Paleogeographic Development of the Circum-Arctic Region with Particular Focus on the Amerasian Basin and Surrounding Regions
Peter Winefield3, Cees van Oosterhout2, Steven Bergman1, Dan Worrall1, Michael DiMarco1, Gary S. Steffens1, Mario Wannier2, Malcolm Ross1, and Andrew Bishop1
1Shell International Exploration & Production, Houston, TX.
2Shell International Exploration & Production, The Hague, Nigeria.
3Shell Petroleum Development Co. of Nigeria, Lagos, Nigeria.
Using regional geology, seismic and well control with newly compiled potential field data, a new tectonic model is proposed that has significant impact on timing and opening of the Amerasian (Canada) and surrounding Circum Arctic regions. This has allowed the generation of a series of tectonic basemaps at specific stratigraphic intervals upon which stratigraphic and structural data were restored to their paleo-positions using PaleoGIS to assist in the generation of paleogeographic maps. In addition, a Circum-Arctic stratigraphic chart was compiled from various sources to validate and constrain the proposed tectonic model and resultant maps. Stratigraphic analyses highlight numerous regional unconformities, as well as proven and potential reservoir and source rock intervals throughout the Arctic from Paleozoic to Cenozoic. The stratigraphy is carbonate-rich in the Paleozoic becoming less so in the Mesozoic and Cenozoic reflecting the gradual shift of landmasses from low to mid-latitudes to high latitude positions through time. This process facilitated regional basin tectonic analysis and extrapolation of proven reservoir and source rock trends into under-explored or data-poor areas highlighting potential ‘white-space’ areas for future exploration.
A selection of paleogeographic maps across the Circum-Arctic are presented ranging from the early Triassic to Paleocene-Eocene times. Key unconformities are recognized that differ from previously published models, such as the Lower Cretaceous Unconformity (LCU) that is interpreted here as a flexural unconformity due to Brookian thrusting. Other workers view the LCU as a break-up conformity associated with the opening of the Amerasian (Canada) Basin. In addition, evidence is also presented for the delineation of the line of suture for the late Silurian to mid Devonian Innuitian Orogeny. This provides a solution to the apparent paradox of Siberian affinities of lower Paleozoic carbonate platform strata in North and Central Alaska as well as in Chukotka and the East Siberian shelf.
AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.���������������������������������������������������������������������������������������������������������