Metallogeny of the Bathurst Mining Camp, Northern New Brunswick

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Goodfellow, W.D., 2007, Metallogeny of the Bathurst Mining Camp, northern New Brunswick, in Goodfellow, W.D., ed., Mineral Deposits of Canada: ASynthesis of Major Deposit-Types, District Metallogeny, the Evolution of Geological Provinces, and Exploration Methods: Geological Association of

Canada, Mineral Deposits Division, Special Publication No. 5, p. 449-469.

METALLOGENY OF THE BATHURST MINING CAMP, NORTHERN NEW BRUNSWICK

WAYNE D. GOODFELLOW

Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8Corresponding author’s email: [email protected]

Abstract

The Bathurst Mining Camp (BMC) hosts 45 volcanic-sediment hosted massive sulphide deposits and 95 occur-rences, including the super-giant Brunswick No. 12 deposit with a geological resource of 230 Mt grading 7.66 wt.% Zn,3.01 wt.% Pb, 0.46 wt.% Cu, and 91 g/t Ag. Ten of these deposits have been brought into production, with a total pro-duction to 1999 of 128 Mt with an average grade of 2.87 wt.% Pb, 6.58 wt.% Zn, 0.93 wt.% Cu, and 82 g/t Ag; onlythe Brunswick No. 12 deposit remains in production.

BMC deposits formed in a sediment-covered back-arc continental rift, referred to as the Tetagouche-Exploits back-arc basin, during periods when the basin was stratified with a lower anoxic water-column. The basin was subsequentlyintensely deformed and metamorphosed during multiple collisional events related to east-dipping subduction of the

basin.Four hydrothermal events spanning 12 to 14 million years have been recognized; the Chester (478 Ma), Caribou

(472-470 Ma), Brunswick (469-468 Ma), and Stratmat (467-465 Ma) horizons. The Stratmat and Brunswick horizons both occur in the Tetagouche Group, whereas the Caribou and Chester horizons are hosted by the California Lake andSheephouse Brook groups, respectively.

There are two major types of iron formation in the Bathurst Mining Camp. Type 1 is a carbonate-oxide-silicate ironformation that is spatially associated with most massive sulphide deposits of the Brunswick ore horizon. Type 2 con-sists of widely distributed Llanvirian Fe-Mn-oxides that are not spatially associated with massive sulphide deposits andformed during a period of oxygenated seawater conditions.

Most deposits are zoned vertically and laterally from a high-temperature, vent-proximal, Cu-Co-Bi-rich veined and brecciated core to vent-distal Zn-Pb-Ag-rich hydrothermal sediments. The vent complex is commonly underlain by ahighly deformed sulphide stringer zone that extends hundreds of metres beneath deposits and consists of veins andimpregnations of sulphides, silicates, and carbonates that cut chloritized and sericitized volcanic and sedimentary rocks.

The massive sulphide deposits formed from low-salinity and high-temperature (>300°C) buoyant hydrothermal flu-ids, which explains the vent-proximal nature of most deposits. The reduced sulphur in BMC deposits originated mostlyfrom an ambient reduced water column. Variations among deposits of different age are controlled by the global secular δ34S curve for sedimentary sulphate and sulphide. The base metals were probably derived from both hydrothermal andmagmatic fluids, whereas elements such as Sn, In, Au, As, and Sb probably originated from magmatic fluids.

Résumé

Le camp minier de Bathurst (CMB) compte 95 occurrences et 45 gisements de sulfures massifs logés dans desroches volcano-sédimentaires, y compris le gisement super géant Brunswick no 12, dont les ressources s'élèvent à 230Mt de minerai titrant 7,66 % massiques de zinc, 3,01 % massiques de plomb, 0,46 % massique de cuivre et 91 g/t d'ar-

gent. Dix de ces gisements ont été mis en exploitation, ce qui a permis de produire, jusqu'en 1999, 128 Mt de mineraititrant en moyenne 2,87 % massiques de plomb, 6,58 % massiques de zinc, 0,93 % massique de cuivre et 82 g/t d'ar-gent. Cependant, de ceux-ci, seul le gisement Brunswick no 12 demeure en exploitation.

Les gisements du CMB se sont formés dans un rift continental d'arrière arc recouvert de sédiments, soit le bassinmarginal de Tetagouche-Exploits, à l'époque où ce bassin présentait une stratification qui comportait une colonne d'eauanoxique inférieure. Le bassin a ensuite été déformé et métamorphisé au cours de multiples épisodes de collision rat-tachés à sa subduction à pendage oriental.

Quatre épisodes hydrothermaux qui se sont écoulés sur 12 à 14 Ma ont été identifiés dans les horizons de Chester (478 Ma), de Caribou (de 472 à 470 Ma), de Brunswick (de 469 à 468 Ma) et de Stratmat (de 467 à 465 Ma). Les hori-zons de Stratmat et de Brunswick se trouvent dans le Groupe de Tetagouche, tandis que ceux de Caribou et de Chester reposent respectivement dans les groupes de California Lake et de Sheephouse Brook.

Le CMB comporte deux principaux types de formations ferrifères. Le premier consiste en des formations ferrièresde carbonates-oxydes-silicates associées sur le plan spatial à la plupart des gisements de sulfures massifs de l'horizonminéralisé de Brunswick. Le second consiste en des oxydes de Fe et de Mn llanvirniens couvrant une grande étendue,qui ne sont pas associés sur le plan spatial aux gisements de sulfures massifs et qui se sont formés pendant une période

où l'eau de mer était oxygénée.La plupart des gisements présentent une zonation verticale et latérale qui va d'un noyau bréchifié, filonien, riche enCu-Co-Bi et voisin d'un évent à haute température jusqu'à des sédiments hydrothermaux riches en Zn-Pb-Ag éloignésde cet évent. Le complexe d'évent se trouve généralement au-dessus d'une zone de filonnets de sulfures fortement défor-mée qui s'étend sur des centaines de mètres sous les gisements et se compose de filons et d'imprégnations de sulfures,de silicates et de carbonates qui recoupent des roches sédimentaires et volcaniques séricitisées et chloritisées.

Les gisements de sulfures massifs sont issus de fluides hydrothermaux en ébullition à haute température (> 300°C)et dans un milieu à faible salinité, ce qui explique pourquoi la plupart d'entre eux se trouvent à proximité d'un évent. Lesoufre réduit dans les gisements du CMB est principalement attribuable à une colonne d'eau réduite ambiante. Les vari-ations parmi les gisements d'un âge différent sont restreintes par la courbe séculaire globale de valeurs de δ 34S rattachéeaux sulfates et aux sulfures sédimentaires. Les métaux communs sont probablement issus de fluides hydrothermaux etde fluides magmatiques, tandis que l'étain, l'indium, l'or, l'arsenic et l'antimoine proviennent probablement de fluidesmagmatiques.



Introduction and History

The Bathurst Mining Camp (BMC) is one of Canada'smost important base metal mining districts, accounting in2001 for 30% of Canada's production of Zn, 53% of Pb, and17% of Ag (Minerals and Metals Sector, Natural ResourcesCanada). The value of production from the BMC in 2001exceeded $500 million and accounted for 70% of total min-eral production in New Brunswick. Approximately 2000 people are directly employed by the mining industry in theBMC. Without the discovery of new ore reserves, miningwill cease in less than ten years at current production rates,eliminating the principal economic activity in northeastern New Brunswick.

Mining has taken place at ten BMC massive sulphidedeposits with a total production to 1999 of 128 milliontonnes with an average grade of 2.87 wt.% Pb, 6.58 wt.% Zn,0.93 wt.% Cu, and 82 g/t Ag, but only the Brunswick No. 12deposit is currently in production (Goodfellow andMcCutcheon, 2003). In addition, 0.337 million tonnes of Cuhave been mined from the Caribou supergene zone, and

1.254 million tonnes containing 136 g/t Ag and 4 g/t Au fromthe Caribou, Murray Brook, and Heath Steele gossans(Boyle, 2003; McCutcheon et al., 2003) (Table 1).

Approximately 70% of the deposits in the BMC were dis-covered in the 1950s using geological, geophysical, and geo-chemical methods (Goodfellow and McCutcheon, 2003).The pace of discovery of major deposits generally wanedafter the 1960s (McCutcheon et al., 2003). Almost everydeposit and occurrence, except for satellite lenses drilledduring underground development of major deposits (e.g.Brunswick No. 12 West Zone and Brunswick Northend),were discovered at the surface or subcropping beneath a gen-erally thin and discontinuous cover of glacial sediment. Thisis not surprising considering that the depth of penetration of

airborne electromagnetic systems is limited to a few hundredmetres (Keating et al., 2003), and conventional stream andtill geochemistry are only effective in detecting deposits thathave a near-surface expression (Leybourne et al., 2003;Parkhill and Doiron, 2003).

Geological and Tectonic Setting

The BMC has been subdivided into four approximatelycoeval groups of volcanic and sedimentary rocks(Tetagouche, California Lake, Sheephouse Brook andFournier groups) that host most of the deposits and overliesedimentary rocks of the Miramichi Group (Fig. 1). The dif-ferent groups comprise blocks and slivers (i.e. theTetagouche, California Lake, Sheephouse Brook, and

Fournier blocks and the blueschist, and Bamford Brook sliv-ers) that represent widely separated, ensialic to ensimatic parts of the Tetagouche-Exploits back-arc basin that were juxtaposed during the Ashgill - Ludlow closure of theTetagouche-Exploits back-arc basin (van Staal et al., 2003a)(Fig. 2, from van Staal et al., 2003a). The BMC is interpretedto have formed in a Sea of Japan style back-arc basin thatopened by rifting of continental crust in the Early Ordovician(Fig. 3).

Most of the deposits occur in the Tetagouche andCalifornia Lake groups. The California Lake Group containsapproximately equal proportions of felsic and mafic volcanic

rocks and probably represents a marginal basin underlain byoceanic and remnant continental crust. The TetagoucheGroup, in contrast, consists mostly of felsic volcanic rocksand was probably deposited in a different extensional basinthat was underlain by mostly continental crust (van Staal etal., 2003a).

Most BMC massive sulphide deposits are associated withsubmarine calc-alkalic felsic volcanic rocks that formedfrom melted continental crust during the initial stages of back-arc rifting. Felsic volcanic rocks consist of flows, sub-marine pyroclastic, volcaniclastic, and epiclastic depositsthat include quartz and quartz-feldspar phyric dacite to rhy-

olite, aphyric and crystal tuffs, hyaloclastites, autobreccias,and sub-volcanic quartz-feldspar porphyries. Continued back-arc rifting produced alkalic and tholeiitic basalt flowsand hyaloclastites, resulting in a bimodal volcanic sequence(Rogers and van Staal, 2003; Rogers et al., 2003). The basalts generally post-date felsic volcanism and associatedmassive sulphide deposits, and their compositions reflect a progression from low degrees of partial melting to more primitive, MORB-like tholeiites. The eruption of MORB-like basalts of the Tetagouche Group (~470-460 Ma) coin-cides with the formation of oceanic crust in the adjacentFournier Group (~465 Ma) and marks the transformation of the Tetagouche-Exploits back-arc rift basin to an oceanicmarginal sea (van Staal et al., 2003a).

The ambient seafloor environment in the Tetagouche-Exploits basin is interpreted to have varied from stratifiedwith anoxic bottom waters during the deposition of region-ally extensive Arenig black shales of the Knights Brook,Patrick Brook, Nepisiguit Falls, and Spruce Lake forma-tions, to well oxygenated during the deposition of Llanvirnian maroon shales and cherts, and returning toanoxic conditions during deposition of the Caradocian black shales (Goodfellow et al., 2003b). The Llanvirinan maroonshales and cherts post-date the formation of most massivesulphide deposits in the BMC (Fig. 2) and are widely dis-tributed, but are chemically similar to Fe- and Mn-oxyhy-

W. D. Goodfellow

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Deposit

Million

tonnes (Mt) Type

Pb

(%)

Zn

(%)

Cu

(%)

Ag

(g/t)

Au

(g/t)

Primary Sulfides

Brunswick No. 12 88.807 present 3.49 8.81 0.34 99.9

Brunswick No. 6 12.197 past 2.15 5.43 0.40 67.0

Captain North Ext (CNE) 0.039 past 4.42 9.97 134.7

Heath Steele ACD Zones 2.472 past 1.73 7.38 0.73 76.7

Heath Steele B Zone 20.723 past 1.75 4.79 0.98 65.5

Caribou 1.343 past 3.24 6.78 0.32 97.0

Restigouche 0.231 past 5.49 6.34 132.9

Wedge 1.504 past 0.65 1.61 2.88 20.6

Chester 0.003 past 1.46

Total 128.455 (avg) 2.87 6.58 0.93 82

Supergene Zones

Caribou 0.337 past 3.66

Gossans

Caribou 0.062 past 171.4 5.35

Heath Steele ACD, B 0.178 past 176 4.77

Murray Brook 1.014 past 61.4 1.79

Total 1.254 (avg) 136.1 3.97

Notes: from McCutcheon et al. (2003)

Heath Steele N-5 and

Stratmat Boundary1.137 past 2.98 8.11 0.35 44.0

TABLE 1. Tonnage and grades of past and present producers,Bathurst Mining Camp.





droxides associated with modern seafloor hydrothermalvents (Goodfellow et al., 2003b). Their high contents of Fe,Mn, Zn, Co, Ni, and P, and positive Ce/Ce* and Eu/Eu*anomalies provide evidence for major hydrothermal activityduring Llanvirnian time. However, most of the metal contentof the hydrothermal fluids that vented at the sea floor appears to have been lost to an oxidized ambient water col-umn and dispersed, consistent with the absence of massivesulphide deposits of this age in the BMC.

