Type Locality:

Not specified. Composite. See Kananaskis and Tunnel Mountain formations.

Distribution:

Maximum thickness of over 610 m (2,000 ft) in westernmost front range sections owing to thickening of the Tunnel Mountain Formation; although the Kananaskis Formation is often not recognized in these sections (McGugan and Rapson, 1964; Scott, 1964a, b). At the type section of the Kananaskis Formation on Mount Chester the Spray Lakes group is 253 m (830 ft) thick. The group thins eastward, and in the easternmost front ranges the Kananaskis thins to a feather edge condensate and the Spray Lakes Group is mainly represented by the Tunnel Mountain Formation, which seldom exceeds 91 m (300 ft) in thickness. The Spray Lakes Group is absent in the foothills subsurface and is apparently absent north of about Windy Point on the David Thompson Highway.

Locality Data:

Thickness(m): Maximum 610, Typical 253.

Lithology:

Brown and grey weathering clastics and carbonates, composed of two formations, in ascending order: the Tunnel Mountain Formation, which comprises brown weathering, cliff forming dolomitic siltstones, sandstones and orthoquartzites with chert nodules and thin chert beds, and occasional silty carbonates in the lower portion; and the Kananaskis Formation, comprising light grey weathering silty limestones and dolomites with blue and grey chert nodules, thin chert beds, and chert breccio-conglomerates.

Relationship:

Overlies the uppermost Mississippian (Visean-Serpukhovian) Etherington Formation and equivalents throughout the area of occurrence. Overlain paraconformably by the Permian Ishbel Group. Equivalent in part to the Amsden Group of central Montana.

History:

McGugan and Rapson (1961b) recognized that the Norquay Formation in the Banff area consisted of a Permian upper portion which they named the Ishbel Formation and a Middle Pennsylvanian (Upper Carboniferous) lower portion which they named the Kananaskis Formation. The Kananaskis was proposed for Middle Pennsylvanian carbonates and the existing Lower Pennsylvanian Tunnel Mountain Formation was restricted to the cliff forming clastics, excluding the limestones and dolomites of the Mississippian Etherington Formation. McGugan and Rapson (1963b) elevated the Permian Ishbel Formation to group status and proposed the name Spray Lakes Group to include the Pennsylvanian Kananaskis formation and Tunnel Mountain Formation (restricted).

Other Citations:

Bamber and Macqueen, 1979; Bamber, Taylor and Procter, 1968; Crickmay, 1960; Halbertsma, 1959; Halbertsma and Staplin, 1960; Henderson, 1989; Hovdebo, 1962; McGugan, 1984; McGugan and May, 1965; McGugan and Rapson, 1961b, 1963b, 1964, 1979; McGugan and Spratt, 1981; MacCauley et al., 1964; Nelson, 1961; Nelson and Rudy, 1961; Norris, 1957, 1965; Richards et al., in press; Steward and Walker, 1980; Scott, 1964a, 1964b.

References:

McGugan, A, and Rapson, J.E., 1963b. Permo-Carboniferous stratigraphy between Banff and Jasper, Alberta; Bull. Can. Petrol. Geol., vol. 11, pp. 150-160.

McGugan, A. and Rapson, J.E., 1961b. Stratigraphy of the Rocky Mountain Group (Permo-Carboniferous) Banff area, Alberta; J. Alberta Soc. Petrol. Geol., vol. 9, pp. 73-106.

McGugan, A. and Rapson, J.E., 1964. Permian and Carboniferous stratigraphy, Crowsnest area, Alberta and British Columbia; Bull. Can. Petrol. Geol., vol. 12, Field Conf. Guidebook Issue, p. 494-499.

Scott, D.L., 1964a. Stratigraphy of the lower Rocky Mountain Supergroup in the southern Canadian Rocky Mountains; University of British Columbia, Vancouver, BC, Ph.D. thesis, 271 p.

Scott, D.L., 1964b. Pennsylvanian stratigraphy, in, Flathead Valley, Fourteenth annual field conference, Fernie, B.C. (August 28, 1964); Canadian Society of Petroleum Geologists (CSPG), Bulletin of Canadian Petroleum Geology, vol. 12 (August), Special Guidebook Issue, pp. 460-493.