The Serra do Caparaó Complex, Mantiqueira Province, Brazil, revisited: metamorphic age constraints by U-Pb and Lu-Hf method in zircon by LA-ICP-MS
Journal of the Geological Survey of Brazil
The Serra do Caparaó Complex, Mantiqueira Province, Brazil, revisited: metamorphic age constraints by U-Pb and Lu-Hf method in zircon by LA-ICP-MS
Autor Correspondente: M. C. Geraldes | [email protected]
Palavras-chave: U-Pb isotopes, Lu-Hf isotopes, LA-ICP-MS, zircon, Ribeira Belt, Gondwana assembly
Resumos Cadastrados
Resumo Inglês:
The U-Pb method was used in order to understand the high-grade metamorphic rocks in the Ribeira Belt (SE Brazil) and Lu-Hf isotopes were applied to investigate the magmatic photolith sources and the tectonic setting of Serra do Caparaó Complex rocks. The results indicate the existence of two thermal events: the first related to a Paleoproterozoic magmatic event and the second one linked to high-grade metamorphism related to the Brasiliano Orogeny. The U-Pb age interval from 2209 to 2060 Ma obtained in zircon grains from the granulitic orthogneiss with TDMcrustal ages ranging from 2.13 to 3.87 Ga may be interpreted as mantle-derived source with important older crust participation in the magma formation; juvenile arc-related rocks were generated at this time as indicated by the positive ƐHf values. The second group of U-Pb ages ranging from 633 to 584 Ma is interpreted as a metamorphic event, resulting from the collisional process related to the Gondwana assembly.