Upper Sweepstakes Creek

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Th; U
Ore minerals gold; chrome spinel; hematite; hydrothorite; ilmenite; magnetite; pyrite; uranothorianite
Gangue minerals garnet; zircon

Geographic location

Quadrangle map, 1:250,000-scale CA
Quadrangle map, 1:63,360-scale B-5
Latitude 65.39
Longitude -161.31
Nearby scientific data Find additional scientific data near this location
Location and accuracy The upper Sweepstakes Creek placer mine is on upper Sweepstakes Creek about 1 mile west-southwest of the landing strip on Granite Mountain. This site includes a prospect approximately 2 miles downstream from the mine. The map site is at the mine symbol in section 15, T. 1 S., R. 13 W., of the Kateel River Meridian. Cobb, 1972 (MF-389), locations 39 and 40.

Geologic setting

Geologic description

Gold has been placer mined from low bench deposits along the east side of the upper Sweepstakes Creek. Depth to bedrock is 15 feet on lower claims. Gravels in the creek bed are 6 to 14 feet deep. On benches 2 to 12 feet of muck overlies 2 to 8 feet of gravel. A few inches of partially-decomposed bedrock was excavated during mining (Harrington, 1919). Sweepstakes Creek drains the southwestern part of the Cretaceous Granite Mountain monzonite pluton. Heavy minerals in the concentrate include chrome spinel, garnet, hematite, hydrothorianite, ilmenite, magnetite, pyrite, uranothorianite, and zircon (Gault and others, 1953).
Geologic map unit (-161.312636745035, 65.3893237101105)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration Small-scale gold-placer mining took place on upper Sweepstakes Creek from the early 1900s until the 1950s. Numerous prospect pits have been dug along the stream benches. In 1947, the U.S. Geological Survey sampled the placer to evaluate its radioactive mineral content (Gault and others, 1953).
Indication of production Yes; small

References

MRDS Number 10307306

References

Smith, S.S., 1917, The mining industry in the Territory of Alaska during the calendar year 1916: U.S. Bureau of Mines Bulletin 153, 89 p.
Reporters Anita Williams (Anchorage, AK)
Last report date 1/12/2000