag 29 nf- 71 13 - 16.8 129.1 Bi 29 nf-4900 481 - 1039.7 216.0 Si0 28.5 27.5 7.5 26.5 2 29 16.5-40.2 Al o 7.2 6.8 2.3 32.3 2 3 29 3.0-11.9 Total Fe 26.3 23.1 13.8 52.6 as Fe o 29 8.4-55.6 2 3 cao 29 7.9-32.2 22.2 20.8 7.3 32.9 MgO 29 < .5- s.s 2.1 1.6 1.4 64.3 K 0.6 228.0 2o 29 <.1- 3.2 0.3 Ti0 6.9 .87 .65 1.2 138.2 2 29 .23- MnO 29 .25- .so .46 .44 .14 30.1 Co 2.3 4.0 175.7 2 29 < .1-15.8 o.s 69 Table XXI Statistical analysis of selected constituents in 13 samples from the Millstream Iron deposit. Trace constituents in ppm., oxides in per cent. Coefficient Constit- Aver- Geometric Standard of Varia- uent Range age Mean Deviation tion X 100 Zn 120-6000 1002 550 1559.2 155.7 Cu 340-8000 4942 3666 2846.1 57.6 Pb nf- 55 19 14 13.9 71.8 As nf- 190 43 14 58.6 137.3 Sb ~ 1- 9.3 2.7 2.0 2.5 89.7 Ni 30- 230 98 78 68.0 69.4 Sr 25- 80 45 43 16.1 35.7 Ba <10- 55 22 18 12 •.4 57.6 Cr <30- 270 81 60 70.1 86.7 Zr nf- 170 110 79 46.0 41.7 v ""70- 150 89 78 41.2 46.1 Co nf- 230 75 41 57.3 76.0 Mo nf- 130 20 - 48.8 244.1 Ag nf- 16 3 - s.s 179.7 Bi nf-1500 212 - 429.7 202.4 Si0 2 7.7-40.0 29.7 27.6 9.4 31.6 Al o 2 3 1.9-12.7 6.9 6.2 2.9 42.7 Total Fe as Fe o 9.4-70 31.5 26.8 18.2 57.9 2 3 Cao 3.1-31.4 23.0 20.1 8.9 38.6 MgO· <. 5- s.o 2.7 2.3 1.4 49.7 K o 2 <: .1- 0.6 0.1 - 0.18 126.9 Tio 2 .14- .96 .56 .so .22 40.0 Mno .25- 1.0 .59 .54 .22 38.1 C02 < .1- 5.2 0.6 0.3 1.4 214.5 70 following table (Table XXII) which is taken from Tupper (oo. cit, 1:). 1698): Table XXII Sulfur isotope ratios of ore deposits in the Niqadoo River - Millstream River area. 3 No. of s 34 Standard Range of DEposit f5 3 Samples mean Deviation s fs34 values Beresford 10 22.18 0.026 22.13 - 22.21 Sturgeon River ll 22.18 0.023 22.15 - 22.21 Nigadoo A 11 22.19 0.031 22.14 - 22.22 B 4 21.92 0.043 21.90 - 22.00 Keymet 13 22.22 0.025 22.15 - 22.29 Pyrite from the Nicholas Denys quartz monzonite-grano 3 diorite has a mean s fs34 ratio of 22.13. ·The Sturgeon River, Nigadoo and Keymet deposits are considered to be epi- genetic fissure deposits~ they are quite dissimilar to the Beresford deposit in terms of geological setting. The sim- s3f 34 ilarity, however, of S ratios is quite striking and probably is indicative of a similar source of sulfur, (ex cluding the Nigadoo B group of analyses). I~mogeneity of sulfur isotope ratios within individual deposits is indicative of an original homogeneous source. Tupper (op. cit.) believed the homogeneous source to be mag- matic hydrothermal solutions associated with the orogenic phase which emplaced the Nicholas Denys stock. 71 ORE GENESIS Ccneral Statement Salient fentnres which must be accounted for in generic considerations are: 1) The magnetite-sulfide deposits are localized within the thermal aureole of the Nicholas Denys quartz monzoni~e granodiorite stock. 2) 'I'he deposits are not confined to a single rock type but are associRted with a granular, garnetiferous skarn and with a porcellaneous calc-silicate to hornfelsic rock~ gross stratigraphic control is evident, however. 3) 'I'he deposits are spatially related to the Main fault of the Rocky Brook Millstream fault system. This fault is localized along a tight anticline whose core is occu?ied by serpentinite. 4) Late, northwest trending faults are conspicuously developed in proximity to the deposits and are considered of imoortance in ore localization elsewhere in the district. Marked, localized pressure gradients would thus exist and would serve, in the conventional sense, as channelways for mobile phases. 5) Initial formation of calc-silicate minerals was followed by the deposition of magnetite and subsequently, sulfides. 6) Concentrations of oxides and sulfides are generally 72 non-correlative. 7) Sulfide distribution is invariably discordant. 8) Sulfur isotope ratios favour a homogeneous source for the sulfide phase. Source of Iron Appreciable concentrations of iron oxides are present in the intercalated conglomerate-argillite and in serpen tinite. Only in proximity to the Millstream Iron deposit is there any geochemical evidence, albeit tenuous, to suggest that conglomerate is depleted in iron oxides. Results of chemical studies on conglomerate in the Beresford area are inconclusive~ there is some petrographic evidence, however, such as localized bleaching, to suggest either reconstitu tion or removal of iron from the unit. Systematic chemical variations are not evident in ser pentinite even though petrographic evidence locally suggests that alteration of serpentine to talc involves the expulsion of existing magnetite. Bleaching of hornfelsic sediments in juxtaposition to the deposits provide a possible substantial source of iron. Though bleaching is widespread and in part related to frac ture patterns associated with late northwest transverse faults and presumably with the emplacement of the Nicholas Denys stock, unequivocal evidence is lacking to support the contention that it has been the