|Quadrangle map, 1:250,000-scale||MC|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the west valley wall of Boulder Creek, a north tributary to Dan Creek (MacKevett, 1974). It is at an elevation of about 4,000 feet, 2,500 feet north-northwest of elevation 4480 in the NE1/4 of section 34, T. 5 S., R. 16 E. of the Copper River Meridian. This is locality 71 of MacKevett (1976); the location is accurate to within a few hundred feet. Cobb and MacKevett (1980) included this prospect under the name 'Snow Bird'.|
Geologic descriptionThe deposit at this prospect consists of a 1.5- to 5-foot-wide quartz-calcite vein that contains bornite, chalcocite, chalcopyrite, and pyrite; the vein is localized along a shear zone in Triassic Nikolai Greenstone (MacKevett and Smith, 1968; MacKevett, 1976). Samples of the vein material contained up to 50 parts per million (ppm) silver, 0.1 ppm gold, 1,000 ppm manganese, and more than 20,000 ppm copper (MacKevett and Smith, 1968, samples 9-12). The prospect was explored by two short adits. 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||(-142.513557277401, 61.3951707394532)|
|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).|
|Workings or exploration||The prospect was explored by two short adits.|
|Indication of production||None|
Additional commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve.
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., 1974, Geologic map of the McCarthy B-5 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-1146, 1 sheet, scale 1:63,360.
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., 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|