Structural and Petrological Evolution of the Snezhnaya Gabbro-Syenite Massif (Southern Baikal Region)

Abstract

The article deals with the structural and petrological evolution of one of the many gabbroid massifs of the Southern Baikal region - Snezhninsky, located near the river of the same name, characterized by the most typical structural and metamorphic paragenesis: comfort with layering of containing rocks, located in a steep twisted wing of asymmetrical folds of latitudinal extension with horizontal hinges and axial planes inclined to the north. the array is complicated by a longitudinal oblique upsurge with a powerful zone of tectonites. The northwestern end of the massif is complicated by the upsurge of the northeastern extension. To a depth, the massif sinks to 4-5 km and there is cut off by another fault of the northwestern extension. The internal structure of the array is characterized by a rather monotonous development of small structural forms: the structures of the magma flow, emphasized by the elongation of flat xenoliths, the asymmetrical folds of the right pattern in the plan, the gradual intertransitions between all varieties of rocks composing the array, indicating a significant warming of all rocks during their formation and assimilation.