|Quadrangle map, 1:250,000-scale||LC|
|Quadrangle map, 1:63,360-scale||B-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Prospect is located about 3.6 km north of the mouth of Portage Creek. Locality 23 of Nelson and others (1985) and locality 15 of MacKevett and Holloway (1977). Sec. 5, T. 3 N., R. 27 W., of the Seward Meridian. Locality accurate within 800 m.|
Only information is that lode claims (U.S. Bureau of Mines, 1973) are located along part of the Lake Clark fault.Near the claims, the fault separates metamorphic rocks of Paleozoic to Mesozoic age and Tertiary volcanic rocks. The claims appear to straddle the Lake Clark Fault and span both lithologies. According to Nelson and others (1983, unit MzPzm), metamorphosed mafic volcanic rocks are the most widespread rocks of this unit; they are aphanitic and were probably originally composed of plagioclase and pyroxene, and locally olivine and amphibole. These rocks have been altered, and they now consist mostly of chlorite, epidote, and fibrous amphibole. Other lithologies of this unit include: phyllite, schist, quartzite, marble, calc-silicate rocks, serpentinite, gabbro, and chert. Unit Tv is described by Nelson and others (1983) to include rhyolitic breccia, ash-flow tuff, flows, and intrusive rocks and subordinate mafic to intermediate flows. Potassium-argon ages for unit Tv range from 56.2 to 62.7 m.y. indicating a Tertiary age for these rocks (Eakins and others, 1978).
|Geologic map unit||(-154.012223968323, 60.3843383711559)|
|Mineral deposit model||Unknown|
|Age of mineralization||Unknown|
|Alteration of deposit||The metamorphic rocks consist mostly of chlorite, epidote, and fibrous amphibole (Nelson and others, 1983).|
|Workings or exploration||Unknown|
|Indication of production||None|
|Reserve estimates||No reserves|
|Production notes||No production|
Additional commentsSite is in Lake Clark National Park and Preserve.
Eakins, G.R., Gilbert W.G., and Buntzen, T.K., 1978, Preliminary bedrock geology and mineral resource potential of west-central Lake Clark quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 118, 15 p., 2 plates, scale 1:25,000.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.
Nelson, W.H., Carlson, C., and Case, J.E., 1983, Geologic map of the Lake Clark quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1114-A, 1 sheet, scale 1:250,000.
Nelson, W.H., King, H.D., Case, J.E., Tripp, R.B., Crim, W.D., and Cooley, E.F., 1985, Mineral resource map of the Lake Clark quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1114-B, 1 sheet, scale 1:250,000.
U.S. Bureau of Mines, 1973, Alaska 1:250,000-scale quadrangle map overlays showing mineral deposit locations, principal minerals, and number and type of claims: U.S. Bureau of Mines Open-File Report 20-73, 95 overlays (updated in 1986, 1987).
|Reporters||D.P. Bickerstaff (USGS)|
|Last report date||6/15/1998|