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 61.6314
Longitude -142.4184
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on the east valley wall of lower Nizina Glacier (MacKevett, 1970 [GQ 844]). It is at an elevation of about 2,800 feet, 800 feet southeast of hill 3018 in the southeast corner of section 1, 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 prospect 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 Permian Hasen 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 (-142.420496980472, 61.6309847667548)
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

MRDS Number A011728

References

MacKevett, E.M., Jr., Cox, D.P., Potter, R.W., III, and Silberman, M.L., 1997, Kennecott-type deposits in the Wrangell Mountains, Alaska--High-grade copper ores near a basalt-limestone contact, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 66-89.
Reporters Travis L. Hudson (Applied Geology, Inc.)
Last report date 1/12/2003