The Galore Creek Copper Deposits

CIM Bulletin, 1966

The Galore Creek copper deposits are situated in the Stikine River district, 640 miles northwest of Vancouver, British Columbia. The deposits are primary cupriferous replacements localized in highly fractured zones lying in altered sedimentary, extrusive and intrusive rocks near the contacts of a potash-rich syenite porphyry complex which forms the core of a structural dome in Upper Triassic volcanic and sedimentary rocks. Ten deposits are distributed over an area of 3.5 by 2 miles and through an elevation range of 4,000 feet. The deposits share many of the characteristic features common to both the porphyry copper type of mineralization and pyrometasomatic deposits. Primary mineralization includes chalcopyrite and bornite, and is associated principally with pyrite and magnetite. The dominant alteration products are hydrothermal biotite and potash feldspar. Gypsum, anhydrite, garnet, chlorite and carbonate are commonly associated with sulphide minerals. Copper oxides, although present, are quantitatively of minor importance. The distribution of certain of the primary minerals reveals hypogene zoning characteristics. The results of stream sediment surveys, and airborne magnetic, ground magnetic and induced polarization surveys show important relationships to geologic structure and mineral deposits.

Keywords: breccia, Buckshot Porphyry, chalcopyrite, Dark Syenite, magnetite, Chalcopyrite, Deposits, Magnetite, mineral, minerals, Porphyry, Rock, Rocks