Unnamed (northwest of Colorado Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Zn
Other commodities Bi; Sn
Ore minerals azurite; bornite; malachite; sphalerite
Gangue minerals epidote; garnet

Geographic location

Quadrangle map, 1:250,000-scale WI
Quadrangle map, 1:63,360-scale B-6
Latitude 67.3992
Longitude -152.7581
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is located about 1.2 miles northwest of the mouth of Colorado Creek and about 6 miles east of the east end of Ernie Lake. The occurrence is at an elevation of about 1,160 meters; it is about 0.2 mile south-southwest of the top of hill 1224, about 0.5 mile northwest of the center of section 29, T. 30 N., R. 23 W., of the Fairbanks Meridian. The occurrence is the site of sample 225 in Dillon and others (1981 [AOF 133B]). The location is accurate.

Geologic setting

Geologic description

This occurrence consists of azurite- and malachite-stained, garnet-epidote skarn that contains bornite and sphalerite (Dillon and others, 1981; sample 225 [AOF 133B]). A sample of skarn contains 7 ppm silver, 200 ppm bismuth, 5,000 ppm copper, 1,000 ppm tin, and 3,000 ppm zinc. The rocks in the area are Proterozoic(?) granitic rocks in contact with Proterozoic(?) marble, quartzite, and metabasite (Dillon and others, 1986).
Geologic map unit (-152.760863436415, 67.3987314478105)
Mineral deposit model Cu skarn deposit (Cox and Singer, 1986; model 18b)
Mineral deposit model number 18b
Alteration of deposit Skarn development. Oxidation of copper mineral(s).

Production and reserves

Workings or exploration Only surface sampling.
Indication of production None