Type Locality:

Along the Athabasca River, between Pelican Rapids and 8 km (5 mi) downstream from Joli Fou Rapids. Joli Fou Section No. 1 is located about 5.5 km (3.4 mi) below Joli Fou Rapids, in NW/ 4 Sec. 22, or SW/4 Sec. 27, Twp. 81, Rge. 17W4M. Joli Fou Section No. 2 is in the north-central part of a series of exposures some 61 m (200 ft) east of the river in the west-central part of Sec. 33, Twp. 81, Rge. 17W4M. Joli Fou Section No. 3 is in an exposure about 8 km (5 mi) downstream from Joli Fou Rapids, on the east side of the valley in NW/4 Sec. 35, Twp 82, Rge 17W4M, some 42.7 m (140 ft) above the river.

Distribution:

The unit is about 33.5 m (110 ft) thick in the Athabasca River exposures, thinning to about 10.7 m (35 ft) to the south of the Lesser Slave Lake area and to about 16.8 m (55 ft) in the Redwater area. The Joli Fou Formation attains a thickness of about 61 m (200 ft) in south-central Saskatchewan. The sequence pinches out in the Rocky Mountain Foothills of southern Alberta, where it is replaced by the lowermost sandstones of the Bow Island Formation. The unit is of widespread distribution in the subsurface of the Western Canada sedimentary basin.

Lithology:

Dark grey, noncalcareous shale, with minor interbedded fine- and medium-grained sandstone. The sandstone occurs as lenses, commonly a few millimetres thick and as graded layers up to several centimetres in thickness, composed of horizontal or very gently inclined laminae. Bioturbated, shaly sandstones form scarce layers several centimetres thick. In the upper part of the unit the interbedded sandstone is quartzose and micaceous, while near the base glauconitic sandstone and quartz arenite are common. Subordinate lithologies include bentonite, pelecypod coquinas, nodular phosphorite and concretionary layers of calcite, siderite and pyrite. In central Saskatchewan the unit consists of interbedded glauconitic sandstone and noncalcareous mudstone of the Spinney Hill Sandstone, overlain by northward thinning Joli Fou shales of much reduced thickness. The Joli Fou Formation includes, at its base the interbedded shady sandstone, siltstone and mudstone of the Cessford (Basal Colorado) Sand in southeastern Alberta.

Relationship:

The Joli Fou Formation is the basal unit of the Colorado Group. In northeastern Alberta it rests on the Grand Rapids Formation of the Mannville Group and is overlain by the Pelican Formation in southern Alberta and southern Saskatchewan. Joli Fou shales rest disconformably on the Pense Formation and equivalent sandstones, marking the top of the Blairmore- Mannville-Swan River sequence, and are overlain by sandstones of the Bow Island-Viking succession. The Viking-Joli Fou contact is a disconformity in west-central Saskatchewan. Where the Viking Formation is absent in parts of southern Saskatchewan the Joli Fou and Big River formations form a sequence of undifferentiated lower Colorado shale. In central Saskatchewan the top of the Joli Fou Formation is defined by a sharp contact with the overlying Flotten Lake Sand. The Joli Fou Formation corresponds to the lower part of the lower Ashville succession (Skull Creek Member) in southern Manitoba and is equivalent to the Skull Creek Shale of north-central Montana and North Dakota. It is equivalent to the Taft Hill and Flood members of the Blackleaf Formation of northern Montana.

History:

Originally designated Pelican shale by McConnell (1892), which usage was continued by McLearn (1917). The name was changed by Wickenden (1949) to avoid confusion with the overlying Pelican sandstone succession.

Other Citations:

Badgley, 1952; Caldwell et al., 1978; Christopher, 1974; Jones, 1961a, 1961b; Maycock, 1967; McConnell, 1893; McLearn, 1917; McNeil and Caldwell, 1981; Price, 1963; Simpson, 1975, 1980; Simpson and O'Connell, 1979; Stelck et al., 1956; Wickenden, 1949.

References:

Wickenden, R.T.D., 1949. Some Cretaceous sections along the Athabasca River from the mouth of Calling River to below Grand Rapids, Alberta (Report and Figure); Geological Survey of Canada, Paper 49-15, 31 p. and Figure 1, Sketch map of area along Athabasca River in Alberta, showing positions of bedrock outcrops and geological sections examined, Scale: 1 Inch to 4 Miles.