|Quadrangle map, 1:250,000-scale||SL|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site is on a wave cut bench and adjacent tidal zone about 1/2 mile west of the mouth of the Okok River on the southwest coast of St. Lawrence Island. It is located within 1/4 mile and is locality 11 of Cobb (1972). Cobb (1980) summarized relevant references under the name 'Unnamed occurrence'.|
Geologic descriptionFine-grained gabbro, exposed on the wave cut bench here, is cut by a 1- to 2-inch wide calcite vein that contains galena, sphalerite, chalcopyrite, and pyrite (Patton and Csejtey, 1971, p. C15). A sample of this vein contained 1,000 ppm silver, 1 % copper, greater than 2 % lead, and greater than 1 % zinc (Patton and Csejtey, 1971, p, C8).
|Geologic map unit||(-171.373756784877, 63.3300753132744)|
|Mineral deposit model||Sulfide-bearing calcite vein in gabbro.|
|Age of mineralization||The gabbro is mapped as part of a mafic Triassic to Permian age assemblage (based on the results of two K/Ar age determinations, 221 +/- 7 and 244 +/- 7 Ma, Patton and Csejtey, 1980). However, the calcite-sulfide vein could be Cretaceous or Tertiary, the age of younger igneous rocks on western St. Lawrence Island (Patton and Csejtey, 1980).|
|Alteration of deposit||Alteration is not described.|
|Workings or exploration||A sample of this vein contained 1,000 ppm silver, 1 % copper, greater than 2 % lead, and greater than 1 % zinc (Patton and Csejtey, 1971, p, C8).|
|Indication of production||None|
Cobb, E.H., 1972, Metallic mineral resources map of the Saint Lawrence quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-465, 1 sheet, scale 1:250,000.
Cobb, E.H., 1980, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in fifteen quadrangles in southwestern and west-central Alaska: U.S. Geological Survey Open-File Report 80-909, 103 p.
Patton, W.W., Jr., and Csejtey, Bela, Jr., 1971, Preliminary geologic investigations of western St. Lawrence Island, Alaska: U.S. Geological Survey Professional Paper 684-C, p. C1-C15.
|Reporters||Travis L. Hudson (Applied Geology)|
|Last report date||9/10/1998|