Unnamed (south of Coal Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag
Ore minerals chalcocite; malachite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-6
Latitude 63.1746
Longitude -146.9319
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,900 feet on the northwest flank of peak 5410 approximately one-half mile south of Coal Creek. The occurrence is in the S1/2SW1/4 section 14, T. 20 S., R. 4 E., Fairbanks Meridian, and corresponds to locality 4 in figure 4 of Cobb (1979 [OFR 79-238]) and locality 3 in table 2 of Nokleberg and others (1991).

Geologic setting

Geologic description

This deposit is in propylitized metabasalt of the Nikolai Greenstone of Late Triassic age, a component of the Tangle subterrane, Wrangellia terrane (Nokleberg and others, 1991). The deposit consists of chalcocite and secondary malachite in quartz-epidote veinlets, in vesicles. and on fracture and joint surfaces (Smith and others, 1973). No samples were collected at the site, but small amounts of silver typically occur in the copper deposits of the Nikolai Greenstone.
Geologic map unit (-146.934163546161, 63.1741573519337)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization The deposits are probably either Cretaceous or early Tertiary in age (see MH060, MH087, and MH100).
Alteration of deposit Propylitic alteration.

Production and reserves

Indication of production None

References