Bulletin of Canadian Petroleum Geology, Vol.47, No.4, 362-374, 1999
Seismic stratigraphy and structure of the Lower Paleozoic, Central Alberta Lithoprobe Transect
Lithoprobe seismic reflection data from the Central Alberta Transect (CAT) an integrated with regional well data to study the lower Paleozoic sedimentary succession in east-central Alberta. Seismic reflection expressions of Cambrian to Middle Devonian strata are described and basement influences on stratigraphy and structure are evaluated. The seismic expression of lower Paleozoic strata in central Alberta is highly variable. Significant regional variations include a gradual westward increase in reflectivity in the Cambrian section, associated with a westward transition from elastic to mixed elastic-carbonate lithofacies, and an abrupt westward decrease in reflectivity in the Middle Devonian section, associated with western depositional limits of the Prairie and Winnipegosis formations. Regional reflection patterns delineate a major sub-Devonian unconformity and associated westward truncation of Upper Cambrian strata. Basement-surface structures are common along the Lithoprobe transect, and include small-scale monadnocks, depressions and escarpments, and a broad high in the eastern transect area. The small basement features affect Middle Cambrian strata, while the broad high affects the entire lower Paleozoic section. Though basement-surface structures are common in east-central Alberta, there is no evidence of systematic linkages between regional basement tectonic domains and their boundaries (as defined from aeromagnetic data) and lower Paleozoic geologic trends.