Granulite Gneiss Belts: The Geodynamic Aspect

Resumo

The features of the structure and tectonic evolution of granulite gneiss belts (GGBs) are analyzed and summarized from the present-day data. Their continent–continent collision tectonic origin is supported, as well as multicycle and an inherited style of evolution expressed in multiple manifestations of granulite facies metamorphism of the belt separated by few 100 Ma. GGBs are permanently mobile structures that exhibit endogenic activity during all stages of their evolution, including intraplate conditions. Their relationship with supercontinental cyclicity is evident from (i) the spatial location of most GGBs in the margins of young oceans that originated during the breakup of Pangea, (ii) the amalgamation and breakup of ancient supercontinents along the GGBs, and (iii) the correlation between various types of granulite metamorphism of these belts and stages of supercontinental cycle. The evolution of these belts leads to complex interaction of plate and mantle plume tectonics, which is expressed in combination of continent–continent collision and underplating. The possible use of GGBs in paleotectonic analysis along with other indicators of geodynamic settings is shown.