The effect of the mantle and core matter phase state on the course of geodynamic processes

Abstract

The study of the course of geodynamic processes in the lower crust and upper mantle proves that an additional energy contribution is made by a change in the phase state of matter with increasing pressure and temperature. The gas phase, composed of hydrogen, oxygen and carbon, turns into a fluid that combines the properties of a liquid and a gas. The result is a change in the behavior of fluid-crystal and fluid-melt systems which significantly accelerates melting and physicochemical interactions in the thermal asthenosphere. These conclusions are confirmed by numerous experimental studies and the results of the study of xenoliths representing the crust and mantle of cratons and active regions. Seismic tomography studies show distinct patterns of inhomogeneities in physical pro­per­ties, reflecting inhomogeneities in the mantle structure. Many works hypothesize, with substantiation, that plumes or fluid flows arise at the boundary of the core and mantle and are factors of all geodynamic processes. Modern ideas about the composition of the Earth's core are based on the statement that it is composed of molten iron with minor impurities of other elements. However, calculations of the energy balance and physical modeling of the redistribution of matter in the core itself show that the removal of volatile components or convective currents do not provide enough energy for the formation of plumes. The assumption that the substance of the core is an electrically conductive ionic liquid in which chemical compounds have completely dissociatedand the electronic structure has no gapradically changes the idea of the energetics of the core and the possibility of initiating plume processes. The properties of a substance in a similar phase state are fundamentally different from the properties of a liquid.