Unnamed (overlooking Cheeneetnuk River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag
Ore minerals pyrite

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale A-5
Latitude 62.073
Longitude -155.105
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is located on a steep east-facing bluff overlooking Cheeneetnuk River; at an elevation of 1,000 feet (305 m) in the NW1/4 sec. 23, T. 23 N., R. 32 W., of the Seward Meridian. The occurrence corresponds to prospect number no. 117 in Gilbert (1981); his station no. 78WG79. The reporter visited the site in 1989.

Geologic setting

Geologic description

The unnamed occurrence is a large zone of pyritic gossan in argillite of the Upper Paleozoic Mystic subterrane near the Cheeneetnuk Thrust Fault system (Gilbert, 1981; Wilson and others, 1998). The pyrite-rich gossan can be traced for more than 300 meters of strike length; mineralized widths were not determined. A Tertiary (37.8 Ma) granite is exposed about one quarter mile from the gossan (Gilbert, 1981). Four grab samples taken along the strike of the zone consistently yielded anomalous copper and silver with values of up to 224 ppm copper and 1.9 grams/tonne silver (Gilbert, 1981).
Geologic map unit (-155.107305098505, 62.0723452828059)
Mineral deposit model Polymetallic replacement? (Cox and Singer, 1986; model 19a?).
Mineral deposit model number 19a?

Production and reserves

Workings or exploration W.G. Gilbert sampled the gossan during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1978 (Gilbert, 1981). Four grab samples taken along the strike of the zone consistently yielded anomalous copper and silver with values of up to 224 ppm copper and 1.9 grams/tonne silver (Gilbert, 1981).
Indication of production None
Reserve estimates None.

References