| The sedimentary basins of Arctic North America and Greenland are extremely diverse in their modes of genesis. This controls the development of petroleum systems within these basins as well as their exposure to post-accumulation destructive forces.
The Canadian - Greenland Shield is a significant controlling influence on basin development in the area due to its 60km thick core of well-annealed, highly buoyant continental crust. During the lower Paleozoic platformal sediments accumulated around the flanks of the generally emergent craton with the reduced oxygen atmosphere being conducive to the accumulation of organic rich, oil prone source rocks of Ordovician, Silurian, Devonian and Carboniferous age. The Caledonian suturing at the end of the Paleozoic provided erosional products to the interior forelands and drove hydrocarbon generation in some of these basins.
The Ellesmerian collision in Northern Canada quickly produces the Parry Island foldbelt and segregates the Sverdrup Basin from the Ellesmerian platform. The Caledonian suture attempted to rift open numerous times. These failed rifts were very conducive to the accumulation of source rocks with lacustrine as well as marine (Kimmeridgian) sources being deposited. The rift flank uplift along East Greenland provided a significant sediment source into the Sverdrup Basin. Rifting temporarily propagates into Labrador and opens Baffin Bay with strike slip motion along Nares Strait during the Cretaceous. The movement of the Alpha Ridge "plume" from the high arctic in the Cretaceous into the North Atlantic drives rifting to the east side of Greenland. The North Atlantic opens in the Early Tertiary with abundant associated volcanism and propagates into the arctic with the opening of the Eurasian Basin. Atlantic rifting drives Greenland back into the Sverdrup margin producing the Eurekan Orogeny.
Pacific subduction profoundly affects the western side of the craton generating the Western Cordillera and the Brooks Range. Associated forelands developed and began to be rapidly loaded with Cretaceous - Tertiary sediment. Paleozoic and Mesozoic sources were augmented with Cretaceous sources and significant generation occurred in Northern Alaska and the Western Canada Sedimentary Basin. These basins are characterized by long distance migration, stratigraphic traps and significant basin margin accumulations with a risk for biodegradation. The Cordillera is a very destructive environment for hydrocarbon accumulation with interior collapse basins and transtensional pull-aparts all presenting poor targets for exploration. The final tertiary draining of the North American continent produced the Mackenzie Delta in the Canada Basin which entered an inside corner of the transform rift margin and has been constantly "forced" by ongoing Cordilleran tectonics resulting in some trap rupture. |
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