Unnamed (east side of Big Eldorado Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Ore minerals chalcopyrite; gold; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NB
Quadrangle map, 1:63,360-scale A-2
Latitude 62.1057
Longitude -141.9405
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 This is locality 38 of Richter and others (1975) and it is included in National Park Service locality WRST-59 (unpublished data).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 setting

Geologic description

A 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).

Production and reserves

Workings or exploration Some surface exploration took place at this prospect after 1967.
Indication of production None

Additional comments

The prospect is in the Wrangell-St. Elias National Preserve.

References