Geophysical processes and biosphere: article

Аnnotation: The neomobilist pleitectonic concept currently plays a leading role in geotectonics. This concept is based on the idea of the division of the Earth’s crust/lithosphere into different-sized plates, blocks, arrays that move laterally as a result of 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 material accumulated to date on geodetic (mainly GPS) measurements of real movements within the Eurasian lithospheric plate indicates that the size of its northern part is significantly increasing in the direction from West to East. The 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, the article provides an interpretation of this elongation of the northern part of the Eurasian lithospheric plate in the direction from West to East. This elongation develops against the background of the predominance of subhorizontal compression stresses in the Earth’s crust of the considered part of Eurasia. 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 tip of the plate (Kolyma Highlands). The surroundings of the Upper Rhine Graben and the Baikal Rift, where subhorizontal stretching prevails, corresponding to the orientation of the geological data known here, 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 in the direction from West to East, while being in a stressed state of subhorizontal near-meridional compression, can occur due to the development of strut stresses in the crust/lithosphere. These stresses are most likely caused by an increase in the volume (and area) of layered rocks as a result of the introduction of additional mineral material into them by deep fluids from the lower crust/upper mantle and its subsequent crystallization.