Pattern of Global Crustal Stresses of the Earth

Abstract

The results of tectonophysical inversion of the global tectonic stress field are considered from the position of explaining the active forces that cause the lithospheric plate movements. The analysis of regularities of the stress state of the main structural elements of Earth’s lithosphere—ocean spreading, transformations, active continental margins, and intracontinental orogeny—is performed. It is shown that the stresses in most of the ocean lithosphere, including subduction zones, correspond to active traction forces from the submerged and weighted part of the lithosphere. A low level of deviatoric stresses in subduction zones and the presence of dynamo pair with sharply different mode of stress state were found. Horizontal compression is observed in the crust of the continental slope, and horizontal tension is observed in the ocean lithosphere, so the boundaries of lithospheric plates should not be considered as a source of increased horizontal compressive stress in the crust of continents. The formation of a horizontal compression regime in the crust of intracontinental orogens, as well as in the crust of active continental margins orogens, is associated with residual stresses of rocks that have been exhumed from the depths of the crust. A generalizing scheme for the formation of the global crustal stress field of the Earth is proposed, which corresponds to modern data on the movements of lithospheric plates and the deep structure of the upper mantle.