|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The West Crash prospect is at an elevation of about 5,330 feet, about 4.6 miles northwest of the junction of Eureka Creek and Broxson Gulch. It is about 0.6 mile west-northwest of the center of section 33, T. 18 S., R. 8 E. The location is accurate.|
The West Crash prospect is in an east-trending, northward-dipping sill of Late Triassic, ultramafic and mafic rocks that are part of the Eureka complex (Rose, 1966; Nokleberg and others, 1992 [MF]; Nokleberg and others, 1992 [Open-File]. The sill is about 100 feet thick at this prospect; it dips north about 40 degrees, and consists of differentiated pyroxenite and gabbro. The footwall of the sill is siliceous volcanic rocks; the hanging wall is argillite, slate, and graywacke. The rocks are locally iron-stained and altered with plagioclase going to saussurite and pyroxene going to actinolite. Malachite and garnierite staining is locally prominent.The West Crash prospect was found by industry in the 1990s. It was examined and sampled by the Bureau of Land Management in about 2003. Bittenbender and others (2007 ) collected four samples. Two samples of gossanous material contained up to 37 parts per billion (ppb) gold, 399 parts per million (ppm) chromium, 872 ppm copper, 4,020 ppm nickel, 118 ppb platinum, and 168 ppb palladium. The other two did not have any notable metals.
|Geologic map unit||(-146.241464561109, 63.3125772088919)|
|Mineral deposit model||Nickel-copper-PGE mineralization in a differentiated mafic-ultramafic sill.|
|Age of mineralization||Genetically related to the emplacement of a Late Triassic mafic-ultramafic complex.|
|Alteration of deposit||The ultramafic rocks rock units are moderately to strongly serpentinized. The rocks are locally iron-stained and altered with plagioclase going to saussurite and pyroxene going to actinolite. Malachite and garnierite staining is locally prominent.|
|Workings or exploration||Found by industry in the 1990s. Examined and sampled by the Bureau of Land Management in about 2003.|
|Indication of production||None|
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.
|Reporters||W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS); D.J. Grybeck (Contractor, USGS)|
|Last report date||5/13/2012|