| Quadrangle map, 1:250,000-scale | MC |
|---|---|
| Quadrangle map, 1:63,360-scale | C-6 |
| Latitude | 61.5489 |
| Longitude | -142.8787 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | This prospect is on the north side of a small cirque valley on the east valley wall of Root Glacier. It is at an elevation of about 4,900 feet, 1,200 feet southeast of elevation 5720 and 4,000 feet east of Root Glacier. The site is in the SE1/4 of section 4, T. 4 S., R. 14 E. of the Copper River Meridian. This is locality 94 of MacKevett (1976); the location is accurate to within about 1,000 feet. |
Geologic descriptionThis prospect is an area of iron- and copper-staining on fractures in Upper Triassic Nizina Limestone (MacKevett, 1972; 1976). It was explored by small and shallow workings. Larger copper deposits in the area (e.g., MC083, MC090, MC091, and MC093) are localized stratigraphically below the Nizina in the lower part of the Chitistone Limestone. 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 | (-142.880784528862, 61.5484649580896) |
|---|---|
| Mineral deposit model | Basaltic Cu (Cox and Singer, 1986; model 23) and/or Kennecott-type copper deposit (after MacKevett and others, 1997) |
| 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 | This prospect was explored by small and shallow workings. |
|---|---|
| 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 |