Sunshine

Prospect, Inactive

Alternative names

Greentree

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcocite; copper oxides; malachite
Gangue minerals carbonate; epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-5
Latitude 63.2393
Longitude -146.4422
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the ridge between Boulder Creek and the Maclaren River at an elevation of approximately 4,400 feet and about 1,000 feet east of the center of section 29, T. 19 S., R. 7 E., Fairbanks Meridian. The location is probably accurate within 1,000 feet. This occurrence corresponds to locality A21 of Kurtak and others (1992).

Geologic setting

Geologic description

Bedrock in the area consists of northwest-striking metabasalt of the Nikolai Greenstone of Late Triassic age (Kurtak and others, 1992; Nokleberg and others, 1991). U.S. Bureau of Mines investigators found several small areas that contained copper-bearing blebs and veins mainly consisting of quartz-carbonate-epidote. Copper minerals include malachite, probably chalcocite, and unspecified 'copper oxide' minerals (Kurtak and others, 1992, table A21). Four of six grab samples collected by the Bureau contained more than 0.1 percent copper. One sample of an epidote-carbonate vein contained 0.71 percent copper. Samples contained only near background concentrations of gold and silver.
Geologic map unit (-146.444461351083, 63.2388706335345)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization Probably Cretaceous or early Tertiary (see MH060).
Alteration of deposit Propylitic alteration of metabasalt; formation of copper-bearing quartz-epidote-carbonate segregations in veins and as blebs.

Production and reserves

Workings or exploration The Sunshine claims were staked by Northland Mines in 1974 and 1975.
Indication of production None

Additional comments

The copper occurrences are very small, extending only a few feet along strike (Kurtak and others, 1992).

References