SYNMETAMORPHIC STRESS-GRANITES IN DEEP LEVELS OF THE EARLY CALEDONIAN COLLISIONAL SYSTEM IN THE WESTERN BAIKAL REGION

Abstract

The study of synmetamorphic granites of the Ol'khon collisional system revealed the abundance of injection veins, dikes, and intrusions. Their emplacement was controlled by ductile strikeslips that postdate and occasionally deform domes. The unique compositional and genetic features of these rocks make it possible to distinguish them as a specific type of granite formed in the course of metamorphism in strike-slip zones (hereinafter, synmetamorphic stress-granites). Their tectonic position is defined by ductile shear deformations at deep levels of the Earth's crust, including the collisional setting. The aim of this work is to describe and compare these granites with synmetamorphic granites, which compose the dome cores and display typical signs of the partial melting of metapelites during basement remobilization.