Crustal basic eclogites in the field of view of the grt-cpx-pl-qz paragenesis

Abstract

The unique properties of garnet have been studied - to preserve their composition under the conditions of a changing regime of metamorphism and to record these changes in the process of development of the complex. Using these qualities in the Grt-Cpx-Pl-Qz paragenesis, it was possible to elucidate the nature of the formation of contrasting series of rocks in eclogite-blueschist complexes: high-pressure boudins and eclogite inclusions in a weakly metamorphosed sequence of the gneisseschist rocks. It has been established that the processes of tectonic melange and coherent development of the host complex are independent successive stages of a single process of metamorphic evolution of the complex.