Winnipegosis Formation

Elk Point Group Stratigraphic range: Early to Middle Devonian PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Sub-units	Upper and Lower Elk Point Group
Underlies	Beaverhill Lake Group, Manitoba Group
Overlies	Precambrian to Silurian formations
Thickness	up to 610 metres (2,000 ft)
Lithology
Primary	Dolomite, halite, anhydrite
Other	Limestone, shale, potash
Location
Coordinates	53°54′19″N 110°37′49″W / 53.9053°N 110.6304°W / 53.9053; -110.6304 (Elk Point Group)Coordinates: 53°54′19″N 110°37′49″W / 53.9053°N 110.6304°W / 53.9053; -110.6304 (Elk Point Group)
Region	Northern plains
Country	Canada United States
Type section
Named for	Elk Point
Named by	J.R. McGehee

The Elk Point Group is a stratigraphic unit of Early to Middle Devonian age in the Western Canada and Williston sedimentary basins. It underlies large area that extends from southern boundary of the Northwest Territories in Canada to North Dakota in the United States. It has been subdivided into numerous formations, many which host major petroleum and natural gas reservoirs.

The formations of the Elk Point Group are composed primarily of carbonate rocks (dolostone and limestone) and evaporitic rocks (halite, anhydrite and potash), with lesser amounts of dolomitic mudstone and shale.

Some of the carbonate formations of the Elk Point Group contain rich assemblages of marine invertebrate fossils, including many species of brachiopods, gastropods, bivalves, cephalopods, crinoids, ostracods and corals. The evaporitic formations are unfossiliferous or contain a few spores and algal remains.