Unnamed (west of upper North Fork Rainy Creek) (ARDF #MH151) Ag, Au, Co, Cu

Unnamed (west of upper North Fork Rainy Creek)

Occurrence, Active?

Commodities and mineralogy

Main commodities	Ag; Au; Co; Cu
Ore minerals	bornite; chalcopyrite; pyrite
Gangue minerals	calcite; garnet

Geographic location

Quadrangle map, 1:250,000-scale	MH
Quadrangle map, 1:63,360-scale	B-4
Latitude	63.3224
Longitude	-145.9683
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	This occurrence is at an elevation of 5,250 feet on a steep ridge on the west side of upper North Fork Rainy Creek. It is in the SE1/4SW1/4 section 26, T. 18 S., R. 9 E., Fairbanks Meridian. It is approximately 500 feet up-slope and northwest of locality 4 of Rose (1965); see MH150.

Geologic setting

Geologic description At this occurrence garnet-skarn-hosted massive sulfide bands as much as one meter wide by several meters long strike northwest (Rose, 1965). An Upper Triassic gabbro crops out a few meters away across talus where it intrudes the Slana Spur Formation of Pennsylvanian age (Nokleberg and others, 1991). Other sulfide bands crop out about 500 feet down-slope in a similar setting. A grab sample of massive chalcopyrite, pyrite, and bornite assayed 0.6 percent copper, 0.2 percent cobalt, and 0.9 ounce of silver per ton (Nokleberg and others, 1991).
Geologic map unit	(-145.970561274583, 63.3219821722222)
Mineral deposit model	Cu skarn (Cox and Singer, 1986; model 18b).
Mineral deposit model number	18b
Age of mineralization	Late Paleozoic or Late Triassic.
Alteration of deposit	A garnet-calcite skarn has developed at this prospect.

Production and reserves

Workings or exploration	A U.S. Geological Survey grab sample of massive chalcopyrite, pyrite, and bornite assayed 0.6 percent copper, 0.2 percent cobalt, and 0.9 ounce of silver per ton (Nokleberg and others, 1991). The occurrence may be on active claims of MAN Resources.
Indication of production	None

References

References Nokleberg, W.J., Lange, I.M., Roback, R.C., Yeend, Warren, and Silva, S.R., 1991, Map showing locations of metalliferous lode and placer mineral occurrences, mineral deposits, prospects, and mines, Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-C, 42 p., 1 sheet, scale 1:250,000. Rose, A.W., 1965, Geology and mineral deposits of the Rainy Creek area, Mt. Hayes quadrangle, Alaska: Alaska Division of Mines and Minerals Geologic Report 14, 57 p., 1 sheet, scale 1:36,000.
Reporters	W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)
Last report date	6/10/2002