USGS Professional Paper 1697 - Alaska Resources Library

252 Metallogenesis and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera
Glacier Gulch (Hudson Bay Mountain) Porphyry Mo (W,
Cu) Deposit
The Glacier Gulch (Hudson Bay Mountain) porphyry Mo
(W, Cu) deposit occurs at Hudson Bay Mountain, Smithers,
B.C., and consists of molybdenite and minor scheelite that
occur in stockwork and quartz vein swarms formed during
two periods of mineralization. The deposits are related to the
intrusion of a sheet-like granodiorite body and a later quartzporphyry
plug into rocks of the Hazelton Group of the Stikinia
terrane (Bright and Jonson, 1976; EMR Canada, 1989;
Atkinson, 1995; MINFILE, 2002). Most intense quartz-molybdenite-scheelite
vein mineralization is related to a crudely
layered granodiorite sheet. An estimated resource of 100
million tonnes grading 0.297 percent MoS 2 and 0.06 percent
WO 3 is defined by surface drilling and underground exploration
(Kirkham, 1967; Bright and Jonson, 1976). Hydrothermal
alteration patterns are irregularly developed.
Huckleberry Porphyry Cu-Mo (Au-Ag) Deposit
The Huckleberry porphyry Cu-Mo (Au-Ag) deposit (fig.
120) consists of chalcopyrite and minor molybdenite that
occur in a stockwork in contact-metamorphosed and altered
Jurassic Hazelton Group tuffs at a contact with a Late Cretaceous
granodiorite porphyry stock of the Burkley Plutonic
Suite (Sutherland Brown, 1969; Carter, 1970; MacIntyre,
1150
1130
0 200 m
1110
1090
1070
1050
1030
1030
1050
1070
1090
1050
1050
1984; EMR Canada, 1989; Mining Review, 1992; Society of
Exploration Geologists Newsletter, no. 20, January, 1995, p.
26; Jackson and others, 1995; MINFILE, 2002). Magnetite
occasionally accompanies chalcopyrite. Potassic, phyllic, and
propylitic alteration haloes surround the stock. The stockwork
consists of quartz and chalcopyrite, and lesser pyrite, molybdenite
that are cut by younger anhydrite veinlets. Associated
with the stockwork is biotite and albite alteration. Estimated,
preproduction reserves, at cut-off grade of 0.30 percent Cu, for
the Main Zone, are 53.7 million tonnes grading 0.445 percent
Cu, 0.013 percent Mo, and 0.06 g/t Au and for the East Zone,
are 108.4 million tonnes grading 0.484 percent Cu, 0.014 percent
Mo, and 0.055 g/t Au (Jackson and Illerbrun, 1995).
Poplar Porphyry Cu-Mo (Ag) Deposit
The Poplar porphyry Cu-Mo (Ag) prospect occurs 40
km to the north of the Huckleberry deposit and consists of
disseminated chalcopyrite and pyrite that occur in a Late
Cretaceous biotite-monzonite porphyry stock (Mesard and
others, 1979; EMR Canada, 1989; House and Ainsworth,
1995). Quartz-chalcopyrite-molybdenite veins are associated
with gypsum gangue. The porphyry stock intrudes volcaniclastic
and epiclastic rocks of the Hazelton Group in the Stikinia
terrane. Estimated resources are 144.1 million tonnes grading
0.368 percent Cu, 0.10 percent MoS 2, and 2.8 g/t Ag (Mesard
and others, 1979).
1130
Main
Zone
14500N
Copper Mineralization
> 0.4% Cu
Hornblende-Biotite-
Feldspar Granodiorite
Porphyry
Contact
Contour in meters
Figure 120. Huckleberry porphyry
Cu-Mo deposit, Bulkley metallogenic
belt, Canadian Cordillera.
Schematic map showing main ore
body. Adapted from Jackson and
Illerbrun (1995). See figure 103 and
table 4 for location.