|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 (Moffit and Mertie, 1923, locality 20, plate 3); 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 of Cobb and Matson (1972) and locality 55 of Winklerand others (1981 [OFR 80-892-B]). Cobb (1979 [OFR 79-1241]) incuded this prospect under the name 'Elliot Cr.'.|
Geologic descriptionSmall veins, lenses, and impregnations of bornite and chalcocite occur in fractured Triassic Nikolai Greenstone (Moffit and Maddren, 1908, 1909; Moffit and Mertie, 1923) . Locally present gangue minerals are commonly quartz and calcite; secondary copper minerals include malachite and azurite. A grab sample of ore from this prospect contained 21.69 percent copper and 1.87 ounces of silver per ton (Mendenhall and Schrader, 1903, p. 26). Post-mineralization faulting has fractured the deposits. The Nikolai Greenstone and overlying Chitistone Limestone are deformed into a large, asymmetric anticline with its axis approximately parallel to Elliot 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||(-144.101994858889, 61.6471328638179)|
|Mineral deposit model||Thin veins, impregnations, 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 has been explored by a combination of open cuts, an adit ,and drifts. About 475 feet of underground workings were in place in 1908 (Moffit, 1909).|
|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.
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., 1909, Mining in the Kotsina-Chitina, Chistochina, and Valdez Creek regions: U.S. Geological Survey Bulletin 379-D, p. 153-160.
Moffit, F.H., and Maddren, A.G., 1908, The mineral resources of the Kotsina and Chitina valleys, Copper River region: U.S. Geological Survey Bulletin 345-C, p. 127-175.
|Reporters||Travis L. Hudson|
|Last report date||12/14/2001|