Maligne Formation

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.[1][2]

Maligne Formation
Stratigraphic range: Frasnian
TypeFormation
Unit ofFairholme Group
UnderliesPerdrix Formation
OverliesFlume Formation
ThicknessUp to about 30 m (98 feet)[1]
Lithology
PrimaryArgillaceous limestone
OtherCalcareous mudstone, shale
Location
Coordinates53°03′00″N 118°05′00″W
Region Alberta
 British Columbia
Country Canada
Type section
Named forMaligne River
Named byP.W. Taylor, 1957.[2]

The formation is fossiliferous and includes remains of brachiopods, crinoids, gastropods, cephalopods, and other marine animals, as well as traces made by burrowing organisms.[1]

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.[1]

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.[1][3]

gollark: Oh, right. That would have been easier than doing it by hand.
gollark: Did you just randomly decide to calculate that?
gollark: Well, you can, or also "it would have about the same mass as the atmosphere".
gollark: Wikipedia says that spider silk has a diameter of "2.5–4 μm", which I approximated to 3μm for convenience, so a strand has a 1.5μm radius. That means that its cross-sectional area (if we assume this long thing of spider silk is a cylinder) is (1.5e-6)², or ~7e-12. Wikipedia also says its density is about 1.3g/cm³, which is 1300kg/m³, and that the observable universe has a diameter of 93 billion light-years (8.8e26 meters). So multiply the length of the strand (the observable universe's diameter) by the density of spider silk by the cross-sectional area of the strand and you get 8e18 kg, while the atmosphere's mass is about 5e18 kg, so close enough really.
gollark: Okay, so by mass it actually seems roughly correct.

References
  1. 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. ISBN 0-920230-23-7.
  2. 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.
  3. Alberta Geological Survey. "Alberta Table of Formations, May 2019" (PDF). Alberta Energy Regulator. Retrieved 24 March 2020.
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