Singletary-O'Neill

Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Pb; Zn
Ore minerals arsenopyrite; galena; gold; pyrite; sphalerite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale D-4
Latitude 60.9725
Longitude -148.3928
Nearby scientific data Find additional scientific data near this location
Location and accuracy The prospect is at an elevation of 900 to 1,000 feet on the south side of Harriman Fiord, about 1.5 miles northeast from the toe of Harriman Glacier. It is located in the NE1/4 section 9, T. 10 N., R. 6 E., of the Seward Meridian. The vein is exposed at 930 feet elevation. This is location 80 of MacKevett and Holloway (1977), location 126 of Cobb and Tysdal (1980), and location S-153 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The prospect is hosted in sheared sandstone and slate of the Upper Cretaceous Valdez Group (Cobb and Tysdal, 1980). Felsic dikes occur in the area (Hoekzema and Sherman, 1983). The mineralization consists of a series of subparallel, locally banded quartz-calcite veins as much as 5 feet wide that generally strike northwest and dip southwest (Hoekzema and Sherman, 1983). The veins contain arsenopyrite, galena, pyrite, sphalerite, and gold. Sulfides occur as podiform masses and disseminated grains in the veins and in the shear gouge.
The workings on the prospect consist of an open cut about 550 feet long and minor stripping (Hoekzema and Sherman, 1983). The U.S. Bureau of Mines sampled this prospect in 1981 and collected four chip samples that ranged in width from 38 to 60 inches and one grab sample. The samples contained 0.03 to 4.9 ppm gold. The best gold values (4.9 ppm gold) occurred in the 38-inch-wide chip sample, which was described as a quartz vein containing no visible sulfides (Hoekzema and Sherman, 1983).
Geologic map unit (-148.394900529419, 60.9719259896255)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Cretaceous or younger; the veins cuts rocks of the Valdez Group of Cretaceous age.

Production and reserves

Workings or exploration
The workings on the prospect consist of an open cut about 550 feet long and minor surface stripping (Hoekzema and Sherman, 1983).
The U.S. Bureau of Mines sampled this prospect in 1981 and collected 4 chip samples that ranged in width from 38 to 60 inches and one grab sample. The samples contained 0.03 ppm to 4.9 ppm gold. The best gold values (4.9 ppm gold) occurred in the 38-inch-wide chip sample, which was described as quartz vein containing no visible sulfides (Hoekzema and Sherman, 1983).
Indication of production None
Reserve estimates The U.S. Bureau of Mines estimated a geologic resource of 1,250 tons of ore having a grade of 0.1 ounce of gold per ton and 0.1 ounce of silver per ton (Hoekzema and Sherman, 1983).

References