Humpback Bay

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Gangue minerals chlorite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale UN
Quadrangle map, 1:63,360-scale C-3
Latitude 53.7667
Longitude -166.9333
Nearby scientific data Find additional scientific data near this location
Location and accuracy Northwest side of Humpback Bay, Makushin Bay. Anomaly no. 9 of Christie (1974).

Geologic setting

Geologic description

This occurrence is a zone of orange to brown iron-staining that covers an irregularly shaped 500 ft (150 m) by 1,000 ft (300 m) area. It consists of finely disseminated pyrite in a variety of host rocks. the host rocks include a coarse-grained feldspar porphyry dacite sill or plug, amygdaloidal andesite flows and pyroclastic rocks, and fine grained feldspar-porphyritic andesite (?). Pyrite occurs in low to moderate amounts in all units; its weathering causes gossanous oxidation. Fracturing is poorly developed, rock is fairly massive.
Geologic map unit (-166.935179181812, 53.7658469559881)
Mineral deposit model Copper porphyry?
Mineral deposit model number 17
Age of mineralization Cenozoic
Alteration of deposit Description suggests propylitic and possibly some argillic alteration; chlorite is the only phase explicitly mentioned. Moderate leaching of some phase (presumably pyrite?) was reported.

Production and reserves

Workings or exploration Five samples were collected, one of which showed 92 ppm copper and one 0.02 ppm gold, otherwise results were unimpressive (Christie, 1974). Presumably, some reconnaissance mapping was conducted.
Indication of production None


MRDS Number A106013


Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reporters Damon Bickerstaff, F.H. Wilson
Last report date 5/8/1996