Unnamed (on upper Sheep River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu
Other commodities Au
Ore minerals malachite

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale A-5
Latitude 62.1224
Longitude -149.0883
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 2,950 feet on the west valley wall of upper Sheep River. The occurrence is in the southeast corner of sec. 33, T. 24 N., R. 2 E., Seward Meridian. The location is accurate to within 1/2 mile. This is locality 98 of Csejtey and Miller (1978) and Singer and others (1978).

Geologic setting

Geologic description

This occurrence consists of malachite-stained float of Cretaceous or Paleocene tonalite (Cobb and Csejtey, 1980). A float sample contains 10 parts per million silver, 0.35 part per million gold, and 5,000 parts per million copper (Miller and others, 1978).
Geologic map unit (-149.090508383242, 62.1218920501058)
Mineral deposit model Porphyry copper-gold (Cox and Singer, 1986; model 20c)
Mineral deposit model number 20c
Age of mineralization Cretaceous or younger; quartz veins(?) cut plutonic rocks of this age.
Alteration of deposit Oxidation of copper minerals.

Production and reserves

Workings or exploration Only limited surface sampling by U.S. Geological Survey (Miller and others, 1978).
Indication of production None


MRDS Number A012186


Reporters D. Bickerstaff (U.S. Geological Survey)
Last report date 10/1/2002