Survey Peak Formation

The Survey Peak Formation is a stratigraphic unit of latest Cambrian to earliest Ordovician age. It 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 Survey Peak near Mount Erasmus in Banff National Park by J.D. Aitken and B.S. Norford in 1967.[2] The Survey Peak Formation is fossiliferous and includes remains of trilobites and other marine invertebrates, as well as conodonts, stromatolites, and thrombolites.[1][2]

Survey Peak Formation
Stratigraphic range: latest Cambrian to earliest Ordovician ~490–475 Ma
TypeFormation
UnderliesOutram Formation
OverliesMistaya Formation, Lynx Group
ThicknessUp to 519 metres (17023 ft)[1]
Lithology
PrimaryLimestone
OtherShale, mudstone, siltstone
Location
Coordinates51°57′16.4″N 116°50′59″W
RegionCanadian Rockies
Country Canada
Type section
Named forSurvey Peak
Named byJ.D. Aitken and B.S. Norford[2]

Lithology and deposition

The Survey Peak Formation formed as a shallow and at times emergent marine shelf along the western shoreline of the North American Craton during latest Cambrian to earliest Ordovician time.[2][3][4] It consists of limestones, calcareous shales and mudstones, and siltstones, and can be subdivided into four informal members: a basal siltstone, overlain in turn by a putty-colored calcareous shale, a limestone and shale unit, and a massive, cliff-forming limestone.[1][2]

Distribution and stratigraphic relationships

The Survey Peak Formation is present in the Rocky Mountains of Alberta and British Columbia. It thickens westward.[1][2] It overlies the Mistaya Formation or the top of the Lynx Group, and is overlain by the Outram Formation.[5] The basal contact is conformable but abrupt. The top contact is gradational.[1][2]

Paleontology

The Survey Peak Formation is considered to be one of the best exposed and most accessible fossiliferous examples of the Cambrian-Ordovician boundary in Canada.[1] It includes several genera of trilobites, as well as brachiopods, conodonts, gastropods, echinoderms, stromatolites, thrombolites, rare graptolites, and others.[1][2]

gollark: I don't know of anything which is distributed like that.
gollark: I doubt in practice you would actually get a normal distribution, but sure.
gollark: I guess.
gollark: No. You still only have one mean, which is going to be somewhere between the peaks.
gollark: Not *necessarily*, a distribution can have multiple peaks.

References
  1. 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. Aitken, J.D. and Norford, B.S. 1967. Lower Ordovician Survey Peak and Outram formations, southern Rocky Mountains of Alberta. Bulletin of Canadian Petroleum Geology, vol. 15, p. 150-207.
  3. 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". Retrieved 2018-07-13.CS1 maint: multiple names: authors list (link)
  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. "Alberta Table of Formations, May 2019" (PDF). Alberta Energy Regulator. Retrieved 24 March 2020.
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