principal or even a 73 source of iron. The quartz monzonite-granodiorite contains a n~gligi ble amount of iron and there is no evidence to suggest that the intrusive represents the possible source 1 perhaps only by assimilating or mobilizing iron contained in the conglome rate band extending on either side of the pluton (Map 1) would the necessary amount of iron be accounted for. Source of Base Metals and Sulfur On the basis of geochemical studies to date, the writer is forced to conclude that there is no obvious relationship between the metal content of a particular rock type and the ore deposits. There is no evidence to substantiate a lateral secretion hypothesis. Sulfur isotope ratios, however, suggest a relationship between sulfur in granitic rocks and in the ore deposits. The isotopic composition of sulfur is similar in all deposits in the Nigadoo River - Millstream River area and the con clusion is reached that the Nicholas Denys stock represents the single, homogeneous source of sulfur involved. Lacking evidence to the contrary and in view of the very local ap9reciable quantity of Cu in the intrusive, the writer contends that base metals represent epigenetic hypo gene mineralization related to the emplacement of the quartz monzonite-granodiorite. 74 Effects of Intrusion The intrusion of the post-tectonic quartz monzonite granodiorite established a marked thermal gradient. Heat liberated from the pluton decomposed the carbonate and argillaceous rocks within the thermal aureole, resulting in the formation of skarn', calc-silicate rocks and hornfels. Water was sweated out of the rocks in the process. Stress associated with the epizonal granitic stock reactivated faults associated with the Rocky Brook - Mill- stream system. Late transverse faults are associated with the skarn deposits and with other deposits in the district~ the obvious tendency would be to invoke these zones as channelways for mobile phases and indeed, several fault zones in the immediate area are mineralized. Such processes as bleaching are controlled, in large part, by the thermal gradient and inherent chemical varia- tions within the rock. Accretion of iron in receptive limy horizons is con trolled, in part, by the thermal gradient~ the mode of migration is a matter of conjecture. Sulfide transport and deposition were also influenced by this gradient, together With superimposed localized pressure gradients associated with late fracture and fault zones. 75 Origin of the Deposits The magnetite-chalcopyrite skarn deposits were form~d by the initial deposition of magnetite immediately following skarnification. In the limy horizons, sufficient co 2 was available to oxidize iron and precipitate magnetite. Iron was probably derived in part from magnetite-bearing conglom erate and through bleaching of argillaceous sedimentary rocks within the Nicholas Denys thermal aureole. Base metals and sulfur, on the basis of available evi dence, appear to be genetically related to the quartz mon- zonite-granodiorite. Sulfides were deposited later than magnetite and presumably at lower temperatures. To solicit diverse sources for the two major components in the skarn deposits is distasteful to the writer but necessitated by lack of evidence to the contrary. The deposits are thus contact metasomatic types. 76 East-northeast trending Middle Silurian sedimentary rocks underlie the area of interest. The intrusion of the Nicholas Denys quartz monzonite-granodiorite of Devonian age has given rise to an ill-defined thermal aureole. The Main fault of the Rocky Brook - l'1illstream fault system is localized along the crest of a tight anticline to the immediate south of the deposits. Serpentinite occupies the axial plane of this fold. Late, generally northwest trending transverse faults spatially related to the ore deposits are conspicuously developed. The Beresford and Millstream Iron contact metasomatic skarn deposits occur in metamorphosed impure limestone and to a lesser extent in altered 1 in part limy, argillaceous beds~ the former is now r~presented by an andradite-diop side-epidote-calcite skarnr and the latter by calc-silicate or hornfelsic bands. The lenticular deposits consist of magnetite, chalco pyrite, and pyrite with lesser sphalerite, pyrrhotite, molyb- denite, arsenopyrite and marcasite. Limonite, hematite, malachite and chalcocite are restricted to weathered expo- sures. The ore deposits represent concentration of Fe, Cu, ~n and to a lesser extent As, Co 1 Bi, Mo, Ag and Au. Depletions are evident in Sr, Ba, oo 2 , CaO and H2o. Iron is believed derived from sedimentary rocks in 77 proximity to the deposits~ bleaching of argillaceous beds and alteration of conglomerate appear to be the processes involved. Base metals and sulfur are genetically related to the period of igneous activity which emplaced the quartz mon zonite-granodiorite stock. The deposits may be categorized as a contact