Gold King

Mine, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Cu; Pb; Zn
Ore minerals arsenopyrite; chalcopyrite; galena; gold; pyrite; sphalerite; stibnite
Gangue minerals carbonate minerals; chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale A-8
Latitude 61.2071
Longitude -146.7329
Nearby scientific data Find additional scientific data near this location
Location and accuracy This mine is 1.7 miles west of Mount Cameron on the east end of a nunatak in the eastern part of Columbia Glacier; it is at an elelvation of about 3,600 feet in the NW1/4 of section 6, T. 8 S., R. 8 W., of the Copper River Meridian. This mine is located to within one-quarter mile. It is locality 2 of Cobb and Matson (1972) and locality 2 of Winkler and others (1981 [OFR 80-892-B]).

Geologic setting

Geologic description

The Gold King mine consists of gold-bearing quartz veins that cut metaflysch of the Valdez Group (Johnson, 1915). The principal vein strikes northwest and dips 50 to 60 degrees south; it is as much as a few feet thick but averages about one foot in thickness. Gouge is developed along one wall and merges into quartz stringer zones in shattered metagraywacke. The quartz veins contain calcite, a cream-colored carbonate mineral, and about 3 per cent sulfides including pyrite, galena, chalcopyrite, sphalerite, and stibnite (Johnson, 1915). The veins were developed by three adits and more than 2,000 feet of underground workings (Johnson, 1915; Cobb, 1979 [OFR 79-1241]; Jansons and others, 1984). A mill was installed on site. and total reported production between 1911 and 1922 was 1,997 ounces of gold and 187 ounces of silver from 1,560 tons of ore (Hoekzema and others, 1986). The average grade indicated by this production is about 1.3 ounces of gold per ton. The U.S. Bureau of Mines collected five chip samples from the area of these deposits that contained 0.09 to 3.4 ppm gold and 0.1 to 1.3 ppm silver; two grab samples contained 4.85 and 45.62 ounces of gold and 1.0 to 1.7 ounces of silver per ton. Six other samples contained as much as 9 ppm gold (Pickthorn, 1982).
These deposits 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 (-146.734973003312, 61.2065760014028)
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 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 The veins were developed by three adits and more than 2,000 feet of underground workings (Johnson, 1915; Cobb, 1979 [OFR 79-1241]; Jansons and others, 1984).
Indication of production Yes; small
Production notes A mill was installed on site, and the total reported production between 1911 and 1922, was 1,997 ounces of gold and 187 ounces of silver, from 1,560 tons of ore (Hoekzema and others, 1986). The average grade indicated by this production is about 1.3 ounces of gold per ton.

References

References

Goldfarb, R.J., Miller, L.D., Leach, D.L., and Snee, L.W, 1997, Gold deposits in metamorphic rocks in Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 151-190.
Hudson, T.L., 1994, Crustal melting events in Alaska, in Plafker, G., and Berg, H. C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, Vol. G-1, p. 657-670.
Pickthorn, W.J., 1982, Stable isotope and fluid inclusion study of the Port Valdez district, southern Alaska: Los Angeles, University of California at Los Angeles, M.S. thesis, 66 p.
Reporters Travis L. Hudson
Last report date 12/14/2001