Devonian Nomenclatural Changes, Swan Hills Area, Alberta, Canada

Abstract

ABSTRACT Extensive development drilling in the Swan Hills area over the past decade has produced considerable subsurface data which now can be used to reassess the Devonian nomenclature in this area. It is proposed that the Swan Hills Member, defined by Fong (1959, 1960) for the hydrocarbon producing carbonate unit of the Beaverhill Lake Formation, be raised to formation status. The off-reef nodular shales or upper Beaverhill Lake unit of Fong (1959, 1960) is designated as the Waterways Formation following Murray (1965); and the basal Beaverhill Lake unit of Fong (1959, 1960) is divided into the Fort Vermilion Formation and part of the Watt Mountain Formation. These three formations (Swan Hills, Waterways, and Fort Vermilion) are collectively referred to as the Beaverhill Lake Group. Cross-sections show these formations to be correlative from the Swan Hills area to the type areas to the north, northeast, and southeast. In the Swan Hills area the Fort Vermilion Formation and the basal portion of the Swan Hills Formation are considered Middle Devonian in age. The upper portion of the Swan Hills Formation and the Waterways Formation are considered Late Devonian in age.