Unnamed (east of West Fork Maclaren River)

Prospect, 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 63.2437
Longitude -146.7202
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is in a west-flowing tributary of the West Fork Maclaren River at an elevation of approximately 4,000 feet, in the NE1/4NE1/4,section 26, T. 19 S., R. 5 E., Fairbanks Meridian. The site corresponds to locality 17 in figure 4 of Cobb (1979 [OFR 79-239]) and to locality 24 in table 2 of Nokleberg and others (1991).

Geologic setting

Geologic description

This deposits consists of small amounts of malachite or chalcocite in quartz-epidote veinlets, in vesicles, or on fracture or joint surfaces in propylitized metabasalt of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991; Smith and others, 1973). Assay data are not available, but small amounts of silver typically accompany copper in the copper deposits of the Nikolai Greenstone.
Geologic map unit (-146.722467032242, 63.2432635625432)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization The mineralization is probably Cretaceous (Nokleberg and others, 1986) or early Tertiary (Stout, 1976). See MH060 and MH100.
Alteration of deposit Propylitic alteration; formation of quartz-epidote veins and vesicle fillings in metabasalt.

Production and reserves

Workings or exploration The copper minerals were reported by Smith and others (1973).
Indication of production None