Shungnak River (ARDF #SH008) Au

Shungnak River

Mine, Inactive

Commodities and mineralogy

Main commodities	Au
Other commodities	Ag; Cu; nephrite
Ore minerals	gold; native copper; native silver; nephrite

Geographic location

Quadrangle map, 1:250,000-scale	SH
Quadrangle map, 1:63,360-scale	D-3
Latitude	66.996
Longitude	-157.305
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	The Shungnak River placer mine is about a mile below the mouth of the river canyon. The deposit probably extends northward into the Ambler river quadrangle. The map site is in the E1/2 section 34, T. 19 N., R. 7 E., of the Kateel River Meridian. Location is accurate to within a radius of 1,000 feet.

Geologic setting

Geologic description Placer gold was first mined from the Shungnak River in 1898. It was mined continuously through 1913, and intermittently on a small scale into the 1950s. Bedrock is predominately lower to mid-Paleozoic black shale and schist; som Jurassic-Cretaceous serpentinite also is in the immediate area. The stream gravels are unfrozen. Typically the top 2 feet of gravel was removed as overburden. The gold is mostly on bedrock, particularly in areas of black shale. The gold is reddish with a dull luster, shaped like flattened shot, and usually in small pieces. Assay value was $16.70 per ounce in 1931. The recovery during 1931 was on the order of $0.90 per cubic yard. Pay streaks were irregular and unpredictable. Magnetite is the most abundant mineral in the concentrates. Occasionally small nuggets of copper and silver were found in the sluice box (Smith, 1913). Some boulders of semiprecious nephrite (jade) were recovered during mining.
Geologic map unit	(-157.307754304728, 66.9954445574161)
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	Gold was first mined from the Shungnak River in 1898. It was mined continuously through 1913, and intermittently on a small scale into the 1950s.
Indication of production	Yes; small
Production notes	Smith (1913) states that a liberal estimate of total production to 1912 would be less than $50,000.
Additional comments Semiprecious quality nephrite (jade) boulders were found during placer mining and in the stream gravels of the Shungnak River (Bernice Sheldon, oral communication, 1991).

References

MRDS Number	A010738
References Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p. Cobb, E.H., 1977, Placer deposit map of central Alaska: U.S. Geological Survey Open-File Report 77-168-B, 64 p., 1 map, scale 1:1,000,000. Mayfield, C.F., and Grybeck, D., 1978, Mineral occurrences and resource map of the Ambler River quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-120-I, 1 sheet, scale 1:250,000. Reed, I.M., 1931, Report on the placer deposits of the upper Kobuk goldfields: Alaska Territorial Department of Mines Miscellaneous Report 37-1, 57 p. Smith. P.S., 1913, The Noatak-Kobuk region, Alaska: U.S. Geological Survey Bulletin 536, 60 p.
Reporters	Anita Williams (Anchorage, AK)
Last report date	12/16/1999