Perdrix Formation

Perdrix Formation
Stratigraphic range: Frasnian
Type Formation
Unit of Fairholme Group
Underlies Mount Hawk Formation
Overlies Maligne Formation, or Flume Formation
Thickness Up to 140 metres (460 ft)
Lithology
Primary Shale
Other Limestone
Location
Region  Alberta
Country  Canada
Type section
Named for Roche à Perdrix
Named by P.E. Raymond, 1930[1]

The Perdrix Formation a geologic formation of Late Devonian (Frasnian) age in the Western Canada Sedimentary Basin.[2] It named for Roche à Perdrix in Jasper National Park, Alberta, by P.E. Raymond in 1930.[1] It was deposited in a marine basin and preserves marine fossils dating back to the Late Devonian period.[3]

Lithology

The Perdrix Formation consists of black, bituminous shales. The upper portion includes nodules and thin nodular beds of argillaceous limestone that increase in frequency upwards and laterally toward the reefs of the Cairn Formation.[3]

Thickness and Distribution

The Perdrix Formation is present as outcrops in the front and main ranges of the Canadian Rockies from Kakwa Lake in northeastern British Columbia to the Ram River area of Alberta. It is also recognized in the subsurface immediately adjacent to the mountain front. Thicknesses range from about 80 metres (260 ft) to 140 metres (460 ft).[3]

Relationship to Other Units

The Perdrix Formation overlies the Maligne Formation or, where the Maligne is absent, the Flume Formation. It is conformably overlain by the Mount Hawk Formation and the contact is gradational. Laterally it interfingers with the Peechee Formation and the reefs of the Cairn Formation.[3]

Paleontology

Tentaculids are ubiquitous in the Perdrix Formation, and brachiopods and pelecypods are present in the more limestone-rich portions.[3]

See also

References

  1. 1 2 Raymond, P.E. 1930. The Paleozoic Formations in Jasper Park, Alberta. American Journal of Science, 5th series, vol. 20, p. 289-300.
  2. ↑ Mossop, G.D. and Shetsen, I., (compilers), Canadian Society of Petroleum Geologists and Alberta Geological Survey (1994). "The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 12: Devonian Woodbend-Winterburn strata of the Western Canada Sedimentary Basin". Retrieved 2014-10-17.
  3. 1 2 3 4 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.
This article is issued from Wikipedia - version of the Friday, October 31, 2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.