Zircon U-Pb ages and Hf isotope compositions of Açucena Granite (Borrachudos Suite): Implications for Statherian-Cambrian tectono-magmatic evolution of the southern border of the São Francisco Craton, Brazil

摘要: Abstract Isotopic Lu–Hf and geochronological studies on the zircon grains of Paleoproterozoic Borrachudos Suite provide constrains evolution tectonomagmatic events that affected southern border Sao Francisco Craton leaded to formation associated iron emerald deposits. The granite records magmatic crystallization in 1740-1688 Ma time range, A2-type geochemical signature. Zircon present hydrothermal anatectic areas with Cambrian age are related gravitational collapse final stages Brasiliano orogen. During this event was deformed metamorphosed amphibolite facies, leading anatexis large amount pegmatite bodies. Hf isotope data hydrothermal/anatectic indicate partial melting were accompanied by fluids enriched radiogenic Hf. These contributed volume hydrous melts (pegmatites), deposits high-grade orebodies.