Rambler

Prospect, Probably inactive

Alternative names

Rambler Gold Mining Co.

Commodities and mineralogy

Main commodities Au
Ore minerals arsenopyrite; gold; pyrite
Gangue minerals carbonate minerals; chlorite; quartz; sericite

Geographic location

Quadrangle map, 1:250,000-scale VA
Quadrangle map, 1:63,360-scale A-7
Latitude 61.2074
Longitude -146.6222
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is about 1.3 miles southeast of Mount Cameron. It is at an elevation of about 3,400 feet in the center of W1/2 section 2, T. 8 S., R. 8 W., of the Copper River Meridian. This prospect is probably located to within one-quarter mile. It is locality 5 of Cobb and Matson (1972).

Geologic setting

Geologic description

A gold-bearing, mineralized fault zone that averages about 1.5 feet in width cuts metaflysch of the Valdez Group (Jansons and others, 1984). The deposit was explored by two short shafts, a 227-foot long adit, and five trenches. At least one test shipment of ore was made in 1916 (Johnson, 1918). The U.S. Bureau of Mines collected three chip samples that contained as much as 0.64 ppm gold and 0.3 ppm of silver. This deposit 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 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 (-146.624253432431, 61.2068791019817)
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 deposit was explored by two short shafts, a 227-foot long adit, and five trenches; the total length of underground workings is about 400 feet (Cobb, 1979 OFR 79-1241]).
Indication of production Undetermined

References

MRDS Number A011446

References

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