PAOC Other

Advanced modal analysis methods1,2 are integrated with seismic reconstructions, gravity/magnetic, and well/core data, revealing the complex geo-history of Pangean organization, and its consequent tectonic break-up, mainly during the Cretaceous and Cenozoic3. Sediment transport systems from orogenic Caledonian and Uralian terrains, as well as Fenno-Skandinavian shield areas, provide a wide variety of basin provenance signatures, as well clastic wedge basin fill sequences, recording the tectonic evolution of convergent margins creating the super-continent Pangea in this region. These sequences are followed by rifting events related to the opening of the Arctic Ocean basins3. Pronounced uplift and erosion episodes of Arctic Greenland-Norwegian continental margins also occur during these times of rifting. Such episodes are here related to the lack of accommodation for Arctic sea-floor spreading rates, where the coupled continental margin drift rate is < ½ of the total ridge spreading rates, resulting in inversion displacement along pre-existing fault systems (inverse Beta motions). In more extreme cases, under-plating of the lithosphere, subduction and regional uplift can be realized over broad areas, which would have significant implications for energy exploration in prospective basin areas, particularly where uplift/erosion exceeds c. 1.5 km resulting from geodynamic crustal compression with shortening of c. 20%. These tectonically uplifted terrains may also contribute to the Earth’s long-term climate shift from greenhouse to icehouse environmental conditions during the Cenozoic, particularly the last 50 Ma4. The lack of accommodation for mainly North-South opening of the Arctic Ocean may be a global consequence of the predominant equatorial East-West spreading creating the Atlantic Ocean further South, including that of the Icelandic ridge system. This appears to be a common feature of Arctic continental margins, and possibly passive margins in general. Ultimately, this lack of accommodation may herald termination of the prevailing Wilson cycle, where initiation of oceanic subduction below the uplifted continental margin followed by the transformation of passive continental margins into a convergent margin with thrust fault deformations, subduction, and volcanism, which begins the next super-continental cycle5. The geologic processes have reduced prospective petroleum reserves in high latitude basins by an estimated 80%, having strategic implication for arctic energy exploration, environmental conservation, and long-term administrative policy.