|Quadrangle map, 1:250,000-scale||MC|
|Quadrangle map, 1:63,360-scale||B-4|
|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.)'.|
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).|
|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 commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve.
Bateman, A.M., 1932, Notes on a Kennecott-type copper deposit, Glacier Creek, Alaska: Economic Geology, v. 27, p. 297-306.
Cobb, E.H., and MacKevett, E.M., Jr., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the McCarthy quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-885, 156 p.
MacKevett, E.M., Jr., 1976, Mineral deposits and occurrences in the McCarthy quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-773-B, 2 sheets, scale 1:250,000.
MacKevett, E.M., Jr., and Smith, J.G., 1968, Distribution of gold, copper, and some other metals in the McCarthy B-4 and B-5 quadrangles, Alaska: U.S. Geological Survey Circular 604, 25 p.
MacKevett, E.M., Jr., and Smith, J.G., 1972, Geologic map of the McCarthy B-4 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-943, 1 sheet, scale 1:63,360.
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.
Miller, D.J., 1946, Copper deposits of the Nizina district, Alaska: U.S. Geological Survey Bulletin 947-F, p. 93-120.
|Reporters||Travis L. Hudson (Applied Geology, Inc.)|
|Last report date||1/12/2003|