EVOLUÇÃO MAGMÁTICA DOS GRANITÓIDES PROTEROZÓICOS DO SETOR SETENTRIONAL DA PROVÍNCIA ESTRUTURAL MANTIQUEIRA, MINAS GERAIS, ESPIRÍTO SANTO, BRASIL.

Resumo

Neoproterozoic granitoid suites in southeastern Brazil are closely related to the different tectonic phaseswithin the Brasiliano tectonic-thermal Event. Petrography, geochemistry and structural features allow toseparate these rocks into pre-, syn-, late and post-tectonic granitoids.The whole emplacement process lasted about 100 Ma: from 595 Ma for the pre-tectonic granitoids, to near490 Ma for the post-tectonic ones. During this interval a 45 Ma magmatic quiet period (from 582 to 537Ma) can also be characterized.Detailed field observations and mapping, coupled with petrological and geochemical and observations,indicate the important role of the Archean and Paleoproterozoic crust in the genesis of these granitoids,showing even evidences of important mantle interactions.Keywords: Mantiqueira Structural Province; Pre-tectonic Granitoids; Syn-tectonic Granitoids; Post-tectonicGranitoids; Geochemical signatures; Magmatic and Tectonic Relationship; Minas Gerais-Brazil.