Nelson

Mine, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; As
Ore minerals azurite; bornite; chalcocite; chalcopyrite; covellite; enargite; malachite; native copper

Geographic location

Quadrangle map, 1:250,000-scale MC
Quadrangle map, 1:63,360-scale B-4
Latitude 61.4506
Longitude -142.3843
Nearby scientific data Find additional scientific data near this location
Location and accuracy This mine is low on the west valley wall of lower Glacier Creek. It is at an elevation of about 2,900 feet, 1,400 feet southwest of the Glacier Creek landing strip, and 2,500 feet north-northwest of elevation 3675. The site is in the NW1/4 of section 9, T. 5 S., R. 17 E. of the Copper River Meridian. This is locality 69 of MacKevett (1976) and it is accurately located. Cobb and MacKevett (1980) include this mine under the name 'Nelson (Glacier Cr.)'.

Geologic setting

Geologic description

This mine is near basalt just above the basal part of a faulted block of Upper Triassic Chitistone Limestone (MacKevett and Smith, 1972). The mineralization characteristically is discontinuous stringers and masses of chalcocite and lesser covellite, enargite, bornite, chalcopyrite, malachite, and native copper along steeply inclined narrow fissures and bedding planes (Bateman, 1932; Miller, 1946; Sainsbury, 1951; MacKevett, 1976). Chip samples across veins of massive sulfide assayed more than 2 percent copper, 0.3 percent arsenic, and 50 parts per million silver (MacKevett and Smith, 1968). The mineralized area is extensively fractured and faulted. The deposits were explored in the 1930s by surface cuts and about 1,100 feet of underground workings in 5 adits on 4 levels (Miller, 1946; Sainsbury, 1951). Some diamond drilling also explored the deposits.
Copper mineralization is common in the Chitistone Limestone and underlying 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 (-142.386361472662, 61.4501785271172)
Mineral deposit model Kennecott-type copper deposit (after MacKevett and others, 1997)
Age of mineralization Cretaceous? Copper mineralization is common in the Chitistone Limestone and underlying 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 was very minor and restricted to thin veneers of malachite and azurite (Bateman, 1932).

Production and reserves

Workings or exploration The deposits were explored in the 1930s by surface cuts and about 1,100 feet of underground workings in 5 adits on 4 levels (Miller, 1946; Sainsbury, 1951). Some diamond drilling also explored the deposits.
Indication of production Yes; small
Production notes Several tons of chalcocite-rich ore were mined by Kennecott Copper Corporation in 1929-30.

Additional comments

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

References

MRDS Number A011706

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