Unnamed (east of lower Nizina Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcocite; malachite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale MC
Quadrangle map, 1:63,360-scale C-4
Latitude 61.6221
Longitude -142.4207
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is in an unnamed drainage on the east valley wall of lower Nizina Glacier (MacKevett, 1970 [GQ 844]). It is at an elevation of about 2,500 feet, 1,500 feet north of elevation 2720, and 1,000 feet east of the center of section 12, T. 3 S., R. 16 E. of the Copper River Meridian. This is locality 114 of MacKevett (1976); the location is accurate to within about 100 feet.

Geologic setting

Geologic description

This occurrence consists of chalcocite- and malachite-bearing quartz-calcite veins as much as 8 inches thick that are localized along faults in Triassic Nikolai Greenstone (MacKevett, 1970 [GQ 844]). The veins can be traced for up to 50 feet. They occur near a major fault juxtaposing Nikolai Greenstone against Cretaceous Moonshine Creek Formation (MacKevett, 1970 [GQ 844]). Copper mineralization is common in Nikolai Greenstone and is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic to Early Cretaceous (MacKevett and others, 1997).
Geologic map unit (-142.422795268147, 61.6216841260626)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23)
Mineral deposit model number 23
Age of mineralization Cretaceous? Copper mineralization is common in Nikolai Greenstone and is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic to Early Cretaceous (MacKevett and others, 1997).
Alteration of deposit Oxidation.

Production and reserves

Indication of production None

Additional comments

The locality is in the Wrangell-Saint Elias National Park and Preserve.

References