SUPERGRUPO ESPINHAÇO: MODELO DE EVOLUÇÃO GEODINÂMICA

The São Francisco Craton in Eastern brazil, one of the major shield areas forming the South AmericanPlatform, had its present-day configuration defined by the remobilisation of its edges during the Brasilianoorogeny in the Neoproterozoic. This tectonic event produced deformation and closure of the Middle toNeoproterozoic basins represented in the neighbouring craton regions. In the south-east boundary area ofthe craton, the Espinhaço Supergroup, a thick metasedimentary sequence, represents one of these basins.This region has a long tectonic history. About 1.7 Ga, after the Paleoproterozoic period of deformationand igneous activity of the Transamazonian Orogeny, the crust was affected by an extensional eventwhich resulted in fragmentation and development of a rift basin where the Espinhaço Supergroup wasdeposited. About 900 Ma, a second extensional event represented by emplacement of mafic dikes in areasadjacent to the craton and formation of a new rift basin toward East is represented. The tectonic evolvedinto continental collision producing crustal shortening and thickening with westward tectonic transportonto the craton.