Quadrangle map, 1:250,000-scale | MC |
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Quadrangle map, 1:63,360-scale | C-7 |
Latitude | 61.6248 |
Longitude | -143.2948 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | This occurrence is on the south end of a large nunatak near the head of Lakina Glacier. It is at an elevation of about 5,600 feet, 2,000 feet west-northwest of elevation 6830 and 8,000 feet southwest of elevation 8597. It is in the NE1/4 of section 7, T. 3 S., R. 12 E. of the Copper River Meridian. This is locality 119 of MacKevett (1976); the location is accurate to within about 500 feet. |
Geologic descriptionThis occurrence consists of secondary copper minerals (assumed to be mostly malachite) in sheared Triassic Nikolai Greenstone (MacKevett, 1976). A sample contained 7 parts per million (ppm) silver, 500 ppm chromium, and 15,000 ppm copper. 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 | (-143.296888088465, 61.6243583533231) |
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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). |
Alteration of deposit | Oxidation. |
Workings or exploration | Only 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 |