Earth:Skoki Formation

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Skoki Formation
Stratigraphic range: Middle Ordovician ~485–470 Ma
TypeFormation
UnderliesOwen Creek Formation
OverliesOutram Formation or Tipperary Quartzite
ThicknessUp to 186 metres (610 ft)[1]
Lithology
Primarydolomite
OtherLimestone
Location
Coordinates [ ⚑ ] : 51°32′00″N 116°03′39″W / 51.5333333°N 116.06083°W / 51.5333333; -116.06083 (Skoki Formation)
RegionCanadian Rockies
Country Canada
Type section
Named forSkoki Mountain
Named byCharles Doolittle Walcott[2]

The Skoki Formation is a stratigraphic unit of Early to Middle Ordovician age that is present on the western edge of the Western Canada Sedimentary Basin in the Canadian Rockies of Alberta and British Columbia.[3] It was named for Skoki Mountain near Lake Louise in Banff National Park by Charles Doolittle Walcott in 1928.[2] The Skoki Formation is fossiliferous and includes remains of brachiopods and other marine invertebrates, as well as conodonts and oncolites.[1]

Lithology and deposition

The Skoki Formation formed as a shallow marine shelf along the western shoreline of the North American Craton during Early to Middle Ordovician time.[3][4] Most of the original limestone was subsequently altered to dolomite. Many beds include quartz sand and silt, and some include layers of brown argillite.[1]

Distribution and stratigraphic relationships

The Skoki is present in the Canadian Rockies of Alberta and British Columbia. It reaches a thickness of up to 186 metres (610 ft) in the southern Rockies and about 500 metres (1800 ft) in the northern Rockies.[1] It conformably overlies the Outram Formation or the Tipperary Quartzite, depending on the location, and underlies the Owen Creek Formation.[5][1]

Paleontology

The Skoki Formation contains several genera of brachiopods, as well as gastropods, conodonts, cephalopods, trilobites, echinoderms, stromatolites, corals, and oncolites.[1]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. ISBN:0-920230-23-7.
  2. 2.0 2.1 Walcott, C.D. 1928. Pre-Devonian Paleozoic formations of the Cordilleran Provinces of Canada; Part 5. Smithsonian Miscellaneous Collections, vol. 75, no. 5, p. 175-368.
  3. 3.0 3.1 Slind, O.L., Andrews, G.D., Murray, D.L., Norford, B.S., Paterson, D.F., Salas, C.J., and Tawadros, E.E., Canadian Society of Petroleum Geologists and Alberta Geological Survey (1994). "The Geological Atlas of the Western Canada Sedimentary Basin (Mossop, G.D. and Shetsen, I., compilers), Chapter 8: Middle Cambrian and Early Ordovician Strata of the Western Canada Sedimentary Basin". http://ags.aer.ca/reports/atlas-of-the-western-canada-sedimentary-basin.htm. Retrieved 2018-07-13. 
  4. Aitken, J.D. 1966. Middle Cambrian to Middle Ordovician cyclic sedimentation, southern Rocky Mountains of Alberta. Bulletin of Canadian Petroleum Geology, vol. 14, no. 6, p. 405-441.
  5. Alberta Geological Survey, 2013. "Alberta Table of Formations; Alberta Energy Regulator". http://ags.aer.ca/table-of-formation. Retrieved 1 May 2018.