|Quadrangle map, 1:250,000-scale||MC|
|Quadrangle map, 1:63,360-scale||C-8|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is on the west side of MacDougal Creek. It is at an elevation of about 3,500 feet, 4,200 feet north of elevation 5710, and 4,000 feet southwest of elevation 5120. The site is in the SE1/4 of section 34, T. 3 S., R. 9 E. of the Copper River Meridian. This is locality 130 of MacKevett (1976) and locality 32 of MacKevett and others (1978). The location is accurate to within about 100 feet. Cobb and MacKevett (1980) included this prospect under the name 'War Eagle'.|
Geologic descriptionThis deposit consists of masses of magnetite and garnet up to 25 feet wide that are associated with sulfide-bearing diopside skarn in Triassic Chitistone Limestone adjacent to a Jurassic granodiorite pluton (Moffit and Mertie, 1923; MacKevett, 1976). The skarn assemblage includes calcite, chlorite, epidote, garnet, diopside, and quartz. The sulfide assemblage in the skarn includes pyrite, pyrrhotite, and chalcopyrite. A 5-foot-long channel sample across an outcrop of massive magnetite contained 62.07 percent iron, but the total resource was estimated to be less than 10,000 tons (Van Alstine and Black, 1946). A sample of skarn contained 1,000 parts per million copper (MacKevett, 1976). The deposit was explored by a 100-foot-long adit and surface cuts.
|Geologic map unit||(-143.744284741729, 61.5597406628299)|
|Mineral deposit model||Fe skarn (Cox and Singer, 1986; model 18d)|
|Mineral deposit model number||18d|
|Age of mineralization||The Fe skarn is probably related to a Late Jurassic intrusive body.|
|Alteration of deposit||Calc-silicate replacement of limestone.|
|Workings or exploration||The deposit was explored by a 100-foot-long adit and surface cuts.|
|Indication of production||None|
|Reserve estimates||A 5-foot-long channel sample across an outcrop of massive magnetite contained 62.07 percent iron, but the total resource was estimated to be less than 10,000 tons (Van Alstine and Black, 1946).|
Additional commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve.
Cobb, E.H., and MacKevett, E.M., Jr., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the McCarthy quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-885, 156 p.
MacKevett, E.M., Jr., 1976, Mineral deposits and occurrences in the McCarthy quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-773-B, 2 sheets, scale 1:250,000.
MacKevett, E.M., Jr., Smith, J.G., Jones, D.L., and Winkler, G.R., 1978, Geologic map of the McCarthy C-8 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-1418, 1 sheet, scale 1:63,360.
Moffit, F.H., and Mertie, J.B., Jr., 1923, The Kotsina-Kuskulana district, Alaska: U.S. Geological Survey Bulletin 745, 149 p.
|Reporters||Travis L. Hudson (Applied Geology, Inc.)|
|Last report date||1/12/2003|