Mineral Deposits and Occurrences

Deposit Types and Classification

Two major deposit types occur in the BMC: 1) classic vol-canic-sediment hosted massive sulphide (VSHMS) deposits,and 2) secondary gold-rich gossans and related supergenezones preserved at some massive sulphide deposits.

The VSHMS deposits are an economically important sub-group of seafloor hydrothermal deposits that are hosted by both sedimentary and bimodal volcanic rocks in sedimented back-arc rifts. VSHMS deposits contain 23.7 Mt of sulphideson average compared to 5.2 Mt for deposits hosted by bimodal volcanic sequences containing minor sediment(Barrie and Hannington, 1999). Furthermore, seafloor hydrothermal deposits formed in sedimented back-arc rifts(i.e. VSHMS and SEDEX deposits) acount for well over

50% of the world's Zn and Pb reserves, and approximately40% of the world's Zn and Pb production.

Deposit Distribution

Four hydrothermal events spanning 12 to 14 million yearshave been recognized in the BMC. From oldest to youngest,these are Chester (478 Ma), Caribou (472-470 Ma),Brunswick (469-468 Ma), and Stratmat (467-465 Ma) ore

W. D. Goodfellow

452

O

H S

2

2

SubductionZone andIsland Arc

OceanicCrust

Back-arcRift

Shelf Land

Sea level

AsthenosphereO c

r u s t

AsthenosphereUpwelling

FelsicVolcanics

MassiveSulphides

GanderianContinent

Basinalsediments

Magma

Syn-riftclastics

e a n i c C

-

Oceanic Crust

FIGURE 3. Formation of the BMC in a back-arc continental rift partly filledwith a clastic sedimentary syn-rift sequence overlain by interbedded black shale and felsic volcanic rocks that host massive sulphide deposits (fromGoodfellow and McCutcheon, 2003).

LLANDOV.

ASHGILL

CARADOC

LLANVIRN

ARENIG

TREMADOC

CAMBRIAN

490 Ma

480 Ma

465 Ma

459 Ma

449 Ma

443 Ma

California Lakeblock

Tetagouche

block

CanoeLanding

Lakenappe

melangeblueschistnappe

SpruceLake

nappe

MountBrittain

nappe

MIRAMICHIGROUP

BBF

CRF

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KBF

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M B F

S L F

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AgeTectonicSetting

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Passivecontinental

margin

Transition

Back-arccontinental

riftFelsic

volcanism

Alkalic basalts

MissingSection

?

MBCBCL

TOM

HeathSteele

nappe

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PBF

KBF

LRF

HS

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TOM

CRF

PBF

TRF

HBF

KBF

LRF

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BMS

ST

Sheep-houseBrook

SRF

SKF

CRF

CSF

PBF

KBF

?

CH

SRF

SKF

CRF

CSF

PBF

KBF

?

CH

MineralizedHorizons

Stratmat

Brunswick/HS

Caribou

Chester

P e r i o

d

O R D

O V I C I A N

S I L

.

RSNFF

SLF FLB

FIGURE 2. Generalized stratigraphic columns showing the age and lithostratigraphy of deposits hosted by the Flat Landing Brook (FLB) and Nepisiguit Falls(NFF) formations, Tetagouche Group, the Spruce Lake (SLF), Mount Brittain (MBF), and formations, California Lake Group, and the Clearwater StreamFormation (CSF), Sheephouse Brook Group (modified from van Staal et al., 2003a). Other formations are Boucher Brook Formation (BBF), Chain of RocksFormation (CRF), Knights Brook Formation (KBF), Little River Formation (LRF), Patrick Brook Formation (PBF), and Slacks Lake Formation (SKF). Alsoshown are the tectonic settings and four major ore horizons. Thicknesses of stratigraphic units are not indicated because they have been modified by intensedeformation and show rapid lateral changes, particularly for felsic volcanic units. Deposits shown are Brunswick No. 6 and 12 (BMS), Caribou (CB), Chester (CH), Canoe Landing Lake (CL), Heath Steele (HS), Murray Brook (MB), Restigouche (RS), and Stratmat (ST).



horizons (Fig. 2). The term "ore horizon" refers to an episodeof hydrothermal activity that led to the formation of massivesulphide deposits hosted at a unique stratigraphic position.The Stratmat and Brunswick horizons both occur in theTetagouche Group, whereas the Caribou and Chester hori-zons occur in the California Lake and Sheephouse Brook groups, respectively.

Of the 45 known deposits in the BMC (McCutcheon et al.,2003), 31 are within the Tetagouche Group (Brunswick andStratmat horizons), 13 are in the California Lake Group(Caribou horizon), and one is in the Sheephouse Brook

Group (Chester horizon). Of the 25 deposits with more than1 Mt of delineated resources, the breakdown by group is 15,9, and 1, respectively. Clearly, the Tetagouche Group con-tains the majority of the deposits in the BMC and also con-tains 63 of the 95 VMS-type occurrences (McCutcheon etal., 2003).

The Brunswick horizon (of the Nepisiguit FallsFormation) is host to most of the deposits in the BMC. Thishorizon also contains the largest and most economicallyimportant deposits. The average tonnage of deposits of theBrunswick, Caribou and Chester horizons, respectively, is between 10 and 20 Mt, although the Chester horizon

(Clearwater Stream Formation) contains only one deposit.Deposits hosted by the Stratmat horizon (Flat Landing Brook Formation) are generally smaller with an average size of 1.57 Mt (Goodfellow and McCutcheon, 2003).

Grade and Tonnage Statistics

The massive sulphide deposits in the BMC range in sizefrom <1 Mt to the super-giant Brunswick No. 12 depositwith geological resources of 229 Mt (Fig. 4A and Appendix1). Massive sulphide deposits average 12.74 Mt with averagegrades of 4.72 wt.% Zn, 1.78 wt.% Pb, 0.64 wt.% Cu, 51 g/t

Ag, and 0.54 g/t Au. Total mineral resources in the BMC for all deposits for which estimates have been made are 496.9 Mt(Goodfellow and McCutcheon, 2003).

Most Bathurst deposits plot near the Pb-Zn axis on a ter-nary Pb-Zn-Cu diagram, and overlap the field for CanadianPb-Zn-Cu deposits; only the Louvicourt and Restigouchedeposits fall in the Zn-Pb field. The average Pb/(Pb+Zn) andCu/(Cu+Pb+Zn) ratios for all deposits are 0.27 and 0.20,respectively. Cu/(Cu+Pb+Zn) ratios are highly variable andrange from very low values for the Flat Landing Brook deposit (0.004), to moderate values for the Brunswick No.12 (0.041), and No. 6 (0.074) deposits, and to high values for

Metallogeny of the Bathurst Mining Camp, Northern New Brunswick

45

.1 1 10 100

0

50

100

RestigoucheBMS North

Rocky Turn

Louvicourt

CNE Heath SteeleWest Grid

Key AnaconTaylor Brook Orvan Brook

Heath Steele ACD Zone

BMS#6

Caribou

Heath SteeleB Zone

BMS#12

StratmatMain

StratmatCentral

StratmatBoundary

StratmatS-1

Wedge HalfmileLake

Canoe Landing

Murray Brook

Chester

Armstrong A

Austin Brook

Flat LandingBrookCaptain

Headway

Nepisguit C Armstrong B

Nepisiguit A, B

Heath Steele

E Zone

Halfmile North

A g

( p p m

)

Million tonnes

100

.1 1 10 100 1000

.1

1

10

Million tonnes

Kuroko DepositsIberian Pyrite BeltBathurst Mining CampMount Read Beltother VHMS deposits

1

1

30

20

3

5

0

0.1 1 10 100 1000

P b + Z

n ( w t . % )

Million tonnes

BMS#12

RockyTurn

CaptainNorth

Restigouche

StratmatMain

StratmatBoundary

StratmatCentral

Louvicourt

Armstrong B

AustinBrook

Chester

Heath SteeleB-zone

CanoeLanding

Lake

MurrayBrook

Spruce Lake Fm.Nepisiguit Falls Fm.Flat Landing Brook Fm.Mount Brittan Fm.Canoe Landing Lake Fm.Cleawater Stream Fm.

HS WestGrid

Key Anacon

StratmatS-1

BMS#6Caribou

Heath Steele ACD-zoneOrvan

Brook

BMSNorth

Headway

Taylor Brook

Flat LandingBrook

HalfmileLake North Heath SteeleE-zone

Wedge

Nepisiguit A

Pabineau

NepisiguitC

NepisiguitB

Armstrong A

Million tonnes

.1 1 10 100 100010

100

1000

10,000

A u ( p p b )

Brunswick # 12

Brunswick # 6

Heath SteeleB-zone

Key Anacon

Halfmile Lake

Flat LandingBrook

Captain

Louvicourt

S

Restigouche Orvan

Brook

CanoeLanding

tratmat

Taylor Brook

Caribou

Wedge

ArmstrongA

McMaster

Rocky Turn

MurrayBrook

Chester

A

C D

B

HalfmileLake

California Lake Group

Tetagouche Group

Flat Landing Brook Fm.

1000

P b + Z

n ( w t . % )

FIGURE 4. Grade versus tonnage plots for massive sulphide deposits. (A) Pb+Zn versus millions of tonnes, BMC. (B) Pb+Zn versus millions of tonnes for

massive sulphide deposits of the BMC, the Kuroko district (Tanimura et al., 1983), the Iberian Pyrite Belt (Sáez et al., 1999), and the Mount Read Belt (Large,1992). (C) Ag versus millions of tonnes, BMC. (D) Au versus millions of tonnes, BMC.



the Heath Steele B-zone (0.215), Chester (0.309), and Wedge(0.426) deposits. Deposits such as Wedge and Chester withhigh Cu/(Pb+Zn) ratios are characterized by a vent complexwith relatively minor bedded ore facies.

Compared to similar deposits elsewhere, the Pb+Zn con-tents of deposits of the BMC are generally higher than for deposits of the Iberian Pyrite Belt (Sáez et al., 1999), over-

lap values for the Kuroko deposits (Tanimura et al., 1983),and are mostly less than those for deposits of the MountRead District (Large, 1992) (Fig. 4B). Ratios of Pb/(Pb+Zn)for Bathurst deposits are generally higher than those for theMount Read deposits (Large, 1992) and lower than for deposits of the Iberian Pyrite Belt (Sáez et al., 1999).

Brunswick horizon deposits are also relatively enriched inPb and Zn compared to deposits in the Caribou horizon(Spruce Lake and Mount Brittain formations) (Fig. 4A); theStratmat deposits in the Flat Landing Brook Formation havegenerally the highest Pb+Zn grades (Fig. 4A). These varia-tions in metal grades among the different ore horizons arereflected by a systematic increase of Zn, Pb, and Ag withdecreasing age, from the Chester horizon to the Stratmathorizon. Copper generally behaves antithetically to Pb, Zn,and Ag, decreasing with decreasing age, except for theStramat deposits where Cu is higher than for Brunswick horizon deposits. Pb/(Pb+Zn) ratios of average deposit com-

positions display a systematic increase from the Caribou tothe Stratmat horizon, whereas Cu/(Cu+Pb+Zn) ratiosdecrease from the Chester to the Brunswick horizon(Goodfellow and McCutcheon, 2003).

Average Ag grades display a wide range, from about 10up to 110 g/t in the Brunswick North deposit (Fig. 4C); Au islikewise highly variable, ranging from about 50 to about

3000 ppb (Fig. 4D) (Goodfellow and McCutcheon, 2003;McClenaghan et al., 2003). Silver is depleted in deposits of the Spruce Lake Formation compared to those hosted by theFlat Landing Brook and Nepisiguit Falls formations. Gold behaves antithetically to Ag and is enriched in deposits of theCaribou horizon relative to deposits of other ore horizons(Fig. 4D). Unlike Zn and Pb (Fig. 4A), Au generally displaysa positive correlation with increasing tonnage (Fig. 4D).

