The Mount Costigan Zn–Pb–Ag Deposit, West-Central New ...

MRR 2012-1: Paper 2
(CD-ROM)
Mineral Resource Report
James A. Walker and Douglas Clark
2012
Energy and Mines
Geological Surveys
The Mount Costigan Zn–Pb–Ag
Deposit, West-Central New
Brunswick, Canada: Stratigraphic
Setting and Evolution of Felsic
Intrusion-Related Mineralization

MADAWASKA
Edmundston
Maine,
U.S.A.
Report
area
Figure preparation
Editing, layout
Translation
Campbellton
RESTIGOUCHE
VICTORIA
CARLETON
Fredericton
YORK
CHARLOTTE
Recommended citation
Report prepared by
NORTHUMBERLAND
SUNBURY
Saint
John
Bathurst
GLOUCESTER
Miramichi
QUEENS
KINGS
KENT
Sussex
SAINT JOHN
Moncton
WESTMORLAND
ALBERT
NEW
BRUNSWICK
Terry Leonard, Gwen L. Martin
Gwen L. Martin
Mineral Resource Report 2012-1:
Paper 2 (CD-ROM)
The Mount Costigan Zn–Pb–Ag
Deposit, West-Central New
Brunswick, Canada: Stratigraphic
Setting and Evolution of Felsic
Intrusion-Related Mineralization
CD-ROM Edition
ISBN 978-1-55471-778-1
ISSN 1911-7582
Online Edition
ISBN 978-1-55471-779-8
ISSN 1717-1237
Le Bureau de traduction, Ministère de l’Approvisionnement et des
Services du Nouveau-Brunswick (Translation Bureau, New Brunswick
Department of Supply and Services)
Walker, J.A., and Clark, D. 2012.TheMount Costigan Zn–Pb–Ag
deposit, west-central New Brunswick, Canada: stratigraphic setting and
evolution of felsic intrusion-related mineralization. New Brunswick
Department of Energy and Mines; Geological Surveys Branch, Mineral
Resource Report 2012-1: Paper 2 (CD-ROM), 50 p.
Geological Surveys Branch
New Brunswick Department of Energy and Mines
Hon. Craig Leonard
Minister of Energy and Mines
October 2012

i
TABLE OF CONTENTS
LIST OF FIGURES AND TABLES.......................................................................................................... i
ABSTRACT..................................................................................................................................... iii
RÉSUMÉ........................................................................................................................................ iv
INTRODUCTION ...............................................................................................................................1
EXPLORATION HISTORY ..................................................................................................................1
REGIONAL GEOLOGY ......................................................................................................................3
DEPOSIT STRATIGRAPHY ................................................................................................................8
LITHOGEOCHEMISTRY ...................................................................................................................11
Mount Costigan Deposit..........................................................................................................12
Felsic Volcanic Rocks .........................................................................................................12
Mafic Dyke ..........................................................................................................................16
Sedimentary Rocks .............................................................................................................16
Lewis Brook Occurrence.........................................................................................................16
Felsic Volcanic Rocks .........................................................................................................16
Mafic Volcanic Rocks..........................................................................................................17
Redstone Mountain Granite ....................................................................................................17
HYDROTHERMAL ALTERATION .......................................................................................................18
MINERALIZATION...........................................................................................................................22
SAMPLE ANALYSES.......................................................................................................................25
Sulphur Isotope Analysis ........................................................................................................25
Radiogenic Lead Isotope Analysis..........................................................................................27
DISCUSSION .................................................................................................................................30
CONCLUSIONS..............................................................................................................................34
ACKNOWLEDGEMENTS ..................................................................................................................44
REFERENCES ...............................................................................................................................44
LIST OF FIGURES AND TABLES
Figure 1 Location of the Mount Costigan deposit and other significant base metal
sulphide deposits within the Chaleur Bay Synclinorium of west-central New
Brunswick. ............................................................................................................ 2
Figure 2 Geology map of the Mount Costigan deposit, showing the distribution
of diamond-drillhole collars and traces, trenches, and mineralization. ................... 4
Figure 3 Cross-section A–A’ through the Mount Costigan deposit....................................... 5
Figure 4 Samples of the Redstone Mountain Granite. ........................................................ 7
Figure 5 Rhyolitic host rocks of the Mount Costigan deposit. ............................................. 9
Figure 6 Pyroclastic volcanic rocks intersected during drilling at the Mount Costigan
deposit. .............................................................................................................. 10
Figure 7 Sedimentary rocks and peperite from the Mount Costigan area. ......................... 11

ii
Figure 8 Major-element lithogeochemical discrimination diagrams for rocks from the
Mount Costigan–Lewis Brook area . ................................................................... 13
Figure 9 Trace-element lithogeochemical discrimination diagrams for rocks from the
Mount Costigan–Lewis Brook area...................................................................... 14
Figure 10 Rare-earth-element data for rocks from the Mount Costigan–Lewis Brook
area. ................................................................................................................... 15
Figure 11 Graphic presentation of mass balance data for host rocks from the Mount
Costigan deposit. ................................................................................................ 20
Figure 12 Hydrothermal alteration in rocks from the Mount Costigan deposit. .................... 21
Figure 13 Mineralization and alteration in drill core samples from the Mount Costigan
deposit. .............................................................................................................. 23
Figure 14 a) Pb–Cu–Zn ternary diagram for assay data from the Mount Costigan
deposit. b) W versus Sn diagram for data from the Mount Costigan deposit,
Lewis Brook occurrence, and Redstone Mountain Granite. ................................. 25
Figure 15 Seawater sulphur isotope curve through time, showing the δ 34 S content of
marine evaporites, barite, and pyrite from the Selwyn Basin. ............................. 28
Figure 16 Radiogenic lead isotope diagrams for host rocks and mineralization from
the Mount Costigan, Shingle Gulch, and Sewell Brook deposits. ........................ 29
Figure 17 Schematic diagram showing the inferred relationship between the Mount
Costigan deposit and the Lewis Brook occurrence, and the similarity of the
Mount Costigan deposit to part of the Cordilleran epithermal Au–Ag deposit
model of Panteleyev (1988)................................................................................ 32
Note: Tables 1 to 3 contained multi-page lithogeochemical data and are compiled
at the end of this report. Tables 4 to 6 appear in the text, where cited.
Table 1 Lithogeochemical data for SLAM Exploration Ltd. drill cores and trenches at
the Mount Costigan deposit. ............................................................................... 36
Table 2 Lithogeochemical data for the Lewis Brook occurrence (Costigan
Mountain Formation), and average values for the River Dee rhyolite and
River Dee basalt (Wapske Formation)................................................................. 40
Table 3 Lithogeochemical data for the Redstone Mountain Granite collected during
this investigation and compiled from previously published data of Whalen
(1993).................................................................................................................. 43
Table 4 Microprobe analyses for points on sample CM08-8-54 m. ................................... 19
Table 5 Sulphur isotope data for bulk sulphides, and sphalerite and galena separates,
from the Mount Costigan deposit......................................................................... 26
Table 6 Temperatures of formation calculated from δ 34 S data for sphalerite and galena
separates from the Mount Costigan deposit. ........................................................... 27

iii
ABSTRACT
Mount Costigan is the largest of several Zn–Pb–Ag sulphide deposits hosted by Early
Devonian felsic volcanic rocks of the Tobique Group in the Chaleur Bay Synclinorium
of west-central New Brunswick. The host sequence at Mount Costigan consists of high
silica (70–76% SiO2), sparsely feldspar–phyric to aphyric rhyolite flows and breccia,
intercalated felsic lithic- and crystal–lithic-lapilli tuff, and subordinate fine-grained
clastic sedimentary rocks. The mineralized zone has a strike length of ~200 m and a
width of up to 300 m, and has been intersected up to 300 m below surface. A historical
resource estimate suggests a mass of mineralized rock of 6–8 Mt. Recent work has
shown that, within this envelope, a subvertical to very steeply east-dipping zone
contains a geological resource of ~0.9 Mt of 4–5% Zn + Pb.
Mineralization is entirely epigenetic. It occurs as stratabound, finely disseminated grains
and coarse patches within lithic tuff, and as massive sulphide veins and veinlets crosscutting
rhyolitic flows. Sulphide mineralogy is dominated by reddish brown to pale
yellow sphalerite (without chalcopyrite inclusions) and subordinate galena, with Zn/Pb
~2. Pyrite is subordinate to sphalerite, and trace chalcopyrite is present. Elevated
levels of silver (up to 132 g/t) and gold (up to 1.88 g/t), as well as anomalous Sn, Sb,
and W, are present within the mineralized zone; however, no minerals have been
identified in which these elements are primary constituents. The δ 34 S for bulk sulphide
in the upper 100 m of the deposit is tightly constrained between 9.2‰ and 9.9‰ and is
coincident with sulphide in equilibrium with Early Devonian seawater. A slightly lower
δ 34 S (7.38‰) from deeper in the system (187 m) implies a larger percentage of
magmatic sulphur at depth.
The Mount Costigan mineralization is interpreted to have formed below the seafloor as
a result of mixing metal-rich, magmatically derived ascending fluids with seawater that
moved laterally through permeable pyroclastic rocks. The source of these metal-rich
fluids may have been the nearby subvolcanic Redstone Mountain Granite. The
subsurface precipitation of sulphides at temperatures of ~200°C allowed the
development of a relatively coarse grain size. The relative lack of brecciation in
deeper parts of the system implies that confining pressure inhibited separation of a
gas phase (i.e., boiling). This model is supported by the recognition of undisrupted and
unmineralized sedimentary units that crossed the core of the mineralized zone, units
that apparently behaved as local barriers to upward egress of mineralizing fluids.
However, the flow of fluids to shallower levels and the concomitant decrease in
confining pressure did allow boiling in the upper part of the system, as indicated by the
development of hydrothermal breccias.

iv
RÉSUMÉ
Le mont Costigan abrite le plus important de plusieurs gisements de sulfures de Zn–Pb–Ag
que renferment les roches felsiques du groupe de Tobique du début du Dévonien, dans le
synclinorium du Centre-Ouest du Nouveau-Brunswick. La succession de roches
encaissantes du mont Costigan comprend des unités à haute teneur en silice (70 à 76 % de
SiO2), des coulées et des brèches rhyolitiques éparses à phénocristaux de feldspath
aphyrique, ainsi que des strates de tuf felsique lithique et cristallin lithique et à lapilli, et des
roches clastiques sédimentaires à grains fins subordonnées. La direction de la zone
minéralisée s’étend sur un axe de plus ou moins 200 m et a une largeur qui peut atteindre
300 m. La minéralisation a été interceptée à une profondeur qui peut atteindre 300 m sous
la surface. Une ancienne estimation des ressources a établi un volume de roches
minéralisées qui se situe entre 6 et 8 Mt. Des travaux récents ont indiqué que dans cette
enveloppe, une zone caractérisée par un pendage subvertical à un angle abrupt vers l’est
contiendrait une ressource géologique de 4 à 5 % de Zn-Pb de plus ou moins 0,9 Mt.
La minéralisation est d’origine entièrement épigénétique. Elle se présente sous forme de grains
fins stratoïdes et de bancs à grains grossiers encaissés dans du tuf lithique et sous forme de
filons de sulfures massifs, et de filonnets de coulées rhyolitiques transversales. La minéralogie
des sulfures se caractérise principalement par de la sphalérite brun rouge à jaune pâle
(sans inclusion de chalcopyrite) et de la galène subordonnée, accompagnée de plus ou
moins 2 éléments de Zn/Pb. La pyrite est subordonnée à la sphalérite et de la chalcopyrite
est présente à l’état de trace. Des teneurs élevées d’argent (jusqu’à 132 g/t) et d’or (jusqu’à
1,88 g/t), et des anomalies de Sn, Sb et de W sont observées dans la zone minéralisée.
Toutefois, aucun minéral dont ces éléments seraient les principaux composants n’a été relevé.
La valeur de δ 34 S du sulfure massif pour les premiers 100 m du gisement à partir de la surface
se situe très exactement entre 9,2 ‰ et 9,9 ‰ et elle correspond à la présence équilibrée de
sulfure dans l’eau de mer du début du Dévonien. Une valeur légèrement plus faible de δ 34 S
(7,38 ‰) observée plus en profondeur dans la minéralisation (187 m) laisse présager un
pourcentage plus important de sulfure d’origine magmatique en profondeur.
La minéralisation du mont Costigan serait apparue sous le fond de l’océan et résulterait d’un
mélange entre, d’une part, de l’eau de mer en déplacement latéral à travers des roches
pyroclastiques perméables et, d’autre part, des fluides ascendants métallifères d’origine
magmatique. Ces fluides ont pu provenir du granite subvolcanique voisin du mont
Redstone. La précipitation de subsurface des sulfures à une température de plus ou moins
200 °C a provoqué l’apparition de grains relativement grossiers. L’absence relative de
bréchification dans les zones plus profondes du système porte à croire que la pression de
confinement a empêché une séparation de phase gazeuse (c’est-à-dire l’ébullition). Ce
modèle d’interprétation est corroboré par la reconnaissance d’unités sédimentaires intactes
et non minéralisées qui ont traversé le coeur de la zone minéralisée, et d’unités qui ont
semble-t-il agi par endroits comme une barrière et bloqué la migration vers la surface des
fluides de minéralisation. Par ailleurs, l’écoulement de fluides vers des zones moins
profondes et la pression de confinement plus faible qui l’accompagnait ont permis l’ébullition
dans la partie supérieure de la minéralisation, comme l’atteste l’apparition de brèches
hydrothermales.

INTRODUCTION
1
The Mount Costigan deposit, Unique Reference Number (URN) 720 in the New Brunswick
Department of Natural Resources (NBDNR) Mineral Occurrence Database (Rose and
Johnson 1990; NBDNR 2011), is located approximately 30 km east-northeast of the village of
Plaster Rock, on the east slope of Costigan Mountain in west-central New Brunswick (Fig. 1).
The deposit is the largest Zn–Pb–Ag sulphide accumulation recognized within the southern
Chaleur Bay Synclinorium (Fig. 1, inset). The synclinorium also contains the Shingle Gulch
and Sewell Brook deposits (URN 102 and URN 986, respectively; Fig. 1) and has a reported
historical (non-NI 43-101-compliant) tonnage estimate of 6–8 Mt (Fyffe and Pronk 1985).
Although the deposit was discovered in the early 1970s, it has not previously benefitted from
detailed mineral deposit studies, primarily because of the lack of sufficient, good-quality drill
core. However, recent drilling by SLAM Exploration (Clark 2004, 2008) has provided cores
sufficient for the stratigraphic and metallogenic assessment presented herein.
The purpose of this investigation is three-fold: 1) to document the position of the deposit within
the volcanosedimentary stratigraphy of the Tobique Group, 2) to document the style of
mineralization and related hydrothermal alteration, and 3) to formulate a model explaining
deposit genesis in order to aid industry in the search for similar deposits.
EXPLORATION HISTORY
The first documented indication of mineralization in the Costigan Mountain area occurred in
1954, when the area was highlighted for its anomalous Pb and Zn in a regional stream
sediment survey (Mount Costigan Mines 1955). Follow-up work, including soil geochemical
and self-potential surveys, outlined anomalous areas but failed to identify in situ mineralization
(MacLean 1963). Likewise, soil geochemical surveys conducted by Silcan Mines Ltd. failed to
identify in situ mineralization (Riddell 1971).
The Mount Costigan deposit (Fig. 2, 3) was discovered by Amoco Ltd. in 1973 while the
company conducted induced-polarization (IP) surveys as a follow-up to earlier work (Maingot
1974). In 1975 Amoco established a grid, conducted soil geochemical and IP surveys, and
drilled holes NBTO-1 to NBTO-5 (Bjornson 1975). Drillholes NBTO-6 to NBTO-25 were put
down in 1976 (Fig. 2), but only holes NBTO-22 through NBTO-25 were filed for assessment
(Bjornson 1976). Holes NBTO-26 to NBTO-28 were drilled in 1977 (Bjornson 1977). Lac
Minerals optioned the Mount Costigan property in the early 1980s and conducted
magnetometer and electromagnetic (VLF) surveys (Lavoie 1982), followed by the relogging of
Amoco’s previously drilled cores, additional magnetometer and VLF surveys, trenching, and
mapping (Crevier 1983). Lac Minerals drilled holes LCO-1 to LCO-10, totalling 1977 m in and
around the area of mineralization in 1983 (Crevier and Gravel 1983; Crevier 1984). Collar
locations for all the above holes are given in Fyffe and Pronk (1985). Later drilling by Lac
Minerals consisted of five drillholes (LCO84-1 through LCO84-5) that totalled 996 m (Crevier
1985). Geochemical samples collected from previously reported drill cores were assayed for
Cu, Pb, Zn, Ag, and Au (Lac Minerals 1989).

