ПРЕОБРАЗОВАНИЯ ГРАНИТОИДОВ В ПРОТРУЗИЯХ ДЗУРАМТАЙ И ТОБХОР (МОНГОЛИЯ И ЗАБАЙКАЛЬЕ)

The specific features of structural-lithological transformations in granitoid protrusions in the Dzuramtai (Southern Mongolia) and Tobhor (Western Transbaikalian area) massifs are outlined in the article. These transformations have contributed to rock disintegration and tectonoclastite development, which are erroneously referred to sedimentary rocks. The features which distinguish tectonoclastites from sedimentary rocks were identified. It was established that the main reason leading to variable manifestations of tectonic disintegration in granitoids is heterogeneity of the composition, structure, and physico-mechanical properties of granites (Dzuramtai massif) and syenites or quartz syenites (Tobhor massif). In addition, the transformations of granitoids were controlled by various stress values and stress deformations during the piercing of variable thickness sedimentary cover by the dome of protrusion. The changes of granitoid tectonic disintegration products by superimposed processes (infiltration water or hydrotherms) and surface weathering, which enhance rock disintegration or, conversely, lead to their lithification were discovered. Local kaolinization of products of tectonic disintegration of granitoids by underground water and development of quartz-kaolin tectonoclastites (which can be mistake for redeposited weathering crust) was recorded in Dzuramtai massif protrusion. The signs allowing identifying of these genetically varying formations were presented.