Unnamed Occurrence (ARDF - ID069; upper Bonanza Creek), Iditarod District, Yukon-Koyukuk Borough, Alaska, USA
This page is currently not sponsored. Click here to sponsor this page.
Geology: This occurrence is a prominent, reddish-brown, goethite-rich gossan developed on pyrite-rich shale of the Upper Cretaceous, Kuskokwim Group (Miller and Bundtzen, 1994; Bundtzen and others, 1988; Miller, Bundtzen, and Gray, 2005). The east-west striking gossan is at least 10 feet thick and can be traced laterally for about 320 feet. A grab sample contained only slightly anomalous silver (100 ppb), mercury (300 ppb) and iron (5.88 percent), and no other metals in anomalous concentration (Bundtzen, Laird, and Lockwood, 1988).
Workings: Surface investigations were done by the Alaska Division of Geological and Geophysical Surveys in 1983 (Bundtzen and others, 1988).
Alteration: Pyrite oxidized to goethite.
Commodities (Major) - Ag; (Minor) - Fe
Development Status: None
2 entries listed. 2 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., Laird, G.M., and Lockwood, M.S., 1988, Geologic map of the Iditarod C-3 quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 96, 13 p., 1 sheet, scale 1:63,360. McGimsey, R.G., Miller, M.L., and Arbogast, B.F., 1988, Paper version of analytical results, and sample locality map for rock samples from the Iditarod quadrangle, Alaska: U.S. Geological Survey Open-File Report 88-421-A, 110 p., 1 sheet, scale 1:250,000. 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. Miller, M.L., Bundtzen, T.K., and Gray, J.E., 2005, Mineral resource assessment of the Iditarod quadrangle, west-central Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-2219-B, scale 1:250,000, pamphlet.