Solomon River (lower)

Mine, Active?

Commodities and mineralogy

Main commodities Au
Other commodities W
Ore minerals gold; scheelite
Gangue minerals garnet; ilmenite; magnetite

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-5
Latitude 64.612
Longitude -164.384
Nearby scientific data Find additional scientific data near this location
Location and accuracy Solomon River is a major drainage that flows south to its mouth on Norton Sound at Solomon. The lower part of Solomon River has been extensively dredged for a distance of 4 miles starting 2 miles above Solomon. This dredged area is between elevations of 25 and 75 feet. This is locality 101 of Cobb (1972, MF 445; 1978, OF 78-181).

Geologic setting

Geologic description

Placer gold was discovered in 1899 and mining started in 1900 when about $10,000 (or 485 fine ounces) were produced (Brooks and others, 1901). Most of the active flood along this part of the river has been extensively worked by dredges starting as early as 1903 (Collier and others, 1908). Stream gravels are generally 3 to 9.5 feet thick with a maximum thickness of 30 feet, and the pay streak was several hundred to over 1,000 feet wide. Locally preserved benches had 8 to 12 feet of gravel with pay thicknesses of 1 to 4 feet over clay layers and bedrock. Gravels were well rounded and generally less than 6 to 8 inches in diameter. A dredge concentrate from about a mile below the mouth of Shovel Creek contained 22 ounces of gold and 9.1 pounds of scheelite per cubic yard (Coats, 1944). Other minerals in dredge concentrates include magnetite, ilmenite, and garnet (Smith, 1910). Dredges operated on various parts of the lower Solomon River up to as recently as 1963. Lu and others (1968) compiled reported production and determined that more than about $2,500,000 dollars, or 125,000 ounces at $20 per ounce, had been produced from the general Solomon River area. This is a minimum estimate of production. Bedrock here is part of a lower Paleozoic metasedimentary assemblage that includes a distinctive black, very fine-grained, graphitic schist (Sainsbury and others, 1972, OFR 511; Till and others, 1986).
Geologic map unit (-164.386604230615, 64.6112548494528)
Mineral deposit model Placer Au-PGE (Cox and Singer, 1986; model 39a); possibly reworked coastal plain deposits.
Mineral deposit model number 39a
Age of mineralization Quaternary; the location and elevation (25 to 75 feet) of this area indicate it was affected by Quaternary sea level fluctuations.

Production and reserves

Workings or exploration Most of the active flood along this part of the river has been extensively worked by dredges starting as early as 1903 (Collier and others, 1908).
Indication of production Yes; medium
Production notes Placer gold was discovered in 1899 and mining started in 1900 when about $10,000 (or 485 fine ounces) were produced (Brooks and others, 1901). Lu and others (1968) compiled reported production and determined that more than about $2,500,000 dollars, or 125,000 ounces at $20 per ounce, had been produced from the greater Solomon River area. This is a minimum estimate of production.

References

MRDS Number A012596

References

Brooks, A.H., Richardson, G.B., Collier, A.J., and W.C. Mendenhall, 1901, A reconnaissance in the Cape Nome and adjacent gold fields of Seward Peninsula, Alaska, in 1900: U.S. Geological Survey Special Publication, p. 1-185, maps.
Lu, F.C.J., Heiner, L.E., and Harris, D.P., 1968, Known and potential ore reserves, Seward Peninsula, Alaska: University of Alaska, Mineral Industry Research Laboratory Report 18, 107 p.
Reporters Travis L. Hudson (Applied Geology)
Last report date 8/19/1999