Unit Name: Cantuar Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Aptian - Albian (125 - 99.6 ma)
Province/Territory: Manitoba; Saskatchewan

Originator: Price, 1963; Maycock, 1967.

Type Locality:
Type section is in the Tidewater Matador Crown No. 1 well, in Lsd. 4, Sec. 25, Twp. 20, Rge. 16W3M, southwestern Saskatchewan, between 825 and 865 m (2,708 and 2,837 ft).

The Cantuar Formation is arbitrarily limited to the Williston Basin region of Saskatchewan, where it comprises three members, (oldest to youngest) the McCloud, Dimmock Creek and Atlas. Its northern limit can be defined as Latitude 52°N, and coincides with the underlying topographic escarpment fronting the southerly dipping Mississippian formations. The formation drapes an Early Cretaceous topography marked by a series of cuestas that become younger southward across the Late Jurassic Vanguard and Jura-Cretaceous Success strata. Accordingly, thickness of the Cantuar Formation ranges regionally and locally from zero to 120 m (395 ft) but is generally greatest overall in the east and locally in subjacent valleys in the west.

Locality Data:
WELL 101042502016W300; TIDE WATER MATADOR CROWN NO 1. Thickness(m): Minimum 0, Maximum 120. Interval(m): From 825, To 865.

Comprises mostly a mudstone indurated arenite incorporating facies of: (a) kaolinite-indurated, white, quartzose sandstones with subordinate kaolinized feldspar, white, unaltered feldspar, grey and black chert and brown sphaerosiderite, and scattered to abundant lenses of lignite and carbonized plant fragments; (b) dark grey, green to grey and olive green mudstone, indurated arenites of quartz, feldspar, lignite flakes, green biotite and chlorite, mudstone and schist fragments, with accessory glauconite, amphibole and pyroxene; (c) dark grey and black carbonaceous mudstone, lignitic mudstones and lignite with variable proportions of arenite (b).

The Cantuar Formation is the middle of the three formations comprising the Mannville Group of southern Saskatchewan, which also includes the overlying Pense and underlying, patchily distributed Success formations. North of Latitude 52°N, by virtue of the attenuation of the Pense Formation the Cantuar correlates with all members of the Mannville from the Dina to the Waseca. In the Williston basin region the Cantuar is represented by those strata of the Inyan Kara below the Fall River Sandstone in North Dakota and the Kootenai Formation of Montana.

The name arose from oil field usage for a Lower Cretaceous producing sand in the Cantuar oil field district northwest of Swift Current, southwestern Saskatchewan, which was assigned to a "Blairmore" Formation (Humphreys and Rogers, 1954; Elphinstone, 1958). This Cantuar sand was redefined and renamed the Success Formation (Christopher. 1974), because the type Section of the Cantuar Formation as defined by Price (op. cit.) does not include the Cantuar sand as earlier identified.

Other Citations:
Christopher, 1984b.

Christopher, J.E., 1974. The upper Jurassic Vanguard and Lower Cretaceous Mannville groups of southwestern Saskatchewan Saskatchewan Dept. Min. Res., Rept. 151.
Christopher, J.E., 1984b. The Lower Cretaceous Mannville Group, northern Williston Basin region, Canada. In: Mesozoic of middle North America; Stott, D.F. and Glass D.J. (Eds.). Can. Soc. Petrol. Geol., Memoir 9.
Elphinstone, N.P., 1958. Geology of the Fosterton field. North Dakota Geol. Soc., Saskatchewan Geol. Soc., 2nd Internat. Williston Basin Symp., p. 79-84.
Humphreys, J.T. and Rogers, M.A., 1954. Difference between the Basal Cantuar and Vanguard Sands; Alberta Soc. Petrol. Geol., Bull., vol. 2, pp. 8-9.
Maycock, I.D., 1967. Mannville Group and associated Lower Cretaceous clastic rocks in southwestern Saskatchewan. Saskatchewan Dept. Min. Res., Rept 96.
Price, Leon L., 1963. Lower Cretaceous rocks of southeastern Saskatchewan (Report, 12 figures, 3 tables, appendix); Department of Mines and Technical Surveys, Geological Survey of Canada, Paper 62-29, 44 p.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: J.E. Christopher
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 07 Aug 2009