Unnamed (northeast of upper Shotgun Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Pt; Cr
Ore minerals chalcopyrite; chromite

Geographic location

Quadrangle map, 1:250,000-scale HE
Quadrangle map, 1:63,360-scale A-6
Latitude 63.07
Longitude -149.86
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is at an elevation of about 5,000 feet on the divide about a mile northeast of upper Shotgun Creek. The map site is on the boundary of secs. 21 and 28, T. 21 S., R. 12 W., of the Fairbanks Meridian. The location is accurate to within 1 mile. This is location 36-C of Hawley and Clark (1974); locality 25 of Cobb (1978: OFR 78-1062); and locality E35 of Balen (1990: OFR 34-90).

Geologic setting

Geologic description

The country rocks in the area of this prospect consist largely of sheared, Devonian serpentinite that forms lenticular and podiform tectonic blocks as much as several hundred meters in size. The prospect consists of chalcopyrite-rich sulfide bodies in the serpentinite. Chromite pods also occur in the serpentinite and platinum group elements may be present. Three samples contained 0.7 ppm silver, 0.04 to 0.06 ppm gold, 300 to 1,500 ppm chromium, 70 to 7,000 ppm copper, 100 to 1,000 ppm nickel, and a trace of platinum (Hawley and others, 1969).
Geologic map unit (-149.862288082404, 63.069519051958)
Mineral deposit model Podiform chromite (Cox and Singer, 1986; model 8a)
Mineral deposit model number 8a
Age of mineralization The ore minerals probably were magmatic segregations in Devonian ultramafic hostrocks, and were partly redistributed during subsequent serpentization.
Alteration of deposit Serpentinite of ultramafic hostrocks.

Production and reserves

Workings or exploration Preliminary surface exploration only. Three samples contained 0.7 ppm silver, 0.04 to 0.06 ppm gold, 300 to 1,500 ppm chromium, 70 to 7,000 ppm copper, 100 to 1,000 ppm nickel, and a trace of platinum (Hawley and others, 1969).
Indication of production None

References