Map
area
Maine,
U.S.A.
o
46 59’00”
Campbellton
CVGS
0 100 km
APA
BMC
Saint
John
CARBONIFEROUS
Terrestrial
sedimentary rocks
EARLY DEVONIAN
Redstone Mountain
Granite
Mafic intrusions
Rocky Brook–
Millstream
Fault
Bathurst
Miramichi
Moncton
Fredericton
CVGS
Connecticut Valley–
Gaspé Synclinorium
APA
Miramichi
Anticlinorium
(Ganderia)
Elmtree Inlier
DW
Chaleur Bay
Synclinorium
BMC
Bathurst
Mining Camp
Aroostook–Percé
Anticlinorium
Plaster Rock
0 8 km
Area of
Figure 2
Tobique Group
Wapske Formation
2
Sewell
Brook
Marine sedimentary rocks
Mainly felsic volcanic rocks
Mainly mafic volcanic rocks
Costigan Mountain Formation
Mainly felsic volcanic rocks
Mainly mafic volcanic rocks
Shingle
Gulch
412.5 ± 2 Ma
Mount
Costigan
Lewis
Brook
LATE SILURIAN
North Pole Stream Granite
CAMBRO–ORODOVICIAN
Miramichi Anticlinorium
Unconformity, fault
Base metal sulphide deposit
Syncline, anticline
Figure 1. Location of the Mount Costigan deposit in west-central New Brunswick, showing other
significant base metal sulphide deposits within the Chaleur Bay Synclinorium (see inset). (Geology
modified from Fyffe and Pronk 1985; Wilson 1990; Smith and Fyffe 2006a, 2006b.)
67 00’00”
o
River Dee
volcanic
rocks
Shingle
Gulch East
Trousers
Lake
U–Pb (zircon) radiometric
age (Wilson et al. 2004)

3
Taylor and Associates acquired the property in 1984 and carried out a VLF survey on the
deposit (Taylor 1995). Chapleau Resources optioned the property in 1996 and conducted a
soil geochemical survey (Turner 1996a), magnetometer and VLF surveys, and geological
mapping (Turner 1996b). In 1998 previously unreported diamond drilling by Chapleau
Resources (drillholes MC97-1 through MC97-3, totalling 750.1 m) and results of a soil
geochemical survey and geological mapping were filed by Taylor and Associates (Walker
1998). The current (2012) property holder, SLAM Exploration Ltd., acquired the property in
2003. That company drilled 475.2 m of core in three diamond drillholes (CM03-1 through
CM03-3) (Clark 2004) and in 2008 drilled an additional 11 holes (CM08-04 through CM08-14),
totalling 2768 m (Clark 2008). In addition to being described in the assessment files cited
above, the Mount Costigan deposit was briefly discussed in Fyffe and Pronk (1985) and was
the subject of a M.Sc. thesis by Cox (1990).
Most of the core drilled during the early exploration campaigns (i.e., those conducted by
Amoco Ltd. and Lac Minerals) has been lost, and only a few of the smaller diameter, handsplit
cores from the LCO series of holes are preserved at the Provincial Government core
storage facility in Madran, northeast New Brunswick. However, the larger diameter (NQ) cores
obtained by SLAM Exploration are stored at Madran and at the SLAM Exploration core shed
in Beresford. The present report is based on the material collected from, and observations
made using, these drill cores as well as on information compiled from the assessment data.
REGIONAL GEOLOGY
The Mount Costigan area is underlain by rocks that are part of the Chaleur Bay Synclinorium,
which extends from the south shore of the Gaspé Peninsula (Québec) for approximately 250
km to the southwest. The Chaleur Bay Synclinorium is divided into northern and southern
parts by the Rocky Brook–Millstream Fault (Fig. 1, inset). North of this structure, the
synclinorium contains sequences of Silurian clastic and carbonate sedimentary rocks, and
felsic and mafic volcanic rocks, which are included in the Quinn Point, Dickie Cove, Petit
Rocher, and Chaleurs groups (Irrinki 1990; Wilson and Kamo 2012). These sequences are
overlain by Early Devonian mafic and felsic volcanic and sedimentary rocks of the Dalhousie
Group. Silurian rocks are largely absent to the south of the Rocky Brook–Millstream Fault,
where the Chaleur Bay Synclinorium instead is underlain mainly by Early Devonian volcanic
and sedimentary rocks of the Tobique Group (St. Peter 1978a, 1978b; Fyffe and Pronk 1985;
Wilson 1990, 1992).
The volcanic and sedimentary rocks of the Chaleur Bay Synclinorium are interpreted to have
been deposited in a transtensional tectonic setting initiated by sinistral and dextral oblique
convergence of the microcontinents of Ganderia (Miramichi Anticlinorium; Fig 1, inset) and
Avalonia (located along the Bay of Fundy, southern New Brunswick) with the continental
margin of Laurentia in the Silurian to Early Devonian, respectively (Dostal et al. 1989; van
Staal and de Roo 1995; van Staal et al. 2009). This interpretation is supported by the overall
bimodal nature of volcanism, although volumetrically significant volcanic rocks of intermediate
composition occur locally. The observation that felsic rocks are most abundant near the base

o
46 59’00”
67 01’00”
67 03’00”
o
o
LCO-6
NBTO-20
NBTO-19
NBTO-21
Mount Costigan
671 m above
sea level
NBTO-18
CM03-1
LCO84-3
A
LCO84-1
LCO84-5
A’
LCO84-2
LCO84-4
Area of
inset map
MC97-1
NBTO-5
o
flat or 90 dip
LCO-2
MC97-2
LCO-1
CM03-3
some volcanic
fragments
LCO-10
NBTO-2
4
NBTO-1
CM03-2
LCO-3
NBTO-4
NBTO-3
LCO-4
NBTO -1 to -28: Amoco (1975–78)
Porphyritic felsic flows
LCO-1 to -10: Lac Minerals (1983)
Felsic lithic-lapilli tuff
NBTO-23
NBTO-26
NBTO-7
CM03-1 to -3: SLAM Expl. (2003)
NBTO-12
LCO-8
CM08-4 to -14: SLAM Expl. (2008)
Felsic crystal tuff
NBTO-28
CM08-13
CM03-1
CM08-05
NBTO-15
NBTO-25
Line of section,
drillhole
Grey to black siltstone
and sandstone; locally
fossiliferous
NBTO-22
CM08-8NBTO-14
CM08-9
CM08-10
NBTO-9
CM08-7
NBTO-6
CM08-4
TNB79-4
NBTO-10
NBTO-11
TNB79-1
CM08-14
CM08-6
Mafic volcanic rocks
TNB79-2
Stream, road
Area of mineralization
125 m
LCO-9
NBTO-24
NBTO-13
NBTO-16
TNB79-3
NBTO-27
o
46 58’00”
NBTO-17
NBTO-8
Figure 2. Geology map of the Mount Costigan deposit, with diamond-drillhole collars and traces, trenches, and limits of surface mineralization.
Figure 1 shows the location of this figure; Figure 3 shows cross-section A–A'. (Geology adapted from Fyffe and Pronk 1985; Clark 2008.)

A’
Zone of quartz–
carbonate veining
A
CM08-9
NBTO-9
NBTO-6
NBTO-17
NBTO-10
CM08-10
NBT0-11
CM03-1
NBTO-25
Projected
from south
NBTO-22
Projected
from north
LCO84-2
LCO84-1
NBTO-5
LCO84-3
5
LCO-9
0 200 m
Drillhole in plane of section
Overburden Coarse lithic tuff
Pyroclastic
tuffs
Core Zone (>4% Zn + Pb)
Crystal–lithic tuff
Drillhole projected
Fine-grained clastic sedimentary rocks
Rhyolitic flows
Drillhole interval projected
Limit of mineralization
Fragmental rocks associated with
massive flows (carapace/sole breccia)
Figure 3. Cross-section A–A’ through the Mount Costigan deposit, looking north-northeasterly (modified from Clark 2008). Figure 2 shows the
location of this cross-section.

6
but give way upsection to dominantly mafic volcanic rocks is interpreted to reflect the
transition from 1) initial rifting with low percentage partial melting of lower crust followed by
magma generated from higher percentage partial melts, to 2) mafic magmas generated in the
upper mantle.
The Tobique Group is divided into two formations: 1) the Costigan Mountain Formation, which
hosts the Mount Costigan deposit and the Lewis Brook Zn–Pb–Ag occurrence (Fig. 1), and
2) the gradationally overlying Wapske Formation (St. Peter 1978a). These formations contain
similar rock types but differ in their relative proportion of sedimentary and volcanic strata. The
Costigan Mountain Formation comprises ~3000 m of dominantly felsic volcanic rock consisting
of pink, light grey, or light green quartz–feldspar porphyry, rhyolitic ash-flow tuff, lapilli tuff and
breccia, and flow-layered rhyolite. The felsic volcanic rocks are intercalated with lesser marine
shale, siltstone, and quartzose to lithic sandstone, and subordinate mafic volcanic rocks. The
Wapske Formation comprises a 7900 m thick sequence of locally pillowed mafic lavas and
related volcanic rocks interlayered with abundant marine sedimentary rocks (shale, siltstone,
and quartzose to lithic sandstone) and minor felsic volcanic rocks
As originally defined by St. Peter (1978a), an isochronous contact between the Costigan
Mountain and Wapske formations was inferred, but later faunal evidence showed that they
were only partly coeval: that is, they had a diachronous relationship (Han and Pickerill 1994).
Mapping by Wilson (1990) indicates that the felsic volcanic rocks of the Costigan Mountain
Formation can be traced only as far north as Trousers Lake (Fig. 1). The current report places
the contact between these two formations on the west side of the large felsic volcanic pile that
hosts the Mount Costigan deposit, approximately 6 km west of the Tobique Group–Redstone
Mountain Granite contact. Assuming an average westerly dip of 35° for the Tobique Group,
the contact is approximately 3.4 km stratigraphically above the base of the Tobique Group
(Fig. 1).
Age control on the Tobique Group is based on paleontological data that consistently yield an
Early Devonian age (St Peter 1978a; Wilson 1990; Boucout and Wilson 1994). A U–Pb
(zircon) age of 412.5 ± 2.0 Ma (Wilson et al. 2004) was obtained from a rhyolite located
approximately 3.5 km along strike to the north-northwest of the Mount Costigan deposit (Fig.
1). Silicified felsic lapilli tuff collected from trenches on the west side of the Mount Costigan
deposit yielded a K–Ar age of 373 ± 19 Ma (Fyffe and Pronk 1985). This younger age
estimate likely reflects a later thermal resetting of the radiometric clock attributable to
Devonian pluton emplacement.
The felsic volcanic rocks hosting the Mount Costigan deposit are part of the Costigan
Mountain Formation and therefore are considered to be among some of the oldest felsic
volcanic rocks in the Tobique Group. Regional mapping suggests that the lowermost strata of
the Tobique Group lie with faulted unconformity against Cambro–Ordovician rocks of the
Miramichi Anticlinorium (Fig. 1). However, immediately east and for some distance south of
the deposit, the contact relationship between the Tobique Group and the Cambro–Ordovician

7
Figure 4. Samples of the Redstone Mountain Granite, showing the porphyritic phase (left and
right) and the microgranitic phase (centre). Pen is 14.5 cm long.
rocks is obscured by the Redstone Mountain Granite, which apparently sutures this contact
(Fyffe and Pronk 1985).
The Redstone Mountain Granite is a pink to scarlet red, medium-grained, biotite–amphibole
granite that has been traced some 15 km along the boundary between the Miramichi
Anticlinorium and Chaleur Bay Synclinorium (Whalen 1993). However, within the intrusion
there is significant variation in grain size. Work during this investigation suggests the
occurrence of at least three distinct phases, but outcrop distribution is insufficient to delineate
phase boundaries. The three phases are 1) a fine-grained red microgranite, 2) a fine-grained
intermediate phase bordering mafic dikes, and 3) a quartz–feldspar porphyry
(Fig. 4). Both
the red microgranite and the quartz–feldspar porphyry contain a small percentage of
ferromagnesian minerals (mostly biotite). Near the southern limit of the pluton, in the vicinity
of Redstone Mountain, the intrusion becomes coarser grained and contains a much higher
percentage of ferromagnesian minerals.
This intrusion has yielded a Rb–Sr age of 409 ± 25 Ma (Fyffe and Pronk 1985); however,
apparent hornfelsing of the intrusion in proximity to the North Pole Stream Granite (417
± 1 Ma) suggests an emplacement age of not younger than 417 Ma (Fyffe and Pronk 1985;
Whalen 1993).

DEPOSIT STRATIGRAPHY
8
The Mount Costigan deposit is hosted by rocks of the Early Devonian Costigan Mountain
Formation (Fig. 1). The lower part of the stratigraphic section is dominated by mafic volcanic
and marine sedimentary rocks, and the upper part, by felsic volcanic and very minor
sedimentary rocks. These strata strike roughly north–south and dip moderately (~45°) to the
west, similar to adjacent parts of the Chaleur Bay Synclinorium (Fyffe and Pronk 1985; Wilson
1990; Walker 2005). Results of this investigation and that of Clark (2008) suggest that the
local deposit stratigraphy is much flatter than the general regional trend, with dips generally
≤20°W (Fig. 3). The flatter stratigraphy in the immediate vicinity of the deposit could be the
result of local block faulting. Alternatively, the shallower dips may be the result of interference
of a moderate structural dip with steep paleotopographic variation such as would be expected
with the emplacement of cryptodomes.
The Mount Costigan deposit occurs within the felsic volcanic sequence (Fig. 2, 3) at and near
the contact between a lower unit of felsic crystal tuff (chloritic) and overlying felsic lithic-lapilli
tuff (Fyffe and Pronk 1985). According to Fyffe and Pronk (1985), these units are overlain by
massive porphyritic rhyolite; a sample collected along strike from this stratigraphically higher
rhyolite yielded the 412.5 ± 2.0 Ma age mentioned above. This simplified stratigraphic
interpretation was based on a limited number of small-diameter drill cores and on limited
outcrop distribution. However, Clark (2008) and the present investigation indicate a more
complex volcanosedimentary stratigraphy, one marked by rapid facies changes and the
absence of definitive marker horizons (Fig. 3).
The host rocks at the Mount Costigan deposit consist of massive rhyolitic flows and
pyroclastic tuffs. The rhyolitic flows are light to medium grey to black, locally bleached, and
aphyric to very sparsely feldspar-phyric. They commonly exhibit primary devitrification
textures such as perlitic fractures (Fig. 5a) and spherulites (Fig. 5b) that range in size from

Figure 5. Rhyolitic host rocks of
the Mount Costigan deposit.
a) Photomicrograph of perlitic
fractures in feldspar-phyric rhyolite
from diamond drillhole (DDH)
CM08-8 at 78.7 m. Photograph was
taken under plain polarized light.
Field of view is 3 mm.
Figure 5. b) Large spherulites
developed in sparsely feldsparphyric
rhyolite from DDH CM08-4 at
151 m. Core diameter is ~4.7 cm.
Figure 5. c) Grey, sparsely feldsparphyric,
flow-layered rhyolite from
DDH CM08-4 at 69 m. Core
diameter is ~4.7 cm.
9
CM08-4
a
b
c

CM08-4
Granitoid
clast
10
a
b
c
Figure 6. Pyroclastic volcanic rocks
intersected during drilling at the
Mount Costigan deposit. a) Coarse
lithic-lapilli tuff from DDH CM08-10
at 11–18.5 m. Core diameter is
4.7 cm.
Figure 6. b) Lithic tuff with granitoid
clast from DDH CM08-4 at 42 m.
Core diameter is 4.7 cm.
Figure 6. c) Rhyolitic flow with
carapace breccia (bottom two runs)
and overlying hyaloclastite (top run)
from DDH CM08-10 at 196–199 m.
Core diameter is 4.7 cm.

