Stages, Mechanism and Geodynamics of Formation of the Folded System of the Greater Caucasus

Abstract

The relevance of the work. The article considers the main important features of the folding system of the Greater Caucasus. The most important feature of the Greater Caucasus is the asymmetric lateral structural zonality of its main linear folded system. It is expressed in the change in the cross section of the region from southwest to northeast of highly compressed folding of moderate and then weak folding into a gentle monocline. In addition to the main linear folding of the northwestern strike in the Greater Caucasus, superimposed transverse structures are developed. The purpose of the work is to study the stages and mechanisms of the folding of the Greater Caucasus. It is established that in the folded structure there are two main stages of the alpine dislocation of the region, which took place under different geodynamic conditions. The first stage of the deformation corresponds to the early-mid-Alpine and early-orogenic stages of development and took place in an atmosphere of northeast tangential compression of the Greater Caucasus. The second stage of dislocation, which represents the late orogenic stage of the region development, took place under conditions of submeridional horizontal compression and led to the formation of interference folding and tectonic covers. Methods: field geological and structural studies of the folded system of the Greater Caucasus, which made it possible to establish its complex and heterogeneous structure. Results. The dynamics and mechanisms of the folding of the Greater Caucasus are examined in a new way and the conditions of folding are established on the basis of an analysis of its structure. The opinion was expressed that the external compression deformations were caused by the manifestation of local, regional and global geodynamic processes in the region, due to the rapprochement of the African-Arabian continent with the Eurasian. It was found that the Black Sea-Transcaucasian microcontinent adjacent to it from the south and its kinematics at different stages of the region’s deformation played a decisive role in the structural formation of the Greater Caucasus. It moved north and moved towards the Greater Caucasus along the plane of the Southern marginal deep fault and caused its alpine dislocation. The general regional formation mechanism of the fold system of the Greater Caucasus was not the currently widely accepted sub-thrust deformation mechanism, but the pre-thrust mechanism of tectogenesis that is more substantiated by the actual material.