|Quadrangle map, 1:250,000-scale||LC|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||On peak 4,910 in the Neacola Mountains. In Sec. 5, T. 8 N., R. 22 W., of the Seward Meridian. Accurate within 5 km.|
Geologic descriptionSkarn deposit: marble interbedded with schist, phyllite, and metamorphosed volcanic rocks in a large roof pendant in granitic rocks. Nelson and others (1983, unit Ki1) describe the granitic rocks as medium-gray, medium-grained sericitized granodiorite. Lambeth (1978) described the occurrence as several occurrences of chalcopyrite in roof pendant of interbedded limestone and andesite. Quite similar to the nearby Glacier Fork occurrence (ARDF number LC008) and another unnamed occurrence (ARDF number LC002). According to Nelson and others (1983, unit MzPzm), some of the metasedimentary rocks may correlate with the Kakhonak Complex of Permian(?), Triassic, and Jurassic age in the Iliamna quadrangle, and some may be graywacke of Jurassic and Cretaceous(?) age that has been metamorphosed by nearby plutonic rocks. Some of the metamorphosed volcanic rocks, especially in roof pendants, are probably part of the volcanic rocks of Tertiary age (Tv).
|Geologic map unit||(-153.202253144112, 60.7993711936251)|
|Mineral deposit model||Cu skarn (Cox and Singer, 1986; model 18b)|
|Mineral deposit model number||18b|
|Age of mineralization||The granodiorite associated with the skarn has a Cretaceous age. The rocks of the roof pendant range in age from Permian (?) to Tertiary (?).|
|Alteration of deposit||Plagioclase phenocrysts in the granodiorite show varying degrees of sericitization (Nelson and others, 1983).|
|Workings or exploration||Unknown|
|Indication of production||None|
|Reserve estimates||No reserves|
|Production notes||No production|
Additional commentsMAS/MILS sequence number 0020930026 (Bureau of Mines, 1995). Site is in Lake Clark National Park and Preserve. This unnamed occurrence may actually be the Glacier Fork occurrence (ARDF number LC008).
Lambeth, R.H., 1978, Mineral appraisal of certain Alaska National Interest Lands, proposed Lake Clark National Park: a summary report: U.S. Bureau of Mines Open-File Report 114-78, 18 p., 4 sheets, 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.
U.S. Bureau of Mines, 1995, Spatial data extracted from the Minerals Availability System/Minerals Industry Location System (MAS/MILS): U.S. Bureau of Mines Special Publication 12-95, CD-ROM.
|Reporters||D.P. Bickerstaff (USGS)|
|Last report date||6/15/1998|