Sunshine; Greentree Prospect, Valdez Creek Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Sunshine; Greentree Prospect	Prospect
Valdez Creek Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

The copper occurrences are very small, extending only a few feet along strike (Kurtak and others, 1992).
Location: 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).
Geology: 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.
Workings: The Sunshine claims were staked by Northland Mines in 1974 and 1975.
Age: Probably Cretaceous or early Tertiary (see MH060).
Alteration: Propylitic alteration of metabasalt; formation of copper-bearing quartz-epidote-carbonate segregations in veins and as blebs.

Commodities (Major) - Cu
Development Status: None
Deposit Model: Basaltic Cu (Cox and Singer, 1986; model 23).

Other Databases

Link to USGS - Alaska:	MH099

Other Regions, Features and Areas containing this locality

References