Uplift and denudation of Arctic Continental Margins: Insights from Comparison with Margins around the World

Paul Green

A considerable body of evidence has been published over recent years to show that Arctic continental margins have undergone a series of broadly synchronous episodes of deeper burial followed by exhumation, and that the elevated topography at many margins today is a relatively recent phenomenon. This evidence comes from a wide variety of paleo-thermal and paleo-burial techniques, (AFTA, VR, sonic velocities, landscape analysis), providing highly consistent results. Nevertheless, some still claim that elevated continental margins of the Arctic are the result of long term erosion of Paleozoic fold belts, enhanced by Neogene climate deterioration and isostatic response to the resulting enhanced erosion rates. Such explanations claim a particular role for glaciation in enhancing elevations at Arctic margins. But as we will show here, continental margins in many parts of the world display very similar topography to Arctic margins, and AFTA studies etc define a very similar style of burial/exhumation evolution to those defined from similar approaches at Arctic margins. These basic observations, including many margins which have never been glaciated, clearly show that development of similar morphologies to elevated Arctic margins is possible without any significant influence of glaciation and is instead governed by tectonic processes. Results from around the world show a close correlation of exhumation events with regional tectonic processes, suggesting that uplift (accompanied by denudation) is caused by stresses transmitted through plates over huge distances. To invoke glaciation to explain the development of elevated Arctic margins represents special pleading, and is unnecessary. While such issues may at first seem esoteric, the implications to hydrocarbon exploration are significant, as the uplift and denudation histories of continental margins exert a critical control on the supply and quality of reservoir horizons in offshore basins and to burial of source horizons. In addition, uplift events at onshore margins are often recognised as unconformities in adjacent offshore basins, with major implications in terms of formation of structures and the timing of source rock maturation. A clear understanding of the true nature of the development of “passive” margin development is therefore key to the search for hydrocarbons, because margins can in fact be quite lively!

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013