Falck Prospect, Copper River Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Falck Prospect	Prospect
Copper River Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Nelson and others (1985) interpret the country rocks as accreted ocean crust. Crowe and others (1992; 1993) and Sainsbury (1993) discuss the genesis of the volcanogenic massive sulfide deposits in this area. Chugach Alaska Corporation, Anchorage, Alaska has control of these lands.
Location: The Falck prospect is at an elevaation of about 2400 ft., about 0.5 mile east of Copper Mountain. It is in S1/2 sec. 36, T. 11 S., R. 8 W., of the Copper River Meridian. The location is accurate to within 1000 ft. This prospect is shown as #12 in Cobb (1972: MF-392) and as C-78 in Jansons and others (1984).
Geology: The country rocks at this prospect are mafic volcanic rocks and sedimentary rocks of the Tertiary Orca Group (Nelson and others, 1985). The deposit consists of sulfide minerals and native copper in veinlets and as disseminations in a northwest-striking, steeply-dipping shear zone in the volcanic and sedimentary rocks (Capps and Johnson, 1915). The sulfides are chalcopyrite, pyrite, pyrrhotite, and sphalerite. Analyses of chip samples contained 0.11% to 7.5% Cu, 240 ppm to 0.68% Zn, and 0.7 ppm to 18.3 ppm Ag (Jansons and others, 1984).
Workings: Capps and Johnson (1915) report a 25 ft. adit and a 15 ft. adit, along with minor surface cuts. In the 1980s only the 25 ft. adit was still accessible (Jansons and others, 1984). Analyses of chip samples contained 0.11% to 7.5% Cu, 240 ppm to 0.68% Zn, and 0.7 ppm to 18.3 ppm Ag (Jansons and others, 1984).
Age: Probably Tertiary based on the age of the host rocks.
Reserves: Inferred reserves of 200 tons @ 2.03% Cu, 0.23% Zn, 13 ppm Ag (Jansons and others, 1984).

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

Other Databases

Link to USGS - Alaska:	CV015

Other Regions, Features and Areas containing this locality

References