Unnamed (on divide between Chistochina Glacier and West Fork Chistochina glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Cu
Ore minerals chalcopyrite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-2
Latitude 63.2157
Longitude -144.8918
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is on a steep ridge west-northwest of peak 5990. It is in the NW1/4NW1/4 of section 4, T. 20 S., R. 15 E., Fairbanks Meridian. The occurrence corresponds to locality 15 on figure 1 of Rose (1967) and locality 6 on figure 6 of Cobb (1979 [OFR 79-238]). The location is probably accurate within 1,000 feet.

Geologic setting

Geologic description

The rocks in the vicinity of this occurrence consist of metabasalts of the Nikolai Greenstone of Late Triassic age (Nokleberg and others, 1991); earlier the rocks were mapped as Mankomen Formation (Rose, 1967). A pyritic unit of the Nikolai Greenstone extends for more than a mile along strike; it is cut by intermediate and mafic dike rocks. The pyritized rock possibly contains a trace of chalcopyrite. Grab sample 6E534 contained 0.02 ounce of gold per ton, 0.18 ounce of silver per ton, and a trace of copper (Rose, 1967, table 5).
Geologic map unit (-144.894029861057, 63.2153045198726)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23).
Mineral deposit model number 23
Age of mineralization Post-Late Triassic, on the basis of the age of host rocks.
Alteration of deposit Sulfidization of metabasalt.

Production and reserves

Workings or exploration Geologic mapping; limited surface sampling.
Indication of production None