J. Coleman1, M. Davis1, J. Cook2, and L. Eggers3
1BP, Houston, TX
2retired, Bloomington, IN
3Briggs & Eggers Orchards, Willcox, AZ
ABSTRACT: Comparative Analysis of the Exploration Potential of the Thrust Belts and Foreland Basins of North America
The Phanerozoic thrust belts and foreland basins (TB/FB) of North America were analyzed as part of a study of 27 petroliferous thrust belts and adjacent foreland basins from around the world to compared and contrast their petroleum systems. These petroleum systems vary significantly in their details, but have several overarching commonalities.
The Arctic Canada TB/FB extends across northernmost Canada into northwest Greenland and is composed of lower Paleozoic petroleum systems. It is consists mostly of continental shelf sedimentary rocks, including a structurally significant salt interval. Lower Paleozoic source intervals apparently source the lower and middle Paleozoic reservoirs; whereas, the upper Paleozoic and Mesozoic source intervals source the post-orogenic sequences. Almost all of the hydrocarbons found to date occur in the post-orogenic, Mesozoic succession.
The Appalachian TB/FB extends from Newfoundland to Mississippi and consists of two Paleozoic petroleum system provinces. Both provinces are developed primarily in continental shelf and slope siliciclastics and carbonates. Major source rock intervals developed in late Precambrian, Cambrian, Ordovician, Devonian, and Carboniferous strata. Significant tectonothermal events, which affected hydrocarbon generation and maturation, occurred in the Ordovician, Siluro-Devonian, and Permo-Carboniferous. The southern province has higher cumulative production as well as yet-to-be-recovered volumes than the northern province.
The Ouachita TB/FB extends from Mississippi to northern Mexico and contains both an upper and lower Paleozoic petroleum systems, which are developed in both siliciclastics and carbonates of deep water slope and continental shelf origin. Major source rock intervals developed in Ordovician, Devonian, and Carboniferous strata, with potential, but unsubstantiated, intervals in the Precambrian, Cambrian, and Silurian. Oil and gas generation apparently was episodically continuous between the Silurian and Triassic.
The Brooks – Colville TB/FB extends across northern Alaska and into northwestern most Canada. It contains mixed, upper Paleozic – Mesozoic petroleum systems, which include strata that were deposited primarily on the paleocontinental shelf. Source rock intervals are found in Triassic, Jurassic, and Cretaceous age rocks. They were buried and began generating hydrocarbons as a result of Cretaceous and Tertiary Colville foreland deposition.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado