Unnamed (south end of Clearwater Mountains, east of Clearwater Creek)

Occurrence, Inactive

Commodities and mineralogy

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

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-6
Latitude 63.1669
Longitude -146.8962
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 4,300 feet about 2.5 miles east-northeast of the junction of Clearwater and Pass Creeks, and about two-tenths of a mile west of the center of section 24, T. 20 S., R. 4 E., Fairbanks Meridian. It corresponds to locality 6 in figure 4 of Cobb (1979 [OFR 79-238]) and locality 5 in table 2 of Nokleberg and others (1991). It is also an unnumbered copper occurrence on plate 2 of Clautice and others (1989) that was originally reported by Smith and others(1973).

Geologic setting

Geologic description

The rock near the occurrence is propylitized basalt of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991). The deposit consists of chalcocite or secondary malachite in quartz veins, in vesicles, and on fracture or joint surfaces of the metabasalt (Smith and others, 1973). No samples were collected at the site, but small amounts of silver commonly accompany copper in deposits in the Nikolai Greenstone.
Geologic map unit (-146.898463821323, 63.1664580281559)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization The copper deposits are probably either Cretaceous or early Tertiary (see MH060 and MH100).
Alteration of deposit Propylitic alteration.

Production and reserves

Workings or exploration There are no significant workings at this site. The occurrence was discovered during geologic reconnaissance (Smith and others, 1973).
Indication of production None

Additional comments

The copper deposits are small and discontinuous.