|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 on the ridge south of Toby Creek. it is at an elevation of about 6,400 feet, 2,500 feet northwest of elevation 7140 and 1,500 feet north of the center of section 12, T. 5 S., R. 17 E. of the Copper River Meridian. This is locality 70 of MacKevett (1976); the location is accurate to within a few hundred feet.|
Geologic descriptionThis occurrence consists of a 2- to 3-foot-wide, malachite- and azurite-bearing vein in a fault zone that cuts Triassic Nikolai Greenstone (MacKevett and Smith, 1972; MacKevett, 1976). A sample of the vein contained 2 parts per million (ppm) silver, 500 ppm arsenic, and 20,000 ppm copper (MacKevett and Smith, 1968, sample 111). 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||(-142.282859112692, 61.4532841586484)|
|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 sampling.|
|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., 1968, Distribution of gold, copper, and some other metals in the McCarthy B-4 and B-5 quadrangles, Alaska: U.S. Geological Survey Circular 604, 25 p.
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|