The study interval, embracing the Dowling, Thistle, Hanson and Chungo Members of the Upper Cretaceous Puskwaskau Formation of west-central Alberta, consists of 14 allomembers, which are grouped into three transgressive-regressive sequences. The sequences are identified based on the stacking patterns of strata, combined with sequence boundaries and maximum flooding surfaces.

The development of the three sequences was mainly controlled by episodic tectonic loading in the thrust belt to the southwest, as indicated by the reciprocal development of systems tracts between the foredeep and distal areas, and the migration of the maximum flooding surface in both depositional strike and dip directions. During active loading, the foredeep area developed a transgressive systems tract, whereas the distal area was subtly elevated and developed a regressive systems tract that prograded towards the thrust belt. Subsequent to the active loading stage was the relative tectonic quiescence stage. This stage is characterised by the development of the regressive systems tract in the proximal region and the transgressive systems tract in the distal area.

The three sequences show dramatic lateral shifts in their depocentres along the thrust belt. The depocentres of each component allomember within a sequence also shift laterally with respect to those above and below. Migration of depocentres on different length and time scales reflects along-strike variation in the locus of maximum thrust activity at the corresponding scales.

Vertical movement of the Peace River Arch in the north and episodic reactivation of basement faults was linked to the tectonic loading events in the thrust belt. The Peace River Arch was active only during formation of sequence III. Uplift of the Arch tilted the basin floor, causing the erosion of strata in the north. Three basement fault trends (NW-SE, NE-SW and E-W) are inferred, based on the isopach deflections. These faults controlled the preservation of strata, local development of depocentres in the distal area, and development of the forebulge. Most of the basement faults were short-lived and were active on the allomember scale, although they may have been reactivated several times during the formation of the study interval.