Geology of Volcanic-Sediment Hosted Massive Sulphide Deposits

Morphology and Architecture

The morphology of massive sulphide deposits in the BMC

ranges from mounds with low aspect ratios (length: thick-ness) to tabular bodies with high aspect ratios (Goodfellowand McCutcheon, 2003). Three types of deposits are recog-nized on the basis of morphology, architecture, textures,mineralogy and metal zoning. Type 1 consists of economi-

W. D. Goodfellow

454

HWHW

HW

HW

HWHW

FW

HW

39,500

40,500

7 6 ,

5 0 0

7 7 ,

5 0 0

7 8 ,

5 0 0

WEST OREZONE

MAIN OREZONE

FW

FW

Geological contact(known; assumed)Fault(known; assumed)

Bedded pyrite(low grade)

Bedded sulphides(Py+Sp+Gn)

HW

FW

Silicate facies

Quartz-feldspar porphyry

Quartzose chloriticschist; interbedded tuff

FLAT LANDING BROOK FM. NEPISIGUIT FALLS FORMATION

Sulphide Facies

Po+Py±Cp±Sp±Gn

Po+Py+Cp+Sp+Gn

Footwall Sedimentary Rocks

Quartzose chlorite-sericiteschist with sulphidedisseminations and laminae

Quartz and feldspar crystal tuff

Quartz and quartz-feldspar augen schist

PATRICK BROOKFORMATION

Argillite, fine tomedium greygreywacke andphyllitic schist

Graphitic schist

SYMBOLS

Stringer sulphidezone (Po+Py+Cp);silicified

Vent ComplexCarbonate-oxide-silicate facies

Iron Formation

HW

N

FIGURE 5. Geology of the 1400-foot level, Brunswick No. 12 deposit showing the general stratigraphy and all the different hydrothermal facies (from Luff et al., 1992).



cally important tabular bodies (e.g. Brunswick No. 12 and No. 6, Heath Steele B-zone, Caribou, Halfmile Lake) that arezoned vertically and laterally from a high-temperature, vent- proximal, veined and brecciated core to vent-distalhydrothermal sediments as follows: 1) vent complex (Po+Mt+Py+Cp+Qtz± Sp±Gn); 2) bedded ores (Py+Sp+Gn±Cp);and 3) bedded pyrite (Py±Sp±Gn). This mineral zonation isreflected by higher values of Cu, Co, Bi, and

Cu/(Cu+Pb+Zn) in vent proximal facies and higher values of Zn, Pb, Ag, Au, Cd, Sn, In, As, Sb, Tl, Hg, andCu/(Cu+Pb+Zn) in vent distal facies. Type 2 deposits arecharacterized by pod-shaped bodies of massive Cu-rich min-eralization interpreted as a vent complex (e.g. Chester,Wedge). It is possible that Type 2 deposits are Type 1deposits that have lost most of their distal facies by erosion.Type 3 deposits are tabular, unzoned, lack a vent complex,and may represent distal or reworked clastic deposits (e.g.Orvan Brook, Canoe Landing Lake).

The vent complex in Types 1 and 2 deposits is commonlyunderlain by a highly deformed sulphide feeder zone thatextends hundreds of metres beneath the deposit. The feeder

zone consists of impregnations and veins of pyrrhotite± pyrite+chalcopyrite+quartz that cut hydrothermally alteredvolcanic and sedimentary rocks.

Hydrothermal Sulphide Facies

Massive sulphide deposits in the BMC are represented byup to five distinct hydrothermal facies: 1) bedded ores,2) bedded pyrite, 3) vent complex, 4) sulphide stringer zone,

and 5) carbonate-oxide-silicate iron formation. TheBrunswick No. 12 deposit is one of the better examples of adeposit where all the facies are well represented in both themain and west ore zones (Fig. 5). The massive sulphides aregenerally fine- to medium-grained and texturally variable.Pyrite, pyrrhotite, sphalerite, galena, and chalcopyrite comprise over 95% of the sulphides; arsenopyrite, marcasite,stannite, tetrahedrite, freibergite, boulangerite, jamesonite, bournonite, magnetite, cassiterite, siderite and quartzaccount for most of the remaining hydrothermal minerals(Stanton, 1959; Roy, 1961; Boorman, 1975; Jambor, 1979;Goodfellow, 2003; Goodfellow et al., 2003a ).


45

FIGURE 6. Photographs of the bedded ores and bedded pyrite facies indeposits of the BMC. (A) Brown sphalerite and grey galena interbandedwith medium-grained pyrite, Brunswick No. 12 deposit; (B) Fine-grained

brown sphalerite interbedded with fine-grained pyrite, Caribou deposit;(C) Weakly bedded fragmental sulphides composed of pyrite, sphalerite

and galena, Taylor Brook deposit; (D) Brown sphalerite and galenainterbedded with pyrite, Orvan Brook deposit; (E) Laminated BeddedPyrite facies, Brunswick No. 12 deposit; (F) Interbanded dark grey chlo-ritic sediment and pyrite with variable sphalerite and galena, Halfmile Lakeand Heath Steele C-zone.

FIGURE 7. Photographs of the vent complex associated with massive sulphide deposits of the BMC. (A) Fragments of pyritic sulphides in a matrixof predominantly pyrrhotite (Po), chloritized (Ch) host rocks, quartz (Qtz),and chalcopyrite (Ccp), Heath Steele deposit; (B) Fragments of massive

pyrite (Py), one of which is cut by a quartz vein, in a matrix of mostly

pyrrhotite (Po) containing blebs and disseminations of chalcopyrite (Ccp),Halfmile Lake deposit; (C) Clasts comprised of pyrite (Py), magnetite(Mgt), and chalcopyrite (Ccp) in a matrix of pyrite, quartz, and ferroan car-

bonate, Caribou deposit; (D) Clasts of strongly chloritized host rocks (Ch)and quartz (Qtz) in a fine-grained matrix of pyrrhotite (Po) with blebs anddisseminations of chalcopyrite (Ccp), Key Anacon deposit.



Bedded Ores consist generally of fine- to medium-grained, interbanded pyrite, brown sphalerite and galena(Fig. 6A, B, E, F). Minor sulphide minerals includearsenopyrite, marcasite, cassiterite, stannite, tetrahedrite and bournonite. Gangue minerals occur as disseminationsthroughout, or form bands consisting of siderite, ankerite,

dolomite, calcite, barite, magnetite, cassiterite, quartz, chlo-rite, muscovite, talc, stilpnomelane, minnesotaite andchamosite. In addition to the most common granular aggre-gates, pyrite displays recrystallized, colloform, framboidaland vuggy textures (Lea and Rancourt, 1958; Stanton, 1959;Boorman, 1975; Chen, 1978; Jambor, 1979; Goodfellow,2003).

Sphalerite bands are commonly wispy and discontinuous,and are interpreted to represent layers of very fine-grained bedded sulphides that have been recrystallized and intenselydeformed. Galena occurs with sphalerite, although it is lessabundant than sphalerite and is generally finer grained than

either sphalerite or pyrite. Galena typically forms blebs,veins, and disseminations in sphalerite and appears to havereplaced sphalerite locally. Chalcopyrite and pyrrhotite arerelatively minor in the bedded ore facies compared to thevent complex. Where chalcopyrite does occur in bedded sulphides, it is as veins that cut other sulphides, and as blebsand disseminations that replace sphalerite and pyrite.

Chalcopyrite also occurs in the interstices of pyrite grainsand as exsolution-like blebs in sphalerite.

The Bedded Pyrite facies (Fig. 6C, D) represents anuneconomic component of many massive sulphide depositsand consists mainly of massive, barren pyrite with minor sphalerite, galena, and chalcopyrite. At the Brunswick No.12 deposit, it forms a discrete facies in the main ore zonewhere it both overlies and is lateral to bedded ores (Fig. 5).The pyrite facies displays a range of macrotextures rangingfrom massive to well bedded and locally collomorphic. Atthe microscopic scale, the pyrite is euhedral to subhedral,and locally framboidal (Chen, 1978).

The Vent Complex is composed of pyrrhotite and/or pyrite breccia that is infilled, variably replaced and veined by pyrrhotite, pyrite, chalcopyrite, magnetite, chlorite, quartz,and ferroan carbonates, mostly siderite (Fig. 5). Individualclasts are rounded to angular, up to 10 cm across, and con-sist of pyrrhotite, pyrite and chloritized host rocks (e.g.Heath Steele, Fig. 7A; Brunswick No. 12, Fig. 7B), and pyrite and magnetite (Caribou, Fig. 7C). At the Key Anacondeposit, the pyrrhotite appears massive with interstitial sili-cates and chalcopyrite (Fig. 7D).

Chalcopyrite veins, blebs and disseminations occur throughout the matrix and locally in clasts. Unlike sphaleritein the bedded ores, sphalerite in the vent complex occursmost commonly as veins and in the matrix of massive pyrrhotite/pyrite breccias. The sphalerite in the Caribou vent

complex is generally dark grey to black and is enriched in Fe(mean = 5.6 wt.%), but is depleted in Cd, Mn and Sn compared to sphalerite from the bedded ores. Galena in theCaribou vent complex contains significantly higher Ag con-tents (mean = 0.11 wt.%) compared to galena from the bed-ded sulphides (mean = 0.006 wt.%). At Caribou, magnetitecommonly forms patches, veins and disseminations in thevent complex and is more abundant than in the bedded ores(Goodfellow, 2003).

The evidence that these breccias formed by vent-related processes includes 1) the absence of bedded textures that arecommon in the distal part of deposits; 2) the occurrence of breccias above a well developed sulphide stringer zone witha vein mineralogy similar to that in the overlying Vent

Complex; and 3) the high chalcopyrite, pyrrhotite, and mag-netite content of the massive sulphides, which is typical of vent-proximal sulphides associated with VHMS depositselsewhere (Large, 1977, 1992; Galley et al., 1995; Sáez etal., 1996; Goodfellow et al., 1999).

The Sulphide Stringer Zone consists of veins and impreg-nations of sulphides in hydrothermally altered sedimentaryand volcanic rocks that underlie the vent complex. Sulphideminerals are predominantly pyrrhotite and/or pyrite with dis-seminations and veins of chalcopyrite, and traces of spha-lerite and galena. Non-sulphide minerals include anhedral tosubhedral quartz and ferroan carbonate minerals. The sul-

W. D. Goodfellow

456

FIGURE 8. Photographs of sulphide stringer zone samples from massive sulphide deposits, BMC. (A) Veins of recrystallized pyrite (Py) cutting quartz-feldspar ‘porphyry’ hydrothermally altered to phengite (Ser) and chlorite(Chl), Nepisiguit Falls Formation, Brunswick No. 12 deposit.(B) Pyrrhotite (Po) veins cutting chloritized (Chl) volcaniclastic rocks

underlying the Brunswick No. 6 deposit. Veins have been transposed intothe penetrative cleavage planes. (C) Brecciated host rocks underlying theKey Anacon deposit infilled and veined by pyrrhotite (Po) with dissemi-nated chalcopyrite (Ccp). (D) Breccia fragments of altered and deformedhost rocks infilled by pyrrhotite, Halfmile Lake deposit. (E) Breccia frag-ments of altered volcanic rocks infilled by pyrrhotite and hydrothermalquartz, Chester deposit. (F) Transposed veins of recrystallized pyrite (Py)and quartz (Qtz) cutting intensely sericitized (Ser) and chloritized (Chl) fel-sic volcanic rocks beneath the Caribou deposit.



phide veins are irregular to anastamosing, continuous to dis-continuous, and are characterized by sharp boundaries withalteration selvages composed mostly of chlorite and mus-covite (Goodfellow, 2003). Most veins have been transposedsub-parallel to bedding by deformation, giving the sulphidestringer zone a stratabound appearance (de Roo and vanStaal, 2003; Luff et al., 1992).

A sulphide stringer zone stratigraphically underlies theBrunswick No. 12 deposit, south of the main and west orezones (Fig. 5). Here, pyrite veins cut chloritized and sericit-ized quartz-feldspar porphyry (Fig. 8A) and crystal tuff of the Nepisiguit Falls Formation (Luff et al., 1992). At theBrunswick No. 6 deposit, pyrrhotite±chalcopyrite veins cutchloritized host rocks (Fig. 8B), whereas the Key Anacon(Fig. 8C) and Halfmile Lake (Fig. 8D) stringer zones arecomposed of clasts of chloritized host rocks suspended in a pyrrhotite chalcopyrite matrix. The sulphide stringer zone atthe Chester deposit is represented by a hydrothermal breccia,with interstitial pyrrhotite±chalcopyrite+quartz and chloritealteration (Fig. 8E), which cuts altered felsic volcanic rocksof the Clearwater Stream Formation (Fyffe, 1995). At the

Caribou deposit, this zone is represented by a network of dominantly pyrite veins (Fig. 8F) that cut pervasively chlori-tized and sericitized sedimentary and felsic volcanic rocks(Goodfellow, 2003).

