Type Locality:

Anglo-Canadian Beaverhill Lake No. 2, in 11-11-50-17W4M, in Alberta, between 1,318.3 and 1,538.3 m (4,325 and 5,047 ft), continuously cored.

Distribution:

The Beaverhill Lake Group is generally between 150 and 220 m (492 and 722 ft) thick in central Alberta. It is recognized in the subsurface in Alberta from the Drumheller area northward to Fort McMurray. The Beaverhill Lake is recognized to the west toward the foothills and thins to zero around the Peace River Arch. Further northwest the Beaverhill Lake Formation, as used by Griffin is recognized as a northwesterly thinning wedge across northern Alberta into the Northwest Territories and northeastern British Columbia, where it loses its identity in the Fort Simpson and Horn River shales at the Slave Point-Sulphur Point-Keg River facies front.

Lithology:

In the type area the Beaverhill Lake Group consists of cyclical beds of limy shales and argillaceous micrites. The following units are now recognized, in ascending order a basal limestone, and the Firebag, Calmut, Christina, Moberly and Mildred members. To the northeast, in the Swan Hills area the Beaverhill Lake Group consists of the thinly bedded dense brown anhydrites of the Fort Vermilion Formation, which are overlain by a stromatoporoid-rich reef complex (Swan Hills Formation). These are overlain and surrounded by the nodular limestones and shales of the Waterways Formation. The Fort Vermilion Formation is not present in the Beaverhill Lake Group south of Swan Hills. As used by Griffin (1965) the Beaverhill Lake Formation of the northern Alberta and northeastern British Columbia consists of argillaceous limestone and calcareous shales, with the shales becoming dominant to the west.

Relationship:

The Beaverhill Lake Formation of the type area and eastern Alberta is overlain conformably by carbonates of the Cooking Lake Formation. West of the Meadowbrook-Rimbey Leduc Reef trend the upper Cooking Lake carbonates are not present, and the Beaverhill Lake is overlain by shales of the Woodbend, locally referred to as the Majeau Lake Shale. The Beaverhill Lake Formation and Group are underlain generally conformably, but locally disconformably by shales, siltstones and evaporites of the Elk Point Group. In northwestern Alberta and northeastern British Columbia the Beaverhill Lake Formation, as defined by Griffin (1965) is disconformably overlain by the Muskwa Formation and conformably and diachronously overlies the Slave Point Formation, which is equivalent to the lower part of the Beaverhill Lake Formation of the type area, and the lower part of the Swan Hills Formation of the Beaverhill Lake Group. In northeastern Alberta the equivalents of the type Beaverhill Lake Formation are the Slave Point and Waterways formations. Further north, into the adjoining District of MacKenzie the equivalents are the Slave Point Formation and the lower part of the Hay River Formation. Northwest of the Slave Point-Keg River facies front the Slave Point, Beaverhill Lake and Waterways lose their identity into shales of the Horn River and Fort Simpson formations which further west are replaced by the Besa River shale. The Beaverhill Lake Formation is replaced to the southeast by the Souris River Formation in southeastern Alberta, Saskatchewan and Manitoba, and is equivalent to part of the Flume Formation of the Fairholme Group of the Rocky Mountains.

History:

The Beaverhill Lake Formation was originally defined, and by inference restricted to the Edmonton area. It was later shown to be equivalent, in whole or in part to the Waterways Formation of northeastern Alberta, which was divided into five members by Crickmay (1957), in ascending order the Firebag, Calmut, Christina, Moberly and Mildred. These members were later recognized in the Beaverhill Lake Formation. In the general Swan Hills area Fong (1959, 1960) proposed the Swan Hills Member for the reefal carbonate in the Beaverhill Lake. Leavitt and Fischbuch (1968) raised the Beaverhill Lake of this area to group status, consisting of the Fort Vermilion, Swan Hills and Waterways formations. Griffin (1965) used the term Beaverhill Lake Formation in northern Alberta and northeastern British Columbia for calcareous shales and argillaceous limestones equating to the Waterways and overlying the Slave Point Formation, which is equivalent to the lower Swan Hills and basal limestone of the type Beaverhill Lake Formation.

Other Citations:

Committee on Slave Point Beaverhill Lake, 1964; Crickmay, 1957; Griffin, 1965; Geological Staff, Imperial Oil Ltd., 1950; Hemphill et al., 1970; Leavitt and Fischbuch, 1968.

References:

Geological Staff, Imperial Oil Limited, Western Division, 1950. Devonian Nomenclature in Edmonton Area, Alberta, Canada. Bulletin of the American Association of Petroleum Geologists, Vol. 34, No. 9, pp. 1807-1825.

Griffin, D.L., 1965. The facies front of the Devonian Slave Point - Elk Point sequence in northeastern British Columbia and the Northwest Territories; Journal of Canadian Petroleum Techology, vol. 4, no. 1, pp. 13-22.