|Ore minerals||chalcocite; malachite|
|Quadrangle map, 1:250,000-scale||MC|
|Quadrangle map, 1:63,360-scale||B-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is low on the south valley wall of the Chitistone River. It is at an elevation of about 2,900 feet, 6,000 feet northeast of the mouth of Toby Creek and 6,500 feet northwest of elevation 6930. The site is in the NE1/4 of section 26, T. 4 S., R. 17 E. of the Copper River Meridian. This is locality 83 of MacKevett (1976); the location is accurate to within a few hundred feet.|
Geologic descriptionThis occurrence consists of chalcocite- and malachite-bearing veinlets and copper-stained amygdules in the lower part of Triassic Nikolai Greenstone (MacKevett and Smith, 1972; MacKevett, 1976). 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||(-142.282065192512, 61.4925859942076)|
|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).|
|Alteration of deposit||Oxidation.|
|Workings or exploration||Only limited surface examination.|
|Indication of production||None|
Additional commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve.
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., 1972, Geologic map of the McCarthy B-4 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-943, 1 sheet, scale 1:63,360.
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|