O SUPERGRUPO ESPINHAÇO EM MINAS GERAIS: CONSIDERAÇÕES SOBRE SUA ESTRATIGRAFIA E SEU ARRANJO ESTRUTURAL

Résumé

This article presents data and interpretations on the Espinhaço Supergroup in Minas Gerais, emphasizingstratigraphic and structural data of the Serra do Espinhaço, where arise sequences from Archean (granites/gnaisses/migmatites and units of lower metamorphic degree) to Neoproterozoic. Espinhaço Supergroup hasit’s development in the end of the Paleoproterozoic until the Mesoproterozoic, and in the Meridional Sectionit’s base is represented by the Guinda Group, with quartzites, phylites and metaconglomerates/breccias offluvial to shallow marine origins, presenting intercalations of metavolcanics and real paleosoils (part ofhematitic phylites). Above arise eolian metasediments of the Galho do Miguel Formation and the marine tofluvial metasediments of the Conselheiro Mata Group. At the Setentrional Sector, three big groups, mainlypresenting continental characteristics (compatible with the opening of a rift), can be recognized formingthis super group in the setentrional sector of the mountain rage: Metavulcanossedimentar Unit, InferiorMetassedimentar Unit and Superior Metassedimentar Unit. The region is structured by a system of inversefaults/ ductile shear zones that cause frequent stratigraphic inversions and that spread marked blocks internallyby open folds to closed with West vergence. The analysis of quantity of deformation proves the non-axialcharacter of these mass transportations, and confirms the location of part of the shear zones.