|Quadrangle map, 1:250,000-scale||HU|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Black Creek placer mine is about 4.5 miles west-northwest of the summit of Indian Mountain. The creek flows northeast for about 2 miles where it joins the Indian River. The area of placer mining on Black Creek extends for about 0.8 miles above its mouth. The coordinates are near the midpoint of placer mining. The location is accurate. May be the same as Synder Creek (See HU024).|
Geologic descriptionPlacer mining began on Black Creek about 1913. The gold-bearing gravels are about 12 feet wide and the depth to bedrock about 20 feet. Eakin (1915) reports that the bedrock is altered Mesozoic strata near a granite pluton. According to Miller and Ferrians (1968), Black Creek flows over the contact between Cretaceous graywacke and mudstone, and Cretaceous granodiorite and quartz monzonite. Eberlein and others (1977) speculate that the gold is probably derived from this contact zone. The graywacke and mudstone have been hornfelsed by the intrusive. Gold panned from the upper reaches of Black Creek is coarse and angular (Miller and Ferrians, 1968). Kurtak and others (1999) collected samples of gravel overlying hornfels bedrock along upper Black Creek. The gravel contains up to 0.84 ounce of gold per cubic yard, 813 ppm arsenic , and more than 2,000 ppm tungsten. According to Kurtak and others (2002), the placer resource is small. The gold-bearing gravels on Black Creek are finer than those on Indian River (HU024), which contain many boulders.
|Geologic map unit||(-153.84923272115, 66.0838626899363)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a)|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Alteration of deposit||Eakin (1915) noted altered bedrock but did not describe the alteration.|
|Workings or exploration||Surface mining.|
|Indication of production||Yes|
|Production notes||Incomplete records indicate that from 1914 through 1942, at least 1,352 ounces of gold were produced from Black Creek (Kurtak and others, 2002).|
Brooks, A.H., 1916, Mineral resources of Alaska, report on progress of investigations in 1915: U.S. Geological Survey Bulletin 642, 279 p.
Cobb, E.H., 1972, Metallic mineral resources map of the Hughes quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-458, 1 sheet, scale 1:250,000.
Cobb, E.H., 1975, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in five quadrangles in west central Alaska (Hughes, Kotzebue, Melozitna, Selawik, Shungnak): U.S. Geological Survey Open-File Report 75-627, 58 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.
Eakin, H.M., 1914, Mineral resources of the Yukon-Koyukuk region: U.S. Geological Survey Bulletin 592-K, p. 371-384.
Eakin, H.M., 1916, Mineral resources of the Yukon-Koyukuk region: U.S. Geological Survey Bulletin 631, 88 p.
Eberlein, G.D., Chapman, R.M., Foster, H.L., and Gassaway, J.S., 1977, Map and table describing known metalliferous and selected nonmetalliferous mineral deposits in central Alaska: U.S. Geological Survey Open-File Report 77-168-D, 132 p., 1 sheet, scale 1:1,000,000.
Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: University of Alaska, Mineral Industry Research Laboratory Report No. 16, 306 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska: Final Report: U.S. Bureau of Land Management Technical Report 50, v. 1 and 2, 845 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Williams, E.M., 1999, Mineral investigations in the Koyukuk mining district, northern Alaska--Progress Report: U.S. Bureau of Land Management Open-File Report 74, 158 p.
Martin, G.C., 1919, Alaska Mining Industry in 1917: U.S. Geological Survey Bulletin 692-A, p. 11-42 .
|Reporters||J.M. Britton (Anchorage)|
|Last report date||8/1/2002|