metaso matic type. 78 SUGGESTIONS ~01-{ .r·U'1'URE WORK The initial intention of the writer was to include a study of trace ferrides resident in magnetite. Such a study, expanded to include other trace constituents of interest, would probably be fruitful in view of the diverse environ ments in which magnetite occurs. Appreciable quantities are present in the skarn deposits, serpentinite and con glomerate~ magnetite also occurs as an accessory in mafic intrusions and the Nicholas Denys stock. Provenance of detrital magnetite in conglomerate may be forthcoming by comparison with results of a study by Davies (1963, personal communication) on magnetite from older, Middle Ordovician iron formations in proximity to the Brunswick massive sul fide deposits. Statistical tests will be applied to establiSh the sig nificance of variations among rock types from different positions within the thermal aureole. If warranted, a study of the influenc~ of temperature on the concentration of selected componP-nts might be of interest. A more detailed study relating mineralogy to whole rock analyses already on hand is envisaged. Where practi cable, mineral separat:~ons should be carried out with atten dant chemical analyses of these fractions. This would further establish the relationships among major, minor and trace constituents. A study of trace element distributions among coexisting 79 skarn minerals might establish whether equilibrium was ob tained during their formation. In view of the proposed use of anisotropic garnet as a geotherrnometer, factors controlling its formation should be investigated. 80 BIBLIOGRAPHY Alcock, F. J. 1935: Geology of the Chaleur Bay region; Geol. Surv., Canada, Mem. 183. 1941: Jacquet River and Tetagouche River map-area; Geol. Surv., Canada, Mem. 227. Barnes, H. L. 1959: The effect of metamorphism on metal distri bution near base metal deposits~ Econ. Geol., vol. 54, p. 919-943. Barth, T. F. W. 1961: Abundances of the elements, areal averages and geochemical cycles~ Geochirn. et Cosmo chim. Acta, vol. 23, p. 1-8. Bastin, E. S. 1957: Inter9retation of ore textures1 Geol. Soc. Arner., Mem. 45. Bilibin, Y. A. 1955: Metallogenetic provinces and epochs. Gosgeo HPkhj __~da t, Mosco~~. Translation available, Librar~', Geol. Surv. Canada. Boyle, R. W. and Davies, J. L. 1964: Geology of the Austin Brook and Brunswick No. 6 Sulphide Deposits, Gloucester COunty, T''e~v Brunswickr Geol. Surv., Canada, Pa9er 63-24, p. 23. Buddington, A. F. 1959: Granite emplacement with special reference to North America 1 Bull. Geol. Soc. Amer., vol. 70, no. 6, p. 671-748. Burnham, c. w. 1959: Contact metamorphism of magnesian liMestone, Crestmore, California~ Bull. Geol. Soc. Arner., vol. 70, p. 879-920. Collins, L. G. and Hagner, A. F. 1959: Host rocks as a source of iron, Ausable Forks maqnetite district, l-~ew York:- Ab::tract, Eco!}_. Geo~, val. 54, p. 1352. Davies, J. L. 1959: Parts of Tetagouche, Jacquet and Nigadoo Rivers 1 Geol. Map 0-5~ New Brunswick Dept. 81 Lan~s and Mines, P.M. 59-1. 1960: The Bathurst Ores~ Unoublished MSc. thesis, Univ. of New Brunswick~ Canada. Davies, J. L., Boyle, R. w., Tupper, W. M., Bachinski, D. J. and Martin, R. 1965: Geology and MQneral Deposits of the Nigadoo River - Millstream River area, Gloucester County, New Brunswick~ Geol. Surv., Canada, in J?reparation. De chow, L:.. W. c. 1959: Geology, sulfur isotopes and the origin of the Heath Steele Mine~ Econ. Geol., vol. 55, p. 539-556. Faust, G. T., Murata, K. J. and Fahey, J. J. 1956: Rel~tion of minor element content of serpen tines to their 0~logical origin~ Geoc'hi.m. et CosiTochim. Acta, vol. 10,· p. 316-320. Faust, G. T. 1963: Minor elements in serpentine - additional data~ Geochim. et Cosmoch:tm. Acta, vol. 27, ?· 665-668. G01dschmidt, V. M. 1954: Geochemistry~ Clarendon Press, Oxford, 730 p. Grc3f, D. L. 1960: Geochemistry of carbonate sediments and sedi mentary rocks~ Part III. Minor element dis tribution~ Ill. Geol. Surv., Circ. 301, p. 71. Green, J. 1959: Geochemical table of the elements for 1959; Bull. Geol. Soc. Amer., vol. 70, p. 1127-1184. Hiqazy, R. A. 195?.: Behavior of trace elements in a fro~t of meta somatic metamorphism~ Geochim. et Cosmochim. Acta, vo1. 2, p. 170-184. Holyk, W. F. 1957: Structure of Northern New Brunswick; In Structural Geology of Canadian Ore Deposits, vol. 2. Ingerson, E. 1962: Problems of geochemistry of sedimentary car bonate rocks~ Geochim. et Cosmochim. Acta, 82 vo1. 26, p. 815-847. Je:nny. c. ?. 1957: 2x~loration in New Brunswick, 1932-1957 7 P~per presented at the Prospectors and Gevel opers Assoc., Ann • .Mtg., Toronto, Canada. Jensen, M. L. 1959: Sulfur isotopes and hydrothermal mineral deposits~ Econ. Geol., vol. 54, n. 374-393. Ku.lliokoski, J. 1961: Temperatures of formation and origin of the Nigaooo and Brunswick Mining and Smelting No. 6 Ce?osits, New Brunswick~ Econ. Geol., vol. 56, no. 8, p. 1446-1455. Lindeman, E. 1913: Austin Brook Iron-Bearing District, New Brunswick; Canada Dent. Mines, Mines Branch, Pu~. ~o. lOS. Linc'lqren, w. 1924: Contact metasomatism at Bingham, Utah; Bull. Geol. Soc. Amer., vol. 35, p. 507-534. Mackenzie, G. s. 1950: The geology and mineral deposits of the Rocky Brook - Millstream Concession: unpub. private report. 