Hydrothermal Sediments

There are two major types of iron formation in the BMC.Type 1 is the carbonate-oxide-silicate iron formation that isspatially associated with most Arenigian massive sulphidedeposits of the Brunswick ore horizon (e.g. Brunswick No.12 and 6, Austin Brook, Heath Steele, Key Anacon) (Saif,1980; Peter and Goodfellow, 1996; Peter and Goodfellow,2003; Peter et al., 2003a,b). None of the other mineralizedhorizons in the BMC (i.e. Chester, Caribou, and Stratmat)contain Type 1 iron formations. Type 2 consists of widelydistributed Llanvirian Fe-Mn oxides that are not spatially or temporally associated with massive sulphide deposits(Goodfellow et al., 2003b). Type 1 iron formations have been divided into four major facies on the basis of mineral-ogy: carbonate (mostly siderite), magnetite, silicate andhematite.

The carbonate facies is composed of mostly interbeddedsiderite, chert, and epiclastic sedimentary rocks (Fig. 9A); beds of apatite occur locally. Siderite layers are variable inthickness and commonly display sharp basal contacts anddiffuse tops, and in some samples the siderite is delicatelylaminated (Fig. 9B). The hydrothermal minerals are domi-

nated by siderite, quartz (after chert), calcite, dolomite, andkutnahorite. Minor phases include apatite, magnetite, stilp-nomelane, spessartine garnet, pyrrhotite, sphalerite, andgalena (Peter and Goodfellow, 1996; Peter et al., 2003b).The apatite locally forms beds whereas the magnetite com-monly occurs as euhedral crystals that intersect bedding planes and clearly postdate sedimentation.

The magnetite facies is commonly associated with thecarbonate facies and consists of magnetite interbanded withsiderite (Fig. 9C, D). Unlike the siderite facies, the magnetite bands do not display internal layering. Major hydrothermalminerals are magnetite, siderite, and quartz (after chert);minor phases include apatite, stilpnomelane, pyrrhotite,

chalcopyrite, sphalerite, and galena (Peter and Goodfellow,1996; Peter et al., 2003b). The lack of distinct layering inmagnetite bands and the secondary growth of magnetite in bedded siderite suggest that magnetite formed after sedi-mentary siderite, either during diagenesis or metamorphism.

The silicate facies is a green to black chloritic schist,locally spotted with siderite (Fig. 9E). It occurs interbedded

with other iron formation facies, and is common near the dis-tal margins of the iron formation. It consists primarily of felted chlorite masses and generally minor chert, stilpnome-lane, phengite, feldspar, biotite, ilmenite, rutile, epidote,apatite, magnetite, spessartine garnet, sphalerite, galena,chalcopyrite, arsenopyrite, and bornite (Peter et al., 2003b).The hematite facies is restricted to the Austin Brook andBrunswick No. 6 deposits where it occurs near the top of thick iron formation sequences. The hematite is interbeddedwith carbonate, magnetite, and silicate facies. Major miner-als are hematite, chert, and magnetite.

Llanvirian Fe-Mn-oxides in maroon chert (Fig. 9F) andshale, Type 2 iron formation, constitute the most widespread


45

FIGURE 9. Photographs of iron formations, BMC. (A) Interbedded cream toorange siderite (Sd) and silicate host rocks, proximal facies, Brunswick No.12 deposit (J. Peter, unpublished). (B) Delicately interlaminated cream togrey siderite (Sd) and host sedimentary rocks; (C) Interlaminated creamsiderite (Sd) and magnetite (Mgt), proximal facies, Brunswick No. 12

deposit (from Peter and Goodfellow, 1996). (D) Dark grey interlaminatedmagnetite and dark grey shale, minor disseminated sulphides, mostly

pyrite, intermediate to distal facies (J. Peter, unpublished). (E) Pale tomedium green chloritic iron formation (Ch) with disseminated carbonatealigned along bedding planes, distal facies (from Peter and Goodfellow,1996). (F) Maroon hematitic (Hem) chert interbedded with alkali basalt,Little River Formation, Brunswick No. 12 area.



chemical sedimentary rocks in the BMC. These rocks havehigh contents of Fe, Mn, Zn, Co, Ni, and P, and positiveEu/Eu* anomalies when normalized to North Americanshale composite (Gromet et al., 1984), and are chemicallysimilar to Fe- and Mn-oxyhydroxides associated with mod-

ern seafloor hydrothermal vents (Goodfellow et al., 2003b).Any base metals present in the venting hydrothermal fluidshave been lost to an oxidized ambient water column and dispersed over large areas of the Tetagouche rift, similar to thefate of metals in modern day black smokers.

Type 1 iron formations provide a valuable stratigraphicmarker for locating sequences favourable to exploration andvectors for defining hydrothermal centres and associateddeposits along mineralized horizons. In general, Type 1 ironformations are zoned laterally such that the thickness andrelative proportion of hydrothermal components increasewith proximity to sulphide deposits (Peter and Goodfellow,

1996, 2003). For example, in the Heath Steele belt the con-tents of siderite, magnetite, and sulphur (Fig. 10A) are high-est in the vicinity of the B, E, H2, and Mowat zones (Peter and Goodfellow, 2003). Most chalcophile elements includ-ing Tl (Fig. 10B), Ag (Fig. 10C), and Pb (Fig. 10D) areanomalously high near massive sulphide deposits. The mosteffective vectors include siderite, magnetite, Fe/Mn, Ba/Al,P/Al, Zn, Pb, Cu, Ag, As, Au, Bi, Cd, Co, Mo, Se, Sb, Sn, In,Tl, and Eu/Eu*, all of which increase with proximity to sulphide deposits (Peter and Goodfellow, 1996, 2003). In addi-tion, the composition of minerals also reflects bulk chemicalchanges of the whole rock; for example, the Fe/Mn ratio in

W. D. Goodfellow

458

Tl ppm

B

Ag ppm

C

Pb ppm

D

S wt.%

A 0 km 2 N

0 km 2 N 0 km 2 N

0 km 2 N

FIGURE 10. Spatial distribution of elements in iron formation associated with massive sulphide deposits, Heath Steele belt, for (A) sulphur; (B) thallium;

(C) silver; (D) lead (from Peter and Goodfellow, 2003).

seafloor

sedimentary rocks

nil

low

mod

high

siderite,stilpnomelane,ankerite, calcite,biotite,chalcopyrite,CO2/Ti, P/Ti,Sr/Ti,Cu (bulk)Fe/Mn(siderite)

magnetite,pyrite,pyrrhotite,

Fe/Mn, S(Bulk)

0 0.5 1 1.5-0.5-1-1.5

sphalerite, galena,Fe/Ti, Eu/Eu*, Pb,Zn ,

Ag,As, Au, Bi, Cd,Hg,In,Sb,Sn,Tl,HTSIX(bulk)

Ba/Ti,1/(Ce/Ce*) (bulk)

water column

Distance (kilometres)

tuffaceous andsedimentary rocks

massive sulphides

feeder zone

hydrothermalalteration

hydrothermalsediment R

e l a t i v

e a

b u n

d a n c e

FIGURE 11. Schematic diagram showing the lateral extent of mineral andchemical halos that surround massive sulphide deposits in the BMC (fromPeter and Goodfellow, 2003).



siderite increases toward deposits as the Fe/Mn ratio of thewhole rock increases.

The size of mineralogical and chemical halos surround-

ing massive sulphide deposits is variable and dependent onthe particular vector (Peter and Goodfellow, 2003). In gen-eral, siderite, stilpnomelane, ankerite, calcite, biotite, chal-copyrite, and Cu are restricted to within about 0.5 km of mineralization, whereas sphalerite, galena, Pb, Zn, Ag, As,Au, Bi, Cd, Hg, In, Sn, Sb, and Tl extend up to 1.5 km frommassive sulphide deposits (Fig. 11).

Hydrothermal Alteration

Both pre- and post-ore hydrothermal alteration is associ-ated with most deposits in the BMC, although hydrothermalalteration has been documented in detail for only a fewdeposits. These include the Brunswick No. 12 (Goodfellow,1975; Juras, 1981; Luff et al., 1992; Lentz and Goodfellow,1993, 1996), Brunswick No. 6 (Nelson, 1983; Yang et al.,2003), Heath Steele (Wahl, 1977; Lentz et al., 1997),Halfmile Lake (Adair, 1992; Yang et al., 2003), and Caribou(Goodfellow, 2003) deposits.

The vent complex associated with most deposits is typi-cally underlain by a highly deformed sulphide feeder zonethat extends hundreds of metres beneath the deposit. Thisfeeder zone is characterized by impregnations and veins of sulphides, silicates, and carbonates that cut hydrothermallyaltered volcanic and sedimentary rocks. Hydrothermal alter-ation is widespread (1-5 km laterally and hundreds of metresvertically) and comprises the following assemblages fromthe core to the margins of the feeder zone (Fig. 12): Zone 1

- Quartz+Fe-rich chlorite+pyrrhotite+chalcopyrite (Fig.13A); Zone 2 - Fe-rich chlorite+phengite +/- pyrite (Fig.13B); Zone 3 - Fe-Mg-chlorite+phengite+albite (Fig. 13C,D); Zone 4 - albite+Mg-rich chlorite (Fig. 13E, F). Volcanicrocks overlying some deposits are also altered to Mg-richchlorite and albite (Luff et al., 1992; Lentz and Goodfellow,1993; Goodfellow, 2003). In general, sulphides, chlorite, and phengite increase, and feldspars decrease with proximity tothe core of the hydrothermal fluid upflow zone. A schematicdiagram showing the spatial distribution of hydrothermalalteration zones typical of the Brunswick No. 12 deposit is presented in Figure 12. Talc is also an important alteration phase in the Stratmat deposits, although the alteration assem-

blages and their distribution have not been documented indetail (Hamilton, 1992).

Compared to similar unaltered rocks, hydrothermallyaltered felsic volcanic rocks in Zone 1 are characterized byelevated Si, Fe, CO2, Cu, Zn, Pb, Ag, Cd, Sn, In, Bi, Tl, As,Sb, and Hg contents, and Eu/Eu* ratios, and are depleted in Na and Ca. The composition of Zone 2 is similar to Zone 1

except for silica, which is not as notably enriched as in Zone1. Zone 3 is enriched in Mg, Mn, CO2, S, and base metals,and depleted in Na, Ca, K, Ba, and Rb as a result of wide-spread hydrothermal alteration of both K-feldspar and pla-gioclase to chlorite and phengite. Anomalous base metal andCO2 contents reflect minor sulphide and carbonate dissemi-nations and veinlets in the distal parts of the hydrothermalupflow zone. Zone 4 is enriched in Mg and Na and depletedin Ca, reflecting the chloritization and albitization of K-feldspar, which originally was probably microcline (Luff etal., 1992; Rogers et al., 2003).


45

PRE-DEFORMATION

Felsic Pyroclastics(Nepisiguit Falls Fm.)

3-5 km 1-3 km 3-5 km

Zone 3

Zone 2Fe-chlorite+/-

phengite(sulphidestringer

zone)

Zone 1

(Quartz+Fe-chlorite)

Zone 3(Fe-Mg-chlorite+

phengite)

Zone 4(Phengite+

Mg-chlorite)

Felsic Volcanics(Flat Landing Brook Fm.)

Mineralized

HorizonZone 3

Sulphide Zone

FIGURE 12. Schematic diagram showing the distribution of the differenthydrothermal alteration zones at the Brunswick No. 12 deposit, BMC (mod-ified from Lentz and Goodfellow, 1994).

FIGURE 13. Hydrothermal alteration facies, Brunswick No. 12 deposit.(A) Photograph of silicified (Qtz) and chloritized (Chl) sedimentary rockswith pyrite (Py) veins and disseminations beneath the vent complex (Zone1 in Fig. 12). (B) Photograph of phengitized (Ser) and silicified quartz (Qtz)

phyric pyroclastic volcanic rocks cut by pyrite (Py) stringers (Zone 2).Feldspars have been destroyed by hydrothermal alteration.(C) Photograph of quartz (Qtz)-feldspar (Kfp) phyric pyroclastic volcanicrocks that have been altered to Mg-rich chlorite and phengite (Zone 3).(D) Photomicrograph of Mg-rich chlorite (Chl) showing a diagnostic olivegreen colour under polarized light (Zone 4). (E) Photomicrograph of chess-

board albite (Ab) alteration of what is was probably a microcline phe-nocryst, Nepisiguit Falls Formation (Zone 4). (F) Photomicrograph of aquartz mosaic replacing a K-feldspar phenocryst in the quartz-feldspar "porphyry", Nepisiguit Falls Formation (Zone 3).



