|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||B-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect area is centered near the southwest end of a small ridge above the divide between North Fork and West Fork Rainy Creek. It is at an elevation of about 4,900 feet in the SE1/4NE1/4 section 34, T. 18 S., R. 9 E., Fairbanks Meridian. It corresponds to locality 5 of Rose (1965), locality 3 of Cobb (1979 [OFR 79-238]), and locality S61 in table 2 of Nokleberg and others (1991).|
The rocks in the prospect area are amphibole 'serpentinite' intruded by two main varieties of gabbro: dark, fine-grained, unmineralized gabbro, and dikes, pods, and plugs of a light-colored propylitically altered and mineralized leucogabbro (Rose, 1965).The mineralization consists of chalcopyrite and pyrite in fractures in shear zones and as disseminations. The gabbro is Late Triassic; it intrudes the Slana Spur Formation of Pennsylvanian age (Nokleberg and others, 1991). The shear zones strike northeast and range to as much as a meter wide and several meters long. A composite surface sample of the mineralized gabbro assayed 1.0 percent copper, 0.01 ounce of gold per ton, and 0.22 ounce of silver per ton (Rose, 1965). A U.S. Geological Survey grab sample contained 6.0 percent copper and 0.017 ounce of gold per ton (Nokleberg and others, 1991).
|Geologic map unit||(-145.987861163904, 63.3129815230303)|
|Mineral deposit model||Porphyry Cu (Cox and Singer, 1986; model 17).|
|Mineral deposit model number||17|
|Age of mineralization||Late Triassic.|
|Alteration of deposit||The propylitically altered gabbro contains saussuritized and albitized plagioclase, and the mafic minerals are altered to actinolite (Rose, 1965).|
|Workings or exploration||
Workings include several pits and trenches and an undetermined number of drill holes completed in 1974 (W.T. Ellis, oral communication, 1996). A composite surface sample of the mineralized gabbro assayed 1.0 percent copper, 0.01 ounce of gold per ton, and 0.22 ounce of silver per ton (Rose, 1965). A U.S. Geological Survey grab sample contained 6.0 percent copper and 0.017 ounce of gold per ton (Nokleberg and others, 1991).The occurrence is on active claims of MAN Resources.
|Indication of production||None|
Additional commentsA sulfur isotope analysis by American Copper and Nickel returned a Del S34 value of 0 (W.T. Ellis, oral communication, 1996). A zero value suggests that the mineralization is probably primary magmatic in origin.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-238, 140 p.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.
Mulligan, J.J., 1974, Mineral resources of the Trans-Alaska Pipeline corridor: U.S. Bureau of Mines Information Circular 8626, 24 p., 9 sheets, scale 1:250,000.
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|