|Quadrangle map, 1:250,000-scale||TK|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This placer prospect is on the Little Oshetna River, 3 miles upstream from the mouth of Conglomerate Creek. The location is accurate to within 1/2 mile.|
The rocks in the drainage of the Little Oshetna river are volcanic rocks, sandstone, and siltstone of the Talkeetna Formation; sandstone, and cobble and boulder conglomerate of the Naknek Formation, that locally overlies conglomerate of the Chinitna Formation; and Tertiary volcanic rocks that overlie Tertiary fluviatile conglomerate (Csejtey and others, 1978). Gold occurs in the alluvial gravel deposits. The lower half of the river has extensive accumulations of gravel up to 50 feet thick and 2000 feet wide. The stream gradient averages 100 feet per mile but it is only 50 feet per mile in the lower section (Kurtak and others, 1992).Placer claims were staked in 1976 by Black Creek Mining Co., and 1982 by R. Swavely. Stream-sediment samples collected by the U.S. Bureau of Mines contain 1 part per million silver, 880 parts per billion platinum, and 0.0001 ounce of gold per cubic yard (Kurtak and others, 1992). The gold in one sample was 764 fine.
|Geologic map unit||(-147.693297175492, 62.1852117947908)|
|Mineral deposit model||Placer Au-PGE (Cox and Singer, 1986; model 39a)|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary placer.|
|Workings or exploration||Placer claims were staked in 1976 by Black Creek Mining Co., and 1982 by R. Swavely. Stream-sediment sampling by the U.S. Bureau of Mines (Kurtak and others, 1992).|
|Indication of production||None|
|Reserve estimates||Little Oshetna River contains an estimated 60 million cubic yards of potentially auriferous alluvium; there is no estimate of grade (Kurtak and others, 1992).|
Additional commentsMAS/MILS number 20760054.
Balen, M.D., 1990, Geochemical sampling results from Bureau of Mines investigations in the Valdez Creek mining district, Alaska: U.S. Bureau of Mines Open-File Report 34-90, 218 p., 2 sheets, scale 1:63,360.
Csejtey, Bela, Jr., Nelson, W.H., Jones, D.L., Silberling, N.J., Dean, R.M., Morris, M.S., Lanphere, M.A., Smith, J.G., and Silberman, M.L, 1978, Reconnaissance geologic map and geochronology, Talkeetna Mountains quadrangle, northern part of Anchorage quadrangle, and southwest part of Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-558-A, 60 p., 1 sheet, scale 1:250,000.
|Reporters||R.K. Rogers (U. S. Geological Survey contractor)|
|Last report date||10/3/2002|