Kahiltna River; Sholan Bar; Round Bend Bar; Red Hill Bar; Boulder Bench Mine, Yentna District, Matanuska-Susitna Borough, Alaska, USA

Gold has also been reported in stream and bench placers on Lake Creek (TL065), which runs parallel to the Kahiltna River on its west side. See also ARDF records TY027, 028, 029 in the Tyonek quadrangle.
Location: U.S. Bureau of Mines MAS/MILS database (1998) locates this area near the confluence of Peters Creek and Kahiltna River on a circular bar in the northwest quarter of Section 14, T. 24 N., R. 9 W., of the Seward Meridian; this placer extends several hundred feet up and down stream from the coordinates given. Also shown as locality 66 by Reed and others, 1978.
Geology: At this locality Bates and Wedow (1953) report stream gravels 6 to 9 feet deep, several hundred yards wide that contain the following ore minerals in concentrate samples: cassiterite, gold, hematite, ilmenite, magnetite, monazite, platinum, scheelite, thorianite, uranothorianite. Robinson and others (1955, p. 2) report concentrates from Sholan Bar contain 0.14% U, 0.05% ThO2, 0.237% eU in concentrates and Round Bend Bar 0.08% U, 0.19% eU in concentrates. Robinson and others (1955, p. 2, 21-22) also report variable amounts of apatite, feldspar, garnet, limonite, pyroxene, quartz, sphene, spinel, tourmaline, zircon in the concentrates. A prospector's sample from a drill hole on the Kahiltna River (probably from Red Hill Bar) contained approximately 25% ilmenite, 20% monazite, 15% zircon, 15% magnetite, 5% platinum, 5% scheelite, 5% uranothorianite, 5% garnet, 3% cassiterite and 2% sphene. Gold has also been reported in stream and bench placers on Lake Creek (TL065), which runs parallel to the Kahiltna River on its west side. Also see ARDF records TY027, 028, 029 in the Tyonek quadrangle.
Workings: The drainage has been prospected and mined by various small scale surface methods.
Age: Pleistocene.

Commodities (Major) - Au; (Minor) - Fe, Pt, Sn, Th, U, W, Zr
Development Status: Undetermined.
Deposit Model: Placer Au-PGE (Cox and Singer, 1986; model 39a).

References:
Bates, R.G., and Wedow, Helmuth, Jr., 1953, Preliminary summary review of thorium-bearing mineral occurrences in Alaska: U.S. Geological Survey Circular 202, 13 p. Brooks, A.H., 1918, Mineral resources of Alaska, 1916: U.S. Geological Survey Bulletin 662, 469 p. Brooks, A.H., 1919, Alaska's mineral supplies: U.S. Geological Survey Bulletin 666-P, p 89-102. Brooks, A.H., 1921, The future of Alaska mining, in Martin, G.C., and others, Mineral resources of Alaska, 1917: U.S. Geological Survey Bulletin 714-A, p. 5-57. C.C. Hawley and Associates, Inc., 1978, Mineral appraisal of lands adjacent to Mt. McKinley National Park, Alaska: U.S. Bureau of Mines Open-File Report 24-78, 277 p., 12 sheets. Capps, S.R., 1912, Gold placers of the Yentna district: U.S. Geological Survey Bulletin 520-F, p. 174-200. Capps, S.R., 1913, The Yentna district, Alaska: U.S. Geological Survey Bulletin 534, 75 p. Clark, A.L., and Cobb, E.H., 1972, Metallic mineral resources map of the Talkeetna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-369, 1 sheet, scale 1:250,000. Clark, A.L., and Hawley, C.C., 1968, Reconnaissance geology, mineral occurrences, and geochemical anomalies of the Yentna district, Alaska: U.S. Geological Survey Open-File Report 68-35, 64 p. Cobb, E.H., and Reed, B.L., 1980, Summaries of data on and lists of reference to metallic and selected nonmetallic mineral deposits in the Talkeetna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-884, 106 p. Joesting, H.R., 1942, Strategic mineral occurences in interior Alaska: Alaska Territorial Department of Mines Pamphlet 1, 46 p. MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000. Martin, G.C., 1919, Alaska Mining Industry in 1917: U.S. Geological Survey Bulletin 692-A, p. 11-42. Mertie, J.B., Jr., 1919, Platinum-bearing gold placers of the Kahiltna Valley: U.S. Geological Survey Bulletin 692-D, p. 233-264. Mertie, J.B., Jr., 1969, Economic geology of platinum minerals: U.S. Geological Survey Professional Paper 630, 120 p. Overstreet, W.C., 1967, The geologic occurrence of monazite: U.S. Geological Survey Professional Paper 530, 327 p. Reed, B.L., Nelson, S.W., Curtin, G.C., and Singer, D.A., 1978, Mineral resources map of the Talkeetna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-D, 1 sheet, scale 1:250,000. Robinson, G. D., Wedow, Helmuth, Jr., and Lyon, J. B., 1955, Radioactivity investigations in the Cache Creek area, Yentna district, Alaska 1945: U.S. Geological Survey Bulletin 1024-A, p. 1-23. Smith, P.S., 1930, Mineral industry of Alaska in 1927: U.S. Geological Survey Bulletin 810-A, p. 1-64. Smith, P.S., 1930, Mineral industry of Alaska in 1928: U.S. Geological Survey Bulletin 813-A, p. 1-72. Smith, P.S., 1932, Mineral industry of Alaska in 1929, in Smith, P.S., and others Mineral resources of Alaska, report on progress of investigations in 1929: U.S. Geological Survey Bulletin 824-A, p. 1-81. Smith, P.S., 1933, Mineral industry of Alaska in 1930: U.S. Geological Survey Bulletin 836-A, p. 1-83. Smith, P.S., 1934, Mineral industry of Alaska in 1933: U.S. Geological Survey Bulletin 864-A, p. 1-94. Smith, P.S., 1936, Mineral industry of Alaska in 1934: U.S. Geological Survey Bulletin 868-A, p. 1-91. U.S. Bureau of Mines, 1998, Minerals Availability System/Minerals Industry Location System (MAS/MILS), Talkeetna quadrangle: Worldwide Web URL http://imcg.wr.usgs.gov/data.html.