| Main commodities | Cu |
|---|---|
| Ore minerals | chalcocite; malachite |
| Quadrangle map, 1:250,000-scale | MC |
|---|---|
| Quadrangle map, 1:63,360-scale | C-6 |
| Latitude | 61.5642 |
| Longitude | -143.1417 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | This prospect is on the north valley wall of Hidden Creek across from the mouth of Glacier Gulch. It is at an elevation of 4,300 feet, 2,800 feet south-southeast of elevation 6514 and 1,700 feet east-southeast of the center of section 36, T. 3 S., R. 12 E. of the Copper River Meridian. This is locality 118 of MacKevett (1976); the location is accurate to within about 1,000 feet. |
Geologic descriptionThe deposit at this prospect consists of a narrow vein of malachite and minor chalcocite that is localized along a fault cutting Triassic Nikolai Greenstone (MacKevett, 1972, 1976). Exploration of this deposit, probably mostly by surface workings, occurred as recently as the 1970s. 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 | (-143.143783605775, 61.5637600185323) |
|---|---|
| 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 | Exploration of this deposit, probably mostly by surface workings, occurred as recently as the 1970s. |
|---|---|
| Indication of production | Undetermined |
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.) |
|---|---|
| Last report date | 1/12/2003 |