Unnamed Occurrence (ARDF - ID074; east of Dishna River), Iditarod Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - ID074; east of Dishna River)	- not defined -
Iditarod Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: 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.
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.

Other Databases

Link to USGS - Alaska:	ID074

Other Regions, Features and Areas containing this locality

References