- Red River Formation
Red River Formation
Stratigraphic range: Caradoc to Ashgill
Type Geological formation Sub-units Fort Garry Member
Cat Head Member
Dog Head Member
Underlies Stony Mountain Formation Overlies Winnipeg Formation Thickness up to 215 metres (710 ft) Lithology Primary Limestone, dolomite Other breccia Location Named for Red River of the North Named by A.F. Foerste, 1929 Coordinates Coordinates: Region WCSB
The Red River Formation is composed of the following subdivisions from top to base: 
- Fort Garry Member: crystalline and micritic dolomite with a argillaceous dolomite breccia in the middle
- Selkirk Member: fossiliferous dolomitic limestone
- Cat Head Member: cherty dolomite, becoming calcareous to the south
- Dog Head Member: fossiliferous dolomitic limestone
The Red River Formation reaches a maximum thickness of 215 metres (710 ft) in the center of the Williston Basin. At the along the Manitoba outcrop belt, it is 150 metres (490 ft) thick and thins out northwards.
Relationship to other units
The Red River Formation is slightly unconformably overlain by the Stony Mountain Formation and sharply overlays the Winnipeg Formation in manitoba, the Deadwood Formation in western Saskatchewan and the Canadian Shield in northern Manitoba.
The lower Red River Formation is equivalent to the Yeoman Formation, while the Fort Garry Member correlates with the Herald Formation.
- ^ a b c d Lexicon of Canadian Geologic Units. "Formation". http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?. Retrieved 2010-02-01.
- ^ Foerste, A.F., 1929. The Ordovician and Silurian of the American arctic and sub-arctic regions. Denison Univ. Sci. Lab J., v. 24, p. 27-79.
- ^ Foerste, A.F., 1929b. The cephalopods of the Red River Formation of southern Manitoba. Denison Univ. Sci. Lab J., v. 24, p. 129-235.
Western Canadian Sedimentary Basin Hydrocarbon history Depositional Regions
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