|Quadrangle map, 1:250,000-scale||NB|
|Quadrangle map, 1:63,360-scale||A-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the lower-west flank of the large ridge east of Nabesna Glacier. It is at an elevation of about 3,500 feet in a small drainage about 5,000 feet west of peak 6045 and 1,500 feet east of the glacier. The site is in the SW1/4 of section 3, T. 4 N., R. 14 E. of the Copper River Meridian. This is locality 7 of Richter (1973), locality 24 of Richter and others (1975), and National Park Service locality WRST-42 (unpublished data). Cobb and Richter (1980 [OFR 80-927]) include this locality as an 'Unnamed prospect'. It is located to within a few hundred feet.|
Geologic descriptionHydrothermally altered porphyry dikes and small masses of quartz diorite contain disseminated pyrite and chalcopyrite; local stockworks of quartz veins with pyrite and chalcopyrite also cut volcanic country rocks (Richter and Matson, 1970 [OFR 70-276]; Richter and others, 1975). Assays of 3 rock samples from this area contained 0.2 to 0.4 ounce gold per ton. One is a 200-foot composite chip sample of pyrite-bearing sericitized porphyry that contained 0.04 ounce of gold per ton and 2,000 parts per million copper (Richter and Matson, 1970 [OFR 70-276]). The altered intrusive rocks are Tertiary in age (Richter, 1973). They cut volcanic rocks and argillite of the upper Paleozoic Tetelna Volcanics (Richter, 1973; 1976).
|Geologic map unit||(-142.832326088903, 62.1544069529768)|
|Mineral deposit model||Disseminated and stockwork veins with copper and gold|
|Age of mineralization||The altered and mineralized intrusive rocks are considered to be Tertiary (Richter, 1973).|
|Alteration of deposit||Quartz-sericite-pyrite replacement and veining.|
|Workings or exploration||Surface prospecting has occurred in this area.|
|Indication of production||None|
Additional commentsThe prospect is in the Wrangell-St. Elias National Preserve.
Cobb, E.H., and Richter, D.H., 1980, Summaries of data on and list of references to metallic and selected nonmetallic mineral deposits in the Nabesna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-927, 117 p.
Richter, D.H., 1976, Geologic map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-932, 1 sheet, scale 1:250,000.
Richter, D.H., and Matson, N.A., Jr., 1970, Geochemical data from the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open-File Report 70-276, 14 p., 1 sheet, scale 1:63,360.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||11/24/2002|