1952: Prospecting and metalliferous minerals in New Brunswick: Paper presented at the Prospectors and Developers Ann. Mtg. 1958: History of mining exploration, Bathurst - Newcastle District; Bull. Can. Inst. ~in. Met., vol. 51, no. 551, p. 156-161. Mason, B. 1952: Principles of Geochemistry, John Wiley and Sons, New York, 310 p. McAllister, A. L. 1954: Structure and ore deposits of northern New Brunswick; paper presented at Prospectors and Developers Assoc., Ann. ·Mtg. 1960: Massive sulfide deposits of New Brunswick; Bull. Can. Inst. ~n. Met,, vol. 53, no. 574, p. 88-98. 83 :1cCartney, W. :c. and ?otter, R • .K. 1962: Mineralization as related to structural defor m::ttion, igneous activity and sedimentation in folded geosynclines~ Can. Min. Journ., vol. 83, no. 4, p. 83-87. Nockolds, s. R. 1954: The average com?Osition of major igneous rock ty9es; Bull. Geol. Soc. Amer., vol. 65, p. 1007-1032. Park, F. B. 1964: Lateral migration of 20 million tons of mag netite ore, Marmora, Ontario; Abstract, Geol. ~o~. Amer., Ann. Mtg., p. 147. Rankama, K. ::tn0 Sahama,,Th. G. 1950: G~chemistry~ Univ. of Chicago Press, Chicago, Illir.~.oi s, 912 p. Sandell, E. B. and Goldich, s. s. 1943: The rarer metallic constituents of some Ameri c~n iqneous rocks. J. Geol., vol. 51, p. 99. Sernenov, A. I. and Serp~~hov, V. I. 1957: General principles of regional metallogenetic analysis, and methods of compiling metallo genetic maps for folded regions; Deot. of Geology and Conservation of Resources of the U.S.S.R., New Series, Issue 22, General Serie<>, V.oscow (in Russian). Shaw, D. M. 1954: Trace elements in pelitic rocks; Part I: Vorcation during metamorphism. p. 1150-1166; Part II: Geochemical relations. p. 1167-1182~ Bull. Geol. Soc. A.>ner., vol. 65. Shaw, D. M. and Bankier, J. D. 1954: Sr~~istical methods applied to geochemistry; 9enchjm. et Cosmochim. Acta, vol. 5, p. 111- 123. Skinner, R. 1953: Bathurst, Gloucester, and Restigouche Counties, New Brunswick; Geol. Surv., Canada, Paper 53- 29. 1955: Tetagouche Lakes, Restigouche, Gloucester, and Northumberland Counties, New Brunswick; Geol. Surv., Canada, Paper 55-32. 84 Smith, C. H. 1957: Bathurst - Nevrcastle nap-area, New Brunswick~ Geol. Surv., Canada, ~ap 1-1957. Smith, C. H. and Skinner, R. 1958: Geology of the Bathurst - Newcastle mineral district, New Bruns\vick~ Bull. C~n. Inst. l'1i ;'l • Met • , vo 1. 51 , p. l. 50-15 5 • StF.tnton, R. L. 1958: Abundances of copper, zinc and lead in some sulfide deposits~ J. Geol., vol.. 66, no. 5, p. 484-502. 1959: ~ineralogical features and possible mode of emplacement of the Brunswick Mining and Smelt ing orebodies, Gloucester County, New Bruns wick~ Bull. Can. Inst. Min. Met., vol. 52, no. 574, p. 66-74. Tupper, w. 1'1. 1960: Sulfur isotopes and the origin of the sulfide deposits of the Bathurst - Newcastle area of northern New Brunswick~ Eoon. Geol., val. 55, no. 8, p. 1676-1707. Tupper, W. M. and Rachinski, D. J. 1965: Geology and geochemistry of the Captain deposit, New Brunswick~ Geol. Surv., Canada, in preparation. Tupper, W. M. and Hart, s. H. 1961: The age of granitic complexes in the Central Highlands and the western part of the Southern Highlands of New Brunswickr Carleton Univ., Geol. Pa?er 61-1, p. 1-8. Turekian, K. and Wedepohl, K. 1961: Distribution of elements in some major units of the earth's crust~ Bull, Geol. Soc. Amer., vol. 72, no. 2, p. 193-286. Young, G. A. 1911: Bathur~t District, New Brunswick~ Geol. Surv., Canada, Mern. 18-E. 85 APPENDIX 1 Major, minor and trace constituents in 246 samples from the Nicholas Denys - Millstream River area are presented in the following tables. Trace constituents are given in ppm., oxides in per cent. Total Fe2o refers to total Fe calculated as Fe o~. Spectrographic determinations of Ti, Mn and Ni are denoted2 by the abbreviation Spec. The tables are derived from computer print-outs and the following code pretains to area and rock type respectively. Area 1 Beresford 2 ~llstream Iron 3 Nicholas Denys-~llstream River Area 4 Stevens Brook Rock Type 1 Serpentinite 2 Serpentinite Breccia 3 Hornfels 4 Skarn 5 Beresford Deposit 6 Millstream Iron Deposit 7 Greywacke-Argillite (non-hornfelsic) 8 Conglomerate 9 Recrystallized Limestone 10 Quartz YDnzonite-Granodiorite 12 Fault ZOnes (undifferentiated) 13 Bleached Hornfels 14 Quartz Veins 15 Imoure Quartzite 16 Quartz Feldspar Porphyry 17 Quartz Feldspar Porphyry {mineralized) 18 Devonian Mafic Igneous Rocks 19 Ordovician Mafic Igneous Rocks 20 Stevens Brook Arsenic Deposit 21 Feldspar Porphyry, Aplite 22 Limy Argillite 23 Arseniferous Metasediments "(i I . Co l OP i mi'h' i c ·• n · l c prct·P0$)1'"'0h 1 c ·'II l y c•s , \J i ch,) l .