Unnamed Occurrence (ARDF - NB005; east of Mentasta Lake), Tok Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - NB005; east of Mentasta Lake)	- not defined -
Tok Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is 3,500 feet east of the Mentasta Lodge on the Glenn Highway. It is at an elevation of about 3,000 feet in the SW1/4 of section 23, T. 13 N., R. 9 E. of the Copper River Meridian. This is locality 7 of Richter (1967) and locality 3 of Richter and others (1975). The location is accurate within a few hundred feet.
Geology: Bornite and minor chalcopyrite fill vesicles and form irregular segregations disseminated through a 400-foot-thick section of Triassic, Nikolai Greenstone (Richter, 1967, 1976). The host metabasalt is highly epidotized and locally cut by veinlets of red jasper. The bornite is associated with calcite and epidote. A grab sample containing copper minerals assayed 1.1 percent copper, 0.02 ounce of gold per ton, and 0.02 ounce of silver per ton (Richter, 1967). Alteration and copper mineralization in Nikolai Greenstone is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic to Early Cretaceous (MacKevett and others, 1997).
Workings: There are no known workings but some surface prospecting has probably occurred.
Age: Cretaceous? Alteration and copper mineralization in the Nikolai Greenstone is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic to Early Cretaceous (MacKevett and others, 1997).
Alteration: Epidotization.

Commodities (Major) - Ag, Cu
Development Status: None
Deposit Model: Basaltic copper (Cox and Singer, 1986; model 23)

Other Databases

Link to USGS - Alaska:	NB005

Other Regions, Features and Areas containing this locality

References