Powooiliak Point

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb
Ore minerals galena
Gangue minerals calcite; pyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale SL
Quadrangle map, 1:63,360-scale C-5
Latitude 63.365
Longitude -171.296
Nearby scientific data Find additional scientific data near this location
Location and accuracy Poowooliak Point is on the southwest coast of St. Lawrence Island, 3 miles east of the mouth of the Okok River. The site is on a wave cut bench at the base of the sea cliff on the north side of Poowooliak Point. It is located within 1/4 mile and is locality 12 of Cobb (1972). Cobb (1980) summarized relevant references under the name 'Poowooliak Point'.

Geologic setting

Geologic description

Pyrite and galena are present in irregular quartz veins cutting kaolinized limonite-stained lithic tuffs. The mineralization is exposed on a wave cut bench below sea cliffs, northwest of Poowooiliak Point. This is close to the mapped contact between a Triassic to Permian age mafic assemblage and Cretaceous volcanic rocks (Patton and Csejtey, 1980). The mineralization described by Patton and Csejtey (1971) is apparently in Cretaceous volcanic rocks.
Berg and Cobb (1967, p. 9) report the presence of a 1/2 to 2 inch calcite vein containing pyrite, chalcopyrite, galena, pyrrhotite, and sphalerite in a small limestone outcrop at Cape Puguviliak (a former name for Poovooiliak Point, Cobb, 1980, p. 58). The source of this description is not identified. The mineralization described by Berg and Cobb (1967) may be in the nearby Triassic to Permian age mafic Permo-Triassic assemblage and a different occurrence than that described and sampled by Patton and Csejtey (1971).
Geologic map unit (-171.29875499066, 63.3640783299253)
Mineral deposit model Polymetallic veins? (Cox and Singer, 1986; model 22c?).
Mineral deposit model number 22c?
Age of mineralization Cretaceous or Tertiary, the age of volcanic and related hypabyssal intrusive rocks on western St. Lawrence Island (Patton and Csejtey, 1980).
Alteration of deposit The lithic tuff is kaolinized and cut by sulfide-bearing quartz veins.

Production and reserves

Indication of production None

Additional comments

Berg and Cobb (1967, p. 9) report the presence of a 1/2 to 2 inch calcite vein containing pyrite, chalcopyrite, galena, pyrrhotite, and sphalerite in a small limestone outcrop at Cape Puguviliak (a former name for Poovooiliak Point, Cobb, 1980, p. 58). The source of this description is not identified. The mineralization described by Berg and Cobb (1967) may be in the nearby Triassic to Permian age mafic Permo-Triassic assemblage and a different occurrence than that described and sampled by Patton and Csejtey (1971).

References