Unnamed Occurrence (ARDF - MH150; west of upper North Fork Rainy Creek), Delta River Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MH150; west of upper North Fork Rainy Creek)	- not defined -
Delta River Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is at an elevation of 4,800 feet on the south side of a gully on the west side of North Fork Rainy Creek. It is in the SW1/4SE1/4 section 26, T. 18 S., R. 9 E., Fairbanks Meridian. It corresponds to locality 4 of Rose (1965) and locality S62 in table 2 of Nokleberg and others (1991).
Geology: This occurrence consists of several small sulfide lenses in hornfels near a small gabbro plug (Rose, 1965). The sulfides are mainly pyrrhotite (probably nickeliferous) partly altered to marcasite and minor amounts of chalcopyrite and pyrite. Upper Triassic leucogabbro is exposed a few hundred feet south of the mineral occurrence, which is in hornfelsed Slana Spur Formation of Pennsylvanian age (Nokleberg and others, 1991). A major fault passes a few hundred feet north of the prospect (Rose, 1965).
Workings: A sample of mineralized hornfels assayed less than 0.1 percent each of copper and nickel, 0.02 ounce of gold per ton, and 0.4 ounce of silver per ton (Rose, 1965). A U.S. Geological Survey sample assayed 0.6 percent copper, 0.2 percent cobalt, 0.004 ounce of gold per ton, and 0.09 ounce of silver per ton (Nokleberg and others, 1991). The occurrence is on active claims of MAN Resources.
Age: Late Triassic.
Alteration: The rock is epidotized and silicified pyroxene-bearing hornfels.

Commodities (Major) - Ag, Au, Cu, Ni
Development Status: No
Deposit Model: Ni-Cu-PGE in differentiated mafic-ultramafic sill.

Other Databases

Link to USGS - Alaska:	MH150

Other Regions, Features and Areas containing this locality

References