GEODYNAMIC ZONING OF WESTERN TRANSBAIKALIA USING COMPUTER LINEAMENT ANALYSIS OF THE DIGITAL ELEVATION MODEL

The article concerns the research of neotectonics and modern seismic activity of the Western Transbaikalia. The region is located on the southeastern flank of the Baikal rift system and is the western boundary of the Amur Plate, representing a transition region between the influence of the Indo-Asian collision, which determines compression deformations and extension during rifting. The purpose of the study is the geodynamic zoning of Western Transbaikalia using computer lineament analysis (LESSA technology) of a digital elevation model (DEM). This analysis made it possible to identify three regions within the study area with different structural patterns: Ust-Selenginsky, Western, and Eastern, which differ in geodynamic settings, the nature of seismicity, the history of relief development, the time and style of neotectonic deformations at  different  stages  of  rifting. The  boundaries  of  the  regions  are  marked  by  extended morpholineaments, gradient zones of density of small lineaments, and thickening of structural lines, coinciding with geological deep faults and zones of deformation localization. The most active fragments of lineaments were identified and their possible kinematics were determined. A zone of concentration of submeridional morpholineaments and supposed plastic flow has been determined, which predetermined the geodynamic history of the region and the possible position of the western paleoboundary of the Amur Plate at the early stage of passive rifting. The role of extended morpholineaments of meridional and NNW strike on the localization of strong earthquakes has been revealed. The influence of the Daurian megaarch on the distribution of extended lineaments of NNW strike is noted.