Unnamed Occurrence (ARDF - NM050; hill 1690), Nome Mining District, Nome Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - NM050; hill 1690)	- not defined -
Nome Mining District	Mining District
Nome Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is on the north-facing slope of hill 1690 (locally called Copper Mountain) at an elevation of 1,150 feet. It is 0.8 mile south of the Nome-Taylor road near the divide between the Nome River and Salmon Lake drainages. It is locality 26 of Hummel (1962 [MF 248]).
Geology: Hummel (1962 [MF 248]) noted that scheelite is present at this locality. The scheelite could be in veins crosscutting the metamorphic host rocks or in older pre-metamorphic tactite deposits (see NM027, NM035, NM041, and NM044). Bedrock in the area is primarily calc-schist with some chloritic and mafic schist, marble, and small orthogneiss bodies (Thurston, 1985, figure 3A). An orthogneiss body 4.5 miles to the northeast has been determined to have a 678 Ma protolith age (Amato and Wright, 1998). The metamorphic rocks are part of the Nome Group and derived from Precambrian to early Paleozoic protoliths (Till and Dumoulin, 1994). The Nome Group underwent regional blueschist facies metamorphism in the Late Jurassic or Early Cretaceous (Sainsbury, Coleman, and Kachadoorian, 1970; Forbes and others, 1984; Thurston, 1985; Armstrong and others, 1986; Hannula and McWilliams, 1995). The blueschist facies rocks were recrystallized to greenschist facies or higher metamorphic grades in conjunction with regional extension, crustal melting, and magmatism in the mid-Cretaceous (Hudson and Arth, 1983; Miller and Hudson, 1991; Miller and others, 1992; Dumitru and others, 1995; Hannula and others, 1995; Hudson, 1994; Amato and others, 1994; Amato and Wright, 1997, 1998). Lode gold mineralization (and related quartz-scheelite veining) on Seward Peninsula is mostly related to the higher temperature metamorphism in the mid-Cretaceous (Apodoca, 1994; Ford, 1993 [thesis]; Ford and Snee, 1996; Goldfarb and others, 1997). A late Proterozoic age, however, is possible for scheelite tactite deposits affiliated with orthogneiss.
Workings: Some small prospecting pits may be present.
Age: Late Proterozoic, early Paleozoic, or mid-Cretaceous.

Commodities (Major) - W
Development Status: None
Deposit Model: Scheelite in veins or disseminated in metamorphic rocks.

Other Databases

Link to USGS - Alaska:	NM050

Other Regions, Features and Areas containing this locality

References