ON THE STRUCTURAL AND MATERIAL HETEROGENEITY OF THE ZONE OF TECTONIC DISCONTINUITY LOCALIZATIONS

The paper presents the results of a complex investigation on an exhumed section of a tectonic fault being a part of the Buguldeisky disjunctive node of the Baykal Rift Zone. The chemical composition of 81 samples taken at the day surface was determined, and their petrographic description was performed. Applying the hierarchical clustering algorithm in the analysis of chemical composition of the samples made it possible to distinguish three groups that characterize fault walls, composed of amphibolite and granite. Also the core of the fault was detected, which is characterized by an insertion of a ferruginous- carbonate material. The petrographic description of the samples confirms the correctness of identifying three groups and allows, additionally, to reveal the dynamometamorphic transformations of minerals localized in the fault core which were produced by high-amplitude seismogenic slips. In the fault core, the rock was subjected to strongest cataclastic deformations with a local frictional heating up to 1000° C. A geoelectric section was constructed across the strike of the fault based on the electrical tomographic measurements. A conductive zone 20 m wide is distinguished in the geoelectric section, which is spatially consistent with the zone of the fault core. Based on a comprehensive study of the exhumed segment, the elements of its occurrence were determined (strike azimuth is 70°, dip angle is 60°), which indicates that the exhumed segment belongs to the Morsky fault.