|Quadrangle map, 1:250,000-scale||VA|
|Quadrangle map, 1:63,360-scale||C-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the west side of upper Copper Creek (Van Alstine and Black, 1946, plate 30); it is at an elevation of about 4,100 feet in the NW1/4 section 25, T. 2 S., R. 7 E., of the Copper River Meridian. This prospect is approximately located, perhaps to within one-quarter mile. It is included in locality 70 of Cobb and Matson (1972) and locality 57 of Winkler and others (1981 [OFR 80-892-B]). Cobb (1979 [OFR 79-1241]) includes this prospect under the name 'Cave'.|
Geologic descriptionA 223-foot-long adit explores this copper prospect in Triassic Nikolai Greenstone (Van Alstine and Black, 1946, p. 129-130). The only mineralization exposed in the adit is a 2- to 12-inch-thick shear zone that contains quartz, bornite, malachite, and some chalcopyrite. The shear zone is located 23 feet in from the portal, trends N 14 W, and dips 7 degrees west. Other shear zones with quartz and calcite were exposed in the adit, but they did not contain copper mineralization. The prospect is only about 30 feet below the contact with overlying Triassic Chitistone Limestone; azurite and malachite films coat some fractures in the nearby limestone. The copper mineralization is believed to be related to the regional mineralizing event that produced the rich Kennecott copper deposits in the McCarthy quadrangle (MacKevett and others, 1997).
|Geologic map unit||(-144.070895477542, 61.671134030489)|
|Mineral deposit model||Vein and fracture fillings in greenstone; probably related to Kennecott-type copper deposits (MacKevett and others, 1997)|
|Age of mineralization||The copper mineralization is believed to be related to the mineralizing event that produced the rich Kennecott copper deposits in the McCarthy quadrangle to the east (MacKevett and others, 1997). This event is interpreted to have accompanied Late Jurassic or Early Cretaceous deformation and metamorphism (MacKevett and others, 1997, p. 88).|
|Workings or exploration||A 223-foot-long adit explores this copper prospect in Triassic Nikolai Greenstone (Van Alstine and Black, 1946, p. 129-130).|
|Indication of production||None|
Additional commentsThis prospect is within the Wrangell-St. Elias National Park.
Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Valdez quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1241, 167 p.
Cobb, E.H., and Matson, N.A., Jr., 1972, Metallic mineral resources map of the Valdez quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-438, 1 sheet, scale 1:250,000.
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.
Van Alstine, R.E., and Black, R.F., 1946, Copper deposits of the Kotsina-Kuskulana district, Alaska: U.S. Geological Survey Bulletin 947-G, p. 121-141.
|Reporters||Travis L. Hudson|
|Last report date||12/14/2001|