Stebbins

Prospects, Inactive

Alternative names

and unnamed (on Percy and Cow Islands)

Commodities and mineralogy

Main commodities Fe
Ore minerals titaniferous magnetite

Geographic location

Quadrangle map, 1:250,000-scale PR
Quadrangle map, 1:63,360-scale D-5
Latitude 54.951
Longitude -131.592
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site represents the locations of three prospects for iron minerals in ultramafic rocks on the the Percy Islands (Sec 8, T. 80 S., R. 92 E., of the Copper River Meridian), Cow Island (Sec 5, T. 80 S., R. 92 E., of the Copper River Meridian), and an adjacent island (Stebbins, Sec 7, T. 80 S., R. 92 E.) for which there either are U.S. Bureau of Mines (1974) claim records, or other published descriptions (Taylor and Noble, 1960; Elliott and others, 1978, locs. 156-158; Cobb and Elliott, 1980, p. 141). The coordinates are for the approximate center of the estimated 6-square-mile outcrop area of the ultramafic rocks and are accurate within about 0.1 mile.

Geologic setting

Geologic description

The Percy Islands, Cow Island, and adjacent islands (Taylor and Noble, 1960, p. 181; Berg and others, 1988) are underlain by metamorphosed undivided Silurian or Ordovician intermediate and mafic intrusive rocks, and by a Cretaceous ultramafic complex, which intrudes the metamorphic rocks. The ultramafic complex consists of olivine pyroxenite with a border zone of hornblende pyroxenite, which in turn is surrounded by gabbro.
The hornblende pyroxenite contains titaniferous magnetite, whose abundance and distribution probably is similar to that on Duke Island (ARDF PR001). A prospect on the Percy Islands has been drilled by private interests, but no data on potential iron resources have been made public.
Geologic map unit (-131.59367600955, 54.9506621059059)
Mineral deposit model Alaska PGE (Cox and Singer, 1986; model 9).
Mineral deposit model number 9
Age of mineralization Cretaceous.

Production and reserves

Workings or exploration A prospect on the Percy Islands has been drilled by private interests, but no data on potential iron resources have been made public.
Indication of production None

References