DEPARTAMENTO DE GEOLOGIA
UNIVERSIDADE FEDERAL DE OURO PRETO
Metamorphic evolution of paragneisses and cordierite granulites of the Nova Venecia Complex, Araçuaí belt
The Araçuaí Orogen (AO), in Brazil, comprises Neoproterozoic-Lower Paleozoic domains formed as part of the Brasiliano-Pan African Orogenic System during the assembly of West Gondwana. The high-grade crystalline core of the AO is today exposed in southeast Brazil – vast areas of high-grade metassedimentary rocks, I- and S-type granitoids provide excellent exposure to understand process of granitoid production, migration and emplacement in colisional orogenic belts. The granitoids constitute five main Supersuites (G1 to G5) that are believed to record a protracted magmatic evolution from ca. 630 to 480 Ma. One of the most striking features of this core is the large exposure of metasedimentary high-grade rocks and S-type peraluminous granitoids that outcrop as voluminous stocks and batholiths distributed for more than 300 km from north to south along the belt. The section I am currently studing exposes a nearly continuous crustal profile from mid-crustal anatectic migmatites and granulites in the southern part of the orogen to progressively shallow-level granitoid plutons and pegmatites towards the north. One key unit that may help constraining metamorphic evolution in the AO is the metasedimentary anatectic Nova Venecia Complex (NVC). I am currently interested in understanding the melting behaviour of NVC protoliths by determining its P-T metamorphic peak conditions and timing of metamorphism in relation to granitogenesis within the area.
Biotita gneiss outcrop in the Nova Venecia Complex