Unnamed Occurrence (ARDF - ID074; east of Dishna River), Iditarod District, Yukon-Koyukuk Borough, Alaska, USA
This page is currently not sponsored. Click here to sponsor this page.
Geology: This occurrence is a pyrolusite-quartz vein in breccia that cuts shale and sandstone of the Upper Cretaceous, Kuskokwim Group, near an altered mafic dike (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005). One sample of semi-massive pyrolusite in a brecciated quartz vein contained 1.58 percent manganese (Bundtzen, Laird, and Lockwood, 1988). The amount of pyrolusite in the sample suggests that the analysis understates the manganese content of the occurrence.
Workings: The Alaska Division of Geological and Geophysical Surveys sampled this occurrence in 1983 (Bundtzen, Laird, and Lockwood, 1988).
Age: Younger than the Upper Cretaceous host rock.
Alteration: Mafic dike is altered to silica and carbonate minerals.
Commodities (Major) - Mn
Development Status: None
Deposit Model: Pyrolusite in quartz vein.
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., Miller, M.L., Bull, K.F., and Laird, G.M., 1988, Geology and mineral resources of Iditarod mining district, Iditarod B-4 and eastern B-5 quadrangles, west-central Alaska: Alaska Division of Geological and Geophysical Surveys Public Data File Report 88-19, 45 p., 1 sheet, scale 1:63,360 scale (largely superseded by DGGS Geologic Report 97, Bundtzen and others, 1992). 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. 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.