-1. f' r " y ' - ~ , i I I <:: r I ' ('. ~"' ~ 1 vrr i'r<' 1, \Jl''" t1 r u n .. '" i c 1... • ,. " • •••• uoo I 1 ,. •• ,. '·' u oo ,. uooo flO• l I 0 •t •n o • 1. ~ l.t \.1 t.t tt~o.l eO\ .t~ .It t~ol ''" .. 11 o\ J•OO at tl t• IXI~ t t l OOO tto ,,., l ' '"' ttQ • • •• ••• '•' ••• " · ' •• , ••• • ., •• 11 • ·• noo U U O&O t t UO _ to .:' .:.":.:•·...:.•.....:.•_.:...... ;:_....::. __,!.!1~ ·· ·.. .!!..!.!.__!.· " • • , ·' •••• ·"' •'" • •• • • • • • •• ,... J • ,.,.' 1 ,. ,,.0 ...... , ••• ·' ••• • •• •• , .. I UOOO I I UH IJO ... •• ·- n ,) h OO •J I t J Ol)QO I I UM IN fU'I I t I ) tO) • t,.t 1,.1 ••• .t •t,t • •' • " •t• • ' •••• •• U .t IUO H U 11000 I U .... '" .:."~··.:•...:..1....:.• -::.....:._..:..._•!.!•::·....:.'··· .,., •••••• ••• ''·' ...... ··-- ...... h •• ' " ' • • ,. *-"' • • "" ... .,,. I I o t tH ' '•" Itt • •' I•• ) t,.l ,ot . I t .11 .t •o ,. .' , .. u 1tooo a u "" u o l'tY l I I ''• ' I ,t .., ...... ·' hU 1 • n o .. ) 0 n 11000 t , • • , ' l t :J ,,, •••• t • • .. •• .., ''·' ·•' ,..., '" f tt• l I ~ ·-· ~ •• to •' noo U UOOO I U laOO IM It n o ••·• ' .• u.. ·'' ...... ,,, I I '·' '·' .. ., 1100 u n ooo 1 a uoo '" fttJ tJ tOO •o.t t.t t.J t.t Jt. l . ot ,tt .t• •• f?O) t•tt I I 1 I •• •• uo '•' 1 000 ' " n u ooo a ro •••• • • \ 0 t • :) . , .. t ' · ' ' :!..._! •' .. ~ -·.!' .•• ·'' ... fttl I I t O I I •• •o .~ noo n t u ooo 1 n o ,... ,,. lD tJCI Jt.9 1 •• l .. t t . O •••• .Ot ,&t e11 ft t I I •• ... •·• n oo u u ~~• a a " " , .., UtO 1 I •• 1 100 • •·• • · • • ·• •·• ••·• .ot .11 ·'' a.t fU I _ _J 1 •• I _ t • 1..1 000 _ U , 1000 noo 1 ' 19 •to ' '•' '•., • •• .t J • .t .OJ .at .ot •' ruo 1 l •o n o ,, u oo ,. n tuoo a a a..o uo ..,. 1 • • • • ••••• t.l ., ,, •• ••, ••• ••• .., lUt .. II ot U OO Ito U l • lOO l JJ ,... •t ,.,, l ' .... '·' ...... , .. , ...... flH __I_._l _ l•_o __IO __ t _ ~ 1.• U ctO Jl t nooo t 1 heo__!.! ttt ll I I ,.. , ... '·' '·' .., ...., .., ·'' .... , -u -• t ' uo ,. u '·' nH ,. t UOOO I U I • M U O nu 1 ' ••••••• •••• '·' l t .t ••• t OI .,, ,, ..., I I •• , t 1• 00 • l t • ltOOO 1 U U N U t e U J I ~ •• , •·• ao.t • ·• u.J .ot · • • ·•• ,.. . I I I 10 , t U OO Jt U U OOO I I U OO !.!,! ~·~· !.!":....!.l _:t_.::__::_....::.____ _: •:..:•::.·:..'.....:.:'·' ao.t l t.t ''·' .t . 01 ·•• ,, ' • ••o aoo ·-- .t U OO J) U ltOOO I I 1100 U O l e GI J I ,.,,'"' U .1 l floO O 16 10 U;IIOO I I UOO fl tt .. l , • • ,,. ,,., , • • • •• , •••••• • I .. ''" . ' ,,., UU I 1 •• ..__ l1 ' ·L-" -1•• "..!_..!!00110 u o •!...... !! .. •• J t •• ' ".' u.' , ·-.:.•__:·:.:•__:•:.:•.:.•_.:.:.. _ ..;·:.:'-l lUt •o 10 t.J ..... 100 ,.. tf"?l•~ u o •• 0 tl • • 11. I t.l • • • . t t eO ,t"J .10 oOt ... '"' ' ) ,., •• 10 •o t . t t O 110 IN Jeo OI • ~ 1•0 I 10 t o .,,. ' ' ,,,, ''•' •. , •.• ..o'·' ,,, ..• ,., ,., 't Itt_ U U O Jt ~ l900UO Itt _ , ;_M::O:,:t:..!,l ...:.>_!_..:., _ _:I~!.;_>O:;>:;O_.:.:J "":::!.O.~•t •...!...J \, J- t . t I .1 te ~ I • f .!_!!.,_•..!.!_..!..:,!_ •• II I •) •O t l 160 IOOUO U lt tU• t J o U » ••' tt.t t•.t t.a '·' t.o z.t ....o t ·' .. .. J 10 YO U OO t J t•O U 10 ftU I J 0 ' ) Q" M {l t t. t Jht •• • • •• l.t •• t •• .. 10 ·'' .. , ·' ...... U l.t • t UO U'O ltOO U JfO_ tt .., !.'~~ --· --- · !!~·· ''·' "·' .., ,...... ,...... ,.,, • , '10 U •' ItO ..u ltO 1000 '' U O Uo U tflt 1 J JO • • , .. , 110~ .,• • ) ...... ,,,, • • , ·' ••• ..,, ••• ...,. • ) 100 .. U U N a • .t )0 •oo 7JO UtUO U O .. , ... I 'I tl,.J lt.t •.t t.t •• o l.t Z.J .tt .t ,.. . 1 _ 10 - tl ___I O__ l _ I • I__ l•t _!]_L..!!,! ,., l_ I O-lJ O ___!,!!__J t)=l~JO~-~·~:IO:::::;';:';:;:;..t..'~·~·~·~I~J~I =~~=:;:::;;;::;::;;~~·~··~·;;:· -.1....!!· ' ~ '.!.'- .-!..:.!... .. I 1 t O U O tt l lel to n o • tQ ltOO itO ItO '' 'T """f'" ) ill 0 --u- ~ ~ . r..- o •• l. .to ol ..,. . I J 110 ) 0# U • •l 100 N O t~~ OO •n tO U O U O 70 ,.,, ' , tl.t J).,J lOa) ••• t .t l.t J . O . t1 .ot ttot --~ ' --l'•- • oo__ .J_ _ I _ ,, aoo u o Ute U I U L l• .:."o.:':.:'..:..' ...:." -=-...:.--=-----~·,.:.!_!' :!_'..:!...... ~ ·' _•. __ • ,,. .. ,,.. I 't 110 ltOO , , I • O • • • i to n•uo n o ••• t-' , , ,., a , •'·' J J .t t.a •·• '·• .r.• .... ·'' '•' tn• I 1 . ,0 •IO .. .t lOt JIO ?1 2100 t e ItO llt .,,,, a , " '•" '·' to.o , •• , '·' · ' • ·• • '' . .. tU\ __ ..L.._, __•o llO 10 t l ,J 100 &'tO l U,_I..Q9G.Jt!_I ~..L..11.t.-l. ";;:;.. =-:..1...:. • -=--...:.--=-----~·~·· !:· ·~·!..!'·' ...... -'·~ _!~· · ·' , . noo l•U I J • • ·• as.t u .t t.J t.o t .a I ' 10 UOO .t t O tt U OO UtiJO ra Jt J OO I·• ... "" .,, ,, I J tl t. t tJ UO t OO UOO 1 U O tt t o , ,.. ,...... ' .. .,. ... . '· J ' ·"" t.t .. '' ... t)Jl __I --J..._. ~··~•· :•..;•~•:.__!._:___.!:.____ ~ u..:!_!!••__!: • ~ ·' .!.:.!_ ,.. ~.o • IO ,.,_. ------....!." _!' ~'" -'"ll 0 l JL-..!.1..-.f.! .. ,. , . .,. ., •• .. 1 tJU ' , ,. •• 0 0 ...... "'·' ., ..... ''·' ... ·' ... •U oO\ ..,,. 