Sedimentary and Stratigraphic Analysis of the Viking Sand in the Edgerton/Wainwright Area, Central Alberta

Russell Walz
University of Regina, Regina, SK

The Viking Formation was deposited within the Western Canadian foreland basin during Albian time, Early Cretaceous. This study examines the lithology, sedimentary facies and stratigraphy of the Viking Formation in the Edgerton/ Wainwright area (NW corner 45-5W4 to SE corner 44-4W4) of central Alberta. The studied section is comprised of, in ascending order, marine offshore shales of the Joli Fou Formation, marine sandstones of the Viking Formation, marine shales of the Westgate Formation, to the Base Fish Scales Marker. Within the Viking Formation, the Viking Sand unit was deposited as a thin sand sheet in a shoreface environment during a lowstand, related to a forced regression. In cores, the Viking Sand unit is demarcated by burrows in-filled with coarse-grained sediments beds of rip-up clasts and structureless sands lenses (up to 5cm). The base of the Viking Sand unit can be interpreted as a Regressive Surface of Marine Erosion (RSME) as course shoreface sands overlie offshore transitional sediments with a sharp contact between the two facies. During a following transgression, parts of the lowstand shoreface deposits became subsequently reworked and redistributed to form linear sand bodies (i.e. Viking Sand unit) trending NW-SE, creating a transgressive surface of erosion (TSE). The TSE is overlain by offshore transitional sediments, which where deposited during a subsequent sea level stillstand. The upper boundary of the Viking Formation is a basin wide transgressive surface of erosion (TSE), marking the end of Viking deposition and onset of deposition of marine shales of the Westgate Formation.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005