Stress–Strain State and GPS Kinematics of the Lithosphere in the Northern Part of Eurasia

— The neomobilist plate tectonic concept is currently at the forefront of geotectonics. This concept is based on the idea of the division of the Earth’s crust/lithosphere into plates, blocks, and massifs of different size that move laterally due to external forces. The greatest importance is attached to their movement due to the viscous coupling of plates with convective flows in the mantle. At the same time, the results available on geodetic (mainly GPS) measurements of real movements within the Eurasian lithospheric plate indicate that the size of its northern part is significantly increasing from west to east. Existing ideas about the geodynamics of the Earth’s crust/lithosphere do not take this phenomenon into account. Based on the materials of systematic repeated GPS measurements and focal mechanisms of earthquake foci, an interpretation of this elongation of the northern part of the Eurasian lithospheric plate to the east is provided in this paper. This elongation develops against the background of the predominance of subhorizontal compression stress in the Earth’s crust of the part of Eurasia under consideration. At the same time, there is a systematic reversal of the orientation of the main compression axis from 147° in the west within the European margin of the plate to 283° at the extreme eastern edge of the plate (Kolyma Highlands). The environs of the Upper Rhine Graben and the Baikal Rift with predominant subhorizontal stretching, corresponding to the known geological data by the orientation, fall out of this pattern. It is assumed that the observed elongation of the Earth’s crust/lithosphere of the considered part of the Eurasian lithospheric plate to the east, while being in a stressed state of subhorizontal near-meridional compression, may occur due to the development of strut stress in the crust/lithosphere. Such stress is most likely caused by an increase in the volume (and area) of layered rocks as a result of the introduction of additional mineral material by deep fluids from the lower crust/upper mantle and its subsequent crystallization.