Unnamed Occurrence (ARDF - EA126; Walker Fork), Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - EA126; Walker Fork)	- not defined -
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is located at water level at the apex of a sharp bend of the Walker Fork of the Fortymile River in section 28, T. 27 N., R. 19 E., of the Copper River Meridian. The location is accurate.
Geology: This occurrence is in a hornblende-biotite granodiorite of the Walker Fork pluton. Biotite from the pluton gives a 40Ar/39Ar plateau age of 99.0 +/- 0.5 Ma (Layer and others, 2002). The pluton is left-laterally offset about one-half mile by a northeast-trending high-angle fault (Werdon and others, 2001). A prominent circular magnetic low along the fault is present in airborne geophysical survey data (Alaska Division of Geological and Geophysical Surveys and others, 1999). The magnetic low corresponds to an area of extensive shearing. The granodiorite is partially altered to chlorite, clay, and calcite. Altered granodiorite that is cut by limonite and quartz veins with ankerite(?) and calcite contains as much as 55 ppb gold (Szumigala and others, 2000).
Age: Associated with a fault that offsets the Walker Fork pluton of Cretaceous age.
Alteration: The granodiorite is partially altered to chlorite, clay, and calcite.

Commodities (Major) - Au
Development Status: None
Deposit Model: Shear zone-hosted lode gold.

Other Databases

Link to USGS - Alaska:	EA126

Other Regions, Features and Areas containing this locality

References