1 0 • • ,, ., 10 0 • • • &100110 ••• " , . , l ' , , , '·' , I ' •• •• • ...... , U ttl__ l J - •A-Jt --l,_t.._..uO_M\.._lJ _ t J l_IOf" ___l_U • O l--&.-.f.. uuu , · ~-1-t... . l '·' '·'...... !!..' _ . u ·•• •__!_ ,,,, , , 01o-t ••• t O nuu , l ' u .. 10 Ut .t •o IJO ))O t UUO Ut u .. 1 , •••o , • •• ,.,.. ••• . ., ...... , •• • ·' , ,., • J ,,..'- _ _...._.__•n•o_-:!•:t.•--L---'•~&-4. tt_~,.l.l...I1~U11.....i. l'J.2...J.OO' ••ct.tJ'-1-.J.. • 1 •• 1t•l t ot 1.1 '•' '•' lo1 ·I• tO\ -nu 1 , ttto ItO •t 10 U O t'\ • O U O U O JIIIU UO •t ••·r -''· ' '·' •·• ' ·' '·' '·' .to •0 , ttn U t1 Jt I I+ ~ U ? UOOUO l)O .,•• 1•.1 •• , ... , 1 . 0 • • ,. ••• ••• ·' l ' ,. I•• ''" I J ,,. --·- •__ ,o _ •,_,1,__,1"..,> _...:.•:..• _ •.!_ •o _ , •• _ u o__ uoo u o 110_ 11 __!.1. !..'.!!_•_ •___ o _ ! __._ --- , , ,. 11.0 •• t ).) 1, 1 l.f L•• ,..,., 1 1 • " --=.!!. "" •• lo II U .,t Itt U l '• hOOIJO I t O I)O tl ,.. , ''·· ..., ··' '·' ...... 11 • • • t,,, 10 ••• • • . .. 110 ...., . u o , . , IUO I 1 I ' •o • •• '"'·' ..... '·' .... ·' '·' •• , • .,, . ot .,~ , . ,.,., _l__t __,o _ ....zcU,__ ...__ .!!-.1.J..".-JJ t J1.,!_U O.• ?OOUO _U ,!t_ !!.-L!._ " !!. -' --·~''---"---''--!---- ' !..._,_u .. • •·• · ' !..·'- 1.1 •• ' ----!.!!. l l • • O U •J t .t tO IJO 110 IMOi tO JO ~ tJ _,. ,,• • J ' .. ,.,., ''·' • • , .,... , •• '·' '·' ...... ,,. UOI 1 t 14 t.t UO t~~ JO · ~~ l900U ~ lfO If!) tt • 0 ...... , '·' ,... , ,., '•' ...... ttO• I 1 0 ; , ... , . _ L_t •o__ t • __\.__j ,. • ' - •' u o no tUiao u o • • •l.• •••• '·' ..... ,,. , •• ltl ., •••• 110t • , nu ' , •o u o 1 .t u u o •oo t u oo ••• "'·' ''·' '·· .. , ...... , ... .. nu •• .. to • t n tto •oo •••no n o u .,,u l 1 11Jt I ' to UO _ 1_ II I • • 10 U O U O U00\10 110 ,,. ' - ~ _ o ,,., fin I 1 ' •• • to •• t t.t •o 11!'1 110 l tOOU O 100 ttO ''·' '"·' t .o n.• •·• •·• •·• .tt . o*l ., . ,. ' , o ttco 11 ~ ••·• , .., ,., t .o '''' .. . a ·l t .o .n . ot .. ' •• .. •' t O ,,,. IU 1..,0 1)) 1• 0 UO .. . ,,., . 0 I 1 •o •lOOt JO 110 U O . o• •• •o •• .. ' •'' ' '- ' _ n -----· ...., ''·· u .o .... '·' ' ·' '•' ... t ••• , .t t 't ltO fU ._•lltl') lfO 110 tt ..., • ., ''·' ''·' Jt. ) ••• . 1 ••• .... •• I ' .. "--· l , l t jt I I '" · ' •• n o tl ~ue uo u M .... "·' '·' ''·' '·' '·' .... ·" , J .. .. '!!!..! _ o__ ._ l t OOUO U O I t O .. 1 • • ., ''" , ' •• •t f't ItO ...... ''·' ...... ,.,, " 1 .00110 • • • ,.,., ' , 0 ,.. . lol o l • • •• •• •• ...... '" ...... "'·' .... '·' l ft. l . ... ,. k , ll 10 , ...... ,.. "' "'" ' , . •o.a u.• ••·• '•• •·• •' ' •' ·•• ... 1 I . Colo1'int1.2t.t•ic . .,,,( Sp t C"-1'1!91 ' ' 1 1 c ..... n • I y ·• , ~ 1 c h v I • 1 .t.· J (. "y - \ I i I I f" t ,~ (. '"~ Ill J .. • ~ i \' ( r" • 1 'I o ' W 'I' \II I \'' I C i, • --:~i--1-1 .. 1 .. I .. I ~ I,. I •· I -.1 .. I ..JI .. I • r:-·1-1 ~~ -t-1-1.. 1.. 1.. 1•;::_r::·l·· .. .l .... 1~:::1 ... j ..... j ...J "'.1 ... 1... ' '"' I • U ') I<~ O'l 1\ 1 10 lot • O I t• IU)lC) l:J:J )0 tt n - '••• 1 • t•a I• •" J.J., ,,. ,,,., '' t•o •~ 1 "•• 1 • to o o ••o• I•.;G . ,,., u,• ' •' 1 •.1 '·' ,, '·' •• 1 .t.t , , I • Ito ,, ,.,. 1 • .. " ' .... ., t• •U I tt ,. It I • 10 .. •• 10 ., t UO) '' U C "U 1 • 1M , I • 1 • 0 ... 11 •·• 1t 110 11 uot •• no ''"O I • 110 • ••• • ,,,, •••••••• • •• ''·' ••• · ' ' ••• ·" J.l .. fftl I • IM ... l t H I • ,. u ••• u ., ,...... I J> .. '""" I • ----.,. 't " -- ·' ,,, ·'' ...... ,. .. •• ,. ,. "'"' uo •• ,, ,,., I • lOO lHO • .... 1 0 • • u ••• • • •• • ·' ,,., ' ' ·' •·• u.o •• ·• •·• .•. ... ~ • uo "'~ - l ,, ... ,.. .. tL I 110 h lOt I ) I U•f I • '' :~· • l t ot tlo • lo6. ol t.t t 'U t • ):)0 ..., '"" t O t1 100 ettiiO HO '"'' ' . . , •• ''·' ••• )t.• , ,, , 1'1 • ' •• '·' , , u o ·' •• • ,. ,, ltltO I .110 Ito . '·" ,,., ,... . ,._, ...... ,,,, .. , .. , ... .. ' • 110 1100 '" • • • ••• uo •ff n l U O I to h ··~ _•_ _!__ __, ____, • • ,' •••••• ,,...... t t ·' ,,. I • .. ,,. •" •"' ,, .,. , ' • 0 h u •• t .t ,._, , ••• '·' •••• ,, ••• · ' " " ' a ,,. ol UO ) t U hOO U \fO U O n ft 110 .. "'" ' I t. ,, ... "·' .... .,.. ·' .. ~ .., .,. ,.. n u 10 •• • • • ,. 1'b ''"'' t • _ !....!..!!._ ___ ,,_, '·' •·• J O.t '·' .o~ ••, •'' a.t ·- __! ,,. U I •" •o II 0 U ltOt 0 .. ''·' · ~ -· .... ''•' .. , ··' ... _,, ,.. UOJ I • 110 11 0~ ,,., I • , ...... ~ ,, ••••••1'11 t ••, ••, '·' I • l•O J • OO I ) 111110 II...... '" U f• I t tH J•.• lt,t lOot Jl. t .-t .1 loO ott ol .... I • U O , zoo l l 1 00 , ,. •• uo ,...... un t • u o ,.. .. .,...... ,, .. ., ...... , '"'' l • ,.. ..•• ... U O• I • o ll ''·' ...... ,.. , .. , ·' ...... ·' ,, t O 110 .. I • ao ., u • ' I ltOOUO IU ,,. , L • '"·• ''·' '·' "·" , ... I·• 'Ut ,.. .. .,...... ,. 10 ..... ,,.,, I • "" ...... ,,_, ,.... .) .. ·"' ... .. I • • O ,, ,, . .. ,,,. 1 • • . n .. .. " '•' lt,t lt.l t c .o '·' '·' t.t • " ' '·' ,,,. I • 110 10 IJ lo t It J O t J tJJhO 110 .. 't• •t tt.• • •I )OoO .t oO~ •1• ot t nn '- ''...!.!"t - •- •- "" ' . .,...... 