The relative changes of major cations in unaltered felsic

volcanic rocks and the different alteration zones at theBrunswick No. 12 deposit are illustrated with an unfolded(FeOT+MgO) - (CaO+Na2O) - Al2O3 - K 2O tetrahedron

(Fig. 14). Altered felsic volcanic and sedimentary rocksshow the same general trend of increasing FeO+MgO at theexpense of the alkali elements bound in feldspar.

Sulphide Deformation and Metamorphism

Deposits of the BMC have been intensely deformed andmetamorphosed during multiple collisional events related tosubduction of the Tetagouche-Exploits back-arc basin. The penetrative polyphase ductile deformation (D1 to D4) thataffected all rock units in the BMC commenced in the Late

Ordovician (Ashgill) and ended in the Late Devonian (vanStaal and de Roo, 1995). Peak metamorphic conditions varyfrom 325 to 400°C and 6 to 7 kb (Currie et al., 2003). The present distribution and morphology of massive sulphidedeposits and associated sulphide stringer zones are mainlycontrolled by D1 and, to a lesser extent, D2 structures (deRoo and van Staal, 2003). The D1 structures formed inresponse to a progressive, thrust-related deformation associ-ated with incorporation of the various blocks into the south-east-facing Brunswick subduction complex (van Staal, 1994)where most rocks were transformed into high pressure-lowtemperature metamorphic tectonites (van Staal et al., 1990).D2 is represented by asymmetrical upright folds and localnarrow shear zones that are thought to be related to trans-

pression induced by oblique convergence. In general, D2refolded and reoriented the shallow-dipping D1 structuresinto "steep belts", producing locally complex fold interfer-ence patterns (van Staal et al., 2003a). D1 and D2 structureswere commonly overprinted by F3 recumbent folds andkinks, and steeply dipping structures were transposed intoD3 "flat belts" where vertical D3 shortening strain was high.Flat belts thus represent areas with significant vertical, duc-tile thinning (de Roo and van Staal, 1994). Where D3 strainwas low, the rocks preserved their overall steep attitude,despite being deformed into open recumbent folds. Most of the Sheephouse Brook block and parts of the Heath Steele

nappe experienced relatively high D3 strain and hence werelargely transformed into a flat belt (van Staal et al., 2003a).

Sulphides were recrystallized and underwent major remobilization during D1 and, to a lesser extent, D2 events.Massive sulphide deposits folded by D2 structures, such asthe Brunswick No. 6 and No. 12 deposits, commonly werethickened in the hinges of the folds (van Staal and Williams,

1984). The extent of mobilization was dependent on thestrain and the ductility of different sulphide minerals. Sincethe strain is highly heterogeneous, even at the deposit-scale,the degree of mobilization is variable within and betweendeposits. Sulphide deformation has resulted in the preferen-tial mobilization of galena and sphalerite into the hinges of F1 and F2 folds, the injection of galena and chalcopyrite intounmineralized wall rocks, and the transposition of sulphideveins in the sulphide stringer zone into subparallelism withthe axial planes of F1 and F2 folds.

The flow of ductile sulphides parallel to F1 axial planes probably contributed to the sulphide banding or tectonic lay-ering that characterizes Pb-Zn-rich zones in virtually alldeposits of the BMC. The only primary sulphide textures preserved are finely laminated pyrite in the bedded pyritezone, pyrrhotite-chalcopyrite breccia in the vent complex(although the latter commonly displays deformational tex-tures), and quartz-sulphide veins in low strain areas withinthe sulphide stringer zone.

Genetic Models

Although deposits of the BMC are generally associatedwith felsic volcanic rocks, the relative timing of hydrother-mal and felsic magmatic events, and the location of depositswith respect to volcanic centres, are highly variable. Theintensity of volcanism may have exerted an important con-trol on the size of individual deposits, since large deposits in

the Brunswick (e.g. Brunswick No. 12 and 6) and HeathSteele belts formed during a major hiatus in felsic volcanismthat is represented by interbedded volcanic sedimentary andminor tuffaceous rocks. Other major deposits such as theCaribou and Canoe Landing Lake deposits are hosted bymostly shale and clearly formed during a major break in vol-canism, although the Caribou deposit was prematurely ter-minated by volcanism of the Spruce Lake Formation.Smaller deposits such as Restigouche, Chester, Armstrong B,Captain North Extension, Devils Elbow, and Flat LandingBrook are hosted by an almost continuous felsic volcanicsequence with few major breaks in volcanism and probablyformed proximal to volcanic centres.

Based on fluid inclusion salinities (3 and 8 wt.% equiva-

lent NaCl, Goodfellow and Peter, 1999) and temperatures>300°C estimated from the pyrrhotite-chalcopyrite-spha-lerite vein assemblage (Luff et al., 1992), the hydrothermalfluids were most likely buoyant and behaved as hydrother-mal plumes (Fig. 15). With continuing fluid discharge, theneutrally buoyant plume would spread laterally, assumingthat there were no major currents in the basin. This disper-sion process may account for the systematic lateral zonationof minerals and elements in hydrothermal sediments associ-ated with massive sulphide deposits along the Brunswick (Peter and Goodfellow, 1996) and Heath Steele belts (Peter and Goodfellow, 2003).

W. D. Goodfellow

460

Na O + CaO

(mole prop.)2

Al O /2 (mole prop.)2 3

Na O + CaO

(mole prop.)2Na O + CaO

(mole prop.)2

MgO + FeO

(mole prop.)T

K O

(mole prop.)2

Unaltered Felsic Volcanic Rocks

Altered Felsic Volcanic Rocks(Brunswick No. 12 Area)

Zone 1 (Fe-rich chlorite + quartz+ sericite + sulphide)

Zone 2 (Mg-rich chlorite + sericite)

Zone 3 (albite + Mg-rich chlorite+ sericite)

albite

K-feldspar

chlorite

s e r i c

i t e

FIGURE 14. Unfolded (MgO+FeOT) - Al2O3/2 - K 2O - (Na2O+CaO) tetra-hedron showing the chemical changes in major elements in the differenthydrothermal zones at the Brunswick No. 12 deposit, BMC (Luff et al.,1992).



The origin of reduced sulfur is asubject of debate (Goodfellow andPeter, 1999). However, the similarityof δ34S values for the Brunswick No.12 and Caribou massive sulphidedeposits and those of pyrite in host black shales remote from mineraliza-

tion supports a common and, there-fore, ambient seawater origin for most of the reduced sulfur (Goodfellow and Peter, 1996;Goodfellow et al., 2003b). Depositsfrom the Caribou, Brunswick, andStratmat horizons fall on the δ34Sevolutionary curve for sedimentary pyrite from the Selwyn Basin, sug-gesting further that the sulphur inthese deposits originated from theglobal ocean reservoir (Fig. 16). Areduced, stagnant water column mayhave played several roles that were

important to the formation of theBathurst sulphide deposits. Theseinclude 1) providing a ready supplyof biogenically reduced sulfur to fixhydrothermal metals, 2) increasingthe capture of metals by preventingsulphide oxidation in buoyanthydrothermal plumes (unlike modern black smokers where >90% of themetals is lost to the oxygenated water column), and 3) reducing the disper-sion of sulphide from vent sites bystrong bottom currents.

The Llanvirian maroon shales andcherts interbedded with alkali basaltsof the Little River and Boucher Brook formations, which overlie the felsicvolcanic rocks, mark a change fromreducing to oxidizing bottom water conditions. A strong hydrothermalsignature in these sedimentary rocksindicates that hydrothermal dischargecontinued well after the formation of most of the massive sulphide depositsin the Camp. The paucity of depositsat this time can be explained by theabsence of ambient seawater H2S tofix hydrothermal metals, and the lossto the water column of most of themetals carried in hydrothermal plumes due to sulphide oxidation andmetal dilution (Goodfellow et al.,2003b).

There are two possible sources of metalliferous fluids thatformed the BMC massive sulphide deposits - hydrothermaland magmatic fluids. Radiogenic lead isotopes (Fig. 17)combined with high Pb/Pb+Zn ratios indicate a crustal metalsource, consistent with a back-arc continental rift setting,although it is unclear whether Pb was leached from conti-nental basement, or was released from magmas that were

generated by melting basement rocks. Perhaps the strongestevidence for a magmatic component in deposits is the strong positive correlation of Sn (and In) with total tonnage (Fig. 18from Goodfellow and McCutcheon, 2003). Gold also corre-lates positively with deposit size, and displays a high positivecorrelation with Sb and As (McClenaghan et al., 2003). If Snenrichment in large deposits was controlled by hydrothermal processes alone, then it follows that the mineralogy and


46

Magm a

Seafloor Vents

AnoxicSulphideParticles Hydrothermal Plume

Bedded Sulphides

IronFormation

Felsic

volcanicsLocal

Seawater

Recharge Black shale

Impervious Cap

F a u l t

Seawater

Recharge

Hydrothermal Fluids

(Zn, Pb, Cu, Ag, Cl)

Sealed Hydrothermal

Reservoir (Permeable

Clastic Sediments)

Magmatic Volatiles

(Sn, In, Au, As, Sb)

Sub-volcanic

IntrusiveIsotherms

SulphideStringer

Zone

Oxygenated

A l t e r a t i

o nZ o n

e

A

3 0 0 C o

MagmaVolatiles

HydrothermalReservoir

Impermeablesediment cap

FelsicVolcanism

Hydrothermalplume

Seawater Recharge

ContinentalCrust

Syn-riftClastics

Oxygenated

Anoxic

B

FIGURE 15. Hydrothermal and sulphide depositional models, BMC. (A) Detailed view of the hydrothermalsystem showing magma driven fluid convection and metal leaching within the hydrothermal reservoir, thedistribution of isotherms, magmatic input of Sn, In, Au, As, and Sb, hydrothermal/magmatic fluid upflowalong reactivated extensional faults, widespread hydrothermal alteration in pre-ore rocks and sediments,venting of hydrothermal fluids at the seafloor forming buoyant plumes, the sedimentation of hydrothermal

plume precipitates and the formation of bedded sulphide facies and associated iron formations, and the zonerefining of bedded sulphides within the area of fluid venting. (B) Back-arc continental rift filled with a syn-rift, highly permeable, coarse-grained clastic sequence sealed by impervious black organic-rich shales of theKnights Brook and Patrick Brook formations. The permeable clastic sequence behaves as a hydrothermalreservoir in areas of high heat flow generated by intrusion of felsic magmas into the underlying attenuated

continental crust. Because of the low permeability of wet muds, recharge of the reservoir probably occurredat the margins of the rift where the sediments were thin. Local convection and the heating of reservoir flu-ids generated isothermal and fluid overpressured conditions. Discharge was likely along reactivated deepextensional faults.



metal ratios of deposits should likewise reflect highly vari-able fluid compositions among deposits. However, this is notthe case, nor is there any correlation of base metal contentsand ratios with deposit size. This suggests, therefore, that thelarge deposits in the BMC are associated with high-levelmagma bodies that have contributed Sn, In, Au, As, and Sbto the hydrothermal system (e.g. Fig. 15A).

The anatomy of the hydrothermal system that formed theBathurst deposits has attributes of both a classic convectivecell driven by a localized heat source proposed for VHMSdeposits, and a permeable hydrothermal reservoir capped byimpervious sediments envisaged for SEDEX deposits (Fig.15B). Because the Bathurst deposits formed in a continental back-arc rift, their proximity to continental sources for sedi-ments ensured that the rift was covered by impermeable andthermally insulating fine-grained clastic sediments. Thesesediments served to seal the hydrothermal reservoir, reducedconductive heat loss and focused fluid discharge at long-lived vent sites. This type of hybrid hydrothermal system is

therefore conducive to the forma-tion of giant deposits and probablyexplains why VSHMS and SEDEXdeposits are generally fewer innumber but an order of magnitudelarger, on average, than massivesulphide deposits hosted by only

volcanic rocks.A second major factor that con-

tributed to the formation of giantdeposits is anoxic ambient seawater that provided both an unlimitedsupply of reduced sulphur to fixmetals, and conditions that pre-vented the oxidation of sulphide particles in buoyant hydrothermal plumes. This probably explainswhy most of the giant PhanerozoicVSHMS (e.g. BMC, Iberian PyriteBelt, Mount Read Belt) andSEDEX deposits (e.g. Red Dog,

Howards Pass, Anvil District) formed during periods of global anoxia in the Late Cambrian, Middle Ordovician(Arenig), Late Ordovician-Early Silurian (Caradoc-Llandovery), and Late Devonian-Early Mississippian.

