Granulite Facies Rocks of Brazil: A Review of their Geologic Setting, Geochronological Evolution, Petrographic and Geochemical Characteristics

Abstract

An attempt to assemble the available data on the granulite facies rocks spread around Brazil is made with a view to discuss their geological setting, geochronological evolution, petrographic and geochemical evolution. The isotopic ages of the granulites fall into different groups ranging from Archaean to Late Proterozoic. The geotectonic evolution of these rock types is discussed in terms of their being either fragments of geochemically differentiated lower crustal layers or eroded segments of modern Cordilleran (Himalayan) type collision belts. The geochemical feature of the rock types demonstrates the non-systematic fractionation of trace elements.