LAYER SEPARATION OF THE EARTH AND MULTILEVEL CONVECTION AS THE BASIS OF A TRULY GLOBAL GEODYNAMIC MODEL

Abstract

The idea of a concentrically zoned earth, consisting of a number of concentric shells, has long been established in science. But we are only beginning to realize that each shell constitutes a self-contained dynamic system. The principle of universal relative mobility governs the interaction of the earth's shells and is the basis of all geodynamics. It shows up especially strikingly in the interaction between the lithosphere, hydrosphere and atmosphere, but it is also valid for the deeper shells of the earth. It appears probable that the interaction between shells is intensified in the periods of vigorous liberation of the internal heat of the earth (because it is this interaction is a prerequisite for heat liberation) and that it becomes weaker in the intermediate periods. The alternation of such periods is also manifested as periodic variations in the volume of the earth. We also suggest that the interaction between shells and the vigor of the processes in the outermost shells were greatest in the early stages of the earth's development, owing to a higher heat flux. This is the reason for the ubiquitous deformation and low-gradient metamorphism of the most ancient, Archaean rocks. Over geologic time the processes in the individual shells became more independent, with a pattern of successive intensification and slackening.