Figure 7. Sedimentary rocks
and peperite from the Mount
Costigan area. a) Blue-grey
siltstone–sandstone with
volcanic debris from DDH
CM08-4 at 192–194 m. Core
diameter is 4.7 cm.
Figure 7. b) Peperitic texture
resulting from interaction
between sparsely feldsparphyric
rhyolite and siltstone–
mudstone. Photograph is from
DDH CM08-4 at 262 m. Core
diameter is 4.7 cm.
LITHOGEOCHEMISTRY
11
Whole-rock lithogeochemical data were obtained in order to ascertain primary rock types and
to document the effects of mineralization-related alteration processes. Twenty samples
(Table 1) were collected from SLAM Exploration drill cores from the Mount Costigan deposit,
including 17 felsic volcanic, one mafic dyke, and two sedimentary samples. An additional
seven samples of felsic volcanic rocks were collected from surface trenches at the deposit
(Table 1). Fifteen core samples (six felsic and nine mafic volcanic) were collected from the
Lewis Brook Zn–Pb–Ag occurrence (Table 2). This deposit is hosted by rocks that occur 1–1.5
km stratigraphically higher than, and approximately 4 km south-southwest along strike from,
the Mount Costigan deposit (Fig. 1). For comparison, Table 2 includes the average compositions
of rhyolitic and basaltic rocks of the Wapske Formation to the north of the Mount Costigan
deposit (i.e., the River Dee rhyolite and River Dee basalt of Wilson 1992: see Fig. 1).
a
b

12
Six samples were collected from various phases of the Redstone Mountain Granite (Table 3);
data for four samples of this granite from Whalen (1993) are also included in Table 3. It should
be noted that one of the samples assigned to the Redstone Mountain Granite by Whalen
(1993; his sample G15-138) is not from this intrusion but more likely is from the North Pole
Stream Granite and has been omitted from the geochemical variation diagrams in the current
report. [Please note: Tables 1 to 3 are compiled at the end of this report, starting on p. 36.]
Mount Costigan Deposit
Felsic Volcanic Rocks
The host sequence at Mount Costigan is dominated by aphyric to very sparsely feldspar- phyric,
high-silica (70–76% SiO2) rhyolite. Most of the rhyolite samples contain 7–11% total alkalis
(Na2O + K2O) and plot in the rhyolite field on the total alkalis versus SiO2 diagram (Fig. 8a).
However, in general the Na2O contents of these rocks are very low (at or below the analytical
detection limit), and most of the samples contain 6–11% K2O (Fig. 8b). The more chloritic
samples collected from Mount Costigan generally have lower silica (57–70% SiO2) and 7–12%
alkalis, and they plot in the trachyte–trachydacite field (Fig. 8a). Given that most samples show
evidence of extensive alkali mobility (Fig. 8c), classification of rock type should be based on
immobile high-field-strength elements (HFSE) rather than on traditional alkali elements, which
are known to be mobile under hydrothermal conditions and therefore are less reliable.
On the Zr/TiO2 versus Nb/Y discrimination diagram, almost all Mount Costigan samples plot
well within the rhyolite field and fall in a tight cluster that has Zr/TiO2 values between 0.1 and
0.2, and Nb/Y values between 0.25 and 0.8 (Fig. 9a). The very tightly constrained Zr/TiO2
values of the felsic rocks imply that all rocks were sourced from a single magma (Fig. 9b). In
contrast, felsic volcanic samples from the Lewis Brook occurrence are slightly less evolved
and plot in the rhyodacite–dacite field with a lower Zr/TiO2 (Fig. 9a). Data from the Redstone
Mountain Granite collected during this investigation and data compiled from Whalen (1993)
show varied Zr/TiO2 values, with data falling on both the Mount Costigan and Lewis Brook
arrays (Fig. 9b); however, the absolute Zr and TiO2 contents are closer to those of the Lewis
Brook rocks. The Zr/Hf value, which is considered to be a reliable gauge of the degree of
fractionation, indicates that samples from Mount Costigan have values >35, typical of most
felsic rocks (Watson and Harrison 1983). In contrast, samples from the Lewis Brook occurrence
and the Redstone Mountain Granite have Zr/Hf values ranging from 20 to 34 (Fig. 9c),
suggesting that both have undergone a higher degree of fractionation than the felsic rocks from
the Mount Costigan deposit.
The profiles of rare earth elements (REEs) for analyzed rocks in the Costigan Mountain area
are given on Figures 10a to 10f. REE profiles for samples of the Mount Costigan rhyolite are
characterized by elevated light-REE (LREE) contents, negative Eu anomalies, and relatively
flat heavy-REE (HREE) profiles, all of which are typical of felsic volcanic rocks ( Fig. 10a).
The contents of base metals, granophile elements, and precious metals in felsic volcanic rocks
from the Mount Costigan deposit are summarized as follows (see Table 1 for details).

a
Na O + K O
b
KO
c
Na O + K O
2 2
2
2 2
14
12
10
8
6
4
2
0
14
12
10
8
6
4
2
tephrite basaltic
trachyandesite
basanite
trachybasalt
picrobasalt
basalt
basaltic
andesite
phonotephrite
basalt
tephriphonolite
andesite
trachyandesite
basaltic
andesite
phonolite
dacite
trachyte
andesite
trachydacite
High-K calc-alkaline series
Calc-alkaline series
SiO 2
dacite
Arc tholeiite series
rhyolite
13
0
45 50 55 60 65 70 75 80 85
14
12
10
8
6
4
2
0
40 45 50 55 60 65 70 75 80 85 90
Na-metasomatism
SiO 2
Igneous
spectrum
0 20 40 60 80 100
100 K O/(Na O + K O)
2 2 2
rhyolite
K-metasomatism
Mount Costigan Deposit
Felsic volcanic rocks (from surface)
Felsic volcanic rocks (from drill core)
Chloritic fragmental volcanic rocks
Mafic dyke
Sedimentary rocks
Lewis Brook Occurrence
Felsic volcanic rocks
Mafic volcanic rocks
River Dee felsic/mafic volcanic rocks
(Wilson 1992)
Redstone Mountain Granite
(this investigation)
Redstone Mountain Granite
(Whalen 1993)
Figure 8. Major-element
lithogeochemical discrimination
diagrams for rocks from the Mount
Costigan–Lewis Brook area.
a) Na2O + K2Oversus SiO 2,
with
field boundaries from Le Bas et al.
(1986). Values recalculated to
100%-free LOI basis. b) K2O versus
SiO 2,
with field boundaries from Le
Maitre et al. (1989). c) Na2O + K2O versus 100*K2O/(Na2O + K2O), with
field boundaries from Hughes
(1972).

TiO (wt %)
Zr/TiO 2
Zr (ppm)
a
2
1
0.1
0.01
3
2
1
0
Zr/Hf
14
0.001
0.01 0.1 1 10
b
200
100
rhyodacite/dacite
andesite
andesite/basalt
Mass
gain
rhyolite
subalkaline basalt
Mass loss
Nb/Y
comendite/
pantellerite
trachyandesite
alkaline
basalt
phonolite
trachyte
Alteration array
Alteration array
0 100 200 300 400 500 600 700
Zr (ppm)
c
600
Figure 9. Trace-element
lithogeochemical discrimination
diagrams for rocks from the Mount
500
Costigan–Lewis Brook area.
a) Zr/TiO2 versus Nb/Y, with field
400
boundaries from Winchester and
Floyd (1977). b) TiO2
versus Zr.
300
c) Zr versus Zr/Hf.
basanite/
nephelinite
Fractionation curve
0
20 30 40 50
Fractionation curve
Mount Costigan Deposit
Felsic volcanic rocks (from surface)
Felsic volcanic rocks (from drill core)
Chloritic fragmental volcanic rocks
Mafic dyke
Sedimentary rocks
Lewis Brook Occurrence
Felsic volcanic rocks
Mafic volcanic rocks
River Dee felsic/mafic volcanic rocks
(Wilson 1992)
Redstone Mountain Granite
(this investigation)
Redstone Mountain Granite
(Whalen 1993)

sample/chondrite
sample/chondrite
sample/chondrite
!
!
!
1000
100
10
1
1000
100
10
1
1000
100
10
1
15
1000
a b
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Figure 10. Rare-earth-element data for rocks from the Mount Costigan–Lewis Brook area. a) Mount
Costigan felsic volcanic rocks. b) Mount Costigan mafic dyke. c) Lewis Brook felsic volcanic rocks.
d) Lewis Brook mafic volcanic rocks. e) Redstone Mountain Granite. f) Mount Costigan sedimentary
rocks. Normalization factors in a) to e) are from Nakamura (1974); normalization factors in f) are for the
North American Shale composite (NASC) from Gromet et al. (1984).
sample/NASC
sample/chondrite
Base metals: Cu is 1 ppm to 143 ppm, Zn is 31 ppm to 7950 ppm, Pb is 7 ppm to 2980 ppm.
Granophile elements: Sn is 1 ppm to 20.6 ppm, W is below the detection limit to 25 ppm,
Sb is 1 ppm to 10.5 ppm, Mo is below the detection limit to 3 ppm.
Precious metals: Au is below the detection limit to 90 ppb, Ag is below the detection limit to
3.8 ppm.
sample/chondrite
100
10
1
1000
c d
100
10
10
e f
1
1
0.1
0.01
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
La Ce Nd Sm Eu Gd Tb Dy Er Yb Lu

Mafic Dyke
16
One sample of a mafic dyke was collected from the SLAM Exploration drill cores at Mount
Costigan. This sample (CM08-8-48 m; Table 1) from drillhole 8 at a depth of 48 m plots in the
basaltic trachyandesite field on the Na2O + K2O versus SiO2 diagram (Fig. 8a), and in the basalt
field on the K2O versus SiO2 diagram (Fig. 8b). However, like most samples in this investigation,
there is evidence of alkali-element mobility, specifically K2O gain and Na2O loss (Fig. 8c). In
terms of HFSE composition, sample CM08-8-48 m plots in the subalkaline basalt field (Fig. 9a)
and has a Zr/TiO2 value of ~0.01, similar to basalts from the Lewis Brook occurrence (Fig. 9a).
The REE profile for this sample (Fig. 10b) is slightly LREE-enriched and has no significant Eu
anomaly. This is similar to the Lewis Brook mafic volcanic rocks (Fig. 10d), except that the
absolute REE content is somewhat higher in the Mount Costigan sample.
Sedimentary Rocks
The two samples of sedimentary rock from the Mount Costigan drill cores (CM08-4-222a,
CM08-4-222b) have high K (up to 11%) and moderate SiO2 (57–59%) contents. The North
American Shale Composite (NASC)-normalized REE data for both samples plot close to parity
for all REEs (Fig. 10f). These rocks have Zr/TiO2 values of ~0.02 (Fig. 9a, 9b), similar to
compositions of sedimentary rocks from elsewhere in the Tobique Group (Walker 2005).
Lewis Brook Occurrence
Felsic Volcanic Rocks
The felsic volcanic rocks from the Lewis Brook Zn–Pb–Ag vein system plot within the rhyolite
field on major-element discrimination diagrams (Fig. 8a). With the exception of one
anomalously low sample, these rocks have SiO2 contents of 70–75%, total alkali contents of
8–9%, and K2O contents of 5–9% (Fig. 8a, 8b). Like the rhyolite from Mount Costigan, most
Lewis Brook samples have alkali-element contents that lie outside the range of normal
volcanic rocks, suggesting they have undergone hydrothermal alteration (Fig. 8c).
The Lewis Brook felsic volcanic rocks have Zr/TiO2 values of ~0.08, consistent with a
rhyodacitic composition (Fig. 9a) and similar to most samples from the Redstone Mountain
Granite (see below). The Zr contents of these rocks range between 92 ppm and 186 ppm,
considerably lower than most rhyolite samples from the Mount Costigan deposit. Similarly, the
TiO2 contents of the Lewis Brook rhyodacite (average 0.18%) are marginally lower than those
of the Mount Costigan rhyolite, which average 0.29% (Fig. 9b).
The Zr/Hf values of the Lewis Brook rhyodacite range between 26 and 34 and are similar to
the range of Zr/Hf values from the Redstone Mountain Granite (see below; Fig. 9c). These
ratios are lower than those of the Mount Costigan rhyolite and may represent a marginally
more fractionated source magma. The Lewis Brook rhyodacite samples are divisible into two
populations on the basis of REE content (Fig. 10c). The first population contains three samples
that are LREE-enriched and have moderate negative Eu anomalies. The second population

17
contains two samples that have flatter profiles (less LREE enrichment) and more prominent
negative Eu anomalies (Fig. 10c).
The contents of base metals, granophile elements, and precious metals in samples of the
Lewis Brook rhyodacite are summarized as follows (see Table 2 for details).
� Base metals: Cu is 4 ppm to 1452 ppm, Zn is 9 ppm to 30 062 ppm, Pb is 22 ppm to 770 ppm.
� Granophile elements: W is at or below the detection limit, Sn is 3 ppm to 7 ppm, Mo is
1.7 ppm to 6.9 ppm, Sb is 1.3 ppm to 3.9 ppm.
� Precious metals: Au is below the detection limit to 211 ppb, Ag is at the detection limit to
5.2 ppm.
Mafic Volcanic Rocks
Mafic volcanic rocks from the Lewis Brook Zn–Pb–Ag vein system have typical to slightly
elevated (Na2O + K2O) contents of 6–10%, and SiO2 contents of 41–60%. They plot across the
basaltic trachyandesite and phonotephrite fields on the Na2O + K2O versus SiO2 diagram (Fig.
8a). As with felsic volcanic rocks from the Lewis Brook occurrence, some of these mafic
volcanic rocks show evidence (high K2O relative to Na2O) of alkali-element mobility (Fig. 8b, 8c).
In terms of HFSE contents (Zr/TiO2 and Nb/Y), these samples plot near the boundary between
the subalkaline basalt and andesite–basalt fields (Fig. 9a). The Zr/Y versus Zr values of these
rocks are typical of within-plate basalts (Pearce and Norry 1979) and are consistent with those
of mafic volcanic rocks elsewhere in the Tobique Group (Dostal et al. 1989; Wilson 1992;
Walker 2005). Chondrite-normalized REE profiles for these rocks have gentle negative slopes
and Eu/Eu* values of near unity: that is, they show no appreciable Eu anomaly (Fig. 10d). The
absence of a Eu anomaly suggests that the magma from which the basalt erupted did not
undergo significant crystal fractionation of plagioclase.
Redstone Mountain Granite
Samples of the Redstone Mountain Granite contain 72–78% SiO2 and 6–9% total alkalis (Fig.
8a), with K2O contents ranging from the detection limit to 5.5% (Fig. 8b). In contrast with the
felsic volcanic rocks described above, the alkali-element contents of the Redstone Mountain
Granite fall near the spectrum of typical felsic igneous rocks, indicating that they have not
undergone significant alkali-element metasomatism related to hydrothermal alteration (Fig. 8c).
In terms of their HFSE content, samples of the Redstone Mountain Granite show some
variation. Three fall in the rhyolite field (Fig. 9a, 9b) and have Zr/TiO2 values of ~0.2,
overlapping the majority of rhyolite samples from Mount Costigan; the remaining samples fall in
the rhyodacite–dacite field (Fig. 9a, 9b) and have Zr/TiO2 values of ~0.08, overlapping the field
of Lewis Brook samples. Most samples of Redstone Mountain Granite have Zr/Hf values ≤35,
similar to those of the Lewis Brook rhyodacite. These data suggest that the Redstone Mountain
Granite is chemically more similar to rhyodacite from the stratigraphically higher Lewis Brook area
than to rhyolite from Mount Costigan. The Redstone Mountain Granite may have undergone a

18
greater degree of fractionation than the source magma of the Mount Costigan rhyolite. REE
profiles of the Redstone Mountain Granite are LREE-enriched and display moderately
negative Eu anomalies (Fig. 10e). Overall, REE profiles of the granite are similar to those of
rhyolite from the Mount Costigan deposit and of the three LREE-enriched rhyodacite samples
from the Lewis Brook occurrence (Fig. 10a, 10c).
The contents of base metals and granophile elements in samples of the Redstone Mountain
Granite are summarized as follows (see Table 3 for details).
� Base metals: Pb is low (several samples lie below the detection limit), Zn is relatively low
(5–28 ppm), Cu content is very low (1–6 ppm).
� Granophile elements: W is low (

19
Results of mass change calculations are presented on Figures 11a to 11g. The majority of
felsic volcanic rocks hosting the Mount Costigan deposit have undergone addition of K2O
(+1 wt % to +6 wt %) and varied loss or gain of CaO (-0.02 wt % to +0.35 wt %). Most
samples have gained MnO (0 wt % to +0.3 wt %). Some samples have undergone MgO loss
with many more gaining MgO (-1 wt % to +3 wt %). Mass addition of MgO is associated with
the more permeable fragmental units and with the margins of larger sulphide veins, and is
coincident with the development of chlorite. All samples exhibit mass losses of Na2O (-2.0 wt
% to -3.5 wt %), Al2O3 (0 wt % to -5 wt %), and SiO2 (0 wt % to -50 wt %). Although some
samples show mass gain of Fe2O3 (total) , most exhibit mass loss with overall mass change
ranging between +1 wt % and -1.8 wt %.
All of the samples analyzed, regardless of their proximity to visible alteration or mineralization,
have lost Na2O and gained K2O. Such widespread alteration is attributed to relatively low-
temperature (

ΔCaO wt %
ΔFe O wt %
2 3
ΔKOwt %
ΔAl O wt %
2
2 3
0.4
0.3
0.2
0.1
0.0
-0.1
1
0
-1
-2
6
4
2
0
-2
-4
10
5
0
-5
Calcite formation
Pyrite
precipitation
K-feldspar
(adularia)
formation
Fe-leaching
-10
-100 -50 0 50 100
SiO 2
20
ΔMnO wt %
0.4
0.3
0.2
0.1
0.0
RDR = 0.05 wt % RDR = 0.05 wt %
RDR = 2.68 wt %
RDR = 4.02 wt %
RDR = 12.57 wt %
RDR = 75.6 wt %
ΔMgO wt %
ΔNa O wt %
2
-0.1
3
2
1
0
-1
-2
1
0
-1
-2
-3
Mn-carbonate
formation
a b
c
Chlorite
formation
Feldspardestructive
alteration
Si-leaching
-4
-100 -50 0 50 100
SiO 2
RDR = 1.17 wt %
e f
g
RDR = 3.47 wt %
Mount Costigan felsic volcanic rocks (from surface)
Mount Costigan felsic volcanic rocks (from drill core)
RDR
River Dee rhyolite
Figure 11. Graphic presentation of mass
balance data for host rocks from the Mount
Costigan deposit. The diagrams show SiO2 on
the x-axis plotted against a) CaO, b) MnO,
c) Fe2O 3, d) MgO, e) K2O, f) Na2O, or g) Al2O3 on the y-axis.
d

200 μm
21
Rhodochrosite
(Mn-carbonate)
Quartz.
a
Adularia
(K-feldspar)
Figure 12. Hydrothermal alteration in rock samples from the Mount Costigan deposit.
a) Photomicrograph showing alteration minerals (adularia and rhodochrosite) in sample of felsic
volcanic rock from DDH CM08-8 at 54 m. Field of view is ~350 μm.
b) Backscatter electron microprobe
image of hydrothermal alteration (adularia, rhodochrosite, and chlorite) in sample CM08-8-54 m.
Microprobe data for sample points 1 to 5 are presented in Table 4.
b

22
Despite the abundance of quartz-veining associated with near-surface base metal
mineralization, all but two samples have undergone SiO2 loss (0 wt % to -40 wt %). It is
hypothesized that SiO2 was leached from the host rocks during ascent of base metal-bearing
fluids and subsequently precipitated as quartz along with base metal sulphides upon cooling
and possible mixing with seawater in shallower parts of the system.
MINERALIZATION
Base metal mineralization at Mount Costigan is epigenetic and hosted dominantly by
heterolithic, matrix-supported felsic lapilli tuff containing fragments that range from 3 mm to
>10 cm in long axis. Fragment content is varied, at 5–20 volume %; however, this
percentage may be higher in some sections, as alteration may obscure primary textures
(Fig. 13a–13c). Surface exposures, where these rocks are cut by numerous quartz veins,
were referred to as ‘vent breccia’ by Fyffe and Pronk (1985). Less commonly, mineralization
occurs as massive sulphide veins that transect rhyolitic flows and locally parallel flowlayering
(Fig. 5c, 13a).
According to earlier workers (Crevier 1984; Fyffe and Pronk 1985), the Mount Costigan
deposit contains a non-NI 43-101-compliant resource of 6–8 Mt of mineralized rock. Within
this envelope of mineralization, a higher grade ‘Core Zone’ was identified (Clark 2008). This
zone comes to surface along its entire length and in section is irregularly shaped (Fig. 3). It is
a tabular body with a north–south strike length of ~150 m, an east–west thickness that ranges
from 4 m to 36 m, and a depth that extends to 200 m. It is not clear what, if any, role structural
breaks exert on the deposit orientation or on the mineralization in the Core Zone, as there is
no evidence for north–south faulting. Furthermore, the absence of north–south-directed
drilling precludes the identification of an east–west-oriented fault, should one be present.
Although no formal tonnages or grade estimates have been published for the Core Zone, a
non-NI 43-101-compliant resource of ~0.9 Mt grading 4–5% Zn + Pb was estimated by Clark
(2008). Drill-core logging and petrographic examination indicate that the mineralogy of the
Mount Costigan deposit is relatively simple and dominated by sphalerite and subordinate
galena. Pyrite is present but not in significant amounts, and chalcopyrite occurs as a trace
phase.
Some results of the present investigation are consistent with those of earlier workers (Crevier
1984; Fyffe and Pronk 1985; Cox 1990), who have described a roughly elliptical mineralized
area with a short axis extending for ~200 m along a north-northeast to south-southwest line
and a long axis extending ~340 m east–west, at a high angle to regional strike. Mineralization
has been intersected at depths of up to 300 m below surface (Fig. 3). However, in contrast to
previous interpretations of an eastward-plunging zone of mineralization (Fyffe and Pronk
1985; Cox 1990), this investigation suggests that the zone of alteration and mineralization,
although irregular, is more or less subvertical to a depth of 300 m. This irregularity is attributed
to stratigraphic variations in primary permeability, which exert significant control on the
distribution of sulphide mineralization (Fig. 3). Sedimentary units intercalated with the volcanic
rocks are commonly barren and may have acted as barriers to mineralizing fluids during

Figure 13. Mineralization and
alteration in drill core samples from
the Mount Costigan deposit. a) Vein
galena–sphalerite and minor pyrite
cutting chlorite-altered rhyolite from
DDH CM08-4 at 75 m.
Figure 13. b) Chlorite–silica–
carbonate-altered breccia with patchy
sphalerite and galena from DDH
CM08-4 at 24 m.
Figure 13. c) Rhyolite-clast breccia
with quartz and minor Fe-carbonate
(siderite) cement from DDH CM08-8
at 120 m.
23
Galena
Galena
Galena
Sphalerite
Fe-carbonate
a
Sphalerite
CM08-4
b
c
Sphalerite

24
their egress to the seafloor. Base metal zoning at Mount Costigan exists only in terms of a
higher grade (>4% Zn + Pb) Core Zone and a lower grade periphery.
Sulphide mineralization occurs in two forms: 1) as finely disseminated grains (

W ppm
30
20
10
25
0
0 5 10 15 20
Sn ppm
Figure 14. a) Pb–Cu–Zn ternary diagram for assay data from the Mount Costigan deposit. b) W versus
Sn diagram for data from the Mount Costigan deposit, Lewis Brook occurrence, and Redstone
Mountain Granite.
also anomalous and range from 1 ppm to 15.1 ppm. Au contents range from below the
detection limit to a maximum of 90 ppb, whereas Ag contents range from 0.8 ppm to 3.4 ppm
(Table 1).
SAMPLE ANALYSES
Sulphur Isotope Analysis
Cu %
Pb % Zn %
Part of this investigation involved collecting a limited number of samples for sulphur isotope
analysis (Table 5). Sampling included mineral separates (sphalerite and galena) as well as
bulk sulphide samples (pyrite + galena + sphalerite). The purpose of this work was to estimate
the temperature of formation for mineralization and to determine what, if any, systematic
sulphur zoning occurs in the Mount Costigan deposit.
Although few samples were analyzed, the data show that S for bulk sulphur increases
slightly with depth. In the near-surface samples (20.9 m, 73.0 m, and 111.5 m), bulk sulphur
ranges between +9.2‰ and +9.72‰, consistent with sulphide in equilibrium with seawater,
δ 34
a
Mount Costigan chloritic
fragmental volcanic rocks
Mount Costigan felsic volcanic
rocks (from drill core)
Lewis Brook felsic
volcanic rocks
Lewis Brook mafic
volcanic rocks
Redstone Mountain Granite

26
according to the global seawater curve for the Early Devonian (Fig. 15; Goodfellow et al.
1993). Likewise, the δ 34 S values for sphalerite and galena separates (Table 5) are coincident
with the global seawater curve and define the maxima and minima, respectively, of the bulk
data. At depth (187.2 m), the δ 34 S for bulk sulphur is lower (7.38‰; Table 5) and falls off the
global seawater curve (Fig. 15). This may be interpreted to suggest a greater magmatic
component in mineralizing fluids deeper in the system; however, results of a single analysis
preclude a conclusive determination. Similar δ 34 S values were reported for sulphide separates
from the Shingle Gulch East deposit (URN 878) (Fig. 1; Walker 2005), located approximately
10 km along strike to the north-northeast of the Mount Costigan deposit, and were interpreted
to reflect the mixing of magmatic fluid (80%) with seawater (20%).
Table 5. Sulphur isotope data for bulk sulphides, and for sphalerite and galena separates, from the
Mount Costigan deposit.
Sample Number Bulk Sulphides or Mineral Separates δ 34 S δ 34 Ssph–δ 34 Sga
CM08-11-20.9-B bulk 9.72
CM08-11-20.9-Ga galena 9.05
CM08-11-20.9-Zn sphalerite 10.71 1.66
CM08-4-73-B bulk 9.91
CM08-4-73-Ga galena 7.57 2.49
CM08-4-73-Zn sphalerite 10.06
CM08-8-111.5-B bulk 9.20
CM08-8-111.5-B bulk 9.58
CM08-8-111.5-Ga galena 7.32 2.75
CM08-8-111.5-Zn sphalerite 10.07
CM08-4-178.4-B bulk 7.38
CM08-4-178.4-Ga galena 5.92 0.78
CM08-4-178.4-Zn sphalerite 6.70
Note: Sulphur isotope analysis conducted by Alison Pye, Stable Isotope Laboratory, Memorial University of
Newfoundland, St. John’s, Newfoundland and Labrador.
Although no comprehensive set of bulk sulphur or δ 34 S data exists for Siluro–Devonian
intrusions in the report area, similar Late Silurian to Early Devonian felsic intrusions in
southwestern New Brunswick display a wide range of δ 34 S values (-7.1‰ to +13‰) and
average +2.2‰ ± 0.5‰ (Yang and Lentz 2010). Assuming similar values for the Redstone
Mountain Granite, the moderately positive δ 34 S contents of bulk sulphur (+9.2‰ to +9.72‰) in
the sulphides suggest that the fluids (or fluid) involved in the mineralizing system were not
dominated by magmatic sulphur, contrary to what would be expected for a magmatically
derived mineralized vent breccia system. The consistency with seawater sulphide values for
the Early Devonian (i.e., the age of the host sequence) leads to the conclusion that
mineralizing fluids interacted with seawater directly, or acquired sulphur from sulphide
minerals that were deposited in equilibrium with seawater.

27
Four pairs of coexisting galena and sphalerite grains were collected for δ 34 S isotopic analysis
in order to calculate temperature of formation. Two of these pairs (from 73.0 m and 111.5 m)
yielded temperatures of formation, based on the calculation of Grootenboer and Schwarcz
(1969), of 242°C and 217°C, respectively, although a higher (≤294°C) temperature can be
calculated using the equilibrium equations of other authors (Table 6). These temperatures are
consistent with mineralogical constraints on the temperature of formation presented later in
this report. Two other sphalerite–galena pairs (from 20.9 m and 178.4 m) returned calculated
temperatures of formation of 357°C and 647°C, respectively. These temperatures are
considerably higher than those calculated from the other samples and likely reflect sampling
from sulphide pairs that were not coprecipitated (i.e., were not in isotopic equilibrium).
Table 6. Temperatures of formation calculated from δ 34 S data for sphalerite and galena separates from
the Mount Costigan deposit (see Table 5).
∆ 34 S = 34 Ssph– 34 Sga
Kajiwara and
Krouse (1971)
o C
Czamanske and
Rye (1974)
o C
Grootenboer and
Schwarcz (1969)
1.66 421 376 357
2.49 294 257 242
2.75 266 231 217
0.78 740 674 647
Radiogenic Lead Isotope Analysis
Lead isotope studies can be effective tools for determining the various sources of Pb and
relative contributions of these sources to mineralizing systems and host rocks. This is possible
because Th and U behave similarly in the magmatic environment in that, during partial melting
and fractional crystallization, both are concentrated in the fluid phase relative to the residuum
(Faure 1986). However, in the realm of aqueous hydrothermal fluids, U is concentrated in the
fluid phase, whereas Th is highly insoluble and remains in the residuum. Likewise, under
oxidizing conditions, U is highly soluble and is easily fractionated from Th (Faure 1986).
The Mount Costigan galena separates display high 207 Pb/ 204 Pb values and plot above the
upper crust evolutionary curve of Zartman and Doe (1981) on a 207 Pb/ 204 Pb versus 206 Pb/ 204 Pb
diagram (Fig. 16a), close to the fields of Avalonian basement (Ayuso and Bevier 1991) and
Siluro–Devonian Ganderian plutons (Whalen et al. 1996). All but one of the galena separates
from the Sewell Brook and Shingle Gulch deposits cluster around the Mount Costigan
samples, suggesting that Pb in all three deposits shares a common source. The array defined
by the galena separates (n = 7) has a Spearman Rank Correlation coefficient (r’) of 0.86, a
slope of 1.09, and an x-intercept of 4.18. In contrast to the galena separates, host rocks from
the Mount Costigan deposit have lower 207 Pb/ 204 Pb values and plot between the orogene and
mantle curves, overlapping the field of the Grenvillian basement (Ayuso and Bevier 1991).
Host volcanic rocks from Sewell Brook and Shingle Gulch lie more or less along the same
array as the Mount Costigan samples. The array defined by the host rock samples (n = 16)
has an r’ value of 0.79 and falls on a line with a slope of 0.18 and an x-intercept of 1.23. This
o C

Tertiary
Cretaceous
Jurassic
Triassic
Permian
Pennsylvanian
Mississippian
Devonian
Silurian
Ordovician
Cambrian
Proterozoic
U
M
L
U
M
L
U
M
L
*
0 +10 +20 +30 +40
Galena
28
(Diagram modified from
Goodfellow et al. 1993.)
Sphalerite
Bulk
Stratified water column
with anoxic waters
Deposition time
of the Tobique Group
Range of bulk
sulphur analyses
δ 34 S (CDT)
‰
Marine Evaporites
(Claypool et al. 1980)
Barite, Selwyn Basin
(Goodfellow and Jonasson 1984)
Bulk = mixture of pyrite, galena, and sphalerite
Pyrite, Selwyn Basin
(Goodfellow and Jonasson 1984;
Shanks et al. 1987)
34
Figure 15. Seawater sulphur isotope curve through time, showing the δ S contents of marine evaporites,
34
barite, and pyrite from the Selwyn Basin. Diagram indicates the approximate δ S contents of galena and
sphalerite (red dots), and bulk sulphur (blue bar) from the Shingle Gulch East deposit.
trend is interpreted to reflect mixing of orogenic and upper crustal Pb. The overlap with both
Grenvillian and Avalonian basement fields might be explained by magma generation in
Grenvillian rocks and subsequent crustal contamination by Avalonian rocks during the
magma ascent.
208 204 206 204
On a Pb/ Pb versus Pb/ Pb diagram (Fig. 16b), galena separates from the Mount
Costigan, Shingle Gulch, and Sewell Brook deposits fall well above the orogene curve, close
to the intersection of the fields of Avalonian and Grenvillian basement. The felsic and mafic
volcanic and sedimentary rock samples plot along an array that begins below the upper crust
evolutionary curve and extends above the curve where it overlaps the lower part of the field
defined by the galena separates. All samples overlap, in part, the field of Grenvillian
basement and the field of Humber Zone and Dunnage Zone plutons (Whalen et al. 1994).
208 204
However, the host rocks from Mount Costigan have lower Pb/ Pb values, at or below the
field of Grenvillian basement, and some samples from the Shingle Gulch deposit have higher
208 204
Pb/ Pb values and plot in the fields of Avalonian basement and Gander Zone plutons.
*

Pb/ Pb
Pb/ Pb
207 204
208 204
15.9
15.8
15.7
15.6
15.5
15.4
15.3
39
38
37
sedimentary
felsic volcanic
mafic volcanic
mineralization
upper crust
Grenvillian
basement
lower crust
orogene
Grenvillian
basement
mantle
100
700
1000
0
900
mantle
Field of Siluro–Devonian Gander
Zone plutons (Whalen et al. 1996)
18 206 204
19
100
1000
500
Pb/ Pb
300
Avalonian
basement
200
100
400
0
Field of Humber Zone and Dunnage
Zone plutons (Whalen et al. 1994)
200
18 206 204
19
100
Pb/ Pb
Shingle Gulch Sewell Brook
0
Field of Siluro–Devonian Gander
Zone plutons (Whalen et al. 1996)
Field of Humber Zone and Dunnage
Zone plutons (Whalen et al. 1994)
300
39.25 39.70
upper crust 200
Mount Costigan
29
600
Avalonian
basement
400
100
orogene
BMC sulphide standard
Redstone Mountain Granite
Age along curve in
100 Ma increments
Figure 16. Radiogenic lead isotope diagrams for host rocks and mineralization from the Mount
207 204 206 204 208 204
Costigan, Shingle Gulch, and Sewell Brook deposits. a) Pb/ Pb versus Pb/ Pb. b) Pb/ Pb
206 204
versus Pb/ Pb. Fields of Avalonian and Grenvillian basement are from Ayuso and Bevier (1991).
Lead evolutionary curves are from Zartman and Doe (1981).
0
a
b

30
The lead isotope data presented herein suggest that the host volcanic rocks at Mount
Costigan are less radiogenic (i.e., have lower 207 Pb/ 204 Pb values) than most rocks from
elsewhere in the Chaleur Bay Synclinorium, implying that their magmas were sourced from
material similar to Grenvillian crust. Grenvillian basement is not known to underlie the Chaleur
Bay Synclinorium; however, Late Ordovician to Early Silurian clastic and carbonate
sedimentary rocks of the Matapedia Group, which conformably underlies the Chaleur Bay
Synclinorium to the west and north of the Rocky Brook–Millstream Fault (Fig. 1, inset), were
sourced from Laurentia and potentially contain a large component of Grenville-derived
sediment. This Grenvillian detritus would have retained the 208 Pb/ 204 Pb value of the parent
material but presumably would have lower 207 Pb/ 204 Pb values because of U loss during the
weathering process (oxidation and aqueous transport). The array defined by the host rock
data (Fig. 16a) may be interpreted to represent contamination of the source magmas by upper
crustal material having Grenville-like lead isotope signatures. It is noteworthy that sedimentary
rocks from stratigraphically higher units, such as the Shingle Gulch deposit, have higher
uranogenic ( 207 Pb/ 204 Pb) and thorogenic ( 208 Pb/ 204 Pb) Pb contents. This trend can be
explained by an increasing percentage of Avalon-sourced sedimentary input over time.
The lead isotope data from sulphide mineralization contrast sharply with those of the host
rocks. The more uranogenic (higher 207 Pb/ 204 Pb) Pb in galena separates is similar to values in
Avalonian basement and/or Siluro–Devonian Ganderian plutons (Fig. 16a). For example, the
Redstone Mountain Granite has 207 Pb/ 204 Pb values similar to those in galena from the Mount
Costigan deposit. It is possible that the higher uranogenic Pb in sulphide minerals is due to
addition of U from hydrothermal fluids. If the mineralizing hydrothermal fluids were sourced
from a felsic magma such as the Redstone Mountain Granite, then the fluid and any
mineralization precipitated from it would have a higher 207 Pb/ 204 Pb value. In contrast, the
208 Pb/ 204 Pb in sulphide minerals would be lower than that of the source intrusion, because the
solubility of Th in hydrothermal fluid is lower than that of U. Consistency in the isotopic ratios
displayed by mineralization from all three deposits implies that the Pb source was the same
and suggests no indication of a mixed-source Pb.
Given the much higher values of 208 Pb/ 204 207 204 206 204
Pb, Pb/ Pb, and Pb/ Pb for the Redstone
Mountain Granite, it is unlikely that this intrusion was the source magma for the host volcanic
rocks at Mount Costigan. However, no lead isotope data have been reported for the Lewis
Brook area, so no comparison can be made with the Redstone Mountain Granite.
DISCUSSION
The sulphide mineralogy at Mount Costigan is dominated by sphalerite and galena with a
Zn:Pb ratio of ~2. In most mineralized intervals, pyrite is volumetrically subordinate to Zn and
Pb sulphides, and chalcopyrite occurs only in trace amounts. The relatively light colour of
sphalerite, which ranges from reddish brown to pale yellow, is attributed to a low Fe content
and is consistent with the low concentration of pyrite in the system. In addition to containing
Zn and Pb, many of the analyzed samples (Table 1) have anomalous concentrations of the
granophile elements W, Sn, Sb, and Au. During petrographic analysis, neither Au nor primary

