Unnamed Prospect (ARDF - MH145; northeast side of West Fork Rainy Creek), Delta River Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Prospect (ARDF - MH145; northeast side of West Fork Rainy Creek)	- not defined -
Delta River Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: This prospect is at an elevation of about 4,200 feet on the north side of West Fork Rainy Creek. It is in the NW1/4NW1/4 section 2 T. 19 S., R. 9 E., Fairbanks Meridian. This site corresponds to locality 7 of Rose (1965) and locality S67 in table 2 of Nokleberg and others (1991).
Geology: Chalcopyrite and oxide-copper minerals occur in two skarn bodies (Rose, 1965). One skarn consists of pyrite, chalcopyrite, magnetite, garnet pyroxene, and quartz in cherty limestone that strikes N75E and dips 68SE. The other skarn consists of amphibole, epidote, and calcite adjacent to a gabbro dike about 150 feet downstream. The limestone is part of the Slana Spur Formation of Pennsylvanian age (Nokleberg and others, 1991). The gabbro could be associated with an Upper Triassic ultramafic-mafic intrusive complex (W.T. Ellis, oral communication, 1996). Rose (1965) collected a sample of skarn that assayed 0.42 percent copper, 0.01 ounce of gold per ton, and 0.40 ounce of silver per ton. The U.S. Geological Survey collected grab samples assaying 5.6 percent copper, 0.07 percent zinc, 0.009 ounce of silver per ton, and 0.035 ounce of gold per ton (Nokleberg and others, 1991).
Workings: Trenches and prospect pits, along with evidence of some placer gold mining, are present. Rose (1965) collected a sample of skarn that assayed 0.42 percent copper, 0.01 ounce of gold per ton, and 0.40 ounce of silver per ton. The U.S. Geological Survey collected grab samples assaying 5.6 percent copper, 0.07 percent zinc, 0.009 ounce of silver per ton, and 0.035 ounce of gold per ton (Nokleberg and others, 1984 [C 939]). The occurrence is on active claims of MAN Resources.
Age: Late Paleozoic or Triassic.
Alteration: A zone several feet wide in a cherty limestone is replaced by skarn with oxidized copper minerals (Rose, 1965).

Commodities (Major) - Ag, Au, Cu
Development Status: None
Deposit Model: Cu skarn (Cox and Singer, 1986; model 18b).

Other Databases

Link to USGS - Alaska:	MH145

Other Regions, Features and Areas containing this locality

References