Unnamed Prospect (ARDF - ID038; east of upper Yankee Creek), Iditarod District, Yukon-Koyukuk Borough, Alaska, USA
This page is currently not sponsored. Click here to sponsor this page.
Geology: This prospect is in altered, quartz-feldspar porphyry dikes and sills that intrude shale and siltstone of the Upper Cretaceous, Kuskokwim Group (Bundtzen and Laird, 1983; Miller and Bundtzen, 1994). The prospect is poorly exposed and the data is based on examination of float, rubble, and geochemical anomalies in rock and soil surveys (North Star Exploration Ltd.; information brochure, 1999). The dikes and sills vary from about 15 to 100 feet thick. The intrusive rocks are cut by hairline fractures filled with quartz and very fine-grained sulfides, mainly arsenopyrite and subordinate pyrite. Iron carbonates, including siderite, are present (Galey and others, 2002). Rock samples collected from mineralized zones contain as much as 5,725 parts per billion (ppb) gold and up to 6,000 parts per million (ppm) arsenic. Soil samples contain up to 250 ppb gold (North Star Exploration, Ltd., press release, Feb. 14, 2002; S. Dashevsky and T.K. Bundtzen, unpublished data, 2002).
Workings: Most of the exploration was in 1998 and 2001 by North Star Exploration, Inc. (Hinderman and others, 1999; Galey and others, 2002; EMEX Corporation press release, February 14, 2002).
Age: Undated; the intrusion on nearby French Joe Mountain has a 40Ar/39Ar age of 71.3 Ma (T.K. Bundtzen, unpub. data, 1999).
Alteration: Phyllic and potassic alteration; secondary biotite has developed in the intrusive rocks.
Commodities (Major) - Au; (Minor) - As
Development Status: None
Deposit Model: Low sulfide gold-quartz vein or Porphyry gold-copper deposit; (Cox and Singer,
5 entries listed. 4 valid minerals.
The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Bundtzen, T.K., and Laird, G.M., 1983, Geologic map of the Iditarod D-1 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 78, scale 1:63,360. 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. Galey, J., Retherford, R., Ellis, W., Harris, R., Deane, S., and Hinderman, T., 2002, 2001 Annual report, Takotna village block: Lakewood, Colorado, North Star Exploration, Inc., AR-01-Takotna, to Doyon Limited: 29 p. 9 sheets and 4 appendices. Hinderman, T., Retherford, R., Bull, K.F., Vanderpool, T., and Bundtzen, T.K., 1999, 1998 annual report, Takotna village block: Lakewood, Colorado, North Star Exploration, Inc., AR-98-Takotna, to Doyon Limited, 57 pages, 4 sheets and 3 appendices. Hollister, V.F., 1992, On a proposed plutonic porphyry gold deposit model: Nonrenewable Resources, vol. 1, p. 293-302. 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.