Unnamed Occurrence (ARDF - GU002; southwest of Monsoon Lake), Chistochina Mining District, Matanuska-Susitna Borough, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - GU002; southwest of Monsoon Lake)	- not defined -
Chistochina Mining District	Mining District
Matanuska-Susitna Borough	Borough
Alaska	State
USA	Country

It is likely that detailed prospecting will find numerous, additional small occurrence of copper sulfide minerals in metamorphosed andesite and basalt in the area. Additional information can be obtained from Ahtna Minerals in Anchorage, Alaska.
Location: The occurrence is near the east end of a six-mile-long, east-trending ridge about 7 to 9 miles south of the Maclaren River. The occurrence is about 4 miles south-southwest of the center of Monsoon Lake. It is in the SE1/4NE1/4, section 34, T. 12 N., R. 8 W., Copper River Meridian, and is located accurately within 1000 feet.
Geology: This occurrence is near the east end of the so-called 'KFC anomalous zone', an elongated east-west zone about 10 miles long which includes the KFC prospect (GU001). This occurrence consists of rubble crop and is coincident with highly anomalous stream sediment values for copper (101-570 ppm ) reported by Castle and Degenhart (1978, figure 6) near the east end of the KFC anomalous zone. Bedrock is mainly composed of schistose basalt and andesite of the Pennsylvanian to Permian, Tetelna Formation. Work to the east of the area (Arehart, 1982) found numerous occurrences of: 1) veinlets and disseminations of bornite, chalcocite, and chalcopyrite; 2) local copper staining in epidotized volcanics; and 3) the Platypus Mountain prospect (GU003), which occurs in a felsic horizon in the volcanics.
Workings: The area was prospected on behalf of the Ahtna Native Regional Corporation in 1977 (Castle and Degenhart, 1978). An area immediately to the east was prospected by Noranda Inc. (Arehart, 1982). The exploration was only in reconnaissance.
Age: Diagenetic or epigenetic remobilization of copper and associated metals in volcanic host rocks of Pennsylvanian to Permian age. Remobilization of copper may have occurred during green-schist metamorphism in the Jurassic(?).

Commodities (Major) - Ag, Cu
Development Status: None
Deposit Model: Cyprus massive sulfide (Cox and Singer, 1986, model 24a)

Other Databases

Link to USGS - Alaska:	GU002

Other Regions, Features and Areas containing this locality

References