Type Locality:

Wells in Elk Point area, Alberta, between Twps. 56 and 57, Rges. 5 and 6W4M; Crickmay (1952) designated, as the type section equivalent strata in the Anglo-Canadian Elk Point No. 11 well, in 2-11-57-5W4M, between 867.5 m (2845 ft) and 1,351 m (4,430 ft).

Distribution:

The lower Elk Point extends northwest from the Meadow Lake Escarpment (approximately 54 deg 31'N, 105 deg 40W to 52 deg 20'N, 123 deg W) to southern District of MacKenzie west of 112 deg W, thence to northeastern British Columbia and southern District of MacKenzie between 122 deg and 124 deg W. The upper Elk Point extends from North Dakota and eastern Montana through southern Manitoba and Saskatchewan, in a northwesterly direction through Saskatchewan into Alberta, spreading east and north of the Peace River uplift into southern District of MacKenzie north of 61 deg N and west into northeastern British Columbia between 124 deg W and 125 deg W. The type section of the Elk Point is 564 m (1,850 ft) thick; it thickens to approximately 610 m (2,000 ft) in eastern Alberta, where the lower Elk Point is thickest; in northwestern Alberta and adjacent British Columbia it ranges from 305 m (1,000 ft) to 488 m (1,600 ft) and thins to less than 152 m (500 ft) over the Tathlina Uplift in southern District of MacKenzie.

Lithology:

The Elk Point Formation was divided by Crickmay (1954) into 9 members of distinctly different lithology, described from top to bottom: Member 1: (Dawson Bay Formation): shale, green, red, grey, partly silty, dolomitic, anhydrite; dolomite, buff, micritic, in part argillaceous; shale, grey, red green. Member 2: (Prairie Evaporite Formation): predominantly halite; thin anhydrite layers in middle and at base; dolomite and shale laminae near base; potash beds commonly interbedded in the top 30.5 m (100 ft) to 61 m (200 ft); grades to anhydrite (Muskeg Formation) near centre of basin in northern Alberta, thence to dolomite (Presqu'ile Formation in southern District of MacKenzie and northeastern British Columbia). Member 3: (Winnipegosis Formation): [modified by Baillie, 1953, from Tyrrell's Winnipegosan]: at the top dolomite, light brown to brown, finely crystalline, with intercrystalline porosity in part; limestone, partly dolomitic, fine-grained to chalky; dolomite, brown to buff, argillaceous, becomes reddish and argillaceous towards base, with sandy streaks. [In the type outcrop the Winnipegosis consists of structureless, fossiliferous dolomite mounds or reefs with fair to excellent vuggy porosity; beds between mounds are light yellowish grey, medium saccharoidal, poorly fossiliferous, bedded dolomite.] Member 4: (Contact Rapids Formation; Chinchaga Formation of northern Alberta subsurface, Hay Camp of northeastern Alberta outcrop area): Brownish grey, very argillaceous dolomite and dolomite shale, underlain by greenish grey and red argillaceous dolomite, red dolomitic shale at base. Member 5: (Cold Lake Formation): Halite, with thin red dolomitic shale at base. Member 6: (Ernestina Lake Formation; Fitzgerald of northeastern Alberta): Anhydrite, light grey at top, underlain by light grey-brown, crypto- to micro-grained limestone, locally anhydritic with salt-plugged porosity. Member 7: Red and green dolomitic shale at base of Member 6. Member 8: (Lotsberg Formation): Type section: Halite, with medium grey, argillaceous dolomite at base in type section; elsewhere a zone about 61 m (200 ft) thick near the base includes thin beds of red and, minor, green calcareous or dolomitic shale. Member 9: (Basal red beds): Brick red, dolomitic or calcareous silty shales, grading downwards into red sandy shale and to greenish grey, fine- to coarse-grained quartzose sandstone.

Relationship:

The Elk Point rests on Precambrian over the Peace River-Athabasca and Tathlina uplifts; overlies strata of Cambrian age from the Meadow Lake Escarpment (108 deg 54'30"W to 113 deg 52'30"W) to the eroded margin of the Cambrian (approximately 55 deg 30'N); the upper Elk Point, beyond the limit of the lower Elk Point rests on the Cambrian in northeastern Alberta and adjacent Saskatchewan; on the Ordovician in western Alberta, Saskatchewan and southwestern Manitoba; it is overlain by the Souris River Formation in Manitoba and Saskatchewan, the Beaverhill Lake Formation of Alberta. Rock units equivalent to part or all of the lower Elk Point include the Burnais and Cedared of the Stanford and Hughes ranges of southeastern British Columbia; the Stone Formation and equivalent Arnica, Funeral and overlying Landry-Manetoe formations, the Headless and Nahanni formations of northeastern British Columbia and southern District of MacKenzie between 128 deg and 132 deg W. The upper Elk Point includes, in the Great Slave Lake area the Pine Point and equivalent Lonely Bay formations and the overlying Horn River Shales, the Presqu'ile and Horn Plateau formations (carbonates) in northeastern British Columbia and adjacent District of MacKenzie carbonates of the Pine Point, Sulphur Point-Presqu'ile, Watt Mountain and Slave Point formations of the upper Elk Point tongue out into the Evie and overlying Otter Park and Muskwa formations which grade westward to the Horn River Formation and equivalent lower part of the Besa River Formation.

Other Citations:

Baillie, 1951, 1953, 1955; Bassett and Stout, 1967; Barss et al., 1970; Belyea, 1959; Belyea and Norris, 1962; Cameron, 1917; Campbell, 1950; Crickmay, 1954, 1957; deWit, 1973; Douglas, 1968; Edie, 1959; Fuller and Porter, 1959; Geological Staff, Imperial Oil, 1950; Grayston et al., 1964; Hriskevich, 1966, 1967; Jones, 1967; Kent, 1964, 1967; Kindle, 1914; Law, 1955; McCamis and Griffith, 1967; McGehee, 1949, 1952; Norris, 1963, 1965; Sandberg, 1961; Sherwin, 1962; Van Hees, 1958; Walker, 1957; Warren and Stelck, 1962