|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||A-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site includes several outcrops of mineralized rock in the cirque of an unnamed glacier east of the Gakona Glacier. They are centered about 2.1 miles north-northeast of VABM 5206 'Ona' and about 0.2 mile north of the center of section 4, T. 20 S., R. 14 E.|
The rocks in the area consist of mafic and ultramafic intrusive rocks associated with volcanic rocks that are probably part of the Pennsylvanian to Permian, Slana Spur Formation (Rose, 1967; Nokleberg and others, 1992 [MF]; 1992 [Open-File]; 1992 [Open-File]; Bittenbender and others, 2007). The volcanic rocks are hornfelsed near the intrusive rocks. Cretaceous K/Ar dates from the mafic and ultramafic rocks probably reflect regional metamorphism and their protoliths may be Paleozoic.Numerous stream-sediment samples collected by the U.S. Geological Survey and Bureau of Land Management that contained anomalous platinum-group elements led to the search for their source (O'Leary and others, 1982; Bittenbender and others, 2003). Bittenbender and others (2007) identified several outcrops, one up to 160 feet long, of pyroxenite and peridotite with persistent but minor chalcopyrite, pyrrhotite, and pyrite. Two, 20-foot samples contained 127 and 65 parts per billion (ppb) palladium, 52 and 36 ppb platinum, 18 and 15 ppb gold, and 824 and 1,005 parts per million (ppm) copper. A sample selected for its high sulfide content contained 144 ppb palladium, 104 ppb platinum, 34 ppb gold, 1,055 ppm copper, and 34 ppm nickel. They considered the mineralization to be too low grade to account for the anomalous PGE in the geochemical samples.
|Geologic map unit||(-145.074222400607, 63.2125972500081)|
|Mineral deposit model||Disseminated chalcopyrite, pyrrhotite, and pyrite in mafic and ultramafic rocks.|
|Age of mineralization||Unclear whether the host rocks are Cretaceous or Paleozoic.|
|Alteration of deposit||Hornfelsing of volcanic rocks adjacent to mafic and ultramafic intrusive rocks.|
|Workings or exploration||Only limited sampling by state and federal agencies.|
|Indication of production||None|
Bittenbender, P.E., Bean, K.W., and Gensler, E.G., 2003, Mineral investigations in the Delta River Mining District, east-central Alaska, 2001-2001: Bureau of Land Management-Alaska Open-File Report 91, 82 p.
Bittenbender, P.E., Bean, K.W., Kurtak, J.M., and Deininger, James Jr., 2007, Mineral assessment of the Delta River Mining District area, east-central, Alaska: U.S. Bureau of Land Management, Alaska Technical Report 57, 675 p.
Nokleberg, W. J., Aleinikoff, J. N., Dutro, J. T., Lanphere, M. A., Silberling, N. J., Silva, S. R., Smith, T. E., and Turner, D. L., 1992, Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-D, 43 p., 1 sheet, scale 1:250,000.
Nokleberg, W.J., Aleinikoff, J. N., Lange, I. M.; Silva, S. R., Miyaoka, R. T., Schwab, C. E., Zehner, R. E., Bond, G. C., Richter, D. H., Smith, T. E., and Stout, J. H., 1992, Preliminary geologic map of the Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Open-File Report 92-594, 39 p. 1 sheet, 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.
O'Leary, R.M., Risoli, D.A., Curtin, G.C., Tripp, R.B., McDougal, C.M., and Huston, D.L., 1982, Final analytical results of stream-sediments, glacial debris, and non-magnetic heavy-mineral concentrate samples from the Mt. Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 82-325, 130 p., 1 sheet, scale 1:250,000.
|Reporters||D.J. Grybeck (Contractor, USGS)|
|Last report date||5/13/2012|