ESTRUTURA E DEFORMAÇÃO BRASILIANA NOS DIQUES MÁFICOS DA SERRA DO ESPINHAÇO MERIDIONAL

Abstract

Mafic dike swarms are abundant in Southern Espinhaço Mountain Range. They are essential tools for theunderstanding of the geodynamic process, marking the beginning of extension tectonic regimes. This paperdescribes the mafic dike swarm of the Southern Espinhaço, their field relationships, petrography anddeformational history. The dykes are: (1) metagabbros with relict igneous textures, N-S oriented, deformedwith un anastomosed protomylonitic foliation; (2) greenschists (sericite-epidote-chlorite schists) withlepidoblastic textures, fine-grained, east-west trending. These dikes represent significant amounts of maficmelts formed during the first stages of the Brasiliano cycle. They have a foliation parallel to the regionalfoliation of the Espinhaço Supergroup, related with the Brasiliano Orogeny.