A sequence stratigraphic framework is proposed for the McMurray Formation of south Athabasca. Detailed log correlations from over 1700 wells demonstrate that there exist stacked, prograding, shoreface parasequence sets that can be regionally correlated over the southern Athabasca Oil Sands Deposit. These parasequence sets represent the highstand systems tract. They are best preserved in the south, and are also preferentially preserved towards the top of the McMurray Formation. However, the dominant depositional elements in the basin are lowstand channels incised into the parasequence sets. These channels are filled with a complex estuarine facies succession consisting dominantly of sandy to muddy estuarine point bars. The basal fill of some of the deeper channel valleys consists of freshwater fluvial point bars.

Statistical facies analysis, using clustering techniques and Markov analysis, differentiates a large database of facies descriptions into three major successions that correspond closely with the proposed stratigraphic framework for the McMurray Formation. These successions are interpreted as: (1) a simple coarsening-upward shoreface succession; (2) a complex of interrelated channel fill deposits; and (3) rooted paleosols. The top of the McMurray Formation appears to be an erosion surface, and may be a sequence boundary.

Wabiskaw sands overlying the McMurray Formation in the Wabasca area are reinterpreted as a lowstand shoreface preserved on a shallow shelf. They can be shown to onlap the shoreline of a Paleozoic highland, which remained exposed to the northwest during early Clearwater transgressions.

The bitumen/water contact in the southern Athabasca deposit is immobile, and dips to the southwest at an angle only slightly less than the reservoir host strata. This dip is caused by subsidence of the foreland trough during the Laramide orogen and indicates that the generated oil had migrated, become trapped, and degraded to immobile bitumen very early at the onset of the Laramide orogen, probably no later than Late Cretaceous. The structure of the reservoir can be restored to its approximate configuration at the time of trapping and oil degradation by mapping the top of the reservoir using the bitumen/water contact as a datum. The trap is shown to be a shallow anticlinal structure of immense size. There was probably a stratigraphic component to the trap to the northeast, where overlying Clearwater shales onlapped the Precambrian regolith.