Problems of Tectonics and Petroleum Potential of the East Arctic Province

Victor Khain, Inna Polyakova, and Nadezhda Filatova
Geological Institute, Russian Academy of Sciences, Moscow, Russia.

The East Arctic area consists of several tectonic units of different types and ages. Its polar sector is occupied by the Amerasia Basin, which is now part of the Arctic Ocean. The adjacent continental margin of Eurasia and North America involves fragments of the Hyperborean craton and Early Paleozoic to Middle Cretaceous orogens. Late Jurassic-Early Cretaceous spreading in the Amerasia Basin gave rise to the Verkhoyansk-Chukchi tectonic zone with the Verkhoyansk-Kolyma collisional system along the deformed continental margins, and syncollisional foredeeps. The Amerasian spreading (Canada and Podvodnikov-Makarov Basins) forerun by Triassic-Jurassic rifting was the initial event in the modern history of the Arctic Ocean. Later Cretaceous and Cenozoic pull-apart and rift basins that arose on shelves and continental slopes of the fringing seas during the opening of the Amerasia and Eurasia Oceans had completed the tectonic framework of the today’s East Arctic.

The Mesozoic-Cenozoic shelf (South Chukchi and New Siberian-North Chukchi) and continental slope (East Siberian on the Podvodnikov Basin periphery) basins on the East Arctic margin may be expected to have high petroleum potential, by analogy with basins of the Arctic and Atlantic passive margins where economic oil and gas fields were discovered.

Oil and gas in shelf basins may be trapped in zones of pinching out sand beds where they meet transversal uplifts, structural closures, and slopes. Reservoirs in slope basins may be associated with the sand fill of canyons and channels on the stepped continental slope.

Most of oil and gas fields may occur in Cretaceous and Mesozoic basins. Natural gas entrapment may occur in synrift sediments of two stratigraphic levels: Late Devonian-Early Carboniferous strata (equivalent of the terrigenous Endicott Group in the Hanna trough) and especially Triassic-Jurassic formations (equivalent to thick shale and turbidite formations of the Beaufort and other basins). Late Cretaceous-Mesozoic basins appear to be mostly gas prone with less significant oil and bitumen resources.

AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia