Unnamed (west of lower Nabesna Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Fe
Ore minerals chalcopyrite; magnetite

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-4
Latitude 62.1519
Longitude -142.9218
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is along the west side of lower Nabesna Glacier. It is at an elevation of about 3,200 feet, about 400 feet west of the glacier. The occurrence is about 0.4 mile south-southwest of the center of section 6, T. 4 N., R. 14 E. of the Copper River Meridian. This is locality 9 of Richter (1973), locality 19 of Richter and others (1975), and National Park Service locality WRST-26 (unpublished data). Cobb and Richter (1980) included this locality as an 'Unnamed occurrence'. It is located to within a few hundred feet.

Geologic setting

Geologic description

Massive magnetite containing pyrite and minor chalcopyrite is present in amphibolitized volcanic rock (Richter and others, 1975). The occurrence is near the contact of volcanic rock with a Tertiary porphyry intrusive. The volcanic rock was first thought to be part of an upper Paleozoic volcanic assemblage but Triassic, Nikolai Greenstone is present along most of the porphyry contact (Richter, 1973; 1976).
Geologic map unit (-142.923924591991, 62.1515054390868)
Mineral deposit model Contact metasomatic Cu deposit
Age of mineralization Tertiary; the age of the nearby porphyry is inferred to be Tertiary.
Alteration of deposit Amphibolitization of mafic volcanic rock.

Production and reserves

Indication of production None

Additional comments

The occurrence is in the Wrangell-St. Elias National Preserve.

References