|Quadrangle map, 1:250,000-scale||MC|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is in outcrops on a bench on the east side of lower Ptarmigan Creek. It is at an elevation of about 3,500 feet and 9,500 feet south of Beaver Creek. The site is about 1,600 feet east-northeast of the center of section 20, T. 2 N., R. 24 E. of the Copper River Meridian. This is locality 185 of MacKevett (1976). It is probably accurate to within 1,000 feet.|
Geologic descriptionThis occurrence consists of pyrite and minor chalcopyrite that coat fracture surfaces in altered Tertiary gabbro (Knaebel, 1970; MacKevett, 1978). The alteration includes abundant replacement by sericitized plagioclase and chlorite. The closely-spaced fractures trend N 70-80 E and are commonly slickensided. The occurrence is near the faulted north contact of gabbro with Jurassic or Cretaceous siliciclastic rocks (MacKevett, 1978).
|Geologic map unit||(-141.042611796484, 61.9421716854915)|
|Mineral deposit model||Pyrite and chalcopyrite along fractures in gabbro|
|Age of mineralization||The gabbro host rock is late Tertiary.|
|Alteration of deposit||Alteration in the gabbro includes abundant replacement by sericitized plagioclase and chlorite.|
|Indication of production||None|
Additional commentsThe locality is in the Wrangell-Saint Elias National Park and Preserve.
Knaebel, Jeff, 1970, Geochemical survey and geological reconnaissance of the White River area, south-central Alaska: Alaska Division of Mines and Geology Geochemical Report 21, 60 p., 4 sheets, scale 1:63,360.
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.
|Reporters||Travis L. Hudson (Applied Geology, Inc.)|
|Last report date||1/12/2003|