DEFORMABLE PLATE TECTONICS AND REGIONAL GEODYNAMIC MODELOF THE ARCTIC REGION AND NORTHEAST ASIA
L.I. Lobkovsky
Shirshov Institute of Oceanology, Russian Academy of Sciences, Nakhimovskii pr. 36, Moscow, 117997, Russia
Keywords: Постулаты тектоники плит, теорема Эйлера, деформируемые плиты, эволюция Арктики и Северо-Восточной Азии в мелу и кайнозое, верхнемантийная конвекция, сопряженная с субдукцией, Postulates of plate tectonics, Euler’s theorem, deformable plates, Cretaceous and Cenozoic evolution of the Arctic and Northeast Asia, subduction-induced upper mantle convection
Abstract
The difficulties and contradictions of the classical concept of plate tectonics are discussed. It was shown the postulate of rigid plates and Euler’s theorem on the motion of rigid body with one fixed point, which is the basis of the kinematic description of plate tectonics, cannot be universally applied, e.g., to the analysis of Cretaceous reconstructions of the North Atlantic and Arctic. The second postulate of the existence of lithosphere as separate and distinct tectonic plates, which is equivalent to the assumption on the continuity of all plate boundaries, is not satisfied. This study provides a generalization of the theory of classical plate tectonics, in which plates are treated as deformable bodies, the concept of deformable plate tectonics. The study also discusses a new regional geodynamic model for the Cretaceous and Cenozoic evolution of lithosphere beneath Arctic and Northeastern Asia. The model is based on the assumption of a laterally extended convection cell in the upper mantle driven by a conveyor-belt-like process of subduction of the Pacific plate. The proposed model provides a physically sound explanation for the standard tectonomagmatic processes, such as island arc roll-back and opening of back-arc basins, formation of continental rift zones and igneous provinces at great distances (over 1000 km) from subduction zones, etc.
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