Geodynamic Modeling of the Process of the Formation and Evolution of Lithospheric Structures: the Experience of Schmidt Institute of Physics of the Earth, RAS

Abstract

The main results obtained at the Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS) in the numerical geodynamic modeling of the structures of the lithosphere are presented. Even in the first models, the objectives were set to describe the time evolution of the boundaries of the layers composing the geological structures, which is necessary for a detailed comparison of the modeling results with the geological and geophysical data. In 1983, the equation of motion for the upper boundary of the model was complemented with the description of sedimentation and erosion. With the use of this equation, not only was it possible to build geodynamic models describing the formation of various types of sedimentary basins but also to perform a mathematical analysis of the problem of determining the rates of paleotectonic movements from the data on thickness, age, and facies composition of sedimentary layers. New data on the processes of the formation and evolution of large-scale tectonic structures are obtained in the model of a rheologically stratified boundary layer of the Earth, asymptotically liked to the model of mantle convection. In particular, the role of small-scale convection in the formation of the lithospheric structures in the tectonic settings of extension and compression is investigated. The numerical results demonstrate the decisive role of the small-scale convection in the asthenosphere in the formation of sedimentary basins (post-rift, on passive continental margins, and foredeep basins). The constructed models served as the base for stating the problems of the interpretation of different geological and geophysical data in the frameworks of the geodynamic models. Examples are presented of the statement of inverse problems and the respective bibliography is provided.