Arthur Grantz, Consulting Geologist (United States)
Robert Scott, Cambridge University (United Kingdom)
Sergey Drachev, P.P Shirshov Institute of Oceanology (Russian Federation)
Thomas E. Moore, U.S. Geological Survey (United States)
James P. Howard, Cambridge University (United Kingdom)
We have identified one hundred and twenty sedimentary accumulations in the Arctic Region (64°-90° N) that are either known to contain, or may possibly contain hydrocarbon deposits. Each accumulation represents one of 13 empirically-defined first-order, unconformity-bounded sedimentary sequences of specific tectonic affinity identified during our study, and does not necessarily represent the total section of sedimentary rock that overlies economic basement in a particular area. Most of the accumulations are morphologic basins but some are platform, shelf or prograded sequences. In many areas two or more of the accumulations are superimposed. The outlines of these accumulations, classified by their first order tectonic character, are displayed on a bathymetric map of the Arctic presented in four quadrants at a scale of 1:4,000,000. Major structural or tectonic features associated with the creation of the basins, or with the enhancement or degradation of their hydrocarbon potential, are also shown. The thicknesses of the sedimentary accumulations, or of selected stratigraphic intervals of each accumulation, are shown by isopachs on the maps where data permit.
Accumulations on continental crust in the Arctic consist of stable shelf and platform deposits, coastal plain and marine deposits, basins created by multiple rift and thermo-isostatic (sag) events, transtensional rift basins, extensional basins of undetermined origin, basins created by pre-breakup extension in continental crust adjacent to a developing ocean basin, basins created by extension in continental crust along the strike of a developing ocean basin, foreland basins and one fore-arc basin at the Pacific rim. Accumulations within or across continental margins in the Arctic include progradational passive margin successions of both existing and extinct ocean basins and synrift half graben deposits in passive continental margins. Small to very thick sedimentary accumulations on oceanic crust are also present.
The predominant sedimentary fills of the Cenozoic Eurasia Basin and the mid-Early Cretaceous to Neogene Amerasia Basin of the Arctic Ocean consist of the prograded sedimentary prisms of the major Lena and Mackenzie River delta systems, respectively. Onshore the Arctic Ocean is ringed by 14 large epicontinental sedimentary basins, many known to be petroliferous, from Arctic Alaska on the west to the West Siberian Basin and Yenisey-Khatanga Trough on the east. In addition, numerous smaller riftogenic and extensional basins underlie the margins of the Labrador Sea, Baffin Bay, the North Atlantic, Canada Basin, eastern Siberia and its continental shelf, and western Alaska.