31
W, Sn, Sb, and Au. During petrographic analysis, neither Au nor primary W, Sn, and Sb
minerals were recognized. Therefore, it is assumed that these elements occur as trace
constituents in sulphide phases (sphalerite, galena, pyrite), although the microanalytical work
necessary to confirm this has not been completed. The elevated granophile-element content
is consistent with a felsic source.
Copper is notable by its almost complete absence at the Mount Costigan deposit. Only a few tiny
grains were identified in thin section, and ‘chalcopyrite disease’ (microscale inclusions of
chalcopyrite in sphalerite) is all but absent. Although the genesis of chalcopyrite disease is still open
to debate, the generally accepted hypothesis is that it results, not from exsolution, but instead
from the interaction of early-formed sphalerite with later Cu-rich hydrothermal fluid (Barton and
Bethke 1987). Consequently, assuming that mineralizing fluids have access to Cu in their source
area, the absence of chalcopyrite disease is generally taken as evidence of low-temperature
sphalerite formation, without subsequent interaction with higher temperature Cu-bearing fluids.
Assuming 1) that the hydrothermal fluid responsible for generating the Mount Costigan deposit
was Cl-rich (ΣCl = one molar), which is likely, given the shallow marine setting in which the
host rocks were deposited, and 2) that a minimum concentration of 1 ppm of each ore metal is
required in the fluid to form a deposit, then a fluid with a temperature of ≤200°C and a pH of

Cordilleran Epithermal Au–Ag Deposit
Model (Panteleyev 1988)
Mount Costigan Deposit
and Lewis Brook Occurrence
Silica cap
Clay alunite cap
Argillic to Phyllic Zone:
clays (illite, sericite at depth)
4 km
silica (banded
and brecciated)
Propylitic Zone: chlorite, illite,
montmorillonite, carbonate, epidote
Mount Costigan deposit:
present erosional level
boiling
zone
Lewis Brook Zn–Pb–Ag
occurrence
quartz, adularia, pyrite, sericite,
calcite, chlorite, rhodochrosite,
fluorite, argentite, electrum
precious
metal
zone
boiling
level
quartz, pyrite, chlorite,
hematite,
fluorite, galena, sphalerite,
chalcopyrite,
argentite
base
metal
zone
350 m
quartz, siderite, pyrite,
pyrrhotite,
arsenopyrite, fluorite,
chalcopyrite,
argentite
Costigan Mountain Formation
silica, adularia,
albite

33
circulated through permeable volcanic units toward a hydrothermal upflow zone (Fig. 15, 17),
similar to those invoked for the formation of VMS deposits (Franklin 1995). As this fluid was
heated to temperatures of up to 150°C and reacted with the host volcanic rocks, quartz was
dissolved, and K-feldspar formed at the expense of plagioclase. Sulphide deposition occurred
when seawater sulphate was reduced by interaction with upwelling magmatic fluid, and/or the
pH changed by reaction with host rocks. This model requires that sulphur was sourced from
shallowly circulating seawater, whereas metals (± minor sulphur) were transported in
magmatic fluid, with sulphide precipitation occurring upon mixing of these two fluids in the
subsurface. In contrast with typical VMS systems in which rapid fluid mixing and cooling result
in the rapid precipitation of very fine-grained sulphide (Barnes 1979), the mineral kinetics of
fluid mixing and sulphide precipitation at temperatures of ~200°C at Mount Costigan allowed
for slower sulphide precipitation and resulted in the formation of relatively coarse-grained
sulphides.
It is possible that the intrusion from which the hypothesized metal-bearing magmatic fluid
was sourced contained anomalously heavy sulphur (i.e., δ 34 S = +9.2‰ to +9.7‰). However,
this model requires that both metals and sulphur (as bisulphide) are transported in the same
fluid. In the neutral to moderately low-pH hydrothermal fluid hypothesized for Mount
Costigan, and assuming ΣS = 1 molal, such a fluid should contain significant Cu and Zn
(Cu/Zn is ≥2 and ≤10) and very little Pb at the estimated maximum temperature of formation
of 220°C (Lydon 1988). However, this is not consistent with the metal ratios exhibited at
Mount Costigan (sphalerite and galena show a 2:1 ratio: Fig. 14a) or with the absence of Cu
mineralization.
Given the apparent stratigraphic control on the distribution of mineralization and alteration
along with the limited development of cross-cutting hydrothermal breccia, it seems likely that,
at the margins of the system, most fluid flow was focused laterally within permeable strata,
whereas at depth in the central part of the system, fluids flowed vertically through existing
fractures at confining pressures that were high enough to prevent boiling. In the central part of
the system at shallow levels, abundant quartz ± carbonate veining and breccia-fill textures
may mark the lower boundary of a boiling zone. In typical epithermal deposits in which a
boiling zone is developed, precious metals (Au and Ag) accumulate above the boiling zone. At
Mount Costigan, Au and Ag are encountered in the higher sections of the system, suggesting
that part of the system may have been lost to erosion.
The salient characteristics of the Mount Costigan deposit can be compared with those of the
Cordilleran epithermal Au–Ag deposits (Panteleyev 1988). Although not a perfect match, the
Mount Costigan deposit does share several attributes of this deposit type (Fig. 17). In
particular, the mineral assemblage quartz–adularia–pyrite–sericite–calcite–chlorite–rhodochrosite
–fluorite ± Au–Ag, which occurs at or immediately above the boiling zone in Panteleyev’s
model, strongly resembles the shallower part of the Mount Costigan deposit. Also, the
sphalerite–galena–pyrite–quartz–chlorite veins that are abundant below the boiling zone in his
model are similar to the massive base metal veins at Mount Costigan.

34
The Redstone Mountain Granite is proposed as a likely source of the metals at Mount
Costigan. Although similar in HFSE contents (Fig. 9a–c) to volcanic rocks at the top of the
Costigan Mountain Formation (Lewis Brook area), the granite is characterized by very low
contents of Zn, Pb, Cu, W, Mo, Sn, Sb, and Au compared with the felsic rocks hosting the
deposit. Likewise, similarities in the uranogenic ( 207 Pb/ 204 Pb) Pb contents of the Mount
Costigan mineralization and Redstone Mountain Granite suggest a possible genetic link (Fig.
16). The anomalously low metal content of the granite may be due to metal sequestration into
a fluid phase during cooling of the intrusion. This fluid phase was introduced into the host
sequence, where it mixed with seawater convecting through the volcanic rocks, and
precipitated sulphide mineralization at temperatures of ~200°C.
Similar, high-level, metal-depleted intrusions within and coeval with the footwall succession of
VMS deposits in the Bathurst Mining Camp of northeastern New Brunswick (Fig. 1, inset)
have been interpreted to reflect depletion following separation of a metal-laden, depositgenerating
fluid phase (McCutcheon and Walker 2008). At a shallower level in the system,
where confining pressure was surpassed by an exsolving gas phase, the fluid would undergo
phase separation (boiling). Boiling promotes sulphide saturation and a decrease in the
solubility of carbonate phases. This explains the high-grade massive sulphide breccia cement
as well as increased quartz–carbonate veining in the shallower parts of the deposit.
CONCLUSIONS
The Mount Costigan Zn–Pb–Ag sulphide deposit is hosted by intercalated heterolithic felsic
lithic- and crystal–lithic-lapilli tuff, massive to flow-layered, aphyric to very sparsely feldsparphyric
rhyolite, and minor intervals of siltstone and sandstone within the Costigan Mountain
Formation. Most of the fragmental textures observed at the deposit are pyroclastic in origin,
rather than hydrothermal breccia as reported by previous authors (Fyffe and Pronk 1985; Cox
1990).The deposit comprises epigenetic mineralization of base metal sulphides that formed
within fragmental volcanic rock in a setting beneath the seafloor. Mineralization occurred at
temperatures below 220°C and involved the interaction of shallowly circulating seawater and
metal-rich, magmatically derived hydrothermal fluid. The deposit displays characteristics of
both subsurface VMS- and Cordilleran-type epithermal Au–Ag systems.
Overall, the mineralized zone is subvertical but highly irregular and strongly dependant on
permeability of primary fragmental (pyroclastic) rocks. It has been intersected to depths of
300 m. Pyroclastic rocks acted as conduits for later circulating hydrothermal fluids and were
the locus for subsequent mineralization and local development of hydrothermal breccia. This
interpretation is supported by the observation that units of unbrecciated sedimentary rock can
be traced through the mineralized zone (Fig. 3). These sedimentary units are generally
unmineralized, although they may be locally cut by massive sulphide veins. The relative
absence of mineralization in these units suggests that sedimentary beds may have acted as
barriers to fluid migration and implies that, for the most part, mineralizing fluids remained
below their boiling point and were channelled through zones (strata) of higher primary
permeability/porosity.

35
The consistency and range (from +7.4‰ to +9.7‰) in δ 34 S of bulk sulphide samples suggests
that Early Devonian seawater was the most likely source of sulphur in this deposit; however,
there is evidence at depth for a component of magmatic sulphur. The metal assemblage (Zn–
Pb ± Sn, W, Ag, Au) was likely derived from a hydrothermal fluid generated during the cooling
of a felsic magma, possibly from the Redstone Mountain Granite. Although no direct link can
be drawn, similarities in the uranogenic ( 207 Pb/ 204 Pb) Pb content of the Mount Costigan
mineralization and the Redstone Mountain Granite suggest a possible link. Likewise, the
atypically low metal content of the Redstone Mountain Granite suggests that, at some point
during its crystallization, its ore metals were effectively sequestered into an evolving
hydrothermal fluid. Such a fluid may have contributed to the Mount Costigan and/or Lewis
Brook mineralizing systems.
Several lines of evidence, including sulphur isotope ratios of coexisting sulphide pairs, the
presence of rhombohedral adularia, and the Zn–Pb-rich, Cu-poor nature of the mineralization,
suggest formation at relatively low temperatures of below 220°C.
Three distinct alteration types are recognized.
� Zone 1 is the most distal alteration type and consists of low-temperature (

36
Table 1. Lithogeochemical data for SLAM Exploration Ltd. drill cores and trenches at the Mount Costigan deposit.
Detection
Limit
Sample
Analytical
Method
CM08-4-
73.8 m
Grey flb
rhy
CM08-10-
60 m
Sparse fsparphyric
rhy with
chloritic
fragments
CM08-4-
145.2 m
Grey aphyric
rhy
CM08-4-
209.8 m
Sparse fspar-
phyric rhy
(grey)
CM08-4-
230.7 m
Fspar-phyric
rhy
CM08-11-
194.2 m
Med. grey sparsely
pink fspar-phyric rhy
(minor ZnS veins)
SiO2 0.01% FUS-ICP 60.35 57.39 62.19 74.44 65.52 73.2
Al2O3 0.01% FUS-ICP 15.27 14.83 14.28 11.9 14.01 11.59
Fe2O3 (total) 0.01% FUS-ICP 3.33 6.25 4.52 2.09 4.76 3.22
MnO 0.001% FUS-ICP 0.158 0.256 0.24 0.112 0.309 0.124
MgO 0.01% FUS-ICP 2.27 5.12 2.42 1 3.9 1.05
CaO 0.01% FUS-ICP 0.21 0.22 0.41 0.14 0.15 0.1
Na2O 0.01% FUS-ICP 0.19 0.18 0.2 0.17 0.15 0.17
K2O 0.01% FUS-ICP 11.18 9.28 10.73 9.54 8.57 8.8
TiO2 0.001% FUS-ICP 0.194 0.788 0.811 0.195 0.298 0.17
P2O5 0.01% FUS-ICP < 0.01 0.14 0.14 < 0.01 0.03 0.02
LOI 0.01% FUS-ICP 2.6 3.45 2.33 1.15 2.7 1.83
Au 1 ppb INAA 90 < 2 22 20 22 24
Ag 0.5 MULT INAA / TD-ICP 3.4 1 0.9 0.8 1.2 0.8
As 1 INAA 8 15.2 45 21 39 23
Ba 1 FUS-ICP 632 482 730 720 521 628
Bi 0.1 FUS-MS 1.9 0.1 < 0.1 < 0.1 1.7 0.3
Cd 0.5 TD-ICP 26.1 15.3 3.7 11.5 < 0.5 19.1
Co 0.1 INAA 1.3 7 8.5 2.3 3.5 1.2
Cr 0.5 INAA < 0.5 37 36.6 22.1 21.9 20.1
Cs 0.1 FUS-MS 0.7 1.9 1.3 0.8 1 0.6
Cu 1 TD-ICP 38 8 143 48 4 73
Ga 1 FUS-MS 24 20 19 16 22 17
Ge 0.5 FUS-MS 1.2 1.3 1.3 1.2 1.2 1.4
Hf 0.1 FUS-MS 10.2 8.7 9 8.1 12.5 7.4
Mo 2 FUS-MS < 2 < 2 < 2 2 3 3
Nb 0.2 FUS-MS 28.1 23.1 17.9 22.9 31.4 18.7
Ni 1 TD-ICP 1 11 6 2 8 3
Pb 5 TD-ICP > 5000 2980 838 1790 1460 621
Rb 1 FUS-MS 339 280 320 270 294 241
S 0.001% TD-ICP 1.14 0.598 0.635 0.385 0.423 1.27
Sb 0.1 INAA 7.6 3.3 5.1 3.2 4 5.2
Sc 0.01 INAA 10.1 15 15.3 7.67 10.4 7.46
Se 0.5 INAA < 0.5 < 3 < 0.5 < 0.5 5.9 < 0.5
Sn 1 FUS-MS 11 14.2 8 5 6 8
Sr 2 FUS-ICP 27 20 46 33 23 29
Ta 0.01 FUS-MS 2.29 1.25 1.49 1.51 1.83 1.57
Th 0.05 FUS-MS 26.9 17.2 18.8 20.8 21.7 19.2
U 0.01 FUS-MS 6.73 4.38 5.25 5.42 5.87 5.24
V 5 FUS-ICP < 5 75 81 8 20 10
W 1 INAA 10 24.3 25 3 7 < 1
Y 1 FUS-ICP 65 55.1 52 55 58 59
Zn 1 INAA / TD-ICP 7950 4500 1340 4380 157 6710
Zr 1 FUS-MS 365 371 385 295 513 280
La 0.05 FUS-MS 47.8 55 31.5 55.6 37.7 67.1
Ce 0.05 FUS-MS 109 111 63.9 108 78.4 132
Pr 0.01 FUS-MS 13.6 11.1 7.98 12.6 9.71 14
Nd 0.05 FUS-MS 50.4 41.6 30.4 48.1 40.8 49.7
Sm 0.01 FUS-MS 11.9 8.89 6.96 10.6 10 11.9
Eu 0.005 FUS-MS 2.47 1.38 0.873 1.12 1.21 1.78
Gd 0.01 FUS-MS 10.9 8.79 6.98 10.2 9.47 11.6
Tb 0.01 FUS-MS 2.07 1.44 1.3 1.79 1.67 1.98
Dy 0.01 FUS-MS 12.4 8.39 8.39 10.7 10.6 11
Ho 0.01 FUS-MS 2.59 1.63 1.84 2.18 2.39 2.17
Er 0.01 FUS-MS 7.45 4.76 5.4 6.12 6.88 5.9
Tl 0.05 FUS-MS 1.45 1.48 1.54 1.37 2.01 1.22
Tm 0.005 FUS-MS 1.2 0.713 0.876 0.948 1.09 0.918
Yb 0.01 FUS-MS 7.86 4.69 5.43 6.11 7.04 5.7
Lu 0.002 FUS-MS 1.12 0.752 0.799 0.853 1 0.795
Notes: 1. All detection limits are in ppm unless otherwise stated. All analyses were conducted by Activation Laboratories Ltd.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry.
3. rhy = rhyolite, flb = flow-banded, fspar = feldspar, xl = crystal.

