Title: Viking Formation Strata of the Western Canada Sedimentary Basin (Poster) [Abstract]
Abstract: ABSTRACT The Viking Formation consists of an interbedded succession of mudstone, interlayered sandstone-mudstone, bioturbated muddy sandstone, sandstone, and conglomerate encased in thick marine shales of the Middle to Late Albian Lower Colorado Group. The formation ranges from 20 m to 35 m thick in the central part of the basin, increasing to 50 m in the southwest, where it merges with the Bow Island Formation in southern Alberta, and is indistinguishable from the Blairmore Group westward in the Foothills Belt. The Viking thins rapidly in subcrop toward the eastern margin of the basin, tending to shale-out almost completely in some regions. Strata correlative with the Viking interval north of the Peace River Arch include the Paddy Member of the Peace River Formation (approximately 15 m thick and dominated by sandstone), and the Pelican Sandstone in northeast Alberta. The Viking Formation has previously been interpreted as comprising a single clastic wedge that prograded basinward in response to orogenic activity to the west. It can be demonstrated that the Viking consists of two principal stratigraphic sequences separated by a major unconformity. The lower progradational succession (highstand systems tract) consists of a series of stacked coarsening-upward shelf-to-shoreface units. The upper succession records transgressive depositional conditions punctuated by lowstand intervals, with a ravinement surface superimposed on an uncomformity at the base. This separates the highstand systems tract from the overlying lowstand and transgressive systems tracts. In the distal or central part of the basin, lowstand and transgressive deposits consist of thin interbedded units of interlayered mudstone-sandstone, mudstone and granular sandstone-conglomerate. Near the western margin of the basin, antecedent linear valleys are filled with thick estuarine sediments deposited during the transgression. End_of_Record - Last_Page 177-------
Publication Year: 1990
Publication Date: 1990-01-01
Language: en
Type: article
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