In summary, the large size of many Bathurst deposits, andVSHMS deposits in general, results from a number of fac-tors including a) hydrothermal architecture consisting of ahydrothermal reservoir capped by impervious fine-grainedsediments, b) prolonged episodes of hydrothermal activity,c) focussed discharge from long-lived vent sites, d) forma-tion during a major hiatus in volcanism, e) anoxic bottomwaters that facilitated the total capture of metals in buoyanthydrothermal fluids, and f) direct magmatic input of metals, particularly in the case of large deposits.

Exploration Methods

Geological

Exploration using geological criteria should focus on thefour major horizons that host sulphide deposits in the BMC.

W. D. Goodfellow

462

LLANDOV.

ASHGILL

CARADOC

LLANVIRN

ARENIG

TREMADOC

C AMBRI AN

O R D O V I C I A N

S I L

.

480 Ma

465 Ma

459 Ma

449 Ma

443 Ma

Epoch/ Age

P e r

i o d

TectonicSetting

GeneralizedStratigraphy

OreHorizons

AmbientSeafloor Environ-

ment

Tetagouche-Exploits

Basinoceanic

crust

Back-arccontinental

riftFelsic

volcanism

Passivecontinental

margin

Transition Alkalic basalts

490 Ma

Brunswick

Anoxic

Anoxic

Oxic

Caribou

Selwyn Basinsecular isotope curve

(Goodfellow, 1987)

HowardsPass

BrunswickNo. 12

Caribou

Stratmat

d34S (per mil)

-5 0 +5 10 15 20 25 30

Chester

Stratmat

490 Ma

FIGURE 16. Average and range of δ34S values for massive sulphide deposits from different ore horizons of the Bathurst Mining Camp, plotted on the Selwyn Basin secular curve for sedimentary pyrite (Goodfellow,1987).

18.18

18.20

18.22

18.24

18.26

18.28

18.30

18.32

15.64 15.65 15.66 15.67

207 204Pb/ Pb

Orvan Brook

Willet Showing

Rocky Turn

Murray BrookChester

Armstrong B

Brunswick #6Wedge

Armstrong A

CaptainCaribou

Key AnaconCanoe LandingRestigouche

Portage Lakes

Strachans LakeStratmat

Stratmat

Heath Steele A-zone

Austin Brook

Brunswick #12

TetagoucheGroup

California LakeGroup

2 0 6

2

0 4

P b /

P b

FIGURE 17. 207Pb/204Pb versus 206Pb/204Pb for massive sulphide depositsof the Bathurst Mining Camp (unpublished data from R.I. Thorpe).

.1 1 10 100 100010

100

1000

S n ( p p m )

Million tonnes (Mt)

Brunswick No.6

Heath Steele

Key Anacon

Halfmile Lake

Flat Landing Bk.

Captain

Stratmat

Taylor BrookWedge

Armstrong A

Orvan Brook

Rocky Turn

Murray Brook

Restigouche Canoe Landing Lake

Chester

Spruce Lake Fm.Nepisiguit Falls Fm.Flat Landing Lake Fm.Mount Brittain Fm.Canoe Landing Lake Fm.Clearwater Fm.

Caribou

McMaster

Brunswick No.12

FIGURE 18. Average tin content of massive sulphides versus geologicalreserves of volcanic-sediment hosted massive sulphide deposits in theBathurst Mining Camp (Goodfellow and McCutcheon, 2003).



These are from oldest to youngest: 1) Chester, 2) Caribou,3) Brunswick/Heath Steele, and 4) Stramat horizons.

The massive sulphide deposits and occurrences of theChester horizon occur within the Clearwater Stream,Sevogle River, and Slacks Lake formations. The Clearwater Stream Formation hosts the only known deposit in the group:

the Chester deposit with mineral resources of 15.72 Mt. TheSevogle River Formation contains three of the four knownoccurrences, and the Slacks Lake Formation hosts the fourthoccurrence (McCutcheon et al., 2003).

The Caribou horizon occurs in the California Lake Group,which includes the Spruce Lake, Mount Brittain, and CanoeLanding Lake formations (Figs. 1 and 2). The Spruce LakeFormation hosts 10 of the 13 deposits and 15 of the 21 occur-rences in the California Lake Group. Caribou is the largestdeposit with mineral resources of 69 Mt.

The Brunswick horizon hosts most of the large and pro-ductive deposits in the Camp including the Brunswick No.12 (229 Mt), Heath Steele B-zone (69 Mt), and Brunswick No. 6 (18 Mt) deposits. All deposits occur in altered mud-

stone and/or volcaniclastic rocks that either postdate or pre-date the massive quartz-feldspar "porphyry" of the Nepisiguit Falls Formation. Most deposits are also associ-ated with laterally extensive carbonate-oxide-silicatehydrothermal sedimentary rocks that define the ore horizonand display mineral and chemical vectors to mineralization(Peter and Goodfellow, 2003).

The Stratmat horizon, the youngest ore horizon in theBMC, occurs in the Flat Landing Brook Formation (Figs. 1and 2). The deposits are small; the largest deposit, StratmatS-1, contains only 4.94 Mt. The Flat Landing Brook Formation consists of aphyric to feldspar (±quartz)-phyric

rhyolitic flows, hyaloclastites, and crackle breccias (Rogerset al., 2003), that are interbedded with minor ash tuff, basaltand mudstone.

Deposits of the BMC are commonly associated with lam-inated black shales and formed when the water column in theTetagouche-Exploits basin was stratified with anoxic and

H2S-rich bottom waters.

Lithogeochemistry

Iron Formations

As discussed in the section "Hydrothermal sediments",the most effective vectors that increase with proximity tosulphide deposits are contents of siderite, magnetite, Zn, Pb,Cu, Ag, As, Au, Bi, Cd, Co, Mo, Se, Sb, Sn, In, and Tl, andratios of Fe/Mn, Ba/Al, P/Al, Eu/Eu* (Peter and Goodfellow,1996, 2003). In general, significant increases in content of siderite, stilpnomelane, ankerite, calcite, biotite, chalcopy-rite, and Cu are restricted to within about 0.5 km of mineral-ization, whereas sphalerite, galena, and notable enrichmentsin Pb, Zn, Ag, As, Au, Bi, Cd, Hg, In, Sn, Sb, and Tl extendup to 1.5 km from massive sulphides.

Hydrothermal Alteration

Hydrothermal alteration is widespread around individualdeposits (1 to 5 km laterally and 100s of m vertically) and iszoned with regard to silicate compositions from the core tothe margins of the hydrothermal fluid discharge conduit (Fig.12). The most visibly obvious manifestations of hydrother-mal alteration are green chloritic schists and sericitic rocks,the obliteration of feldspar phenocrysts in porphyritic vol-canic rocks, and the occurrence of veinlets and dissemina-tions of sulphides and ferroan carbonate. In the proximal


46

FIGURE 19. Down ice dispersion of Zn, Sn, Cu, In, Pb, and Tl in basal till at the Halfmile Lake deposit, Bathurst Mining Camp (from Parkhill and Doiron,2003).



core, the highly silicified facies hasa pale green to off-white appear-ance (Fig. 13).

Within alteration zones, chloriteFe/(Fe+Mg) ratios and the abun-dance of most ore-forming and -associated elements generally

increase from the outer margins of the alteration zones to the core of hydrothermal fluid upflow zone.The increase of these elementstoward the centre of hydrothermalfluid discharge is accompanied bythe addition of Si, Mg and K at theexpense of Na, Ca and Sr bound infeldspars and what was probablyoriginally glass (e.g. Fig. 14 fromGoodfellow and McCutcheon,2003).

Till, Soil and Stream Sediment

GeochemistryGeochemically anomalous till

defines dispersal trains that extendmore than 500 m down-ice fromthe Halfmile Lake, Restigouche,and Stratmat mineral deposits(Parkhill and Doiron, 2003).Indium, Sn, and As, and to a lesser extent Cu, Pb, Ag, and Zn in the<0.063 mm fraction of basal till, are the best indicators of massive sulphide deposits. As an example, the HalfmileLake deposit is reflected by Zn, Cu, Pb, Sn, In, and Tl dispersion trains that extend approximately 1 km down ice fromthe mineralization (Fig. 19). The suite and concentration of indicator elements in anomalous tills vary, depending ongeological history and the proportions of fresh and preglacially weathered bedrock and mineralized detritus inthe glacial sediments (Klassen, 2003). Element contents gen-erally increase with decreasing grain size. Some indicator elements (Sn, Sb) are anomalous only in fractions finer thansilt-size (<0.045 mm), likely reflecting the grain size of their host minerals in bedrock.

Lead isotopes have been used for the first time in theBMC for fingerprinting Pb sources in glacial till dispersiontrains (Hussein et al., 2003). The Pb isotope ratios(206Pb/204Pb) in basal sediments systematically decreasetoward the Halfmile Lake deposit, approaching values for

massive sulphides (206

Pb/204

Pb = 18.24,207

Pb/204

Pb =15.68, and 208Pb/204Pb = 38.20) and define a dispersal trainthat extends 600 m eastward from the mineralization in adirection broadly consistent with the ice-flow direction(Parkhill and Doiron, 2003). Lead isotope ratios, when plot-ted against Pb abundance data, define curves that are consis-tent with the mixing of two end members, one represented by the sulphide deposit and the other by the host rocks(Hussein et al., 2003).

A geochemical study of soils at the Restigouche depositrevealed that conventional leaches (aqua regia) of B-horizonsoil for Pb, Cu, Ag and As can be used successfully on a

regional scale to locate the Restigouche Zn-Pb deposit (Hallet al., 2003). However, selective extractions, hydroxylaminehydrochloride, and enzyme leaches provide better targetdelineation and contrast. By far the greatest contrast of anomaly-to-background signal is shown by Pb in B-horizon

soil (enzyme>hydroxylamine>total), As in soil by thehydroxylamine leach, and As in humus by aqua regia. The preferred medium to locate deeply buried mineralization ishumus digested by a conventional aqua regia attack and ana-lyzed for As, Pb, Ag, and Cu (Hall et al., 2003).

The Restigouche and Murray Brook deposits are bothreflected by Pb anomalies in stream sediment; the MurrayBrook deposit displays a strong Zn anomaly whereas theRestigouche deposit is characterized by a weak Zn anomalyin sediments (Fig. 20). Tin is elevated in streams draining theDevil's Elbow deposit and in other streams that have noknown mineralization. Base metal dispersion from knownsulphide deposits is generally restricted (typically less than 1

to 2 km), indicating that sampling should be carried out at adetailed scale (500 m intervals or less along streams).

Aqueous Geochemistry

Stream-water Zn anomalies extend up to 4 km down-stream from the Restigouche deposit (< 2 km for Pb) but aremore restricted at other massive sulphide deposits in theBMC (Leybourne and Goodfellow, 2003; Leybourne et al.,2003). The type and magnitude of the stream metal anom-alies are controlled by 1) the extent of sulphide oxidation,2) the major ion composition of ground and surface waters,and 3) the local hydrology, which controls the depth of recharge of oxygenated waters and the discharge of ground-

W. D. Goodfellow

464

FIGURE 20. Proportional symbol plots of Pb, Zn, and Sn abundances in the minus 80-mesh fraction of sedi-ments from streams draining the Restigouche-Murray Brook area, northwestern Bathurst Mining Camp (fromdata in Leybourne et al., 2003).



waters into the stream system. The dispersion distance of metals in stream waters and sediments is controlled by pH,adsorption of elements onto precipitating Mn- and Fe-oxy-hydroxides, and dilution by unmineralized stream base-flow.The partial extraction of elements in stream sedimentsallows for the identification of the most labile phases(adsorbed and bound to amorphous Mn- and Fe-oxyhydrox-

ides) and yields greater anomaly contrast for some metals(e.g. Pb, Zn, Tl), but reveals essentially the same anomaliesas identified using total acid extraction techniques.

Surface waters are an effective exploration tool, even in amature mining camp such as the BMC, and offer the poten-tial of detecting sulphide deposits concealed at depth. Thelocal hydrology around deposits determines whether a con-cealed target has a surficial expression (Leybourne and

Goodfellow, 2003; Leybourne et al., 2003).

