Maligne Formation Explained

Maligne Formation
Type:Formation
Prilithology:Argillaceous limestone
Otherlithology:Calcareous mudstone, shale
Namedfor:Maligne River
Namedby:P.W. Taylor, 1957.[1]
Region:
Country: Canada
Coordinates:53.05°N -118.0833°W
Unitof:Fairholme Group
Underlies:Perdrix Formation
Overlies:Flume Formation
Thickness:Up to about 30 m (98 feet)[2]

The Maligne Formation is a stratigraphic unit of Late Devonian (Frasnian) age. It is present on the western edge of the Western Canada Sedimentary Basin in the Rocky Mountains and foothills of Alberta and British Columbia. It consists primarily of argillaceous limestone and calcareous mudstone, and was named for the Maligne River in Jasper National Park by P.W. Taylor in 1957.

The formation is fossiliferous and includes remains of brachiopods, crinoids, gastropods, cephalopods, and other marine animals, as well as traces made by burrowing organisms.

Lithology and thickness

The Maligne Formation was deposited in a marine environment. It consists of thin-bedded dark grey to black argillaceous limestone and calcareous mudstone. In some areas it includes thin interbeds of shale. It is generally 12 to 30 m (39 to 98 ft) thick.

Distribution and relationship to other units

The Maligne Formation is present in Canadian Rocky Mountains and foothills between the Kakwa Lakes area of northeastern British Columbia and the Cline River area of west-central Alberta, a distance of about 300 km (186 mi). It overlies the Flume Formation and is overlain by the Perdrix Formation. It grades laterally into the carbonate rocks of the upper Cairn Formation.[3]

Notes and References

  1. Taylor, P.W. 1957. Revision of Devonian nomenclature in the Rocky Mountains. Journal of the Alberta Society of Petroleum Geologists, v.8, no. 8, p. 190–191.
  2. Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba, p. 720–721. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. .
  3. Web site: Alberta Geological Survey . Alberta Table of Formations, May 2019 . Alberta Energy Regulator . 24 March 2020.