|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||This occurrence is at an elevation of 3,500 feet at the mouth of an east-flowing tributary to the stream(s) in Broxson Gulch, approximately in the center of the NW1/4 section 35, T. 18 S., R. 8 E., Fairbanks Meridian. The occurrence corresponds to locality 17 of MacKevett and Holloway (1977), locality 33 in figure 4 of Cobb (1979 [OFR 79-238]), and locality 3 on figure 3 of Rose (1966 [ADMM GR 20]).|
This record describes two mineral localities: asbestos in dunite, and base metals in slate near the dunite.
The asbestos deposit is in an Upper Triassic serpentinized dunite sill that can be followed for more than 5 miles (Rose, 1966 [ADMM GR 20, figure 3]). The dunite is part of the informally named Eureka ultramafic complex that occupies strands of the Broxson Gulch thrust fault (Nokleberg and others, 1991; W.T. Ellis, unpublished data, 1996). The deposit consists of chrysotile asbestos in the dunite. Rose (1966 [ADMM GR 20, p. 20]) reported 0.25-inch veinlets of chrysotile in bedrock at the site and found prospectors' samples of larger veins nearby.Paleozoic slate near the dunite is marked by gossan that carries anomalous amounts of copper, lead, and zinc (MacKevett and Holloway, 1977, p. 37, locality 17).
|Geologic map unit||(-146.169464018488, 63.315078486535)|
|Mineral deposit model||Serpentinite-hosted asbestos (Cox and Singer,1986; model 8d). The base metal-bearing gossan in slate may be a sedimentary-exhalative deposit.|
|Mineral deposit model number||8d|
|Age of mineralization||The dunite host of chrysotile is of Late Triassic age; the chrysotile may have formed during Cretaceous faulting and regional metamorphism (Nokleberg and others, 1991). The base metal-bearing gossan in slate is Paleozoic or younger.|
|Workings or exploration||The occurrence is on active MAN Resources claims.|
|Indication of production||None|
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.
Nokleberg, W.J., Albert, N.R.D., Bond, G.C., Herzon, P.L., Miyaoka, R.T., Nelson, W.H., Richter, D.H., Smith T.E., Stout, J.H., Yeend, Warren, and Zehner, R.E., 1982, Geologic map of the southern Mount Hayes quadrangle, Alaska: U.S. Geological Survey Open-File Report 82-52, 27 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 Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)|
|Last report date||6/18/2001|