High Grade

Mine, Probably inactive

Alternative names

Golden Sunlight

Commodities and mineralogy

Main commodities Au
Other commodities Pb
Ore minerals arsenopyrite; galena; gold; limonite; pyrite
Gangue minerals carbonate minerals; chlorite; quartz; white mica

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale A-7
Latitude 61.194
Longitude -146.3404
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect, locality 26 of Cobb and Matson (1972), is near Mineral Creek about one-third mile north of the mouth of Wood Creek in section 8, T. 8 S., R. 6 W., of the Copper River Meridian. It is approximately located, perhaps within 1 mile.

Geologic setting

Geologic description

Iron-stained and gold-bearing quartz veins in shear zones cut metaflysch of the Valdez Group (Brooks, 1912; Johnson, 1915). The 2- to 3-foot-thick shear zones contain quartz-carbonate veins that are less than 3 inches thick. The veins contain pyrite and galena (Johnson, 1915). Two adits, one 60 feet long and the other 140 feet long in 1914, explored these veins (Johnson, 1915). These veins are 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 devolatilization 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).
Geologic map unit (-146.34244698771, 61.1934806423748)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization 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 of deposit Oxidation; the quartz veins are iron-stained. Country rocks to gold-bearing quartz veins in Valdez Group metaflysch can be variably silicified, carbonitized, and sericitized (Goldfarb and others, 1997).

Production and reserves

Workings or exploration Two adits, one 60 feet long and the other 140 feet long in 1914, explored these deposits (Johnson, 1915).
Indication of production Undetermined

References