Tectonic and Stratigraphic Highlights of a Major Emerging Hydrocarbon Province, Offshore Mackenzie Delta, Canadian Beaufort Sea

The regional geological context of a major emerging hydrocarbon province has been clarified by interpretation of > 22,000 km 2D regional deep seismic PSDM survey acquired over the last 5 years in water depths ranging from < 20 m to > 2,500 m in the southeastern sector of the Canada basin. Dominated since the Late Cretaceous by deltaic sedimentation primarily sourced from the Mackenzie River this basin is a tectonic composite that blends the attributes of a transform margin, passive margin and foreland basin draped over a Late Paleozoic (Ellesmerian) compressional orogen that developed upon a very thick Proterozoic-Early Paleozoic passive margin.

In the Mackenzie delta transition zone new OBC lines show a very thick (10-15 km) strongly-progradational mud-dominated Proterozoic passive margin that was succeeded by Cambrian salt, overlain by a siliciclastic- and carbonate-dominated Lower Paleozoic platform, all of which was strongly overprinted by Ellesmerian compression. New streamer lines in the M’Clure Strait between Banks and Prince Patrick Island show some details of folding and faulting of the Proterozoic and Paleozoic strata below thin Mesozoic cover which may help explain the relationship between Ellesmerian and Mesozoic structural elements related to the rifting of the Canada basin. New streamer lines offshore Banks Island fully image the continent-ocean transition in that area and for the first time permit recognition of a linked extensional-compressional detachment system offshore Banks island that has deformed Cretaceous through Recent strata and has produced large and laterally-continuous anticlinal traps. The deepest part of the basin yet surveyed is underlain by oceanic crust with an elongate structural trough and flanking ridges that are contiguous with a NNW-trending gravity low in the central Canada basin. This morphology is compatible with an extinct oceanic spreading center and supports a rotational origin for the Canada basin during at least part of its evolution. This deep-seated extensional structure was reactivated by compression in the early Miocene resulting in regional uplift (the Tulluk high).

Deposition of rich source rocks during the Cretaceous and early Tertiary, combined with high quality Cenozoic siliciclastic reservoirs, thick interbedded shales and abundant structure combine to create a variety of favorable hydrocarbon plays.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California