Tectonostratigraphic Evolution of the Mackenzie Delta-Beaufort Sea Foldbelt

Timothy P. Seeley¹ and Deborah Spratt^2
1 Talisman Energy, Calgary, AB
² University of Calgary, Calgary, AB

The Mackenzie Delta-Beaufort Sea Foldbelt (MDBSF) is a Cretaceous-Tertiary age foldbelt developed on the Canadian continental shelf of the Arctic Ocean. It is estimated that one billion barrels of recoverable oil and nine Tcf of recoverable gas have been found to date and that six billion barrels of oil and 55 Tcf of gas remain undiscovered in the MDBSF (Eaton, 2001).

Modeling of the motions between the proto-Pacific, Pacific and North American plates has shown an age correlation between the motions of the plates and uplift in the Brooks Range with development of the MDBSF as a foreland foldbelt. The evolution of the MDBSF on the Canadian continental shelf allows for a unique opportunity to study the structural evolution of a foldbelt and the controls of the evolving structures on depositional patterns with only limited interference from erosion.

Using a regional 2D seismic grid, the MDBSF is shown to consist of low-amplitude, long-wavelength folds with deformation becoming less intense in the foreland. Previous research has shown that the Cretaceous to Recent shelf edges for the Mackenzie Delta rapidly migrated basinward as the MDBSF propagated basinward (Willumsen and Cote, 1982). In addition, filling of the synclinal troughs associated with the growth of folds within the MDBSF is supported by the transition from down-lapping to on-lapping deposition. Smaller scaled, gravity driven, structures are also identifiable in the MDBSF.