Unnamed Occurrence (ARDF - MC014; lower Ptarmigan Creek), Chisana Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - MC014; lower Ptarmigan Creek)	- not defined -
Chisana Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

The locality is in the Wrangell-Saint Elias National Park and Preserve.
Location: 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.
Geology: This 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).
Age: The gabbro host rock is late Tertiary.
Alteration: Alteration in the gabbro includes abundant replacement by sericitized plagioclase and chlorite.

Commodities (Major) - Cu
Development Status: None
Deposit Model: Pyrite and chalcopyrite along fractures in gabbro

Other Databases

Link to USGS - Alaska:	MC014

Other Regions, Features and Areas containing this locality

References