Unnamed Occurrence (ARDF - ID141; southwest of Granite Mountain), Iditarod Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - ID141; southwest of Granite Mountain)	- not defined -
Iditarod Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is at an elevation of about 1,250 feet, about 5 miles southwest of the summit of Granite Mountain on a northeast-trending ridge It is about 0.8 mile east-northeast of hill 1265 and about 0.6 mile south-southwest of the center of section 2, T. 25 N., R. 41 W., Seward Meridian. The location is accurate.
Geology: This occurrence is a mineralized zone of uncertain size and orientation in iron-oxide-bearing hornfels derived from sandstone of the Upper Cretaceous, Kuskokwim Group; the hornfels is associated with a swarm of monzonite dikes (Miller and Bundtzen, 1994; Bundtzen and Miller, 1997; Miller, Bundtzen, and Gray, 2005). One grab sample of mineralization contained 2,000 parts per billion (ppb) silver, 500 parts per million (ppm) copper, 600 ppm arsenic, 50 ppm antimony, 150 ppm lead, 3.0 ppm bismuth, 20.00 percent iron, and more than 2,000 ppm boron (McGimsey and others, 1988). The iron oxides are probably an oxidization product of sulfides; the high boron content suggests that tourmaline or axinite may be present in the altered sandstone.
Workings: Samples were collected by the U.S. Geological Survey and Alaska Division of Geological and Geophysical Surveys in the 1980s (McGimsey and others, 1988).
Alteration: Iron oxide alteration.

Commodities (Major) - Ag, Cu; (Minor) - As, B, Bi, Fe, Sb
Development Status: None
Deposit Model: Polymetallic vein (Cox and Singer, 1986; model 22c).

Other Databases

Link to USGS - Alaska:	ID141

Other Regions, Features and Areas containing this locality

References