Geological evolution and hydrocarbon habitat of the ‘Arctic Alaska microplate’

Abstract

Depositional sequence mapping has been used to analyse the late Devonian to Recent geologic evolution and hydrocarbon habitat of north Alaska and northwest Canada. Eight depositional megasequences have been identified, each of which records a discrete, major phase of basin evolution. The three oldest megasequences are named the Ellesmerian and reflect deposition on a subsiding fold belt terrane. We name thc subsequent two megasequences of early Jurassic to Aptian age, the Beaufortian. They record a 100 Ma period of extension during which a Jurassic failed rift episode was followed by onset of the successful rift episode in the Hauterivian. This extension led to the opening of the oceanic Canada Basin. The final three megasequences record geographically distinct pulses of Brookian orogenesis.The major proven hydrocarbon habitat occurs on the Barrow Arch of north Alaska. This is a volumetrically large, but greatly restricted, hydrocarbon province, which developed as a result of constructive interference between Beaufortian rift and Brookian orogenic tectonics. Two other, relatively minor, hydrocarbon provinces have also been discovered. They are the Mackenzie Delta and Kugmallit Trough provinces of northwest Canada, which developed in passively subsided basins, located just beyond the influencc of Brookian orogenic uplift.

Structure and stratigraphy of the Hanna Trough, U.S. Chukchi Shelf, Alaska

“…Hubbard et al (1987) and Haimila et al (1990) published regional studies of the Chukchi and Beaufort Seas based on proprietary seismic data. Regional studies, also based on proprietary seismic data, were published as Minerals Management Service agency reports by Thurston and Theiss (1987), Craig et al (1985), and Sherwood et al (1998).…”

“…3C). These strata represent a distinct tectonic event and have been variously distinguished along the Beaufort margin as the Rift sequence (Craig et al, 1985), the Beaufortian sequence (Hubbard et al, 1987), or the Barrovian sequence (Carman and Hardwick, 1983). Because it is more general, we prefer the term Rift sequence for rocks deposited during the Mesozoic rifting episode on the northern Chukchi Shelf.…”

Ranking "White space" Frontier Regions - An Arctic Example Illustrating the Power of Integrating Plate Tectonic Reconstructions into Regional Evaluations

“…; (ii) 'strikeslip' models where the central Canada Basin opened by spreading normal to the Arctic Alaska basin margin (e.g Dutro, 1981;Hubbard et al, 1990)Lawver et al, 2002)…”