Unit Name: Swan Hills Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Middle Devonian - Late Devonian (397.5 - 359.2 ma)
Age Justification: The reefal facies of the Swan Hills Formation are populated mainly by sub-spherical, dendroid, bulbous and tabular stromatoporoids, with minor occurrences of crinoids, brachiopods, gastropods, ostracods and algae. The lagoonal facies contain quantitatively far less fossils, primarily of the stromatoporoid genus Amphipora.
Province/Territory: Alberta

Originator: Fong, G., 1959, p. 95-108; 1960, p. 195-209.

Type Locality:
Home Regent "A" Swan Hills 10-10-67-10W5M, in Alberta, between 2489.3 and 2590.8 m (8167 and 8500 ft). The name is derived from the Swan Hills, which rise above a relatively flat muskeg-plain area north of Whitecourt, Alberta.

Distribution:
In the general Swan Hills area Divisions I to III form a reef-rimmed platform on which isolated reef complexes of Division IV to IX are situated and the formation ranges fronds over 152 m (500 ft) to less than 15 m (50 ft) in thickness. The formation extends southward and westward and thins into the outcrop area, where it is known as the Flume Formation. Divisions I to III of the Swan Hills Formation extend northward from the type area around the Peace River Arch, across northern Alberta into the Northwest Territories and northeastern British Columbia, where they are known as the Slave Point Formation. These Slave Point-lower Swan Hills carbonates terminate at the margin of the Sulphur Point-Keg River facies front in northeastern British Columbia and the Northwest Territories.

Locality Data:
WELL 100101006710W500; HOME REGENT A SWAN HILLS 10-10-67-10. Interval(m): From 2489.3, To 2590.8.

Lithology:
The reef complexes constituting the Swan Hills Formation consist essentially of two contrasting rock types: a lagoonal series of facies consisting of dense, micritic, pelletoidal limestones with only minor skeletal material; and a reef to forereef series of facies consisting of coarse-grained, commonly porous, bioclastic, organically constituted limestones. The Swan Hills Formation generally is a limestone unit, although some reef complexes are dolomitized.

Relationship:
The Swan Hills Formation is underlain conformably by evaporites of the Fort Vermilion Formation and, southwest of the Swan Hills area by clastics of the upper Elk Point Group. The Swan Hills reef complexes are overlain and surrounded by nodular shale and micrites of the Waterways Formation. To the south the upper part of the Swan Hills Formation is correlative with the Flume Formation of the Rocky Mountain outcrop, and to the north the lower part of the Swan Hills Formation (Divisions I to III) is correlative with the Slave Point Formation.

History:
In 1959-60 Fong introduced the term Swan Hills as a member of the Beaverhill Lake Formation for the oil-producing carbonate at Swan Hills and divided it into a lower dark brown member and an overlying light brown member. Leavitt and Fischbuch (1968) raised Fong's Swan Hills Member to formational status and included it, along with the Fort Vermilion Formation and the Waterways Formation in the Beaverhill Lake Group. Later Fischbuch (1968) divided the Swan Hills Formation into nine informal units designated from bottom to top as Divisions I to IX, and suggested that the Middle to Upper Devonian boundary occurs between Divisions V and Vl.

Other Citations:
Fischbuch, 1968; Fischbuch and Havard, 1977; Fong, 1959, 1960; Havard and Oldershaw, 1976; Hemphill and Smith, and Szabo, 1970; Leavitt, 1968; Leavitt and Fischbuch, 1968; Murray, 1966.

References:
Fischbuch, N.R., 1968. Stratigraphy of the Devonian Swan Hills reef complexes of central Alberta; Bull. Can. Petrol. Geol., vol. 16, no. 4, pp. 446-537.
Fong, G., 1959. Type section Swan Hills Member of the Beaverhill Lake Formation, Alberta Journal of the Alberta Society of Petroleum Geologists, vol. 7, pp. 95-108.
Fong, George, 1960. Geology of Devonian Beaverhill Lake Formation, Swan Hills area, Alberta, Canada, American Association of Petroleum Geologists (AAPG), AAPG Bulletin, vol. 44 (February), pp. 195-209.
Leavitt, E.M. and Fischbuch, N.R., 1968. Devonian nomenclatural changes, Swan Hills area, Alberta, Canada; Canadian Society of Petroleum Geologists (CSPG), Bulletin of Canadian Petroleum Geology, vol. 16, no. 3 (September), pp. 288-297.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: P.A. Monahan; N.R. Fischbuch
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 24 Mar 2009