Copper King; Hector Group Prospect, Valdez Creek Mining District, Matanuska-Susitna Borough, Alaska, USAi

Regional Level Types
Copper King; Hector Group Prospect	Prospect
Valdez Creek Mining District	Mining District
Matanuska-Susitna Borough	Borough
Alaska	State
USA	Country

Location: The Copper King prospect is at an elevation of about 3,500 feet near the head of Long Creek. The site is near the east boundary of sec. 9, T. 20 S., R. 11 W., of the Fairbanks Meridian. The location is accurate to within 0.25 mile.
Geology: Copper King is primarily a skarn prospect. The country rocks are hornfelsed Permo-Triassic calcareous siltstone and conglomerate that are intruded by Upper Cretaceous(?) quartz porphyry dikes. The deposit consists chiefly of massive chalcopyrite, pyrite, and pyrrhotite in a skarn zone 20 to 40 feet thick exposed for about 200 feet at the surface. Subsidary zones of quartz stockwork veining and of sulfide disseminations also occur (unpublished report by Addwest Minerals International Ltd., 1997). The pattern of mineralization suggests a zonal distribution of Cu around quartz porphyry intrusions. This is the only prospect in the district explored primarily for copper, and is also the only prospect in the area where arsenopyrite has not been found (Hawley and Clark, 1974). In addition, molybdenite is more abundant here than at the other prospects. Samples taken at various times contain as much as 7.34% copper, 4.9 ounces of silver per ton, and 0.22 ounce of gold per ton (Cobb, 1978: OFR 78-1062).
Workings: Workings include soil grids, 1,500 feet of trenching and 9 drill holes with over 1,700 feet completed. A limited, ground-based TEM survey has also been used to outline skarn zones. Samples taken at various times contain as much as 7.34% copper, 4.9 ounces of silver per ton, and 0.22 ounce of gold per ton (Cobb, 1978: OFR 78-1062).
Age: Late Cretaceous(?).
Alteration: Skarn zones contain diopside, epidote, sericite, and anhydrite.

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

Other Databases

Link to USGS - Alaska:	HE049

Other Regions, Features and Areas containing this locality

References