Quadrangle map, 1:250,000-scale | MC |
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Quadrangle map, 1:63,360-scale | C-4 |
Latitude | 61.5032 |
Longitude | -142.3075 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | This occurrence is on a bluff east of lower Contact Gulch. It is at an elevation of about 4,900 feet, 1,500 feet south of the center of section 22, T. 4 S., R 17 E. of the Copper River Meridian. This is locality 84 of MacKevett (1976); the location is accurate to within about 1,000 feet. |
Geologic descriptionThis occurrence consists of bornite-bearing veins to 6 centimeters thick that occur in a 2-meter-wide fault zone that cuts Triassic Nikolai Greenstone (MacKevett, 1976). A sample of the mineralization contained 200 parts per million (ppm) silver, more than 20,000 ppm copper, and 7 ppm molybdenum. The widespread deposition of copper in Triassic greenstone and limestone of the area is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980). | |
Geologic map unit | (-142.309567646745, 61.5027848825381) |
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Mineral deposit model | Basaltic Cu (Cox and Singer, 1986; model 23) |
Mineral deposit model number | 23 |
Age of mineralization | Cretaceous? The widespread deposition of copper in Triassic greenstone and limestone of the area is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980). |
Workings or exploration | Limited surface sampling. |
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Indication of production | None |
Additional commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve. |
ReferencesMacKevett, 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.
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Reporters | Travis L. Hudson (Applied Geology, Inc.) |
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Last report date | 1/12/2003 |