Table 1 (cont’d). Lithogeochemical data for SLAM Exploration Ltd. drill cores and trenches at the Mount Costigan deposit.
Sample
CM08-4-
264 m
Rhy fragment
from xl lithic
tuff with
alkali granite
fragment
CM08-4-
90.7 m
Sil-K fspar cement
from rhy fragmental
containing
dissem’nated
sulphides
CM08-4-
254.8 m
Highly altered
felsic
fragmental
37
CM08-11-
148.4 m
Mottled/altered
grey flb rhy
very sparse
fspars
CM08-11-
74.5 m
Green-grey
flb rhy with
minor fspar
phenocrysts
CM08-12-
175 m
Fsparphyric
rhy
with minor
sulphide
CM08-12-
252.2 m
Massive
grey rhy
CM08-12-
273.5 m
Massive
grey rhy
with pink
fspar
phenocrysts
SiO2 69.82 84.92 57.37 76.24 60.82 74.74 74.76 71.54
Al2O3 11.82 5.96 16.12 11.34 17.35 11.9 11.35 12.4
Fe2O3 (total) 3.31 2.07 3.17 1.71 4.31 1.88 1.94 2.62
MnO 0.354 0.085 0.609 0.1 0.245 0.095 0.038 0.142
MgO 4.18 0.6 6.33 0.52 2.07 0.46 0.34 1.12
CaO 0.34 0.04 0.59 0.15 0.04 0.09 0.23 0.46
Na2O 0.15 0.12 0.2 0.22 0.2 0.22 0.16 1.79
K2O 7.02 4.1 11.37 8.98 12.09 9.69 9.57 7.17
TiO2 0.444 0.088 0.389 0.149 0.245 0.168 0.169 0.42
P2O5 0.06 < 0.01 0.05 0.01 0.02 0.02 0.02 0.07
LOI 3.02 1.09 3.99 0.67 1.75 0.76 1.4 1.5
Au 14 38 70 < 1 < 1 5 8 < 1
Ag 0.8 1.2 1.8 < 0.5 0.5 < 0.5 < 0.5 < 0.5
As 25.9 22.6 99 12 8 14 10 27
Ba 365 231 350 904 836 856 843 705
Bi 0.1 < 0.1 0.8 0.3 < 0.1 < 0.1 < 0.1 < 0.1
Cd 3.1 19.4 < 0.5 < 0.5 1 1.3 2.2 < 0.5
Co 9 2 3.9 < 0.1 1.3 1.2 1.2 3.1
Cr 66 22 19.3 29.3 15.6 33.6 18.4 31.5
Cs 1.7 0.7 2.4 1 1 1.2 0.6 0.5
Cu 124 13 50 8 1 10 6 10
Ga 15 8 21 16 23 18 13 18
Ge 1.1 2.5 1.5 1.4 1.7 1.4 1 1.1
Hf 7.1 4.3 14.5 7.9 12.6 8.3 8 8.3
Mo < 2 < 2 < 2 < 2 2 < 2 < 2 < 2
Nb 19.6 13.1 36 24.5 37.8 24.4 23.7 23.6
Ni 29 9 4 2 2 2 1 5
Pb 687 2810 61 121 201 162 94 7
Rb 262 146 414 268 384 287 271 212
S 0.621 0.572 0.977 0.162 0.145 0.232 1.02 0.558
Sb 5.6 15.1 3.2 1.4 1.4 1.3 2 0.9
Sc 10 3 13.5 6.94 12.8 8.02 6.47 12.5
Se < 3 < 3 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5
Sn 11.3 6.5 6 7 13 6 5 8
Sr 39 9 65 50 26 41 37 54
Ta 1.08 0.68 2.11 1.6 2.48 1.63 1.46 1.41
Th 12.1 8.14 24.6 20.8 32.5 21.3 19.2 18.4
U 3.29 2.5 6.58 5.43 8.01 5.57 5.11 4.98
V 49 < 5 23 < 5 8 < 5 < 5 24
W 2.6 1.8 < 1 5 16 4 < 1 8
Y 39.4 30 69 65 84 67 40 61
Zn 1170 6240 191 214 216 772 809 31
Zr 291 179 609 279 436 298 300 331
La 51.3 20 83 63.9 92.1 73.8 59.9 63.3
Ce 106 46.4 162 124 172 141 120 121
Pr 10.2 4.64 19.1 14.3 21 16.4 13.7 14
Nd 37.1 17.1 74.5 54.8 80.4 62.5 51.8 54.6
Sm 7.06 3.69 15.3 11.5 16.3 13 10.4 11.5
Eu 1.23 0.663 2.65 1.27 2.82 1.52 1.02 1.69
Gd 6.75 3.43 13.2 11.1 15.2 12.5 8.82 11
Tb 1.07 0.6 2.22 1.89 2.57 2.06 1.35 1.85
Dy 6.26 3.71 13.4 11.6 14.9 12.1 7.42 10.9
Ho 1.27 0.79 2.85 2.38 3.17 2.44 1.46 2.22
Er 3.79 2.54 8.07 6.7 9.11 6.65 4.18 6.16
Tl 1.59 0.83 2.79 1.37 2.01 1.34 1.33 1.01
Tm 0.584 0.396 1.27 1.05 1.43 1.01 0.647 0.94
Yb 4.01 2.7 8.12 6.59 9.27 6.59 4.37 6
Lu 0.638 0.433 1.17 0.914 1.33 0.904 0.637 0.856
Notes: 1. All detection limits are in ppm unless otherwise stated. All analyses were conducted by Activation Laboratories Ltd.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry.
3. rhy = rhyolite, flb = flow-banded, fspar = feldspar, xl = crystal.

Table 1 (cont’d). Lithogeochemical data for SLAM Exploration Ltd. drill cores and trenches at the Mount Costigan deposit.
Sample
CM08-13-
22 m
Felsic
fragmental
with chloritic
clasts
CM08-12-
298.5 m
Crystal–
lithic
tuff
38
CM08-12-
175 m
Grey
massive
rhyolite
CM08-8-
48 m
Mafic
dyke
CM08-4-
222b m
Finegrained
sandstone
CM08-4-
222a m
Siltstone
SiO2 62.18 72.83 73.64 49.77 56.81 59.34
Al2O3 14.41 12.27 12.28 13.95 16.54 16.8
(total)
Fe2O3
4.79 2.76 1.97 10.99 8.91 7.53
MnO 0.37 0.191 0.093 1.473 0.385 0.376
MgO 2.57 1.13 0.47 6.37 4.42 4.21
CaO 0.04 0.37 0.08 1.41 0.89 0.82
Na2O 0.15 1.62 0.24 0.12 0.65 0.88
K2O 11.05 7.14 9.78 6.45 4.95 5.13
TiO2 0.206 0.313 0.173 2.354 0.951 0.947
P2O5 0.04 0.05 0.01 0.49 0.17 0.14
LOI 2.94 1.27 0.92 5.34 4.85 4.03
Au 13 < 2 < 2 15 < 2 4
Ag 0.9 0.6 0.5 2.3 0.4 < 0.5
As 246 5.7 20 159 73.5 22
Ba 709 724 851 374 413 451
Bi 0.4 < 0.1 < 0.1 0.1 0.2 0.3
Cd 4.7 0.8 1.1 0.8 0.9 0.8
Co 1.8 3 2 31 23 23.1
Cr 12.2 22 21 22 174 159
Cs 1.1 0.6 1.4 1.9 6.5 5.6
Cu 4 4 12 12 31 34
Ga 13 16 17 20 21 22
Ge 1.4 1.2 1.3 2.2 1.7 1.8
Hf 10.3 8.3 7.7 5.7 4.3 4.9
Mo < 2 < 2 < 2 < 2 < 2 < 2
Nb 27.8 23.4 25.2 20 18 17.7
Ni 3 3 3 18 112 103
Pb 147 221 166 320 209 213
Rb 387 214 296 221 235 225
S 2.06 0.028 0.182 0.716 1.09 0.164
Sb 5.4 1 1.2 10.5 2.4 1.3
Sc 8.74 9 8 31 22 22.3
Se < 0.5 < 3 < 3 < 3 < 3 < 0.5
Sn 3 13.8 17.8 11.5 9.8 4
Sr 31 45 40 42 40 46
Ta 1.84 1.39 1.49 0.98 0.92 1
Th 23.8 17.8 19.4 7.47 9.85 10.9
U 5.21 4.5 4.99 3.75 2.66 2.91
V 6 24 6 338 158 147
W < 1 2.1 2.4 9.2 1.1 4
Y 67 50.4 70.2 49 36.7 33
Zn 158 395 748 486 405 327
Zr 375 329 275 258 183 209
La 46 66.5 77.4 34.7 36.3 38.8
Ce 109 134 153 78.8 79.2 78.1
Pr 13.7 13 15 8.32 8.08 9.12
Nd 54.8 47.1 55.2 33.8 31.2 36.3
Sm 12.2 9.53 11.5 7.99 6.78 7.64
Eu 1.09 1.6 1.47 2.5 1.71 1.68
Gd 11.7 8.96 11.7 8.51 6.61 6.77
Tb 2.11 1.43 1.85 1.36 1.08 1.14
Dy 12.8 8.04 10.5 7.82 6.15 6.61
Ho 2.64 1.56 2.08 1.48 1.2 1.32
Er 7.36 4.57 5.99 4.15 3.47 3.64
Tl 4.86 0.95 1.35 2.57 1.03 0.97
Tm 1.15 0.69 0.89 0.61 0.515 0.543
Yb 7.31 4.63 5.8 3.92 3.32 3.57
Lu 1.01 0.745 0.916 0.605 0.51 0.485
Notes: 1. All detection limits are in ppm unless otherwise stated. All analyses were conducted by Activation Laboratories Ltd.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry.
3. rhy = rhyolite, flb = flow-banded, fspar = feldspar, xl = crystal.

Table 1 (cont’d). Lithogeochemical data for SLAM Exploration Ltd. drill cores and trenches at the Mount Costigan deposit.
Sample
ET-1
(surface)
Crystal–
lithic tuff
ET-2
(surface)
Crystal–
lithic tuff
39
ST-1A
(surface)
Crystal–
lithic tuff
ST-1B
(surface)
Crystal–
lithic tuff
ST-2
(surface)
Crystal–
lithic tuff
ST-3
(surface)
Crystal–
lithic tuff
ST-6
(surface)
Crystal–
lithic tuff
SiO2 72.7 69.9 72.5 77.2 80.1 79.6 67.3
Al2O3 13 12.6 12.2 10.6 8.37 9.33 14.1
Fe2O3 (total) 1.92 1.21 2.06 1.55 2.14 1.4 3.36
MnO 0.4 0.31 0.18 0.09 0.15 0.12 0.23
MgO 2.63 3.12 2.26 1.15 2.24 1.6 3.87
CaO 0.05 0.06 0.05 0.04 0.05 0.04 0.03
Na2O 0.1 0.1 0.14 0.1 0.08 0.09 0.13
K2O 7.06 8.98 7.44 6.88 4.76 6.49 8.13
TiO2 0.234 0.177 0.219 0.193 0.136 0.184 0.166
P2O5 0.03 0.02 0.02 0.02 0.02 0.02 0.01
LOI 1.9 1.7 1.6 1.25 1.5 1.05 2.05
Au 5 < 2 < 2 5 20 14 39
Ag 3.8 1.7 0.9 0.9 1.3 0.5 1.1
As - - - - - - -
Ba 634 591 597 703 399 501 474
Bi - - - - - - -
Cd - - - - - - -
Co 4 1 -0.5 -0.5 -0.5 -0.5 -0.5
Cr 16 10 9 11 13 21 9
Cs 1 1 1 1 1 -0.5 -0.5
Cu 19.3 7.6 4.8 9.9 33.7 18.3 21.1
Ga - - - - - - -
Ge - - - - - - -
Hf 7.9 7.2 9.3 7.4 4.5 6.6 7.7
Mo - - - - - - -
Nb 33 23 22 23 17 17 25
Ni 13 6 6 3 5 5 6
Pb 1690 510 226 139 404 598 354
Rb 282 320 316 241 168 240 258
S - - - - - - -
Sb 7.9 2.9 3.2 3.8 20.6 11.2 3.1
Sc 9 8 12 10 7 8 9
Se - - - - - - -
Sn - - - - - - -
Sr 22 30 22 19 12 17 19
Ta 1.7 1.6 1.6 1.3 1.3 0.8 2.1
Th 26.7 23.4 23.2 19 15 15 26.3
U 7.5 6.8 6.5 5.6 5 4.3 7.3
V 4 2 -2 2 6 5 3
W 4 4 11 3 8 7 10
Y 55 64 64 55 43 53 71
Zn 321 264 149 125 110 59.1 130
Zr 314 292 396 351 186 308 293
La 50.1 48.1 75.5 41 67.4 73.7 96.4
Ce 154 95 167 95 130 140 201
Pr - - - - - - -
Nd 41 45 68 38 55 60 91
Sm 7.23 10.2 13.9 7.67 10.3 12 17
Eu 1.2 1.6 2 1.3 1.3 1.8 2.3
Gd - - - - - - -
Tb 1.1 2 2 1.4 1.3 1.7 2.5
Dy - - - - - - -
Ho - - - - - - -
Er - - - - - - -
Tl - - - - - - -
Tm - - - - - - -
Yb 6.66 6.16 6.77 5.48 4.7 5.2 7.85
Lu 1.07 1 1.1 0.88 0.74 0.81 1.23
Notes: 1. All detection limits are in ppm unless otherwise stated. All analyses were conducted by Activation Laboratories Ltd.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry.
3. rhy = rhyolite, flb = flow-banded, fspar = feldspar, xl = crystal.

40
Table 2. Lithogeochemical data for the Lewis Brook occurrence (Costigan Mountain Formation), and average values
for the River Dee rhyolite and River Dee basalt (Wapske Formation).
Detection
Limit
Sample
Analytical
Method
LB99-3-
43 m
LB99-3-
82 m
LB99-3-
106 m
LB99-3-
108.5 m
LB99-3-
185.2 m
LB99-3-
79.5 m
Rhyodacite Rhyodacite Rhyodacite Rhyodacite Rhyodacite Rhyodacite
SiO2 0.01% XRF 69.8 74.5 74.8 69.3 71.5 64.8
Al2O3 0.01% XRF 13.3 11.1 9.87 9.66 12.8 11
Fe2O3 (total) 0.01% XRF 2.81 1.86 2.57 4.37 1.47 5.26
MnO 0.001% XRF 0.06 0.04 0.05 0.07 0.06 0.04
MgO 0.01% XRF 0.73 0.2 0.38 0.56 0.55 0.49
CaO 0.01% XRF 1.09 0.27 0.39 1.26 1.12 0.7
Na2O 0.01% XRF 2.78 0.16 0.29 0.6 0.1 1.23
K2O 0.01% XRF 5.4 8.53 7.28 7.6 8.8 7.04
TiO2 0.001% XRF 0.26 0.14 0.12 0.14 0.18 0.26
P2O5 0.01% XRF 0.03 0.02 < 0.01 0.02 0.02 0.03
LOI 0.01% XRF 2.89 1.75 2.29 3.65 2.94 4.74
Au 1 ppb INAA 6 18 < 2 58 < 2 211
Ag 0.5 INAA 0.6 1.3 < .5 2.4 < .5 5.2
As 1 INAA 87.6 77.1 69.8 177 11.6 248
Ba 1 INAA 740.6 877.2 798.9 810.4 801.3 784.6
Bi 0.1 FUS-MS 6.8 1.4 0.5 2.8 < .5 4.2
Cd 0.5 TD-ICP 0.5 3.8 16.4 48 < .2 98.3
Co 0.1 INAA 10.1 3.7 2.2 4.4 2 7.8
Cr 0.5 INAA 71 101 115 95 80 101
Cs 0.1 INAA 2.1 1 0.8 0.9 2.9 1.3
Cu 1 TD-ICP 70 35 206 556 4 1452
Ga 1 FUS-MS 16.5 9 12.4 12.8 13.4 11.9
Ge 0.5 FUS-MS - - - - - -
Hf 0.1 INAA 7.6 4.3 3.8 3.8 4.7 5.7
Mo 2 INAA 4.3 4.9 4.3 1.7 2.2 6.9
Nb 0.2 FUS-MS 13.8 11 7.8 9.1 15.5 10.2
Ni 1 INAA 10 5 2 5 5 4
Pb 5 TD-ICP 120 667 132 770 22 547
Rb 1 INAA 177.8 277.4 233.9 236.5 276.5 226.7
Sb 0.1 INAA 1.8 1.9 1.3 2.5 1.5 3.9
Sc 0.01 INAA 5.4 3.6 3.2 3.5 5.6 4.6
Se 0.5 INAA < 3 < 3 < 3 < 3 < 3 < 3
Sn 1 INAA 5 3 4 4 6 7
Sr 2 FUS-ICP 52.4 69.9 43.2 57.9 76.6 66.9
Ta 0.01 INAA 1.7 1.2 0.9 0.9 1.7 1
Th 0.05 INAA 29.8 21.3 17.6 17.3 26.2 15.7
U 0.01 INAA 11.6 7.9 6.1 5.8 9.2 6.5
V 5 FUS-ICP 19 10 9 11 12 13
W 1 INAA 2 2 2 2 2 2
Y 1 FUS-ICP 42.8 29 26.3 25.4 44.2 38
Zn 1 INAA 106 692 5225 11209 9 30062
Zr 1 FUS-MS 223.5 123.4 104.8 115 130.6 191.4
La 0.05 INAA 55.3 35.5 13.4 53 53.9 16.9
Ce 0.05 INAA 89.4 62.4 24.3 113.5 88 31.8
Pr 0.01 INAA 9.42 6.57 2.87 11.82 9.22 3.51
Nd 0.05 INAA 39.6 25.4 12.6 44.3 36.6 14.5
Sm 0.01 INAA 7 4.6 2.8 6.9 7.1 3
Eu 0.005 INAA 0.84 0.47 0.29 0.68 0.99 0.43
Gd 0.01 INAA 6.21 4.54 2.66 5.61 6.78 3.58
Tb 0.01 INAA 1.1 0.76 0.57 0.85 1.19 0.73
Dy 0.01 INAA 6.81 4.85 3.84 4.63 7.31 5.35
Ho 0.01 INAA 1.42 1.02 0.85 0.9 1.42 1.27
Er 0.01 INAA 4.39 3.09 2.65 2.65 4.26 4.05
Tl 0.05 INAA 0.4 0.4 0.3 0.4 0.8 0.5
Tm 0.005 INAA 0.66 0.51 0.37 0.45 0.66 0.65
Yb 0.01 INAA 4.61 3.31 2.86 2.87 4.19 4.1
Lu 0.002 INAA 0.75 0.52 0.49 0.45 0.75 0.74
Notes: 1. All detection limits are in ppm unless otherwise stated. INAA, FUS-MS, TD-ICP, FUS-ICP analyses carried out by Acme Analytical. XRF
analyses carried out by Lakefield Analytical.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry, XRF = X-ray
fluorescence.

