Unnamed (west of lower Nabesna Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Au; Co
Ore minerals cobaltite; gold
Gangue minerals calcite

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-4
Latitude 62.1468
Longitude -142.9239
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 3,400 feet and about 700 feet west of the glacier. The occurrence is about 0.4 mile north-northwest of the center of section 7, T. 4 N., R. 14 E. of the Copper River Meridian. This is locality 10 of Richter (1973), locality 20 of Richter and others (1975), and National Park Service locality WRST-27 (unpublished data).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

A 10- to 20-cm-wide calcite vein contains gold and cobaltite (Richter and others, 1975). The vein contains up to 10 ounces of gold per ton (Richter and others, 1975). The vein is in highly altered and limonite-stained Triassic, Nikolai Greenstone(?) near the contact with a Tertiary porphyry intrusion (Richter, 1973).
Geologic map unit (-142.926024400906, 62.1464050087253)
Mineral deposit model Vein
Age of mineralization Tertiary? The age of the nearby porphyry is inferred to be Tertiary.
Alteration of deposit The host rock to the vein is strongly hydrothermally altered (Richter, 1973).

Production and reserves

Indication of production None

Additional comments

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