USGS Professional Paper 1697 - Alaska Resources Library

ish Columbia and consists of several belts of scheelite-stibnite
and cinnabar-stibnite veins that occur along major faults in
the Methow and Cadwalleder terranes in southwestern British
Columbia (fig. 103; tables 3, 4) (Nokleberg and others, 1997b,
1998). The significant deposits are at Tungsten Queen, Tungsten
King, Silverquick, Manitou, Eagle, and Red Eagle.
The Tungsten Queen and Tungsten King W-Sb polymetallic
vein deposits consist of banded, chalcedony-quartzstibnite-scheelite
veins that occur in pervasively silicacarbonate-altered
ultramafic rocks (Schiarrizza and others,
1989). The Tungsten Queen deposit is hosted by listwanitealtered
ultramafic rock along branched fractures in the
Relay Creek-Marshall Creek Fault system (Schiarrizza and
others, 1990). The spatially separated Silverquick, Manitou,
and other similar Hg-Sb vein prospects consist of cinnabar
that occurs as fracture-coatings and disseminations in both
the Bridge River Greenstone and a Cretaceous conglomerate.
These deposits may be a later overprint (Schiarrizza and
others, 1989).
The Eagle and Red Eagle prospects consist of cinnabarcarbonate
veins that occur in subsidiary shears in the Bridge
River Greenstone, adjacent to the Bridge River-Yalakom Fault
system (Schiarrizza and others, 1990). The Hg-Sb vein deposits
of the Tyaughton-Yalakom metallogenic belt are clearly
associated with the Eocene dextral-slip faults of the Talakom,
Relay Creek, and Fortress Ridge Fault systems (Schiarrizza
and others, 1989, 1990). The W-Sb occurrences also occur
along the Relay Creek fault may be related to probable latest
Cretaceous to Eocene dikes.
The vein deposits of the Tyaughton-Yalakom metallogenic
belt are herein interpreted as forming during intrusion
of the younger part of the Coast-North Cascade plutonic belt.
The Tyaughton-Yalakom metallogenic belt is related to Fish
Lake-Bralorne metallogenic belt of granitic-magmatismrelated
deposits.
Gambier Metallogenic Belt of Porphyry Cu-Mo
and Zn-Pb-Cu Skarn Deposits (Belt GB),
Southern British Columbia
The Gambier metallogenic belt of porphyry Cu-Mo
and Zn-Pb-Cu skarn deposits (fig. 103; tables 3, 4) occurs in
southern British Columbia and is associated with a linear belt
of early Tertiary plutons that are part the southwestern Coast
Plutonic Complex. The discordant felsic stocks intrude older,
larger, concordant and more mafic plutons and metamorphic
pendants of the Coast Plutonic Complex. These granitoid
rocks are part of the extensive Late Cretaceous and early Tertiary
Coast-North Cascade plutonic belt, which occurs along
the western and central parts of the Canadian Cordillera for
several thousand km (Nokleberg and others, 1994c, 1997c;
Monger and Nokleberg, 1996). The significant deposits in the
belt are porphyry Cu-Mo deposits at Gambier Island, Hi-Mars
(Lewis Lake), and O.K., and a Zn-Pb skarn deposit is at Lynn
Creek (table 4) (Nokleberg and others 1997a,b, 1998).
Late Cretaceous and Early Tertiary Metallogenic Belts (84 to 52 Ma) (figs. 102, 103) 255
Gambier Island Porphyry Cu-Mo Deposit
The Gambier Island porphyry Cu-Mo (Zn-Pb) deposit
consists of pyrite, chalcopyrite, and molybdenite that occur as
disseminations, fracture fillings and veinlets (EMR Canada,
1989; Mining Review, 1990; Fox and others, 1995; MINFILE,
2002). Both sulfide-bearing and sulfide-free quartz veins
occur in the deposit. The deposit forms a broad arcuate zone
1,200 m long by 200 m wide in an elliptical-shaped, early
Tertiary quartz porphyry stock of the Coast Plutonic Complex
and adjacent volcanic rocks. Estimated resources are 114
million tonnes grading 0.29 percent Cu and 0.018 percent
MoS2 (MINFILE, 2002). The quartz porphyry stock intrudes
volcanic rocks of the Cretaceous Gambier Group that is part of
the Gravina-Gambier overlap assemblage.
Hi-Mars Porphyry Cu-Mo Deposit
The Hi-Mars porphyry Cu-Mo deposit consists of a
widespread occurrence of chalcopyrite and molybdenite
that occurs as disseminations and fracture fillings in a small
Cu-Mo (Au-Ag) porphyry deposit that is part of the Coast
Plutonic Complex (British Columbia Department of Mines,
and Petroleum Resources, 1972, Geology, Exploration, and
Mining, p. 272; George Cross Newsletter no. 49, March 10,
1978). The deposit, which occurs 7 km northeast of Powell
River, contains an inferred resource of 82 million tonnes
grading 0.3 percent Cu (George Cross Newsletter No. 49,
March 10, 1978); this resource may be for several zones in
the deposit. The deposit probably is similar in age and genesis
to the adjacent O.K. deposit.
O.K. Porphyry Cu-Mo Deposit
The O.K. porphyry Cu-Mo deposit consists of a stockwork
with chalcopyrite, molybdenite, and pyrite with minor
sphalerite and bornite that occur in fractures, as quartz stringers,
irregular veinlets, blebs and as disseminations (Meyer and others,
1976; EMR Canada, 1989; Mining Review, 1992; MIN-
FILE, 2002). The deposit is mainly enclosed in a composite,
narrow, northwest-trending, elliptical granodiorite pluton that
contains a narrow leucogranite porphyry dike along the exis
of the pluton. Although both intrusions contain a quartz vein
stockwork, most of the Cu-Mo sulfides occur in the granodiorite
within a few hundred meters of the contact with the leucocratic
porpohyry dike. The plutonic rocks are part of the Coast Plutonic
Complex (Woodsworth and others, 1991). The age of the granitoids
range in the Coast Plutonic Complex range from Jurassic to
Tertiary. The deposit age is interpreted as Late Cretaceous. The
deposit contains a resource of 104.9 million tonnes grading
0.46 percent Cu and 0.028 percent MoS2 (Meyer and others,
1976; MINFILE, 2002).
Lynn Creek Zn-Pb Skarn Deposit
The Lynn Creek Zn-Pb skarn deposit consists of sphalerite,
galena, pyrrhotite, chalcopyrite and pyrite in quartz veins and
calc-silicate skarn. The deposit is hosted in shear zones in a roof