Table 2 (cont’d). Lithogeochemical data for the Lewis Brook occurrence (Costigan Mountain Formation), and
average values for the River Dee rhyolite and River Dee basalt (Wapske Formation).
Sample
LB99-3-
113.5 m
LB99-3-
119 m
LB99-3-
131 m
LB99-3-
138.5 m
41
LB99-3-
155 m
LB99-3-
176.7 m
LB99-3-
186.8 m
LB99-3-
19.4 m
LB99-3-
41 m
Basalt Basalt Basalt Basalt Basalt Basalt Basalt Basalt Basalt
SiO2 44.7 45.3 45.6 44.3 45.4 41.8 44.2 59.4 59.9
Al2O3 16.4 17 15.2 17 16.9 15.4 15.3 16.1 16.4
Fe2O3 (total) 10.3 7.68 7.92 11.9 7.12 7.76 8.36 8.33 7.41
MnO 0.49 0.23 0.3 0.42 0.19 0.34 0.22 0.11 0.09
MgO 4.77 6.09 4.29 2.75 4.98 3.98 3.64 4.08 3.79
CaO 2.46 7.57 5.04 1.1 7.14 7.43 6 0.93 1.16
Na2O 0.96 2.96 1.65 1.97 2.47 0.08 1.85 1.97 1.39
K2O 6.53 4.28 3.82 6.19 4.83 5.52 4.28 3.09 3.81
TiO2 1.32 1.24 1.16 1.5 1.11 1.59 1.58 1.12 1.01
P2O5 0.18 0.15 0.14 0.21 0.17 0.19 0.18 0.16 0.18
LOI 9.35 7.13 14.2 11.8 9.35 13.4 14.2 4.6 5.07
Au < 2 < 2 < 2 2 < 2 < 2 < 2 3 3
Ag < .5 < .5 < .5 0.6 < .5 < .5 < .5 < .5 < .5
As 49.5 8.6 36.9 77.6 21.5 157 13.4 13.8 29.3
Ba 773.3 555.7 371.1 682 556.5 150.8 616.4 418.2 371.3
Bi < .5 < .5 < .5 < .5 < .5 < .5 < .5 < .5 < .5
Cd 4.3 < .2 < .2 10.4 < .2 0.2 < .2 < .2 < .2
Co 32.3 32.1 27.2 32 29.7 32.2 27 26.5 21.9
Cr 210 234 200 190 225 179 176 157 168
Cs 8 4.7 9.2 7.1 7.6 6.9 8 7.3 7.2
Cu 71 26 28 110 34 36 46 45 41
Ga 26.7 16.8 14.1 38.8 16.2 20.8 18.3 21.7 21.3
Ge - - - - - - - - -
Hf 2.7 2.2 2.1 3.1 2.5 3.4 3.1 5.3 5.3
Mo 1 0.6 1 1.3 0.6 1.4 1.2 0.6 0.8
Nb 6.8 5.3 4.7 7.3 6.3 7.2 6.8 14.2 13.5
Ni 63 71 58 72 72 50 41 78 90
Pb 1582 10 10 3741 12 31 5 14 11
Rb 217.7 167.9 158.3 204.6 206.5 281.9 195.3 134.1 167.2
Sb 1.3 0.6 2.1 2.5 1 5.8 1.3 0.9 1.4
Sc 30.3 28.3 28.3 29.9 27.8 31.5 31.4 24.4 21
Se < 3 < 3 < 3 < 3 < 3 < 3 < 3 < 3 < 3
Sn 2 1 2 8 2 2 2 3 4
Sr 110.6 354.4 174.2 83.2 226.1 128.7 317.8 81.3 53.2
Ta 0.5 0.2 0.2 0.4 0.4 0.4 0.4 1.1 0.9
Th 3.5 2.2 1.7 3.2 2.6 3.2 3.7 9.8 11
U 1.4 < .5 1.3 2 1.4 1.3 1.5 3.3 3.9
V 207 182 173 211 169 229 248 160 132
W 4 < 1 < 1 6 < 1 6 4 2 1
Y 21.2 20 17.9 33.4 20.2 27 23.5 28.6 31.4
Zn 1336 83 75 3707 67 79 66 85 88
Zr 101 84.3 72.7 112.8 92.5 112.9 112.5 186.1 181.7
La 16.2 13.6 12.5 22.9 14 18.4 13.6 29.7 38.9
Ce 30.8 26.5 23.5 41.2 30.2 34.4 28.7 55.6 69
Pr 3.7 3.07 2.76 4.67 3.32 4.09 3.49 6.39 8.06
Nd 18 15.8 12.9 22.3 16.1 19.9 18 28.5 34.8
Sm 3.6 3.5 3.1 4.8 3.5 4.3 3.5 5.3 6.9
Eu 1.34 1.41 1.13 2.34 1.25 1.41 1.37 1.3 1.31
Gd 3.95 3.62 3.21 5.07 3.74 4.45 4.26 4.98 6.01
Tb 0.62 0.58 0.52 0.91 0.61 0.77 0.67 0.78 0.96
Dy 4.06 3.67 3.36 6.13 3.96 4.61 4.4 5.17 5.41
Ho 0.82 0.72 0.65 1.2 0.71 0.92 0.9 1.07 1.08
Er 2.36 1.98 1.72 3.38 2.1 2.64 2.46 3.16 3.24
Tl 0.5 0.4 0.3 0.6 0.4 0.4 1.4 0.3 0.5
Tm 0.35 0.3 0.26 0.53 0.31 0.38 0.37 0.51 0.46
Yb 2.09 1.76 1.62 3.22 1.97 2.45 2.38 3.11 3.12
Lu 0.39 0.3 0.3 0.53 0.32 0.45 0.37 0.56 0.54
Notes: 1. All detection limits are in ppm unless otherwise stated. INAA, FUS-MS, TD-ICP, FUS-ICP analyses carried out by Acme Analytical. XRF
analyses carried out by Lakefield Analytical. See Wilson (1992) for analytical methods and detection limits.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry, XRF = X-ray
fluorescence.

Table 2 (cont’d). Lithogeochemical data for the Lewis Brook occurrence (Costigan Mountain Formation), and
average values for the River Dee rhyolite and River Dee basalt (Wapske Formation).
Sample
42
River Dee Basalt
(Wilson 1992) *
River Dee Rhyolite
(Wilson 1992) *
n = 3 n = 6
SiO2 51.11 75.61
Al2O3 16.6 12.57
(total)
Fe2O3
9.43 2.68
MnO 0.19 0.05
MgO 7.42 1.17
CaO 8.73 0.05
Na2O 3.68 3.47
K2O 1.09 4.02
TiO2 1.5 0.19
P2O5 0.23 0.09
LOI - -
Au - -
Ag
As
- -
Ba 140 483
Bi - -
Cd - -
Co - 4.3
Cr 247 35
Cs - -
Cu 30 10
Ga - -
Ge 15 16
Hf - 8.4
Mo - -
Nb 6 25
Ni 80 9
Pb - -
Rb 40 142
Sb - -
Sc - 3.4
Se - -
Sn - -
Sr 252 61
Ta - 2
Th - 22
U - -
V 247 -
W - -
Y - -
Zn 86 43
Zr 133 274
La - 40
Ce - 92.95
Pr - -
Nd - -
Sm - 11.72
Eu - 0.87
Gd - -
Tb - 1.99
Dy - -
Ho - -
Er - -
Tl - -
Tm - -
Yb - 6.26
Lu - 0.97
Notes: 1. All detection limits are in ppm unless otherwise stated. INAA, FUS-MS, TD-ICP, FUS-ICP analyses carried out by Acme Analytical. XRF
analyses carried out by Lakefield Analytical. See Wilson (1992) for analytical methods and detection limits.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry, XRF = X-ray
fluorescence.

43
Table 3. Lithogeochemical data for the Redstone Mountain Granite collected during this investigation and compiled
from previously published data of Whalen (1993).
Detection
Limit *
Sample From This Investigation From Whalen (1993)
Analytical
Method
RS-
1
RS-
2
RS-
5
RS-
7
RS-
P
RS-
Renous
G15-
144 *
G15-
147 *
G15-
152 *
G15-
305 *
SiO2 0.01 wt % FUS-ICP 72.82 76.33 78.38 71.75 74.67 75.23 73 75.1 72.8 75.7
Al2O3 0.01 wt % FUS-ICP 13.35 11.51 12.12 13.57 12.23 12.2 13.75 12.35 13.7 12.5
Fe2O3 0.01 wt % FUS-ICP 3.4 2.16 1.87 3.4 1.7 2.14 0.82 1.16 0.82 0.65
MnO 0.001 wt % FUS-ICP 0.032 0.014 0.028 0.072 0.021 0.023 0.04 0.01 0.03 0.01
MgO 0.01 wt % FUS-ICP 0.79 0.05 0.11 0.49 0.28 0.07 0.26 0.06 0.35 0.25
CaO 0.01 wt % FUS-ICP 2.11 0.51 0.52 1.09 0.59 0.65 1.14 0.56 1.45 0.66
Na2O 0.01 wt % FUS-ICP 5.08 3.42 6.38 5.15 2.79 3.64 3.98 4.13 3.75 4.29
K2O 0.01 wt % FUS-ICP 1.06 4.41 0.1 2.07 5.4 4.57 4.82 4.69 4.48 4.13
TiO2 0.001 wt % FUS-ICP 0.384 0.137 0.121 0.392 0.209 0.131 0.29 0.15 0.3 0.2
P2O5 0.01 wt % FUS-ICP 0.05 0.01 < 0.01 0.14 0.03 < 0.01 0.05 0.02 0.06 0.04
Total 0.01 FUS-ICP 99.93 99.05 100.3 99.28 98.72 99.24 - - - -
Au 1 ppb INAA 1 < 1 < 1 < 1 < 1 < 1 11 0.3 < 0.3 < 0.3
Ag 0.5
MULT INAA
/ TD-ICP
< 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 - - - -
As 1 INAA 18 7 26 15 17 13 0.3 < 0.2 0.5 1
Ba 1 FUS-ICP 450 860 19 495 584 913 617 756 581 810
Be 1 FUS-ICP 4 2 2 4 3 3
Bi 0.1 FUS-MS 1 0.4 1 1.5 0.8 0.6 1 < 0.1 < 0.1 < 0.1
Br 0.5 INAA < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 1.2 0.9 1.1 < 0.3 0.6
Cd 0.5 TD-ICP < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5
Co 0.1 INAA 6.8 1.9 < 0.1 3.8 < 0.1 < 0.1 2.8 1.4 3.4 1.9
Cr 0.5 INAA 29.7 10.4 18 14.4 21.2 16.2 2 1 3 3
Cs 0.1 FUS-MS 1.1 1.6 0.2 0.4 1.4 0.5 5.2 0.7 2.7 1.1
Cu 1 TD-ICP 2 2 2 3 1 6 2 1 3 1
Ga 1 FUS-MS 19 17 22 19 15 21 18 17 18 16
Ge 0.5 FUS-MS 1.9 2.3 1.9 2.3 2.2 2.3 - - - -
Hf 0.1 FUS-MS 8 7.3 11.1 8.2 4.5 8.9 6.3 7.9 4.8 6.5
Mo 2 FUS-MS < 2 < 2 < 2 < 2 < 2 < 2 < 0.5 < 0.5 < 0.5 3
Nb 0.2 FUS-MS 13.9 19.2 33 18.2 11.3 26.1 15 25 14 22
Ni 1 TD-ICP 15 4 4 5 4 3 2 2 6 1
Pb 5 TD-ICP < 5 < 5 < 5 < 5 12 < 5 12 7 28 4
Rb 1 FUS-MS 40 127 4 58 186 128 196 141 188 119
S 0.001 wt % TD-ICP 0.007 0.003 0.004 0.005 0.003 0.004 - - - -
Sb 0.1 INAA 0.1 0.2 < 0.1 0.1 < 0.1 < 0.1 0.3 0.2 0.2 0.3
Sc 0.01 INAA 6.39 5.32 1.42 8.55 4.71 4.04 5.9 7.7 6.9 6.8
Sn 1 FUS-MS 10 4 10 5 7 7 2.5 1.5 < 0.5 8.5
Sr 2 FUS-ICP 256 66 59 147 117 81 87 56 108 89
Ta 0.01 FUS-MS 1.33 1.63 2.58 1.48 1.45 2.06 1.2 1.6 1.3 1.5
Th 0.05 FUS-MS 26 18.4 24 18.8 27.3 25.9 25 20.3 22 22
U 0.01 FUS-MS 6 3.77 6.69 4.62 6.33 6.62 5.9 4.9 6.6 4.8
V 5 FUS-ICP 27 < 5 < 5 13 12 < 5 15 2 20 15
W 1 INAA < 1 < 1 < 1 < 1 < 1 < 1 3 0.8 1.5 2
Y 1 FUS-ICP 48 39 73 47 34 79 48 69 47 65
Zn 1
INAA /
TD-ICP
12 11 17 28 17 10 25 10 24 5
Zr 1 FUS-MS 305 243 324 352 134 265 204 232 147 168
La 0.05 FUS-MS 51.9 41 57.6 58 38.8 88.1 64 74 43 64
Ce 0.05 FUS-MS 102 94 138 124 78.6 156 103 136 85 114
Pr 0.01 FUS-MS 11.5 9.39 14.8 13.5 8.54 20.1 - - 9.4 -
Nd 0.05 FUS-MS 40.7 34.9 56.6 50.3 30.1 75.1 41 55.5 34.1 50
Sm 0.01 FUS-MS 8.57 7.43 12.9 10.1 6.13 15.7 7 10.65 6.78 11.3
Eu 0.005 FUS-MS 1.26 0.947 0.764 2.28 0.825 1.61 1.29 1.63 0.87 1.01
Gd 0.01 FUS-MS 8.05 6.72 12.2 9.02 6.03 14.3 - - 6.48 -
Tb 0.01 FUS-MS 1.44 1.17 2.31 1.48 1.01 2.49 1.35 1.8 1.07 1.8
Dy 0.01 FUS-MS 8.4 7.2 14.3 8.88 6.53 15.2 - - 7.01 -
Ho 0.01 FUS-MS 1.74 1.52 2.97 1.78 1.29 3.07 - - 1.5 -
Er 0.01 FUS-MS 5.24 4.4 8.84 5.26 3.84 8.65 - - 4.2 -
Tl 0.05 FUS-MS 0.18 0.44 < 0.05 0.28 1 0.59 < 1 < 1 7 < 1
Tm 0.005 FUS-MS 0.83 0.696 1.4 0.808 0.641 1.34 - - 0.59 -
Yb 0.01 FUS-MS 5.49 4.89 8.8 5.5 4.23 8.87 4.51 6.35 4.04 6.51
Lu 0.002 FUS-MS 0.865 0.779 1.44 0.845 0.633 1.38 0.68 0.94 0.58 1.02
Notes: 1. All detection limits are in ppm unless otherwise stated. All analyses were conducted by Activation Laboratories Ltd.
2. FUS-ICP = metaborate/tetraborate fusion-inductively coupled plasma emission spectrometry, INAA = instrumental neutron activation analysis,
FUS-MS = metaborate/tetraborate fusion-mass spectrometry, TD-ICP = total digestion-inductively coupled plasma mass spectrometry.
* Compiled data: see Whalen (1993) for analytical methods and detection limits.

