Unnamed Occurrence (ARDF - WI037; northwest of Colorado Creek), Koyukuk Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - WI037; northwest of Colorado Creek)	- not defined -
Koyukuk Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: 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.
Geology: 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).
Workings: Only surface sampling.
Alteration: Skarn development. Oxidation of copper mineral(s).

Commodities (Major) - Ag, Cu, Zn; (Minor) - Bi, Sn
Development Status: None
Deposit Model: Cu skarn deposit (Cox and Singer, 1986; model 18b)

Other Databases

Link to USGS - Alaska:	WI037

Other Regions, Features and Areas containing this locality

References