Metallogenesis and Tectonics of the Russian Far East, Alaska, and ...

0.15% Cu (ox), 0.127 g/t Au, and 0.007% Mo; and (2) in the sulfide zone, 768.3 million tonnes grading 0.232 Cu, 0.122 g/t Au,
and 0.007% Mo (Brown, 1995; Seraphim and Rainboth, 1976; McMillan, 1991). The stock and associated dikes exhibit K-Ar
isotopic ages which range from a hornblende age of 61.4 for biotite-altered quartze diorite, to a biotite-hornblende age of 55.5 Ma
for contact-metamorphosed sedimentary rock in the outer part of the deposit (Brown, 1995). The deposit occurs 75 km southeast
of Fish Lake.
Origin of and Tectonic Controls for
Fish Lake-Bralorne Metallogenic Bell
The Fish Lake-Bralome metallogenic belt is defined by the distribution of a suite of small, Late Cretaceous to Eocene,
quartz monzonite and quartz diorite stocks which are part of the Coast Plutonic Complex but occur east of the main part of the
batholith. The plutons are essentially coeval with plutons marking the eastern edge of the Coast suite, and probably represent the
eastern limit of Late Cretaceous-Eocene magmatism in the southern part of the continental-margin arc. The Coast Plutonic
Complex is part of the Coast-North Cascade plutonic belt.
Three major pulses of mineralization are interpreted for the Fish Lake-Bralome belt (Schiarizza and others, 1997): (1)
The older, Late Cretacous deposits in the belt are interpreted as forming along early Late Cretaceous reverse to sinistral faults
which are interpreted as forming during the last part of contractual deformation which was associated with subduction; (2) The
younger, latest Cretaceous to Paleocene deposits in the belt occur along dextral-slip faults, such as the Castle Pass fault and may in
part be controlled by an extensional bend in the fault system (Schiarizza and others, 1997). And (3) the still younger, porphyry
occurrences and associated polymetallic vein deposits are associated with Middle Eocene granodiorite plutons which occur along
dextral fault systems.
Tyaughton-Yalakom Metallogenic Belt of
WSb Polymetallic Vein and Hg-Sb Vein
Deposits (Belt TY) Southern British Columbia
The Tyaughton-Yalakom metallogenic belt of W-Sb polymetallic vein and Hg-Sb vein deposits occurs in southern British
Columbia and consists of several belts of scheelite-stibnite and cinnabar-stibnite veins which 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-quartz-stibnite-
scheelite veins which occur in pervasively silica-carbonate-altered ultramafic rocks (Schiarrizza and others, 1989). The Tungsten
Queen deposit is hosted by listwanite-altered 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 which 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 cinnabar-carbonate veins which 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-magmatism-related 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-PbCu skam deposits (fig. 103; tables 3,4) occurs in southern
British Columbia and is associated with a linear belt of early Tertiary plutons which 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 krn (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 skam deposit is at Lynn Creek (table 4) (Nokleberg and others 1997a, b,
1998).
Gambier Island Porphyry Cu-Mo Deposit
The Gambier Island porphyry Cu-Mo (Zn-Pb) deposit consists of pyrite, chalcopyrite, and molybdenite which occur as
disseminations, fracture fillings and veinlets (EMR Canada, 1989; Mining Review, 1990; Fox and others, 1995; MINFILE, 2002).