Unnamed

Occurrence, Inactive

Commodities and mineralogy

Main commodities Pb; Zn
Ore minerals galena; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SL
Quadrangle map, 1:63,360-scale C-5
Latitude 63.44
Longitude -171.12
Nearby scientific data Find additional scientific data near this location
Location and accuracy This site is on an unnamed stream that flows southeast to its mouth at Poowooliak Bay on the southwest coast of St. Lawrence Island, 7 miles northeast of Poowooliak Point. The site is about 2 miles upstream of the mouth and is located within 1/2 mile. It is locality 13 of Cobb (1972) and Cobb (1980) summarized relevant references under the name 'Unnamed occurrence'.

Geologic setting

Geologic description

Galena and sphalerite are present in quartz veins cutting altered andesitic volcanic rocks (Patton and Csejtey, 1971, p. C15). One grab sample contained 150 ppm copper, 2,000 ppm lead, 3,000 ppm zinc, and 10 ppm silver (Patton and Csejtey, 1971, p. C8). Some of the nine stream sediment samples from this drainage contain anomalous metal concentrations, 2 samples have 100 and 200 ppm lead, one has 0.5 ppm silver, one has 15 ppm molybdenum, and nine contain 700 to 1,500 ppm barium (Patton and Csejtey, 1972).
Geologic map unit (-171.122750427366, 63.4390853153756)
Mineral deposit model Polymetallic veins? (Cox and Singer, 1986; model 22c?).
Mineral deposit model number 22c
Age of mineralization The andesitic volcanic rocks are mapped as part of a mid-Cretaceous assemblage of diverse lithologies and compositions, but the mineralization here could be 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 volcanic rocks here are altered but the nature of the alteration, except for the presence of quartz veins, is not described.

Production and reserves

Workings or exploration One grab sample contained 150 ppm copper, 2,000 ppm lead, 3,000 ppm zinc, and 10 ppm silver (Patton and Csejtey, 1971, p. C8). Some of the nine stream sediment samples from this drainage contain anomalous metal concentrations, 2 samples have 100 and 200 ppm lead, one has 0.5 ppm silver, one has 15 ppm molybdenum, and nine contain 700 to 1,500 ppm barium (Patton and Csejtey, 1972).
Indication of production None

References