Geologic descriptionThis occurrence is in Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991). The unit was mapped as Boulder Creek volcanics by Stout (1976). The deposit consists of quartz-calcite-epidote veins that contain disseminated pyrite, chalcopyrite, and bornite and the oxidized copper minerals azurite and malachite. The veins occupy steep north- to northeast-trending joints that cut the limbs of the Amphitheater syncline (Stout, 1976). The veins range from less than an inch to about a foot thick. |
Geologic map unit |
(-146.105347165411, 63.1444740609899) |
Mineral deposit model |
Basaltic Cu (Cox and Singer, 1986; model 23). |
Mineral deposit model number |
23 |
Age of mineralization |
The quartz veins are localized in north-northeast-trending faults and joints that cut across the folded limbs of the Amphitheater syncline. They postdate the folding, which is of Jurassic age, and are probably either Cretaceous, related to regional metamorphism and granitic plutonism (Nokleberg and others, 1986; Kurtak and others, 1992), or early Tertiary (Stout, 1976). |
Alteration of deposit |
Oxidation of the copper minerals. |