СРАВНИТЕЛЬНЫЙ АНАЛИЗ ЛИНЕЙНЫХ ЭЛЕМЕНТОВ РЕЛЬЕФА И ГЕОФИЗИЧЕСКИХ ПОЛЕЙ БУРЕИНСКОГО И СИХОТЭ_АЛИНСКОГО ОРОГЕНОВ

Abstract

The Bureya and Sikhote-Alin orogens located in the northeast of the Amurian Plate are characterized by different levels of seismic activity. The analysis of the structure of the orogens based on the geophysical data and the study of the features of the relief using the WinLess program yielded the lines of the prevailing elongation of rose diagrams, lineaments, the density of lineaments of the diagonal systems, the total lineament density as an indicator of tectonic disturbance of the upper crust. On the basis of these data, it was established that both orogens are subject to tectonic impact of external sources (zones of the Indo-Asian interaction and the Pacific Plate), but the intensity of the process in the Bureya orogen is higher. The tectonic disturbance of the near-surface horizons of the earth’s crust in the Bureya orogen is also increased in comparison with the Sikhote-Alin orogen. The first orogen is characterized by large zones with maximum total density of northeast- or northwest-oriented lineaments localized along the axial line of the orogen; in the second case, there is a series of smaller zones of maximum density of lineaments with different directions randomly distributed throughout the orogen. The analysis of the relief, the crustal thickness and the magnetic field reveals compression regimes in the northern part of the Bureya orogen and the southern part of the Sikhote-Alin orogen and the transition from compression to extension in the other parts of the orogens.