South Kodiak Island Beaches

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Cr; PGE
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale TI
Quadrangle map, 1:63,360-scale D-2
Latitude 56.98
Longitude -154.44
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site is a part of a 30-mile stretch of beach exhibiting patchy, small concentrations of finely-divided placer gold. Approximately 8 miles of this beach is within the Trinity Islands quadrangle, extending from northwest of the Low Cape triangulation station southeast to beyond Gump triangulation station (Cobb, 1972, MF 468, locality 2; Cobb, 1973, Bulletin 1374, figure 11, locality 1; MacKevett and Holloway, 1977, locality 1). Although there has been mining and prospecting activity within this section of beach, most descriptions apply to the more extensive beach to the northwest in the Karluk quadrangle (see ARDF KR030).

Geologic setting

Geologic description

Placer gold deposits on the west coast of Kodiak Island have been worked since the early 1890s (Becker, 1897, p. 86); however, mining activity has been sporadic at best. The latest reported mining or prospecting work was done by 2 men in 1950-52 (Cobb, 1973, Bulletin 1374). Cobb estimates that total gold production is probably not more than a few thousand ounces. Concentrations of gold and other heavy minerals tend to occur in small, thin patches which appear and disappear according to variability of wave action and tides. No well-defined pay streaks occur. Approximately 95 percent of these beach concentrates is magnetite; the remainder consists of pyrite, chromite, and a little gold and platinum. No estimates of gold values within these patchy zones of heavy minerals have been reported. The immediate source of the gold appears to be the nearby bluffs of glacial gravels and tills, which are constantly being eroded by wave action. The gold content of the glacial deposits is extremely low as shown by the lack of visible gold where they have been prospected.
An analysis of placer PGE concentrate from the beach (Maddren, 1919, p. 316) is as follows: 26.9 percent iridium-osmium, rhodium; 6.1 percent iridium from part of iridium-osmium; 0.1 percent rhodium from part of iridium-osmium; 55.3 percent platinum; 2.4 percent iridium; 6.4 percent iron; 0.3 percent gold; 0.7 percent rhodium; 0.1 percent palladium; 0.6 percent copper; 0.08 percent nickel; trace silver and zinc.
Geologic map unit (-154.44230468081, 56.9792175787854)
Mineral deposit model Gold-PGE placer (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary

Production and reserves

Workings or exploration These deposits have been worked sporadically using small portable rockers and sluice boxes.
Indication of production Yes; small

Additional comments

Descriptions of beach placers in the Kodiak region are so generalized that it is difficult to discern which descriptions are pertinent to any given location.

References