10 ,t It JS H t J I UO I t t I l' f)Jt I • ...... ''·· .... ,...... , l • , , .. • • • •·• 1 ,,., '"'' I t t I• .. aoc , . , '"'I I \ 0 ..-. t• • t •• ,,, I • u 1 n .,, u : " '~ I' t •• •' t "'' ' ,.. , 11 J•o " "' •••hiS 1· '' ao, ...... '·· ,,, ... I·• 1 • J•o •coo • lol l'tO J • t O ftt l 't • O U!l tt lUI I t 1 tiO ... , ...... ''·' '·' .. •'' .., I t ,,_,., • f'"l) .. 4 ) ,) 1• 0 I • II) •l tUO 110 ltl 1 01 ,.,. ' ~ ,,., , • u o ,.. .. I 1.1 ,, 11 IU I 1t 6t lt 1Ut I t .,.. ... ,.... ,,.. ... ·' ...... '"' l • ) 00 • • , , " ...... u ~. ' ., tt , , , ...... IJt •• nu t • ' • , . .. , . ...o lo 1)0 lo) ) 0 4 1 1 \ t••IID U U Uh I t 0 1t ll Jl I• IPOO h O tl I I U ,,., ' . 1ot J ,.l t O o 1• ' )oO •• •I• •I) •I 1 41 ItO H OO ,. t O tt IIOOUO UO t'\ Jl h OJ I t U O ? U ~ .. ' ' ·' ..., ...... , ''·" ••• .1 · ' " ••• · ' I t JIO 111 01')0 " U lo ) 10 • t U tU IOO 1t U U ,.., , . .... , .... ,. .''•"" ,., ·"' .•. .... •' , ,. ~ ..,~ I UIIU':' It) . 1.1 11 \ U Ia. U a.'t tt-&• I • ""'·' "·" , "'·' ,,- .. l t U O h OO ,. ... 11 .... ., '" u , _, '""'"'' au n o .,, '•o• I • f' U U OO ''·' "·' ,,, . ... '·' ·'' _,, ·' 1 t ' ' G lJGO 10 ... • • • .., ,. .,..,...... , ,.,, , . .. ' • ..• ., 1 000 rtat I • , • l\0~ ... , ·' ,, ... us to n eo •• , "~ I 6 U ? I y ,. ·' ,, 110 ,,. ,,.,. • • u .. •• ,., .. ' ''•' hot )t J l tll ) o l lot oil) o lJ . ot I I It 10 • ••• 1 0 , .,. , ..., . uo ,, •• '•" I 1 I f l '-0 • o I> ,. ., .. uo '" uoouo , . ., ... ., t ' ) J I M' ttO tt • ._ a•. l ),• tt l Jot l oO • ' " .to 1•1 . ' •• It .. II ·' .tO hO H O t•:J:JIIO U • O\l • 1 ,... ,.. ,.. , .., .... ,., . ' • O ,. ,.... n IU U O UOOIU 1?0 110 " ·' . , 110 u o u oou o ••• .,,. .. ., . ' a t•OO ••• t • .l l••• t.ll t•• " •' 1.1 1 110 oil oOt •on •o .. o_ JO 1• . t to n o .,., , . ,ouo hO . ' """" w ~ _o o_~ ,.:J., ,,., ••••••• , . ... • •• "'• " '·"' ••••o. •o ol U tiO ••O I JOOlOO U U 10 . ' •• '''" , , , ••• 1•. 41 ••• '·' "·' '·" ••• .., • .,.. ,.,. I o ,.,. .. I l o• UO U O t• I JOOU~it UO t •o U flo• l • ,., ••::., a s :.~ t l . t •~ · ' ''•' •· • , ••• t '·• ,Jo .1 I • - ___ , • ~ ,... 140 ., , .. .,.,.,, u c .. .__ ... nt~f_L_! _ o . ., _--2. ~& o1o .,., u.\ th\ ' '- ' •· • ... ·' ,.,. ·I' .. JUt I o •o •• )0 U OO IIO 110 ,.,. · ' 1 111 0 uo uo ,,., 1 • o t•oo . , ,~n • t.o ... ' to.• t•·• lo> .., '·' ...... I 0 •• " JO •·• no u o u r•oouo n o uc Hh I I UOI I t I!!__ 1 00~ U O lo ~t tiO 1'1 0 I' HOOUO U O U O t9 Hit I~-· .,!. ~ U ., ) tot,ll t • .'f ll.l '•" '•' " • ' l .t .It . Ot I & '"·• II ,J 100 110 61 U OOI • O U O ItO u u l • t o I III :.O l~~tt J,...... t .J e1 IS •• l hl ••• lef l o• lrO o lt •' ,,,"'' I 0 ·' n o uo •• J too••o 1 0 0 uo u H OI I II t O I 0 •• ·' teo uo ,,. uoouo no u o - '..! h\t 1 I I 0 . o ,. uoo no uo 1t.U l I ,, " '~ .. 1\ ·' ~ · ., -. •••• , •• •••o .... · · ' '·' '·' ... 10 71 ••oouo ,.. ..,. .... · ' ltll'll I t O ••.t I• I ~ ~ t • •• ••• • • '·• ... '~·· t • I o , '" 110 • 000110 1 • 0 JOO II ·' .. " ...... '''' I •_ !_ _o__ o_ ••• , ""!.! •••• ' · ' ~·' '·"' ,,. ... ·!! I o " ,,. • , .t U O J M U t'JOOUO J'tO U O M 0 "" .,,. ' . ••·• ''·• ''·' 11.o •·• 1 .~ t . o .to a.o , .. ' • o • ' hO ItO •t IHOUO U O 100 Jt I UO l I ,,., . , t o •• ''·' 11.t •·• t.• ·• •·• .11 .1 ' . . •' lJO "40 J OO J OO~ l f O ttq lOO ~ .,.,, " -' ~-· - ''·" ,,, •• , • • '·' \,ll • • ,,, , ,, . ... .,,.. )l I I to •• •' U O 11 0 •• )eOO U O U O UO ,,.... t • ''·' .... , ..... , .• '·' ·" '·" .o, ·' "'' I 11 U'O 100 ,. , , n o uo I M ••••• to uo 100 tn• I I • t. 't , ,.,, l1.t S.l Joe l oO lot . u .ot I t I tO t) 1410 ItO 'l h OO h O ItO U:O •••• •• • , ••••••••••, ·' ,,, . o- ...... , . .. ~~-· 0 ' . •• .. .t u o 1 00 n n oouo u o tto f OOJ I 0 0 0 ••·• •• ·• at, L t . o '•• • "' '·' . oe .a I • J OO •• 110 ... . , . •to ,_ .. , ... ,. ., nao 1 • • • • J Og.., ...... , '·' ••• , •• , • , •• ·'' · " ' u . o I 9 10 .. 10 f 1.1 It tiO ., tUtU , • ., ' _ . 0 ...... '•' ,.... ,, ...... ,,,, ' " Ut• I • 0 l I 41 00 ItO .. JO ·' to uvo a•o •1t n n •o ''· · .... , •••• ,., .... ·" ' .... •'' tl.l ,.,, t • I 9 10 .. " ' •·• • • 1•00 n o 1100 1 n ••, • • ., '·' • • •• . J •• ·'' . ol -,, •• I • ,. •• .. Jt ·' • • , ... ' ' • ·•• a ...... ,,. "'·' .. ~ '·"' ,,_I t t • eooo u o 1•0 ltt41 U O •to •t U J I Jt ItO ''·' ... .. , ···' ., ... ·'' .., , ... .,.,.. ., ) 0 , ., 0 I ' ltoO •• 10 U t I Jt U l O ,,,..' . ••• .... ' ·' ' ""' ·• .t •• ••• • •• , , •• .,. I t H G . •• ,, •• ••oo n "' .. , n ... "''·'!. •_!!!_ _ o__ o __ - - ... '·" '·' .... ·' ·' .. , ., .. ~, .. l t f 6 t J O • 10 J O ItO .. .. t • • • no IIUO 0 • •.• ''·' J.• ••• · ' '·' ·"'' ·'' .•• 1 10 I )tO J\0 , •••• .. •o .. ·I "" ...... • ''·' •••• , •• '·' ... • •• • •• ••• . ot •••• 1 10 ' ,,... ., II I '''O \ Jl 0 0 0 If)) t10 fO. t lt.l l t J I.e 1. 1 loO oU ,.,_ .,e; •• .. , ...... I . .. ,,. ,.... ll 10 " " '' ~.J ••• ••·• ••·" '•' •·• '·' , .., .,, ... .ot , • 10 I J OO U O ... I O .. II U 0 tHO ItO 'tO , a U·' lot 1.0 leO '·' •'" oOJ • 0) "" I U U O lOOO to~ UCiw • • • t O lOO llO til Ill U O I U un 1 & ~ _ o " ''·" ' !