|Quadrangle map, 1:250,000-scale||SM|
|Quadrangle map, 1:63,360-scale||D-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||About 0.8 miles of Crooked Creek above the mouth of Crevice Creek have been mined in the Sleetmute quadrangle. The placer extends upstream for another 6 miles into the Iditarod quadrangle. The placer in the Sleetmute quadrangle extends through the east half of section 16, T. 22 N., R. 49 W. The coordinates are the center of the placer in the Sleetmute quadrangle. The mine is locality 1 of Miller and others (1989). The location is accurate.|
The Crooked Creek placer deposit is a southern extension of the gold placer deposits in Donlin Creek in the Iditarod quadrangle (ARDF ID176; Bundtzen Miller, and Hawley, 2004) About 1 mile of the placer is in the Sleetmute quadrangle; the rest is in the Iditarod quadrangle.The Crooked Creek placer above the mouth of Crevice Creek in the Sleetmute quadrangle consists of an ancestral alluvial terrace deposit that is a southerly extension of the 'Donlin Bench' (Cady and others, 1955). This gold-bearing bench is approximately 20 feet above the present stream level; it is up to 1 mile long and there is 10 to 100 feet of gravel over bedrock. Gold was mainly concentrated where gulches flow into Crooked Creek; thus mining was mainly in zones about 300 to 600 feet long and 300 to 450 feet wide at the mouth of Crevice Creek and just below Anaconda Creek. The principal heavy minerals recovered during placer mining are gold, cinnabar, arsenopyrite, and a trace of cassiterite. According to Bundtzen and others (1987), at least 4,200 ounces of gold and 120 ounces of silver were recovered from Crooked Creek in both the Sleetmute and Iditarod quadrangles from 1911 to 1956. However, the amount mined in the Sleetmute quadrangle alone is not known.
|Geologic map unit||(-158.260297513998, 61.9946643046667)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Tertiary or early Quaternary; based on similarities with other dated placers in interior Alaska (Hopkins and others, 1971; Hamilton, 1994).|
|Alteration of deposit||None.|
|Workings or exploration||Placer deposits were discovered on Crooked Creek in 1910 and production began in 1911 (Cady and others, 1955; Cobb, 1972, [MF 368]). Exploration and development cuts were first made by horse and scraper and then by diesel-driven machinery (Maddren, 1911 and 1915; Brooks, 1912; Mertie, 1936; Cady and others, 1955).|
|Indication of production||Yes|
|Production notes||Old, heavily vegetated, filled pits and bulldozer cuts that were observed in 1984 (T.K. Bundtzen, unpublished field data) indicate that the last placer mining in Crooked Creek took place many years previously. According to Bundtzen and others (1987), at least 4,200 ounces of gold and 120 ounces of silver were recovered from Crooked Creek in both the Sleetmute and Iditarod quadrangles from 1911 to 1956. However, the amount mined in the Sleetmute quadrangle alone is not known.|
Brooks, A.H., 1912, The mining industry in 1911, in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1911: U.S. Geological Survey Bulletin 520-A, p. 17-44.
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., and Hawley, C.C., 2004, Alaska Resource Data File (ARDF) for the Iditarod Quadrangle: U.S. Geological Survey Open File Report 2004-1311.
Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, The central Kuskokwim region, Alaska: U.S. Geological Survey Professional Paper 268, 132 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Sleetmute quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-368, 1 sheet, scale 1:250,000.
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Dillingham, Sleetmute, and Taylor Mountains quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-606, 92 p.
Hamilton, T.D., 1994, Late Cenozoic glaciation of Alaska, in, Plafker, G., and Berg, H.C., eds., The Geology of Alaska: Boulder, Colorado, Geological Society of America, The Geology of North America, v. G-1, p. 813-844.
Hopkins, D.M., Matthews, J.V., Wolfe, J.A., and Silberman, M.L., 1971, A Pliocene flora and insect fauna from the Bering Sea region: Paleoecology, vol. 9, p. 211-231.
Maddren, A.G., 1911, Gold placer mining developments in the Innoko-Iditarod region: U.S. Geological Survey Bulletin 480-I, p. 236-270.
Maddren, A.G., 1915, Gold placers of the lower Kuskokwim, with a note on copper in the Russian Mountains: U.S. Geological Survey Bulletin 622-H, p. 292-360.
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., Belkin, H.E., Blodgett, R.B., Bundtzen, T.K., Cady, J.W., Goldfarb, R.J., Gray, J.E., McGimsey, R.G., and Simpson, S.L., 1989, Pre-field study and mineral resource assessment of the Sleetmute quadrangle, southwestern Alaska: U.S. Geological Survey Open-File Report 89-363, 115 p., 3 plates, scale 1:250,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)|
|Last report date||5/3/2003|