Geophysics

Geophysics has played an important role in the discoveryof massive sulphide deposits in the BMC (see McCutcheonet al., 2003). As part of the EXTECH II project, a multi- parameter (magnetic, electromagnetic and radiometric), hel-icopter-supported and high-resolution (200 m line spacing)survey was flown over the entire camp (Thomas et al., 2000;Chung, 2003; Keating et al., 2003; Shives et al., 2003). Theobjectives were two-fold: 1) to support the 1:20,000-scalegeological mapping of the Camp, and 2) to stimulate explo-ration by identifying new targets for mineral exploration.Because of the poor rock exposure (1-2%), airborne geophysical data were used extensively in producing a new1:100,000-scale geological map of the BMC (van Staal et al.,2003b).

The apparent conductivity map generated from the 4433Hz coplanar electromagnetic data clearly outline bedrock geology (Fig. 21). Conductive units, particularly carbona-ceous sedimentary rocks of different age and in different for-mations, are distinct and very well defined, and have beenused to support detailed geological mapping below a thincover of glacial sediments. The conductivity maps corre-spond very well with the calculated first vertical derivativeof the magnetic field (Fig. 22) and help distinguish between


46

FIGURE 21. Apparent conductivity of the Bathurst Mining Camp generatedfrom the 4433 Hz co-planar electromagnetic data (Keating et al., 2003).Also shown is an outline of the geology (van Staal et al., 2003b), deposits(circles), and occurrences (squares) in the BMC (Goodfellow andMcCutcheon, 2003).

FIGURE 22. Vertical magnetic gradient of the Bathurst Mining Camp gener-ated from data collected by a helicopter survey at 200 m line spacing(Keating et al., 2003). Also shown is an outline of the geology (van Staal etal., 2003b), deposits (circles), and occurrences (squares) in the BMC(Goodfellow and McCutcheon, 2003). Scale as in Figure 21.

FIGURE 23. Total magnetic field of the Bathurst Mining Camp generatedfrom data collected by a helicopter survey at 200 m line spacing (Keatinget al., 2003). Also shown is an outline of the geology (van Staal et al.,2003b), deposits (circles), and occurrences (squares) in the BMC(Goodfellow and McCutcheon, 2003). Scale as in Figure 21.



bedrock and overburden conductivity responses (Keating etal., 2003). The vertical gradient is very effective in delineat-ing geological units, fold structures, and fault offsets (vanStaal et al., 2003b). The total magnetic field (Fig. 23) is con-trolled mostly by 1) the distribution of units dominated by basalt, particularly the highly magnetic alkali basalts such asthose overlying the Brunswick No. 12 deposit, 2) magnetite-rich iron formation associated with deposits of theBrunswick horizon, and 3) pyrrhotite-magnetite-rich ventcomplexes and sulphide stringer zones.

The release of the geophysical maps led directly to thediscovery of the Camelback massive sulphide deposit and

the identification of several new anomalies with high min-eral potential that were staked and are currently being eval-uated (Fig. 24). Most deposits in the BMC are characterized by coincident, circular to oval positive magnetic and appar-ent conductivity anomalies of variable intensity. This is par-ticularly true in the northwest part of the BMC where thehost rocks are dominated by weakly magnetic and poorlyconductive felsic volcanic rocks. The magnetic responsereflects magnetite and pyrrhotite, which are concentrated inmost massive sulphide deposits in the Camp. The magnetiteoccurs in vent complexes where it forms a magnetite-pyriteassemblage (Goodfellow and McCutcheon, 2003) or in iron

W. D. Goodfellow

466

FIGURE 24. Mineral potential prediction map for VMS deposits in the BMC, generated by a discriminant analysis model using five layers: middle and lowfrequency conductivity, RTP total magnetic field and vertical gradients of RTP magnetic data, and the radiometric Th/K ratio. The 37 discovered deposits areshown as black squares. The inset is a detailed view of the Brunswick No. 12 deposit (from Chung, 2003).



formations that overlie deposits of the Brunswick horizon(Peter and Goodfellow, 1996, 2003). The pyrrhotite is com-monly associated with chalcopyrite in vent complexes andsulphide stringer zones of many of the deposits and alsooccurs in iron formations.

Gravity anomalies related to near-surface deposits rangefrom the exceptionally large 4 mGal amplitude, premining

signature of the Brunswick No. 6 deposit to very smallanomalies, such as the 0.25 mGal amplitude anomaly asso-ciated with the Key Anacon deposit. There is no linear rela-tionship between tonnage and amplitude for the deposits of the BMC, although a linear relationship is apparent betweenamplitude and deposit thickness (Thomas, 2003). The pres-ence of positive gravity anomalies is primarily a function of the proximity of massive sulphide deposits to the bedrock surface, which explains why most deposits of the BMC havea gravity anomaly. However, the potential of the gravitymethod for locating deeply buried sulphide deposits in theBMC is demonstrated by discovery of the Maybrun sulphidedeposit beneath 180 m of Carboniferous sedimentary cover (Thomas, 2003).

Potential for Known and New Deposit Types

Since most deposits in the BMC either outcrop at the sur-face or subcrop below thin glacial sediments, there is a high potential for deposits concealed at depth below thick sequences of glacial sediments or within rock formations.There is also a high potential for lode gold deposits in major structures that separate blocks that were juxtaposed in the New Brunswick subduction complex (van Staal et al.,2003a).

Knowledge Gaps

Detailed maps of the Quaternary geology are required toevaluate the massive sulphide potential in areas where theglacial sediments are thick, since virtually all deposits either outcrop or subcrop below <10 m of glacial sediments. Also,detailed basal till geochemistry and mineralogy would beeffective in locating deposits concealed beneath thick sequences of till.

• Construction of 3-D geological maps of the BMC thatcan be used to target mineralized horizons concealed atdepth.

• Systematic, detailed and multi-parameter geochemistryof stream and seep sediment and water using MC-ICP-MS technology that allows precise analyses of elementsand diagnostic isotopes. This data would not only assistin the detection of concealed deposits but also provide

baseline data for the environmental assessment of theimpact of mineral development on the surface environ-ment.

• For deposits such as Brunswick No. 12 that are overlain by highly magnetic alkali basalts, the magnetic anomalyassociated with massive sulphides is partly masked byanomalies generated by the basalts. Similarly, the highlyconductive carbonaceous shales can mask electromag-netic anomalies associated with massive sulphides. Thisis major problem in exploring for deposits in the BMC because of the close stratigraphic relationship betweenorganic-rich black shales and sulphide mineralization. To

address this problem, it will be necessary to better under-stand the physical properties of organic-rich sedimentaryrocks and to develop more effective geophysical methodsthat can discriminate between different types of conduc-tive rocks.

• Development and testing of deeply penetrating airbornegravity and ground seismic methods for detecting mas-

sive sulphide deposits in the BMC.

Acknowledgements

This synthesis of the metallogeny of the BMC is basedmostly on new research generated by the EXTECH II proj-ect and published recently in Economic Geology Monograph11, 2003. John Lydon and Steve McCutcheon are thanked for thorough reviews this paper. Jennifer Owen and IngridKjarsgaard are thanked for helpful editorial comments onthis and an earlier version of the paper, respectively.

ReferencesAdair, R. N., 1992, Stratigraphy, structure, and geochemistry of the

Halfmile Lake massive-sulfide deposit, New Brunswick: Explorationand Mining Geology, v. 1, p. 151-166.

Barrie, C. T., and Hannington, M. D., 1999, Classification of volcanic-asso-ciated massive sulfide deposits, in Barrie, C. T., and Hannington, M. D.,eds., Volcanic-Associated Massive Sulfide Deposits: Processes andExamples in Modern and Ancient Settings: Reviews in EconomicGeology, v. 8, Society of Economic Geologists, p. 2-10.

Boorman, R. S., 1975, Mineralogical review of lead-zinc-copper sulphidedeposits, Bathurst-Newcastle area, New Brunswick, New Brunswick Research and Productivity Council, Report No. 5128, 249 p.

Boyle, D. R., 2003, Preglacial weathering of massive sulfide deposits in theBathurst Mining Camp: economic geology, geochemistry and explo-ration applications, in Goodfellow, W. D., McCutcheon, S. R., andPeter, J. M., eds., Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Maine: Economic GeologyMonograph 11, Society of Economic Geologists, p. 689-721.

Chen, T. T., 1978, Colloform and framboidal pyrite from the Cariboudeposit, New Brunswick: Canadian Mineralogist, v. 16, p. 9-16.

Chung, C. F., 2003, Use of airborne geophysical surveys for constructing

mineral potential maps, in Goodfellow, W. D., McCutcheon, S. R., andPeter, J. M., eds., Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Maine: Economic GeologyMonograph 11, Society of Economic Geologists, p. 879-891.

Currie, K., van Staal, C. R., Peter, J. M., and Rogers, N., 2003, Conditionsof metamorphism of the main massive sulfide deposits and surroundinghost rocks in the Bathurst Mining Camp, in Goodfellow, W. D.,McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick, and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 65-78.

de Roo, J. A., and van Staal, C. R., 1994, Transpression and recumbentfolding: steep belts and flat belts in the Appalachian Mobile Belt of northern New Brunswick, Canada: Geological Society of AmericaBulletin, v. 106, p. 541-552.

——— 2003, Sulfide remobilization and sulfide breccias in the HeathSteele and Brunswick deposits, Bathurst Mining Camp, New

Brunswick, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M.,eds., Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 479-496.

Fyffe, L. R., 1995, Regional geology and lithogeochemistry in the vicinityof the Chester VMS deposit, Big Bald mountain area, New Brunswick,Canada: Exploration and Mining Geology, v. 4, p. 153-173.

Galley, A. G., Watkinson, D. H., Jonasson, I. R., and Riverin, G., 1995, Thesubsea-floor formation of volcanic-hosted massive sulfide; evidencefrom the Ansil Deposit, Rouyn-Noranda, Canada: Economic Geology,v. 90, p. 2006-2017.

Goodfellow, W. D., 1975, Major and minor element halos in volcanic rocksat Brunswick No. 12 sulphide deposit, N.B., Canada, in Elliot, I. L., andFletcher, W. K., eds., Geochemical Exploration 1974: Elsevier,Amsterdam, p. 279-295.


46



——— 1987, Anoxic stratified oceans as a source of sulphur in sediment-hosted stratiform Zn-Pb deposits (Selwyn Basin, Yukon, Canada):Chemical Geology, v. 65, p. 359-382.

——— 2003, Geology and genesis of the Caribou deposit, Bathurst MiningCamp, northern New Brunswick, in Goodfellow, W. D., McCutcheon,S. R., and Peter, J. M., eds., Massive Sulfide Deposits of the BathurstMining Camp, New Brunswick, and Northern Maine, EconomicGeology Monograph 11, Society of Economic Geologists, p. 327-360.

Goodfellow, W. D., and McCutcheon, S. R., 2003, Geological and geneticattributes of volcanic-associated massive sulfide deposits of theBathurst Mining Camp, northern New Brunswick - a synthesis, inGoodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds., MassiveSulfide Deposits of the Bathurst Mining Camp, New Brunswick, and

Northern Maine: Economic Geology Monograph 11, Society of Economic Geologists, p. 245-301.

Goodfellow, W. D., and Peter, J. M., 1996, Sulphur isotope composition of the Brunswick No. 12 massive sulphide deposit, Bathurst MiningCamp, N.B.:Iimplications for ambient environment, sulphur source andore genesis: Canadian Journal of Earth Sciences, v. 33, p. 231-251.

——— 1999, Reply: Sulphur isotope composition of the Brunswick No. 12massive sulphide deposit, Bathurst Mining Camp, N.B.: implicationsfor ambient environment, sulphur source and ore genesis: CanadianJournal of Earth Sciences, v. 36, p. 127-134.

Goodfellow, W. D., Zierenberg, R. A., and ODP Leg 169 Shipboard ScienceParty, 1999, Genesis of massive sulphide deposits at sediment-covered

spreading centers,in

Barrie, C. T., and Hannington, M. D., eds.,Volcanic-associated Massive Sulfide Deposits: Processes andExamples in Modern and Ancient Settings, Reviews in EconomicGeology, Society of Economic Geologists, v. 8, p. 297-324.

Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M., 2003a, Massivesulfide deposits of the Bathurst Mining Camp and northern Maine;introduction and summary of findings, in Goodfellow, W. D.,McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 1-16.

Goodfellow, W. D., Peter, J. M., Winchester, J. A., and van Staal, C. R.,2003b, Ambient marine environment during formation of massive sul-fide deposits of the Bathurst Mining Camp: importance of reduced bot-tom waters in metal precipitation and sulfide preservation, inGoodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds., MassiveSulfide Deposits of the Bathurst Mining Camp, New Brunswick, and


Gromet, L. P., Dymek, R. F., Haskin, L. A., and Korotev, R. L., 1984, The"North American shale composite": its compilation, major and traceelement characteristics: Geochimica et Cosmochimica Acta, v. 48,

p. 2469-2482.

