TYPES OF PLANETARY MORPHOSTRUCTURES

Abstract

A classification of planetary morphostructures must be based on the main differences of the structure of the earth’s crust. Proceeding from this principle, the following planetary morphostructures may be singled out: continent platforms, the ocean’s bed, gecsyn- cline and transition areas, and middle seamounts. The Cenozoic time is characterized by the further development of former and the formation of new geosynclines, by an inten­sive deflection of the oceanic floor and the development of groove genesis resulting in the formation of middle ridges. The deflection of the continent platforms’ margins in the Cenozoic era is conditioned either by the influence of the processes in geosyncline areas, or by the effects of the deflecting oceanic floor. Differentiated intensive vertical movements of the so-called activated platforms and the formation of mountain structures in the place of ancient platforms is, probably, associated w ith the spreading of the groove genesis onto the continental earth crust and with the latter's conversion.

The greater part of the earth’s surface (more than Г00 mln sq. km) at the present time is undergoing negative vertical movements indicatii g a contraction, rather than an enlargement of the Earth in the recent geological epoch.