Unnamed (east of lower Nabesna Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Zn
Ore minerals chalcopyrite; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-4
Latitude 62.1176
Longitude -142.8255
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is in an unnamed drainage on the lower-west flank of the large ridge east of Nabesna Glacier. It is at an elevation of about 4,000 feet, 7,800 feet northwest of peak 7445 and 3,000 feet east of the glacier. The occurrence is about 0.2 mile northeast of the center of section 22, T. 4 N., R. 14 E. of the Copper River Meridian. This is locality 13 of Richter (1973), locality 26 of Richter and others (1975), and National Park Service locality WRST-44 (unpublished data). Cobb and Richter (1980 [OFR 80-927]) included this locality as an 'Unnamed occurrence'. It is located to within a few hundred feet.

Geologic setting

Geologic description

A quartz-pyrite vein with chalcopyrite and sphalerite cuts a quartz-eye- bearing rock that is either a volcanic flow rock or a shallow intrusive in upper Paleozoic, Tetelna Volcanics (Richter, 1973; Richter and others, 1975). A channel sample across a 1-foot-wide quartz vein with pyrite, chalcopyrite, and sphalerite contained 0.06 parts per million (ppm) gold, 15 ppm silver, more than 20,000 ppm copper, 700 ppm lead, and more than 10,000 ppm zinc (Richter and Matson, 1970 [OFR 70-276]).
Geologic map unit (-142.827625341032, 62.1172041485745)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Cretaceous or Tertiary? The upper Paleozoic host rocks are locally cut by Cretaceous and Tertiary intrusive rocks associated with base metal mineralization elsewhere in the Nabesna A-4 quadrangle (Richter, 1973).
Alteration of deposit Quartz veining.

Production and reserves

Workings or exploration Some surface prospecting has probably occurred here.
Indication of production None

Additional comments

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

References