|Quadrangle map, 1:250,000-scale||ID|
|Quadrangle map, 1:63,360-scale||C-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is on the summit of a north-trending ridge about 5 miles east of the Dishna River and 0.7 mile southeast of hill 1335. It is at an elevation of about 1,500 feet, about 0.2 mile east of the center of section 34, T. 31 N., R. 43 W., of the Seward Meridian. The location is accurate.|
Geologic descriptionThis 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.
|Geologic map unit||(-157.315381551735, 62.7337272386812)|
|Mineral deposit model||Pyrolusite in quartz vein.|
|Age of mineralization||Younger than the Upper Cretaceous host rock.|
|Alteration of deposit||Mafic dike is altered to silica and carbonate minerals.|
|Workings or exploration||The Alaska Division of Geological and Geophysical Surveys sampled this occurrence in 1983 (Bundtzen, Laird, and Lockwood, 1988).|
|Indication of production||None|
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.
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of Geological and Geophysical Surveys Public Data File Report 88-19, 45 p., 1 sheet, scale 1:63,360 scale (largely superseded by DGGS Geologic Report 97, Bundtzen and others, 1992).
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.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)|
|Last report date||5/18/2003|