Williams Gentzler

Mine, Probably inactive

Alternative names

Ethel Mining Co.
Cash

Commodities and mineralogy

Main commodities Au
Other commodities Pb
Ore minerals arsenopyrite; galena; gold; pyrite; pyrrhotite
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 61.217
Longitude -146.2681
Nearby scientific data Find additional scientific data near this location
Location and accuracy This mine is on the south side of the glacier at the head of Glacier Creek. It is identified on the USGS Valdez A-7 topographic map (1996) as the Cash mine with an adit symbol. It is locality 30 of Cobb and Matson (1972).

Geologic setting

Geologic description

A gold-bearing quartz vein, 18 to 24 inches thick, cuts metaflysch of the Valdez Group (Brooks, 1912; Johnson, 1915) at this site. Sulfide minerals include pyrrhotite, pyrite, and galena (Johnson, 1915). One grab sample contained 0.24 ounce of gold per ton and and 6.8 ounces of silver per ton (Jansons and others, 1984). By 1915, the mine was developed by about 100 feet of underground workings, including a 30-foot drift along the vein that exposed a 25- to 30-foot-long ore shoot (Johnson, 1915). An arrastre was constructed, and some concentrate was recovered from riffles. Some efforts to redevelop this mine occurred in the late 1920s (Cobb, 1979 [OFR 79-1241]); the total length of underground workings is about 245 feet (Jonsons and others, 1984). This vein is probably similar to others that are widespread 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 (-146.270156123674, 61.2164825890739)
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 By 1915, the mine was developed by about 100 feet of underground workings, including a 30-foot drift along the vein that exposed a 25- to 30-foot-long ore shoot (Johnson, 1915). An arrastre was constructed, and some concentrate was recovered from riffles. Some efforts to redevelop this mine occurred in the late 1920s (Cobb, 1979 [OFR 79-1241]); the total length of underground workings is about 245 feet (Jansons and others, 1984).
Indication of production Yes; small
Production notes An arrastre was constructed, and some concentrates were recovered from the riffles. Some efforts to redevelop this mine occurred in the late 1920s (Cobb, 1979 [OFR 79-1241]).

References

MRDS Number A011471

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.
Reporters Travis L. Hudson
Last report date 12/14/2001