Unnamed Occurrence (ARDF - ID063; upper South Fork; Otter Creek), Iditarod Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - ID063; upper South Fork; Otter Creek)	- not defined -
Iditarod Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is on a southwest-facing ridge that overlooks the head of the North Fork of Otter Creek. It is about 1.3 mile northeast of hill 1861 and 0.8 mile west-northwest of hill 1953. The prospect is at an elevation of about 1,700 feet near the center of section 2, T. 28 N., R. 45 W., of the Seward Meridian. The location is accurate.
Geology: This occurrence is part of a gossan about a mile long that is developed on sulfide-bearing sandstone and siltstone of the Upper Cretaceous, Kuskokwim Group (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005). The gossan contains zones of quartz veinlets, silica-carbonate alteration in altered mafic dikes, and iron-oxide-cemented sandstone breccias. The orientation of the zone is uncertain. Grab samples contain up to 200 parts per billion (ppb) gold, 1,000 ppb silver, 1,900 parts per million (ppm) arsenic, 3,300 ppb mercury, 116 ppm antimony, and 300 ppm zinc (McGimsey and others, 1988).
Workings: Surface samples were collected by the Alaska Division of Geological and Geophysical Surveys and the U.S. Geological Survey in 1986 (McGimsey and others, 1988).
Age: Unknown; altered dikes have not been dated.
Alteration: Silica-carbonate alteration in mafic dikes.

Commodities (Major) - Ag, Au; (Minor) - As, Hg, Sb, Zn
Development Status: None
Deposit Model: Hot springs gold-silver? (Cox and Singer, 1986; deposit model 25a).

Other Databases

Link to USGS - Alaska:	ID063

Other Regions, Features and Areas containing this locality

References