|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 near Rainbow Creek on the north side of Elliott Creek valley (Moffit and Maddren, 1909, p. 64); it is at an elevation of about 4,100 feet in the SW1/4 section 35, T. 2 S., R. 7 E., of the Copper River Meridian. This prospect is approximately located, perhaps to within one-half mile. It is included in locality 65 Cobb and Matson (1972) and locality 55 of Winkler and others (1981 [OFR 80-892-B]).|
Geologic descriptionBornite and chalcopyrite occur in calcite veins as much as 2 inches thick in irregularly fractured Triassic Nikolai Greenstone (Mendenhall and Schrader, 1903; Moffit and Mertie, 1923). A composite high-grade sample was reported to contain 25 percent copper (Mendenhall and Schrader, 1903). The Nikolai Greenstone and overlying Chitistone Limestone are deformed into a large, asymmetric anticline with its axis approximately parallel to Elliott Creek. 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||(-144.102194839456, 61.6466328467727)|
|Mineral deposit model||Veins, disseminations, 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||This prospect was explored with open cuts, some as early as 1902 (Mendenhall and Schrader, 1903).|
|Indication of production||None|
Additional commentsThis prospect is within the Wrangell-St. Elias National Park.
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.
Mendenhall, W.C., and Schrader, F.C., 1903, The mineral resources of the Mount Wrangell District, Alaska: U.S. Geological Survey Professional Paper 15, 71 p., 1 sheet.
Moffit, F.H., and Maddren, A.G., 1909, Mineral resources of the Kotsina-Chitina region, Alaska: U.S. Geological Survey Bulletin 374, 103 p.
Moffit, F.H., and Mertie, J.B., Jr., 1923, The Kotsina-Kuskulana district, Alaska: U.S. Geological Survey Bulletin 745, 149 p.
|Reporters||Travis L. Hudson|
|Last report date||12/14/2001|