|Quadrangle map, 1:250,000-scale||NB|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of about 4,850 feet on the east side of Big Eldorado Creek, a drainage on the west flank of Gold Hill. It is 6,500 feet west-northwest of the summit of Gold Hill. The prospect is near the center of the south boundary of section 21, T. 4 N., R. 19 E. of the Copper River Meridian. This is locality 38 of Richter and others (1975) and it is included in National Park Service locality WRST-59 (unpublished data). Cobb and Richter (1980) included this prospect under the name 'Big Eldorado (lode)'. It is located to within a few hundred feet.|
Geologic descriptionA quartz vein that contains pyrite, chalcopyrite, and gold cuts syenodiorite of the Chisana pluton at this prospect (Richter and others, 1975). The site is on the west flank of Gold Hill where the Chisana pluton is in contact with Cretaceous volcanic and volcaniclastic rocks (Richter and Jones, 1973). The Chisana pluton varies from clinopyroxene diorite to monzonite and has a K/Ar age of 110 +/- 3.0 Ma (Richter, Lanphere and Matson, 1975).
|Geologic map unit||(-141.942627581418, 62.1053341218153)|
|Mineral deposit model||Polymetallic vein? (Cox and Singer, 1986; model 22c)|
|Mineral deposit model number||22c?|
|Age of mineralization||Probably related to Mid-Cretaceous? pluton; the vein is in the Chisana pluton which has has a K/Ar age of 110 +/- 3.0 Ma (Richter, Lanphere, and Matson, 1975).|
|Workings or exploration||Some surface exploration took place at this prospect after 1967.|
|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., and Jones, D.L., 1973, Reconnaissance geologic map of the Nabesna A-2 quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-749, 1 sheet, scale 1:63,360.
Richter, D.H., Lanphere, M.A., and Matson, N.A., Jr., 1975, Granite plutonism and metamorphism, eeastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||11/24/2002|