Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Ore minerals chalcopyrite

Geographic location

Quadrangle map, 1:250,000-scale LC
Quadrangle map, 1:63,360-scale D-1
Latitude 60.8
Longitude -153.2
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 setting

Geologic description

Skarn 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).

Production and reserves

Workings or exploration Unknown
Indication of production None
Reserve estimates No reserves
Production notes No production

Additional comments

MAS/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).


MRDS Number A106359


Reporters D.P. Bickerstaff (USGS)
Last report date 6/15/1998