|Quadrangle map, 1:250,000-scale||ID|
|Quadrangle map, 1:63,360-scale||B-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The lower Chicken Creek placer mine extends for about 2 miles above its mouth. The coordinates are at the midpoint of the deposit in the NE1/4 section 15, T. 26 N., R. 47 W., of the Seward Meridian. The location is accurate. Lower Chicken Creek is locality 27 of Cobb (1972 [MF 363]); also described in Cobb (1976 [OFR 76-576]).|
The gold-bearing gravel in the modern stream channel of Chicken Creek and alluvial fans that feed into it are derived from the erosion of the Chicken Mountain lode deposit (ID109) and reworking of residual gold placers on the southern flank of Chicken Mountain. A landslide dams the valley of Chicken Creek valley at an elevation of about 800 feet and separates this placer from the upper Chicken Creek placer (ID108) (Bundtzen and others, 1992; Bundtzen and Miller, 1997; Miller, Bundtzen, and Gray, 2005).
Bedrock in lower Chicken Creek is mainly sandstone and argillite of the Upper Cretaceous, Kuskokwim Group (Miller and Bundtzen, 1994). When the site was visited by Mertie in 1933 (Mertie, 1936), the placer cut was 12 to 30 feet deep and exposed 10 to 30 feet of gravel that included cobbles of sedimentary rocks up to 3 feet in diameter. The depth to bedrock at the mouth of the creek was 90 feet (Mertie, 1936, p. 215). In addition to gold, the principal heavy minerals include cinnabar, chromite, ilmenite, and zircon. The gold varies from 850 to 870 fine and averages 861 fine (Bundtzen, Cox, and Veach, 1987).Based on past production records, Bundtzen and others (1992) estimated that lower Chicken Creek produced at least 24,800 ounces of gold and 3,174 ounces of silver from 1912 to 1985. The production records from 1940 to 1980 are not available.
|Geologic map unit||(-157.963965521831, 62.346143317126)|
|Mineral deposit model||Placer Au deposit (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Probably Quaternary.|
|Workings or exploration||Exploration and mining on lower Chicken Creek began in 1911 and the deposit was drilled in 1912 (Eakin, 1914). The deposit was probably mined nearly continuously from 1913 until World War II. Early drift mining later gave way to open cut mining methods and large-scale hydraulic removal of overburden (Mertie, 1936). Much of the modern mechanized mining on Chicken Creek was carried out by Flat Creek Placers, Inc. mainly in the 1950s and 1960s, using a dragline and bulldozer. Richard Wilmarth began mining the property in the mid-1990s.|
|Indication of production||Yes|
|Reserve estimates||Some low grade gold resources occur in deep ground near the mouth of Chicken Creek (John Fullerton, oral communication, 1986).|
|Production notes||Based on past production records, Bundtzen and others (1992) estimated that lower Chicken Creek produced at least 24,800 ounces of gold and 3,174 ounces of silver from 1912 to 1985. The production records from 1940 to 1980 are not available.|
|MRDS Number||A015069; A015070; D002696|
Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 242-286.
Bundtzen, T.K., Cox, B.C., and Veach, N.C., 1987, Heavy mineral provenance studies in the Iditarod and Innoko districts, western Alaska: Process Mineralogy VII, The Metallurgical Society, p. 221-246.
Bundtzen, T.K., Miller, M.L., Laird, G.M., and Bull, K.F., 1992, Geology and mineral resources of Iditarod mining district, Iditarod B-4 and eastern B-5 quadrangles, southwestern Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 97, 46 p., 2 sheets, scale 1:63,360.
Cobb, E.H., 1972, Metallic mineral resources map of the Iditarod quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-363, 1 sheet, scale 1:250,000.
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction material) in the Iditarod and Ophir quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-576, 101 p.
Mertie, J.B., Jr., 1936, Mineral deposits of the Ruby-Kuskokwim region, Alaska: U.S. Geological Survey Bulletin 864-C, p. 115-245.
Miller, M.L., and Bundtzen, T.K., 1994, Generalized geologic map of the Iditarod quadrangle, Alaska showing potassium-argon, major oxide, trace element, fossil, paleocurrent, and archeological sample localities: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-A, 48 pages; 1 sheet, scale 1:250,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)|
|Last report date||5/24/2003|