|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||A-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is southeast of the terminus of the glacier at the the head of West Fork Chistochina River and at an elevation of about 4,100 feet. It is in the W1/2NE1/4 section 13, T. 20 S., R. 14 E., Fairbanks Meridian. The occurrence corresponds to locality 9 on figure 1 of Rose (1967) and locality 2 on figure 6 of Cobb (1979 [OFR 79-238]). The location is probably accurate within 1,000 feet.|
Geologic descriptionThe rocks near this site are andesite of the Slana Spur Formation of Pennsylvanian to Permian age (Richter and Dutro, 1975). The andesite is intruded by Mesozoic (?) quartz monzonite and is partly replaced by pods as much as 5 feet wide that have abundant chalcopyrite, pyrite, and magnetite in a gangue of quartz, epidote, chlorite, and an unspecified carbonate mineral (Rose, 1967). Rose found a boulder near the site that contained rhodonite, rhodochrosite, and quartz but could not determine if it was locally derived or transported.
|Geologic map unit||(-144.975223216969, 63.1840992691218)|
|Mineral deposit model||Cu skarn (Cox and Singer, 1986; model 18b).|
|Mineral deposit model number||18b|
|Age of mineralization||Possibly Mesozoic, on the basis of the association with a quartz monzonite pluton of that age.|
|Alteration of deposit||Replacement of andesite by masses of skarn-like pyrite-chalcopyrite-magnetite accompanied by chlorite, epidote, quartz, and a carbonate mineral.|
|Workings or exploration||The natural exposure of mineralized andesite is in an abandoned stream channel; the occurrence was not found during the investigations of I.M. Lange and W.J. Nokleberg in 1979 and 1980.|
|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.
Richter, D.H., and Dutro, J.T., Jr., 1975, Revision of the type Mankomen Formation (Pennsylvanian and Permian), Eagle Creek area, eastern Alaska Range, Alaska: U.S. Geological Survey Bulletin 1395-B, p. B1-B25.
|Reporters||W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)|
|Last report date||6/27/2003|