Hall, G.E.M., Parkhill, M.A., and Bonham-Carter, G. F., 2003, Conventionaland selective leach geochemical exploration methods applied to humusand B horizon soil overlying the Restigouche VMS deposit, BathurstMining Camp, New Brunswick, in Goodfellow, W. D., McCutcheon, S.R., and Peter, J. M., eds., Massive Sulfide Deposits of the BathurstMining Camp, New Brunswick, and Northern Maine: EconomicGeology Monograph 11, Society of Economic Geologists, p. 763-782.

Hamilton, A., 1992, Geology of the Stratmat boundary and Heath Steele N-5 zones, Bathurst Camp, northern New Brunswick: Exploration andMining Geology, v. 1, p. 131-135.

Hussein, A. A., Lochner, C., and Bell, K., 2003, Application of Pb isotopes

to mineral exploration in the Halfmile Lake area, Bathurst, NewBrunswick, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M.,eds., Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 679-688.

Jambor, J. L., 1979, Mineralogical evolution of proximal and distal featuresin New Brunswick massive sulfide deposits: Canadian Mineralogist,v. 17, p. 79-87.

Juras, S. J., 1981, Alteration and sulfide mineralization in footwall felsic andmetasedimentary rocks, Brunswick No. 12 deposit, Bathurst, NewBrunswick, Canada: Unpub. M.Sc. thesis, University of NewBrunswick, Fredericton, 208 p.

Keating, P., Thomas, M. D., and Kiss, F., 2003, Significance of high reso-lution magnetic and electromagnetic survey for exploration and geo-logical investigations, Bathurst Mining Camp, in Goodfellow, W. D.,

McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick, and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 783-798.

Klassen, R. A., 2003, The geochemical and physical properties of till,Bathurst Mining Camp, New Brunswick, Canada, in Goodfellow, W.D., McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Depositsof the Bathurst Mining Camp, New Brunswick, and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 661-678.Large, R. R., 1977, Chemical evolution and zonation of massive sulfide

deposits in volcanic terrains: Economic Geology, v. 72, p. 549-572.

——— 1992, Australian volcanic-hosted massive sulfide deposits: features,styles and genetic models: Economic Geology, v. 87, p. 471-510.

Lea, E. R., and Rancourt, C., 1958, Geology of the Brunswick Mining andSmelting orebodies, Gloucester County, New Brunswick: CanadianInstitute of Mining and Metallurgy Bulletin, v. 61, p. 95-105.

Lentz, D., and Goodfellow, W. D., 1993, Petrology and mass balance con-straints on the origin of quartz augen schist associated with theBrunswick massive sulphide deposits, Bathurst, New Brunswick:Canadian Mineralogist, v. 31, p. 877-903.

——— 1994, Character, distribution, and origin of zoned hydrothermalalteration features at the Brunswick No. 12 massive sulphide deposit,Bathurst Mining Camp, New Brunswick, in Abbott, S. A., ed., CurrentResearch: New Brunswick Department of Natural Resources and

Energy, Minerals Resources, Information Circular 94-1, p. 94-119. ——— 1996, Intense silicification of footwall sedimentary rocks in the

stockwork alteration beneath the Brunswick No. 12 massive sulphidedeposit, Bathurst, New Brunswick: Canadian Journal of Earth Sciences,v. 33, p. 284-302.

Lentz, D. R., Hall, D. C., and Hoy, L. D., 1997, Chemostratigraphic, alter-ation, and oxygen isotopic trends in a profile through the stratigraphicsequence hosting the Heath Steele B Zone massive sulphide deposit,

New Brunswick: Canadian Mineralogist, v. 35, p. 841-874.

Leybourne, M. I., and Goodfellow, W. D., 2003, Processes of metal solu-tion and transport in groundwaters interacting with undisturbed mas-sive sulfide deposits, Bathurst Mining Camp, New Brunswick, inGoodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds., MassiveSulfide Deposits of the Bathurst Mining Camp, New Brunswick, and


Leybourne, M. I., Boyle, D. R., and Goodfellow, W. D., 2003,

Interpretation of stream water and sediment geochemistry in theBathurst Mining Camp, New Brunswick: application to mineral explo-ration, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds.,Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 741-761.

Luff, W. M., Goodfellow, W. D., and Juras, S. J., 1992, Evidence for afeeder pipe and associated alteration at Brunswick No. 12 massive-sul-fide deposit: Exploration and Mining Geology, v. 1, p. 167-185.

McClenaghan, S. H., Goodfellow, W. D., and Lentz, D. R., 2003, Gold inmassive sulfide deposits, Bathurst Mining Camp: distribution and gen-esis, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds.,Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 303-326.

McCutcheon, S. R., Luff, W. M., and Boyle, R. W., 2003, The BathurstMining Camp, New Brunswick, Canada: history of discovery and evo-

lution of geological models, in Goodfellow, W. D., McCutcheon, S. R.,and Peter, J. M., eds., Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Maine: Economic GeologyMonograph 11, Society of Economic Geologists, p. 17-35.

Nelson, G. A., 1983, Alteration of footwall rocks at Brunswick No. 6 andAustin Brook deposits, Bathurst, New Brunswick, Canada: Unpub.M.Sc. thesis, University of New Brunswick, Fredericton, 236 p.

Parkhill, M. A., and Doiron, A., 2003, Quaternary geology of the BathurstMining Camp and implications for base metal exploration using drift

prospecting, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M.,eds., Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 631-660.

Peter, J. M., and Goodfellow, W. D., 1996, Mineralogy, bulk and rare earthelement geochemistry of massive sulphide-associated hydrothermal

W. D. Goodfellow

468



sediments of the Brunswick horizon, Bathurst mining camp, NewBrunswick: Canadian Journal of Earth Sciences, v. 33, p. 252-283.

——— 2003, Hydrothermal sedimentary rocks of the Heath Steele Belt,Bathurst Mining Camp, New Brunswick 3. Application of mineralogyand mineral and bulk composition to massive sulfide exploration, inGoodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds., MassiveSulfide Deposits of the Bathurst Mining Camp, New Brunswick, and


Peter, J. M., Goodfellow, W. D., and Doherty, W., 2003a, Hydrothermalsedimentary rocks of the Heath Steele Belt, Bathurst Mining Camp,

New Brunswick 2. Bulk and rare earth element geochemistry andimplications for origin, in Goodfellow, W. D., McCutcheon, S. R., andPeter, J. M., eds., Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Maine: Economic GeologyMonograph 11, Society of Economic Geologists, p. 391-415.

Peter, J. M., Kjarsgaard, I. M., and Goodfellow, W. D., 2003b,Hydrothermal sedimentary rocks of the Heath Steele Belt, BathurstMining Camp, New Brunswick 1. Mineralogy and mineral chemistry,in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds.,Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 361-390.

Rogers, N., and van Staal, C. R., 2003, Volcanology and tectonic setting of the northern Bathurst Mining Camp: Part II - mafic volcanic constraintson back-arc opening, in Goodfellow, W. D., McCutcheon, S. R., andPeter, J. M., eds., Massive Sulfide Deposits of the Bathurst MiningCamp, New Brunswick, and Northern Maine: Economic GeologyMonograph 11, Society of Economic Geologists, p. 181-201.

Rogers, N., van Staal, C. R., McNicoll, V., and Theriault, R., 2003,Volcanology and tectonic setting of the northern Bathurst MiningCamp: Part I - extension and rifting of the Popelogan Arc, inGoodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds., MassiveSulfide Deposits of the Bathurst Mining Camp, New Brunswick, and


Roy, S., 1961, Mineralogy and paragenesis of the lead-zinc-copper ores of the Bathurst-Newcastle district: Geological Survey of Canada Bulletin72, 31 p.

Sáez, R., Almodovar, G. R., and Pascual, E., 1996, Geological constraintson massive sulphide genesis in the Iberian pyrite belt: Ore GeologyReviews, v. 11, p. 429-451.

Sáez, R., Pascual, E., Toscano, M., and Almodóvar, G. R., 1999, The Iberiantype of volcano-sedimentary massive sulphide deposits: MineraliumDeposita, v. 34, p. 549-570.

Saif, S. I., 1980, Petrographic and geochemical investigation of iron forma-tion and other iron-rich rocks in Bathurst District, New Brunswick,Current Research Part A, Paper 80-1A, Geological Survey of Canada,

p. 309-317.

Shives, R. B. K., Ford, K. L., and Peter, J. M., 2003, Mapping and explo-ration applications of gamma ray spectrometry in the Bathurst MiningCamp, northeastern New Brunswick, in Goodfellow, W. D.,McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Deposits of the Bathurst Mining Camp, New Brunswick, and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 819-840.

Stanton, R. L., 1959, Mineralogical features and possible mode of emplace-ment of the Brunswick Mining and Smelting orebodies, Gloucester County, New Brunswick: Canadian Institute of Mining and Metallurgy

Bulletin, v. 570, p. 631-642.Tanimura, S., Date, J., Takahashi, T., and Ohmoto, H., 1983, Geologic set-

ting of the Kuroko deposits, Japan: Part II. Stratigraphy and structure of the Hokuroko District, in Ohmoto, H., and Skinner, B. J., eds., TheKuroko and Related Volcanogenic Massive Sulfide Deposits,

Economic Geology Monograph 5, Society of Economic Geologists, p. 24-38.

Thomas, M. D., 2003, Gravity signatures of massive sulfide deposits,Bathurst Mining Camp, New Brunswick, Canada, in Goodfellow, W.D., McCutcheon, S. R., and Peter, J. M., eds., Massive Sulfide Depositsof the Bathurst Mining Camp, New Brunswick, and Northern Maine:Economic Geology Monograph 11, Society of Economic Geologists,

p. 799-817.

Thomas, M. D., Walker, J. A., Keating, P., Shives, R., Kiss, F., andGoodfellow, W. D., 2000, Geophysical atlas of massive sulphide signa-tures, Bathurst Mining Camp, New Brunswick: Geological Survey of Canada Open File 3887, p. 105 p.

van Staal, C. R., 1994, Brunswick subduction complex in the CanadianAppalachians: Record of Late Ordovician to Late Silurian collision

between Laurentia and the Gander margin of Avalon: Tectonics, v. 13, p. 946-962.

van Staal, C. R., and de Roo, J. A., 1995, Mid-Paleozoic tectonic evolutionof the Appalachian Central Mobile belt in northern New Brunswick,Canada: collision, extension collapse and dextral transpression, inHibbard, J. P., Staal, C. R. v., and Cawood, P. A., eds., Current per-spectives in the Appalachian-Caledonian Orogen: GeologicalAssociation of Canada, Special Paper 41, p. 367-389.

van Staal, C. R., and Williams, P. F., 1984, Structure, origin and concentra-tion of the Brunswick 12 and 6 orebodies: Economic Geology, v. 79,

p. 1669-1692.

van Staal, C. R., Ravenhurst, C. E., Winchester, J. A., Roddick, J. C., andLangton, J. P., 1990, Evidence for a post-Taconic blueschist suture innorthern New Brunswick, Canada: Geology, v. 18, p. 1073-1077.

van Staal, C. R., Wilson, R. A., Fyffe, L. R., Langton, J. P., McCutcheon, S.R., Rogers, N., McNicoll, V., and Ravenhurst, C. E., 2003a, Geologyand tectonic setting of the Bathurst Mining Camp and its relationship tocoeval rocks in southwestern New Brunswick and adjacent Maine - asynthesis, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M.,eds., Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 37-60.

van Staal, C. R., Wilson, R. A., Rogers, N., Fyffe, L. R., Gower, S. J.,Langton, J. P., McCutcheon, S. R., and Walker, J. A., 2003b, A NewGeological Map of the Bathurst Mining Camp and Surrounding Areas- A Product of Integrated Geological, Geochemical and GeophysicalData, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M., eds.,Massive Sulfide Deposits of the Bathurst Mining Camp, New

Brunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 61-64.

Wahl, J. L., 1977, Rock geochemical exploration at the Heath Steele andKey Anacon deposits, New Brunswick: Unpub. Ph.D. thesis, Universityof New Brunswick, 429 p.

Yang, K., Scott, S. D., and Goodfellow, W. D., 2003, Footwall alterationassociated with massive sulfide deposits in the Bathurst Mining Camp,

New Brunswick: implication for seafloor hydrothermal mixing processes, in Goodfellow, W. D., McCutcheon, S. R., and Peter, J. M.,eds., Massive Sulfide Deposits of the Bathurst Mining Camp, NewBrunswick, and Northern Maine: Economic Geology Monograph 11,Society of Economic Geologists, p. 435-456.


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Documents

Metallogeny of the Bathurst Mining Camp, Northern New Brunswick