-..! '1·' •• "·' •. , •. , .•• . ol ,.,. I U 110 10~ I•" ••• u, t• no , • .,. "' ••• ,., ,,. ' u 0 •• to.... . , •• ·• ., • ·' . ot ·•' .,., .ot I II ,. , .,. u o :t.t t•o tto t•o uoo •• uo ••o '"·• "'' ' u 0 • • 't1, · ·~ ''·" ••• , ·· ' ••• • •• ••• ·'" . .. . . , , , I II l ilt ) .. I • •o • 1 • • • uo to u .oo •• uo uo n ,,,, ' .)!_ o ...... ···' ••• t .• .,..~ ••••~ . ,, ...!., '" ,,., 1000 u a IMO'\Jn. o '" to uo II I I 10 ttn t U ••tt ,,., '•·• ,. ., ''·- ,, '•' . ~ ·•• .oa •• , tut I U 0 111 t~ ' " uoo t oo '•oo , ., •·• •• -. ••• u oa u o "o • '·' , . , '·' . 1 ' ·" • .,, ·•~ ·'' .ot ,,.''" nu 1 u _ o _ •• .. II ' ' U ' '·· ·~·· ·~·' ••• '·' • •• .., · •' l•l I • I 0 •• II I ' " ' 'u • 1f ''·' ··' ll.l •••• '·' • •• ·'' .... · ~ · " ,,,,"•' ,,. t u . ., ,.. .,. 10 •• ••• •• ., . ,. . ,, ... uo .. ., .,., ,,_, .... '·' '·' ... ·'' ... "" I U .. , ...... , ... JJ4 ll Jill$ 110 ,.,.. ' u ••·• t o., • ·• , .,,, ,., 1... '·" . at ' '•' ..... t II •o I. .... 1 100 no uno •• •••,' u .,.. .. , .. ... , ••• ·' 1 . 1 ••••• , ••, ,, , ~ ,. ,., ... .. •• ., •• uo . ,. ...,,...... ,. ·~ ttu ' u • ~ t t vv 1 6~ ) U r ~ I"•' t.l &t•t " • ' • " l o O rtt • • ...... •• ,t fO tl't l • D t HOU ) 1&0 IU U~ ,,,. a n t o _ o · " ,,,_.., J ... oo .. ,., ••· • •·• , , ,, 1 . ~ •·• •·t .to · ' , • .., • u • ... , 1 u 100.) ll ~J • oe ...N '•' n ••• u e •u • • n• o.t » • • • , •••• • • ••• • t . t ,.. • •• ·'' • .,. c~, I o•· i m~·tr· i c ., n \I ~~e ctro yP'"P' ' i c 21nco Y '-·<-s , ' ichol r-s l)pny s - M i I I ~tr'e,, m r~ I V <' l' · rcA , ~cw Brun~wick , . , 1 u ,. "" ' " 100 . .... n t 1 U O ._.0 IJO U OO l•o UO UO ... .. ,., .. , ''·"' '·' .. '·' ·'' ·' l ,, 1&6 •• t~ • • ••• • ... 64!) ''"' ''"'"' uo u o , .. 1 ..!.!....._!_ _._ tt.• ''•' ••l J l e• i . O ••• l , o ,,. ,., nu u t l ,.. , • • ' • • 11\0 · ~ ., '·' ''"" .. u u ' ... 0 ''·" ,.. '·' ...... ··' ··' ... • O ... to .l u •• n II I ''" l , . 0 • • , .. , • •• •• ••• , ..... •• ·"' - ~ · .u ••• •t , , ._ 1., •t uo U 'M u.ooa-o uo " ''·" ••••••o '·' ,1 ··' '·' • • , • • I• l 1•0 •UO lttiiO '••' . ·~--·--·- " ,... ,. ·~ • •• 0 .. . .. ' ••••••• , •• , t.l '·' 1.0 ·'' • • • ·' tu• 1 0 J4 t eO IU I I 10 • .., .. , ... ,.,. .., l , a lt <4 00 ...... U JJO 11 •t ' I O .. ,,.!._!_.J_._.__ o - -·-- ···" •••o •••• "·' ••& •• ,.. ·'· •• ... , I It liD 1• " 1·' • • , ,. uo t10o h no n nu t u , I U ... .. •• , a,t u •~r u lUts '' uo h "··· ,. 1Ul1 )) ... . _J I I• •• ·' . , l iJ"' ., ~... ,•• , ,_,.__o__ •• . , •• ' ' ·' • • , ••• •• 1 '•' ••• ••• •• I t • . ,, l ,. .. n •' "0 al l'? lU u uo tt n l&•t I \ 0 ... , .,_, '·' ...... ··' ·'' .. I l• U O tiO •• '•' u o J t O :uo tooouo uo •o " , , ••• 11 ) 1• •• .. n • 1 n t•o '"'" .,•ootoo Joo •• , 0 0 t O •' • O no l•O l'>OOUO ItO U M .. • ~'~ "'' .. , ., \J ... l '!tO l I 110 UO .. .. •• ' 10 • tttU' 1• ... •• .. .. I .. -~ ~~~~ ~.....,!. te _ o_ 0 _ o IOOIM' If""' •t.• U.l I 'tot • • o • •• .s t.o .l. .1 ,. , ., , ,, .,. ,., • Joe J 1 u 0 ltJC . •• ...... o 1 ~000 to. • u.t at.o '·• '·" ... ·'' ·' .... • I• .. J Itt "' liO 1l IMOUO r•o c: ,,.... ,, ...... ''·' .... , •• , ••••., ••• , .JJ • •• , .. •• .. • I Ill ) J..iO 170 10001-N It~ .&-.---.. '., ---:. '-'· I - ~ \ /- AFPENOIX 2 / >A'-'P<.E ~OCATIONS NICHO~A S DENY -MILLST REAM RI VER AREA --·- , I I ~ \ ' ' \ ' ' ' ' ' '' ' \ ' ' ..... -- - APPENDIX 3 DIAMOND DRILL HOLE SECTIONS SAMPLE POSITIONS MILLSTREAM IRON-BERESFORD COPPER AREA SCAL E 1' • 400' 92 APP.c;NDJ:X 4 Dia~ond Drill Ho le Sections and Sample Locations LEG.c;Nu • s i a.•• . , overburden Feldspar Porphyry *' Diabase - s • Se rpentinite Hornfels c=::Z::s'.-i;:JI Recrystallized Limestone Skarn Oonglomerate-Argillite m··:<:; .• ,.,, Ore ~ ·~ Breccia Fault Zone Sample location and number 99 VITA The a~thor was born on April 21, 1941, in Ottawa, On~ario, Canada. He received his primary and secondary education in Ottawa. He then entered Carleton University in Ottawa, graduating with first class honours in geoloqy in June, 1963. While at Carleton, he was awarded a Mercy Neal Southam Entrance Scholarship, held a J. P. Bickell Foundation Scholarship for four years and was awarded the prize of the Canadian Institute of Mining and Metallurgy. Upon graduation, he was awarded the Senate Medal. He entered the Missouri School of Mines and M~tallurgy in September, 1963, and has held a graduate assistantship in the Department of Geology. The author has been employed by Falsonbridge Nickel Mines, ·sherritt-Gordon Mines and Kerr-Addison Gold Mines in various parts of Canada. He has also spent two field sea sons with the Geological Survey of Canada and is presently on leave from that organization. He is a member of several professional societies and is also a member of Sigma Gamma Epsilon, an earth science honour fraternity.