STRUCTURAL-TECTONIC DIVISIBILITY OF THE EARTH›S CRUST AND ITS REFLECTION IN AREAS OF DIFFUSE RIFTING

Abstract

The study of the fragmentation phenomenon and divisibility of rocks is of great importance for understanding the essence of the seismic process, solving the problems of the mining industry, and identifying the parameters and mechanisms of fault-fracture tectonics. A fundamentally significant contribution to the development of this direction was made by Academician Mikhail Alexandrovich Sadovsky. Usually, the problem of divisibility is сonsidered in the context of fault-fracture tectonics, but divisibility is determined not only by linear structures (faults, lineaments), but also by the existence of three-dimensional geological provinces with structural and material content characteristic only of these provinces. This type of divisibility is practically not studied. The article describes the areas of areal rifting: the Provinces of basins and ridges (North America), the Selengino-Vitim zone (Western Transbaikalia), the Sunda shelf (the Malay Archipelago), which are elements of the volumetric divisibility of the earth›s crust and at the same time have an internal divisibility of a higher rank. The study is based on a comparative structural and tectonic analysis using both author›s and literary material. The objects considered in the article form tectonically isolated lenticular planar geological bodies with an individual morphostructure, geological history and geodynamic conditions of formation. They are bounded by fault zones and are represented by structural paragenesis of brittle-plastic diffuse (dispersed) shear, which is characterized by the fragmentation of rock masses into a system of linearly ordered uplifts and troughs. The existence of such morphostructural ensembles (paragenesis) reflects the 3D tectonic divisibility of the crustal scale.