Cube; Three-In-One Mine, Prince William Sound Mining District, Valdez-Cordova Census Area, Alaska, USAi

Regional Level Types
Cube; Three-In-One Mine	Mine
Prince William Sound Mining District	Mining District
Valdez-Cordova Census Area	Census Area
Alaska	State
USA	Country

Location: This mine is about one-half mile east of Shoup Bay and one-third mile southwest of peak 2733; it is at an elevation of about 1,500 feet in the NW1/4 section 31, T. 8 S., R. 7 W., of the Copper River Meridian. This mine is probably located to within one-quarter mile. It is locality 17 of Cobb and Matson (1972) and locality 14 of Winkler and others (1981 [OFR 80-892-B]).
Geology: A gold-bearing quartz vein cuts metaflysch of the Valdez Group at the Cube mine (Johnson, 1915). The mineralized zone trends northwest, dips from 50 degrees south to vertical, and is reported to have been traced for a few thousand of feet of strike length. The quartz vein varies from 3 to 10 feet thick, averages about 2 feet in thickness, and contains gold, arsenopyrite, galena, chalcopyrite, and sphalerite (Johnson, 1915). This deposit was developed by two adits, one 900 feet long and one 400 feet long, that were connected by a 160-foot raise. The Cube mine produced 73 ounces of gold (Jansons and others, 1984). A U.S. Bureau of Mines grab sample from this area contained 0.031 ounce of gold per ton and 2.1 ounces of silver per ton (Jansons and others, 1984). The Cube vein is probably similar to other gold-bearing quartz veins cutting metaflysch of the Valdez Group in the southern Valdez quadrangle. Data summarized by Goldfarb and others (1997) show that gold-bearing quartz veins in the Valdez Group commonly contain pyrite, arsenopyrite, carbonate minerals, chlorite, and white mica and formed from water-rich fluids with 5 to 15 mole percent CO2 and significant amounts of CH4, N2, and H2S. The vein-forming fluid salinities were less than 8 percent, vein formation temperatures ranged from 225 to 375 degrees centigrade, and emplacement depths varied from 3 to 10 kilometers. The vein-forming fluids were produced by metamorphic devolatization reactions. Radiometric dating indicates that the veins formed from 57 to 49 Ma (Goldfarb and others, 1997, p. 171), when deep parts of the accreted Valdez Group flysch underwent high-grade metamorphism and partial melting (Hudson, 1994).
Workings: This deposit was developed by two adits, one 900 feet long and one 400 feet long, that were connected by a 160-foot raise.
Age: Radiometric dating indicates that the gold-bearing quartz veins in the Valdez Group formed from 57 to 49 Ma (Goldfarb and others, 1997, p. 171), when deep parts of the accreted Valdez Group flysch underwent high-grade metamorphism and partial melting (Hudson, 1994).
Alteration: Country rocks to gold-bearing quartz veins in Valdez Group metaflysch can be variably silicified, carbonitized, and sericitized (Goldfarb and others, 1997).
Production: The Cube mine produced 73 ounces of gold (Jansons and others, 1984).

Commodities (Major) - Au; (Minor) - Cu, Pb, Zn
Development Status: Yes; small
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Other Databases

Link to USGS - Alaska:	VA111

Other Regions, Features and Areas containing this locality

References