Unnamed (on Asik Mountain)

Occurrences, Inactive

Commodities and mineralogy

Main commodities Cr; Fe
Other commodities Cu; Ni; PGE
Ore minerals chromite; magnetite

Geographic location

Quadrangle map, 1:250,000-scale NT
Quadrangle map, 1:63,360-scale B-1
Latitude 67.4502
Longitude -162.4171
Nearby scientific data Find additional scientific data near this location
Location and accuracy The main occurrence is about 2.0 miles southwest of the summit of Asik Mountain near hill 1370. A second, more minor occurrence is near the top of Asik Mountain. The main occurrence is near the center of Section 27, T. 23 N., R. 16 W., of the Kateel River Meridian. The occurrences are accurate to within one mile.

Geologic setting

Geologic description

Disseminated chromite and magnetite occur widely in dunite of the ultramafic body at Asik Mountain (Degenhart and others, 1978). The body has poorly defined layering. The structure in the area is complex, but generally it appears that the pluton has intruded carbonate rocks of Paleozoic, possibly Devonian, age. The contact appears to be nearly conformable, suggesting that the intrusive may be sill-like.
The dunite often contains up to 2 percent disseminated chromite and analyses of samples show contain minor amounts of copper, nickel, and platinum-group elements. Two anomalous areas of chromium on Asik Mountain were outlined by soil samples; samples from these areas contained more than 600 parts per million (ppm) chromium and 450 ppm nickel (versus background values of less than 200 ppm chromium and 100 ppm nickel). Degenhart and others (1978) collected one sample of pyritic syenodiorite on the west side of Asik Mountain that contained more than 500 ppm copper (Degenhart and others, 1978). They also describe a 'modest buildup of chromium and nickel' in tan to brown weathered dunite near the southwestern part of Asik Mountain and a 'lesser chromium buildup' associated with peridotite at the peak of Asik Mountain.
Geologic map unit (-162.419966977424, 67.449545609927)
Mineral deposit model Podiform chromite (Cox and Singer, 1986; model 8a).
Mineral deposit model number 8a

Production and reserves

Workings or exploration Limited surface and soil sampling in the late 1970s.
Indication of production None
Reserve estimates None.

Additional comments

The occurrence is now within the Noatak National Preserve which is closed to exploration and mining.

References