Metamorphism and partial melting in ancient orogens

Abstract

This research project aims to investigate the the tectonic evolution of ancient orogens through the study of metamorphic rocks. Metamorphism and partial melting are direct consequences of the thermal relaxation that follows the collisional stage in orogens. The shape of the P-T paths, melting reactions and mineral paragenesis are reflexes of the tectonic history the rock underwent, so the characterization of textures, type of metamorphism and melting, determination and calculation of intensive variables can be used as tools to access and infer part of the tectonic story of orogen. Two model regions are chosen to research, the Southern Brasília Orogen and Itatins Complex. In both units will be investigated metamorphic rocks of green schist to granulite facies, for determination of P-T conditions, metamorphic paths, melting process, textures, mineral growth, behavior of trace elements in minerals in various textural contexts, in situ dating, and thermodynamic modeling. (AU)