The Colorado Group in the Cold Lake heavy oil area, east-central Alberta: Biostratigraphy, paleoenvironments and regional correlations

The Colorado Group in the heavy oil area of Cold Lake, north-eastern Alberta represents a relatively condensed section of mudstone dominated sedimentation within the Western Interior Sea. Two long cores covering the entire Colorado Group provide a unique opportunity for a detailed multidisciplinary study in order to establish a biostratigraphic framework and to interpret paleoenvironmental changes in an area that has received attention only for its heavy-oil bearing Mannville Group. Regional stratigraphic wireline log correlations established broad geometries of the stratigraphic subdivisions, as established in the reference cores.; Five foraminiferal zones and nine subzones are recognized. Several intervals barren of foraminifera characterize the study area and reflect anoxic/dysoxic events. Paleoenvironmental interpretations are based on sedimentological, micropaleontological, paleoecological, nannofossil, geochemical (Rock Eval) data and log correlations. The Joli Fou Formation represents continuous transgression of the seaway after the Mannville unconformity. The Viking Formation in the Cold Lake area consists of a transgressive-regressive cycle. (Abstract shortened by UMI.)...