MELT INCLUSIONS IN THE CONTEXT OF CRUSTAL MELTING:A COMPARATIVE STUDY WITH LEUCOSOMES

Abstract

Partial melting is a key geological process, notably prevalent in orogenic environments marked by high-grade metamorphism all around the world. This study delves into anatexis, particularly within the upper amphibolite and granulite facies rocks of the Andrelândia Nappe in the São Francisco Craton, where the identification of leucosomes, peraluminous granitic bands intricately associated with gneiss, prompts an exploration into the potential involvement of in situ anatectic processes. This research aims to obtain a comparative analysis of results from experimental petrology runs, offering holistic insights into the main geological processes that controlled the evolution of this region, but also to elucidate the intricate relationships between partial melting, metamorphic evolution, and orogenic mechanisms. We propose taking a new approach focusing on melt inclusion studies for peritectic minerals associated with partial melting and experimental petrology techniques developed in the last decade that have never been implemented in Latin America. With the results from these experiments, we will have measured data on the extent to which crustal melting, even at low rates, can substantially influence the overall bulk composition of rocks, and most importantly, we will obtain experimental evidence of compositional correlation, or lack thereof, between P-T conditions of rocks without partial melting, and with rocks that just start to melt, studying their inclusions, with melt inclusions or not and their leucosomes, delving the geological understanding we have on such complex process as partial melting. This study presents a remarkable opportunity with considerable benefits, offering significant potential for advancing geological knowledge in the continent.