ACKNOWLEDGEMENTS
44
Thank you to SLAM Exploration Ltd. for providing access to confidential assessment data.
Alison Pye at the Stable Isotope Laboratory, Memorial University of Newfoundland, conducted
the sulphur isotope analyses. Douglas Hall at the University of New Brunswick, Fredericton,
conducted the microprobe analyses. Cyndie Pitre is thanked for GIS work and Reg Wilson
and Steve McCutcheon are thanked for numerous discussions of Early Devonian stratigraphy
and metallogenesis. This manuscript benefitted greatly from thorough review by Reg Wilson.
REFERENCES
Ayuso, R.A., and Bevier, M.L. 1991. Regional differences in lead isotopic compositions of
feldspar from plutonic rocks of the northern Appalachian Mountains, U.S.A. and Canada:
a geochemical method of terrane correlation. Tectonophysics, 10, p. 191–212.
Barnes, H.L. 1979. Solubilities of ore minerals. In Geochemistry of Hydrothermal Ore Deposits,
2 nd edition. Edited by H.L. Barnes. John Wiley and Sons, New York, p. 404–460.
Barrett, T.J., and MacLean, W.H. 1994. Chemostratigraphy and hydrothermal alteration in
exploration for VHMS deposits in greenstones and younger volcanic rocks. In Alteration
and Alteration Processes Associated with Ore-Forming Systems. Edited by D.R. Lentz,
Geological Association of Canada, Short Course Notes, 11, p. 433–467.
Barton, P.B. Jr., and Bethke, P.M. 1987. Chalcopyrite disease in sphalerite: pathology and
epidemiology. American Mineralogist, 72, p. 451–467.
Bjornson, B. 1975. Report of work on the Ogilvie (Costigan Mountain) Group for Amoco
Canada Petroleum Company Ltd. Mining Division. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 470298.
Bjornson, B. 1976. Report of work on the Ogilvie (Costigan Mountain) Group for Amoco
Canada Petroleum Company Ltd. Mining Division. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 470390.
Bjornson, B. 1977. Report of work on the Costigan–Ogilvie Group for Amoco Canada
Petroleum Company Ltd. Mining Division. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 470448.
Boucot, A.J., and Wilson, R.A. 1994. Origin and early radiation of terebratuloid brachiopods:
thoughts provoked by Prorensselaeria and Nanothyris. Journal of Paleontology, 68, p.
1002–1025.
Clark, D. 2004. Report of work on the Mount Costigan Property for 2003 for SLAM Exploration
Ltd. New Brunswick Department of Natural Resources; Lands, Minerals and Petroleum
Division, Assessment Report 475748.
Clark D. 2008. Report of work on the Costigan property. New Brunswick Department of
Natural Resources; Lands, Minerals and Petroleum Division. Assessment Report 476661.
Claypool, G.E., Holser, W.T., Kaplan, I.R., Sakai, H., and Zak, I. 1980. The age curves of
sulfur and oxygen isotopes in marine sulfate and their mutual interpretation. Chemical
Geology, 28, p. 199–260.
Cox, N.D. 1990. Geology of the Mount Costigan Pb–Zn deposit, west-central New Brunswick.
Unpublished M.Sc. thesis, University of Ottawa, Ontario, Canada, 176 p.

45
Crevier, M. 1983. Report of work for the first year of the initial exploration period on the Mount
Costigan Property by Lac Minerals Ltd., for Amoco Canada Petroleum Company Ltd. New
Brunswick Department of Natural Resources; Lands, Minerals and Petroleum Division,
Assessment Report 472943.
Crevier, M. 1984. Report of work on the Mount Costigan claim Group for Lac Minerals Ltd.
New Brunswick Department of Natural Resources; Lands, Minerals and Petroleum
Division, Assessment Report 473035.
Crevier, M. 1985. Report of work for the 3 rd year of the initial exploration period on the Mount
Costigan Property for Lac Minerals Ltd. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 473131.
Crevier, M., and Gravel, L. 1983. Report of work on the Mount Costigan property for Lac
Minerals Ltd. New Brunswick Department of Natural Resources; Lands, Minerals and
Petroleum Division, Assessment Report 472980.
Czamanske, G.K., and Rye, R.O. 1974. Experimentally determined sulfur isotope
fractionations between sphalerite and galena in the temperature range 600 o to 275 o C.
Economic Geology, 69, p. 17–25.
Dong, G., and Morrison, G.W. 1995. Adularia in epithermal veins, Queensland: morphology,
structural state and origin. Mineralium Deposita, 30, p. 11–19.
Dostal, J., Wilson, R.A., and Keppie, D. 1989. Geochemistry of Siluro–Devonian Tobique belt
in northern and central New Brunswick (Canada). Canadian Journal of Earth Science, 26,
p. 1282–1296.
Faure, G. 1986. Principles of Isotope Geology. John Wiley and Sons Inc., New York, 589 p.
Franklin, J.M. 1995. Volcanic-associated massive sulphide base metals. In Geology of
Canadian Mineral Deposit Types. Edited by O.R. Eckstrand, W.D. Sinclair, and R.I.
Thorpe. Geological Survey of Canada, Geology of Canada No. 8, p. 158–183.
Fyffe, L.R., and Pronk, A. G. 1985. Bedrock and surficial geology—rock and till geochemistry
in the Trousers Lake area, Victoria County, New Brunswick. Report of Investigations 20,
Lands, Minerals and Petroleum Division; New Brunswick Department of Natural
Resources, 74 p.
Galley, A.G. 1995. Target vectoring using lithogeochemistry: applications to the exploration for
volcanic hosted massive sulphide deposits. CIM Bulletin, 88, p. 15–27.
Goodfellow, W.D., and Jonasson, I.R. 1984. Ocean stagnation and ventilation defined by δ 34 S
secular trends for barite and pyrite, Selwyn Basin, Yukon. Geology, 12, p. 583–586.
Goodfellow, W.D., Lydon, J.W., and Turner, R.J.W. 1993. Geology and genesis of stratiform
sediment hosted (SEDEX) zinc-lead-silver sulphide deposits. In Mineral Deposit
Modelling. Edited by R.V. Kirkham, W.D. Sinclair, R.I. Thorpe, and J.M.S. Duke.
Geological Association of Canada, Special Paper 40, p. 201–251.
Gromet, L.P., Dymek, R.F., Haskin, L.A., and Korotev, R.L. 1984. The “North American Shale
Composite:” its compilation, major and trace element characteristics. Geochimica et
Cosmochimica Acta, 48, p. 2469–2482.
Grootenboer, J., and Schwarcz, H.P. 1969. Experimentally determined sulfur isotope
fractionation between sulfide minerals. Earth and Planetary Science Letters, 7,
p. 162–166.

46
Han, Y., and Pickerill, R.K. 1994. Palichnology of the Lower Devonian Wapske Formation,
Perth-Andover–Mount Carleton region, northwestern New Brunswick, eastern Canada.
Atlantic Geology, 30, p. 217–245.
Hughes, C.J. 1972. Spilites, keratophyres and the igneous spectrum. Geology Magazine, 109,
p. 513–527.
Irrinki, R.R. 1990. Geology of the Charlo area; Restigouche County, New Brunswick. New
Brunswick Department of Natural Resources and Energy; Mineral Resources, Report of
Investigation 24, 118 p.
Kajiwara, Y., and Krouse, H.R.1971. Sulfur isotope partitioning in metallic sulfide systems.
Canadian Journal of Earth Sciences, 8, p. 1397–1408.
Lac Minerals. 1989. Report of work on the Mount Costigan claim Group for Lac Minerals Ltd.
New Brunswick Department of Natural Resources; Lands, Minerals and Petroleum
Division, Assessment Report 473621.
Lavoie, C. 1982. Report of work on the Mount Costigan Project by Long Lac Explopration for
Amoco Canada Petroleum Company Ltd. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 472881.
Le Bas, M.J., Le Maitre, R.W., Streckeisen, A., and Zanettin, B. 1986. A chemical
classification of volcanic rocks based on the total alkali-silica diagram. Journal of
Petrology, 27, p. 745–750.
Leitch, C.H.B., and Lentz, D.R. 1994. The Gresens approach to mass balance constraints of
alteration systems: methods, pitfalls, examples. In Alteration and Alteration Processes
Associated with Ore-Forming Systems. Edited by D.R. Lentz. Geological Association of
Canada, Short Course Notes, 11, p. 161–192.
Le Maitre, R.W., Bateman, P., Dudek, A., Keller, J., Lameyre Le Bas, M.J., Sabine, P.A.,
Schmid, R., Sorensen, H., Streckeisen, A., Wolley, A.R., and Zanettin, B. 1989. A
Classification of Igneous Rocks and Glossary of Terms. Blackwell, Oxford, 193 p.
Lydon, J.W. 1988. Volcanogenic massive sulphide deposits, part 2: genetic models. Geoscience
Canada, 11, p. 195–202. In Geoscience Canada Reprint Series 3. Edited by R.G. Roberts,
and P.A. Sheahan, p. 155–181.
MacLean, W.H. 1963. Report of work on the Mount Costigan Claim Group for Mount Costigan
Mines Ltd. New Brunswick Department of Natural Resources; Lands, Minerals and
Petroleum Division, Assessment Report 470302.
Maingot, P.J. 1974. Report on Ogilvie (Costigan Mountain) Group, Tobique follow-up project,
New Brunswick. Amoco Petroleum Company Ltd. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Assessment Report 470297.
McCutcheon, S.R., and Walker, J.A. 2008. Volcanological constraints on the genesis of
Brunswick-type VMS deposits in the Bathurst Mining Camp. Abstract, GAC/MAC Joint
Annual Meeting, Quebec City, Quebec, Canada, p. 108.
Mount Costigan Mines. 1955. Report of work on the Mount Costigan Claim Group for Mount
Costigan Mines Ltd. New Brunswick Department of Natural Resources; Lands, Minerals
and Petroleum Division, Assessment Report 470300.
Nakamura, N. 1974. Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and
ordinary chondrites. Geochemica et Cosmochimica Acta, 38, p. 757–775.

47
New Brunswick Department of Natural Resources (NBDNR). 2011. New Brunswick Mineral
Occurrence database. >. Accessed
October 2011.
Panteleyev, A. 1988. A Canadian Cordilleran model for epithermal gold-silver deposits.
Geoscience Canada, 11, p. 195–202. In Geoscience Canada Reprint Series 3. Edited by
R.G. Roberts and P.A. Sheahan, p. 31–43.
Pearce, J.A., and Norry, M.J. 1979. Petrogenetic implications of Ti, Zr, Y and Nb variations in
volcanic rocks. Contributions to Mineralogy and Petrology, 69, p. 33–47.
Riddell, J.E. 1971. Summary report on properties in the Gulquac River–Costigan Mountain
area for Silcan Mines Ltd. New Brunswick Department of Natural Resources; Lands,
Minerals and Petroleum Division, Assessment Report 470303.
Rose, D.G., and Johnson, S.C. 1990. New Brunswick computerized mineral occurrence
database. New Brunswick Department of Natural Resources; Lands, Minerals and
Petroleum Division, Mineral Resource Report 3, p. 69.
St. Peter, C. 1978a. Geology of head of Wapske River. Map area J-13, NTS 21 J/14. Map
Report 78-1. Including map at 1 inch:1/4 mile scale. New Brunswick Department of
Natural Resources; Lands, Minerals and Petroleum Division, Map Plate 78-1.
St. Peter, C. 1978b. Geology of parts of Restigouche, Victoria and Madawaska counties,
northwestern New Brunswick, NTS 21 N/8, 21 N/9, 21 O/5, 21 O/11, 21 O/14. Report of
Investigations 17, New Brunswick Department of Natural Resources and Energy; Mineral
Resources Division, 69 p.
Shanks, W.C., III, Woodruff, L.G., Jilson, G.A., Jennings, D.S., Modene, J.S., and Ryan, B.D.
1987. Sulfur and lead isotope studies of stratiform Zn–Pb–Ag deposits, Anvil range,
Yukon: basinal brine exhalation and anoxic bottom-water mixing. Economic Geology, 82,
p. 600–634.
Smith, E.A, and Fyffe, L.R. (compilers). 2006a. Bedrock geology of the Plaster Rock area
(NTS 21 J/14), Victoria County, New Brunswick. New Brunswick Department of Natural
Resources; Lands, Minerals and Petroleum Division, Map Plate 2006-15, 1:50,000 scale.
Smith, E.A, and Fyffe, L.R. (compilers). 2006b. Bedrock geology of the Tuadock Lake map area
(NTS 21 J/15), Victoria County, New Brunswick. New Brunswick Department of Natural
Resources; Lands Minerals and Petroleum Division, Map Plate 2006-16, 1:50,000 scale.
Taylor, M. 1995. Report of work on the Costigan Claim Group for Michael Taylor. New
Brunswick Department of Natural Resources; Lands, Minerals and Petroleum Division,
Assessment Report 474671.
Thompson A.J.B., and Thompson, J.F.H. 1996. Atlas of alteration: a field and petrographic
guide to hydrothermal alteration minerals. Mineral Deposits Division, Geological
Association of Canada, ISBN 0-919216-59-5, p. 119.
Turner, R.W. 1996a. Report of work on the Costigan project for Chapleau Resources. New
Brunswick Department of Natural Resources; Lands, Minerals and Petroleum Division,
Assessment Report 474792.
Turner, R.W. 1996b. Report of work on the Costigan project for Chapleau Resources. New
Brunswick Department of Natural Resources; Lands, Minerals and Petroleum Division,
Assessment Report 474793.

48
van Staal, C.R., and de Roo, J.A. 1995. Mid-Paleozoic tectonic evolution of the Canadian
Appalachian Central Mobile Belt in northern New Brunswick, Canada: collision,
extensional collapse and dextral transpression. In Current perspectives in the
Appalachian–Caledonian Orogen. Edited by J.P. Hibbard, C.R. van Staal, and P.A.
Cawood. Geological Association of Canada, Special Paper 41, p. 367–389.
van Staal, C.R., Whalen, J.B., Valverde-Vaquero, P., Zagorevski, A., and Rogers, N. 2009.
Pre-Carboniferous, episodic accretion-related, orogenesis along the Laurentian margin of
the northern Appalachians. In Ancient Orogens and Modern Analogues. Edited by J.B.
Murphy, J.D. Keppie, and A.J. Hynes. Geological Society, London, Special Publication
327, p. 271–316.
Walker, J.A. 2003. Base-metal deposits of the Siluro-Devonian Tobique–Chaleurs Belt, West
Central New Brunswick, Canada. In Abstracts Volume, I st Joint Meeting Northeastern
Section, Geological Society of America, and the Atlantic Geoscience Society. Halifax
Nova Scotia, 35, Issue 3, p. 19.
Walker, J.A. 2005. Petrogenesis and tectonic setting of Devonian volcanic and related rocks
and their control on mineralization at the Shingle Gulch East Zn–Pb–Ag sulfide deposit,
northwest New Brunswick. Unpublished Ph.D. thesis, University of New Brunswick,
Fredericton, 430 p.
Walker, J.A. 2010. Stratigraphy and lithogeochemistry of Early Devonian volcano-sedimentary
rocks hosting the Nash Creek Zn–Pb–Ag deposit northern New Brunswick. In Geological
Investigations in New Brunswick for 2009. Edited by G.L. Martin. New Brunswick
Department of Natural Resources; Lands, Minerals and Petroleum Division, Mineral
Resources Report 2010-1, p. 52–97.
Walker, R.T. 1998. Report of work on the Costigan Claim Group for Michael Taylor. New
Brunswick Department of Natural Resources; Lands, Minerals and Petroleum Division,
Assessment Report 475097.
Watson, E.B., and Harrison, T.M. 1983. Zircon saturation revisited: temperature and
composition effects in a variety of crustal magma types. Earth and Planetary Science
Letters, 64, p. 295–304.
Whalen, J.B. 1993. Geology, petrography, and geochemistry of Appalachian granites in New
Brunswick and Gaspésie, Québec. Geological Survey of Canada Bulletin 436, p. 124.
Whalen, J.B., Jenner, G.A., Hegner, E., Garipey, C., and Longstaffe, F.J. 1994. Geochemical
and isotopic (Nd, O and Pb) constraints on granite sources in the Humber and Dunnage
zones, Gaspésie, Québec, and New Brunswick: implications for tectonics and crustal
structure. Canadian Journal of Earth Sciences, 31, p. 323–340.
Whalen, J.B., Jenner, G.A., Longstaffe, F.J., and Hegner, E. 1996. Nature and evolution of the
eastern margin of Iapetus: geochemical and isotopic constraints from Siluro–Devonian
granitoid plutons in the New Brunswick Appalachians. Canadian Journal of Earth
Sciences, 33, p. 140–155.
Wilson, R.A. 1990. Geology of the Riley Brook area, New Brunswick, NTS 21 O/3E, part of 21
O/2W. New Brunswick Department of Natural Resources; Lands, Mines and Petroleum
Division, Map-Plate 90-162, 1:50,000 scale.

49
Wilson, R.A. 1992. Petrographic features of Siluro–Devonian felsic volcanic rocks in the Riley
Brook area, Tobique Zone, New Brunswick: implications for base-metal mineralization at
Sewell Brook. Atlantic Geology, 28, p. 115–135.
Wilson, R.A., and Kamo, S.L. 2012. The Salinic Orogeny in northern New Brunswick:
geochronological constraints and implications for Silurian stratigraphic nomenclature.
Canadian Journal of Earth Sciences, 49, p. 222–138.
Wilson, R.A., Burden, E.T., Bertrand, R., Asselin, E., and McCracken, A.D. 2004. Stratigraphy
and tectono-sedimentary evolution of the Late Ordovician to Middle Devonian Gaspé Belt
in northern New Brunswick: evidence from the Restigouche area. Canadian Journal of
Earth Sciences, 41, p. 527–551.
Winchester, J.A., and Floyd, P.A. 1977. Geochemical discrimination of different magma series
and their differentiation products using immobile elements. Chemical Geology, 20, p.
325–343.
Yang X.-M, and Lentz, D.R. 2010. Sulfur isotopic systematics of granitoids from southwestern
New Brunswick, Canada: implications for magmatic–hydrothermal processes, redox
conditions, and gold mineralization. Mineralium Deposita, 45, p. 795–816.
Zartman, R.E., and Doe, B.R. 1981. Plumbotectonics—the model. Tectonophysics, 75, p.
135–162.