Unnamed (west of Fish Lake)

Occurrence, Active

Commodities and mineralogy

Main commodities Cr
Ore minerals chromite
Gangue minerals olivine; serpentine

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-5
Latitude 63.2354
Longitude -146.0664
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence, west of Fish Lake at an elevation of 4,100 feet, is about a half-mile west-northwest of VABM Wild. It is in the SE1/4SW1/4 section 29, T. 19 S., R. 9 E., Fairbanks Meridian. The occurrence corresponds to locality 70 in table 2 of Nokleberg and others (1991).

Geologic setting

Geologic description

The rock at this occurrence is the Fish Lake mafic-ultramafic intrusive complex of Late Triassic age, which is believed to be a lopolithic feeder of the Nikolai basalt flows (Nokleberg and others, 1991). The occurrence consists of serpentinized olivine-pyroxene cumulate containing disseminated chromite. Grab sample 79ZN026A of this material contained more than 5,000 parts per million chromium (Nokleberg and others, 1992, table 2, locality 70).
Geologic map unit (-146.068655459173, 63.2349775467946)
Mineral deposit model Chromite disseminated in layered mafic-ultramafic complex.
Age of mineralization Late Triassic, the age of the host rock.
Alteration of deposit Serpentinization.

Production and reserves

Workings or exploration The occurrence is on active Fort Knox Gold Resource claims.
Indication of production None