Unnamed Occurrence (ARDF - ID019; west of upper Brown Creek), Innoko Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - ID019; west of upper Brown Creek)	- not defined -
Innoko Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is at an elevation of about 2,400 feet on a knob near the head of Brown Creek. It is about 0.4 mile north-northwest of hill 2665 in the SW1/4, section 23, T. 33N., R. 40W., of the Seward Meridian. The location is accurate.
Geology: This occurrence consists of a pod of pyrrhotite in dense hornfels, about 650 feet from the east contact of the Cretaceous, Beaver Mountains pluton. The pod is poorly exposed. From rubble scattered across the hillside, the pod is is estimated to be 6 feet thick and 90 feet long. Two grab samples contained an average of about 20 percent iron, 1.0 parts per million (ppm) silver, 200 ppm copper, and 40 ppm antimony (Miller and Bundtzen, 1994; Miller, Bundtzen, and Gray, 2005).
Workings: The occurrence was mapped and sampled by the Alaska Division of Geological and Geophysical Surveys in 1979 (Bundtzen and Laird, 1982).
Age: Probably related to the Beaver Mountains pluton which has been dated at 70.1 Ma. (Bundtzen and Laird, 1982).
Alteration: In hornfels near contact of granitic pluton.

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

Other Databases

Link to USGS - Alaska:	ID019

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References