West Fork Prospect, Bonnifield Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
West Fork Prospect	Prospect
Bonnifield Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: The West Fork prospect is at an elevation of about 4,500 feet, in the south wall of an east-flowing branch of West Fork Little Delta River. The map site is about 4 miles southwest of the junction of Forgotten Creek, in the NW1/4 of sec. 11, T. 13 S., R. 1 E., of the Fairbanks Meridian. The location is accurate to within 0.5 mile.
Geology: The country rocks at the West Fork prospect are Upper Devonian(?) felsic metavolcanic rocks consisting of schist and phyllite, locally containing relict phenocrysts of quartz, orthoclase, and plagioclase (Wilson and others, 1998). The deposit consists of stratiform layers of massive pyrite, galena, and sphalerite, accompanied by quartz and sericite. Samples of a 20-30-centimeter-wide massive-sulfide horizon contained 3.68% lead, 4.05% zinc, 131 grams of silver per tonne and 0.38 grams of gold per tonne (www.grayd.com, 1999).
Workings: The prospect has been explored by surface sampling, geophysical work, and one drill hole (Inmet Mining, personal communication, 1999). Samples of a 20-30-centimeter-wide massive-sulfide horizon contained 3.68% lead, 4.05% zinc, 131 grams of silver per tonne and 0.38 grams of gold per tonne (www.grayd.com, 1999).
Age: Mineralization was probably syngenetic with the Upper Devonian(?) host rocks.
Alteration: Quartz and sericite.

Commodities (Major) - Ag, Pb, Zn; (Minor) - Cu
Development Status: None
Deposit Model: Kuroko massive sulfide (Cox and Singer, 1986; model 28a)

Other Databases

Link to USGS - Alaska:	HE120

Other Regions, Features and Areas containing this locality

References