Slope Creek

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Bi; Cu
Ore minerals bismuth; copper; gold; silver
Gangue minerals barite; magnetite

Geographic location

Quadrangle map, 1:250,000-scale GU
Quadrangle map, 1:63,360-scale D-1
Latitude 62.791
Longitude -144
Nearby scientific data Find additional scientific data near this location
Location and accuracy Slope Creek (Cobb, 1979, p. 26-27; OF 79-1247), which is unnamed on the Gulkana D-1 topographic map, is a tributary to Porcupine Creek in the SE1/4NE1/4, section 25, T. 12 N., R. 7 E., Copper River Meridian. The creek has been placer mined into the Nabesna D-6 quadrangle and the coordinates above are of the boundary between the two quadrangles. The mine is locality 18 of Richter and Matson (1972) and locality 17 of MacKevett and Holloway (1977). The location is accurate within 500 feet.

Geologic setting

Geologic description

Slope Creek has produced a small amount of placer gold that probably was derived from low-grade porphyry and vein deposits in upper Slope Creek (GU 020). The placer gold is accompanied by magnetite, native silver, native bismuth, native copper, and possibly barite (Moffit, 1944; Richter, 1966). As in Grubstake Creek (GU017) which is over the divide to the west, the gold is fine-grained and wiry, which suggests a short distance of transport (Richter and Matson, 1968).
Geologic map unit (-144.002191504635, 62.7906113235433)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a)
Mineral deposit model number 39a
Age of mineralization Holocene placer.

Production and reserves

Workings or exploration Small-scale placer mining took place from about 1934 to the 1950s, and possibly more recently.
Indication of production Yes
Production notes Placer deposits in Slope and Grubstake Creeks (GU017) have been mined intermittently since 1934. Total production from both is probably less than $30,000 (about 857 ounces) (Richter and Matson, 1968).

Additional comments

See also Grubstake Creek (GU017) and Boulder Creek (GU016).

References

MRDS Number A011848

References

Nokleberg, W.J., and (seven) others, 1994, Metallogeny and major mineral deposits of Alaska and Metallogenic map of significant metalliferous lode deposits and placer districts of Alaska, in Plafker, G. and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, Vol.. G1, p. 855-904, Plate 11, scale 1:2,500,000.
WGM Inc., 1980, 1979 Summary report of gold potential, Slana District, Ahtna project: WGM Inc., 10 p., map, scale 1:63,360. (Report held by Ahtna Mineral Co., Anchorage, Alaska).
Reporters W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (U.S. Geological Survey)
Last report date 11/30/2000