Makushin Valley SE

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag
Ore minerals pyrite
Gangue minerals magnetite

Geographic location

Quadrangle map, 1:250,000-scale UN
Quadrangle map, 1:63,360-scale C-3
Latitude 53.9
Longitude -166.7167
Nearby scientific data Find additional scientific data near this location
Location and accuracy Southeast side of Makushin Valley. Anomaly no. 6 of Christie (1974).

Geologic setting

Geologic description

Color anomaly in Unalaska Formation (see Drewes and others, 1961) associated with porphyritic diorite. Diorite is weakly altered, contains miarolitic cavities, less than 0.5 percent pyrite and more than 2 percent magnetite. Fracturing is local strongly developed and strikes east and northeast. No chalcopyrite seen. Zone containing more than 2 percent pyrite is roughly 600 ft (180 m) by 4,000 ft (1220 m).
Geologic map unit (-166.718586531105, 53.8991386276086)
Mineral deposit model Copper porphyry
Mineral deposit model number 17
Age of mineralization Cenozoic
Alteration of deposit Possibly propylitic and argillic alteration. Partial leaching, fractures largely leached.

Production and reserves

Workings or exploration Single sample reported, reconnaissance mapping. Sample showed 90 ppm copper and 1.4 ppm silver.
Indication of production None


MRDS Number A106010


Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps.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 5/3/1994