|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 north side of a glacial valley that is an unnamed north tributary to Cross Creek. It is at an elevation of about 6,600 feet, 6,000 feet southwest of peak 8233, and 4,400 feet northwest of peak 7115. The prospect is near the center of the NW1/4 of section 36, T. 4 N., R. 15 E. of the Copper River Meridian. It is locality 16 of Richter (1973), locality 34 of Richter and others (1975), and National Park Service locality WRST-49 (unpublished data). Cobb and Richter (1980) included this prospect under the name 'Cross Cr.'. It is located to within a few hundred feet.|
Geologic descriptionThis prospect was known as early as 1909 (Moffit and Knopf, 1909). It is a zone of intense hydrothermal alteration in upper Paleozoic volcanic rocks of the Tetelna Volcanics that contains fragments of volcanic rock cemented by quartz with minor pyrite, galena, sphalerite and chalcopyrite (Richter, 1973; Richter and others, 1975). A sample of a galena- and sphalerite-bearing, quartz vein from a strongly limonite-stained area contained 0.06 parts per million (ppm) gold, 50 ppm silver, 100 ppm copper, more than 10,000 ppm lead, and more than 10,000 ppm zinc (Richter and Matson, 1970 [OFR 70-276]). The limonite-stained alteration zone is 2,000 feet across and appears to be localized in the contact zone of a Tertiary porphyry complex that intrudes rocks of the upper Paleozoic Tetelna Volcanics (Richter, 1973, Richter, 1976).
|Geologic map unit||(-142.599028728613, 62.0840077175449)|
|Mineral deposit model||Polymetallic veins (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c|
|Age of mineralization||Tertiary. The alteration zone appears to be localized in the contact zone of a Tertiary porphyry complex with rocks of the upper Paleozoic Tetelna Volcanics (Richter, 1973; Richter, 1976).|
|Alteration of deposit||The host rocks to this deposit are highly altered but the type and extent of alteration have not been reported. The area is iron-stained.|
|Workings or exploration||This prospect was known as early as 1909 (Moffit and Knopf, 1909). There has been surface prospecting.|
|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.
Moffit, F.H., and Knopf, Adolph, 1909, Mineral resources of the Nabesna-White River district: U.S. Geological Survey Bulletin 379-D, p. 161-180.
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|