Infill Model Research Articles

Growth Faulting and Syntectonic Casting of the Dawson Creek Graben Complex: A North American Craton-Marginal Trough; Carboniferous-Permian Peace River Embayment, Western Canada

The Dawson Creek Graben Complex was a 150 {times} 300 km, craton-perpendicular trough near the western North American craton margin. Sedimentary infill spanned 100 million years, and this tectonically controlled basin provides a comparison with other craton-marginal troughs or aulacogens, such as the Big Snowy, Uinta, Delaware, and Southern Oklahoma. The authors suspect that the graben complex was controlled by outboard, Antler-like orogeny and perhaps some strike-slip control. This syntectonic graben infill model provides a basis for developing new structural-stratigraphic plays in this mature basin. This extensional trough rests on a former basement arch and is centered in the broadly downwarped Peace River embayment. Sediment infill records several graben casting stages beginning with westernmost down-dropping, which then extended eastward and was accompanied by an increase in growth-type block faulting. Subsidence and faulting decay was followed by a retreat to western areas and tectonic stabilization. The complex was an arcuate half-graben, steep to the north, that widened asymmetrically and increased in depth to the west through time. The complex contained a principal half-graben with neighboring satellite grabens; throughout the complex are numerous kilometer-scale horst and graben blocks. The horsts subsided slower than neighboring grabens. This differential subsidence along block-bounding syn- andmore » postdepositional growth-type normal faults controlled formation and bed thickness, as did inter- and intraformational unconformities.« less