The São Francisco Craton (CSF) is the main geological unit of Minas Gerais State. Morphologically, the CSF constitutes a huge N-S depression, the São Francisco River valley, bordered by two tilted plateau, the Planalto do Espinhaço at east and the Planalto do Alto Paranaíba at west. These highlands resulted from Neogene uplift of the folded belts frontal parts that deformed the CSF margins during the Upper Proterozoic. This uplift took place after the Late Cretaceous-Paleocene planation (Sul-americana Surface, King 1956) responsible for the stronger flattening of the Brazilian Platform. Resulting from the same evolution, the two southeastern coastal ranges (Serra do Mar and Serra da Mantiqueira) correspond to uplifted blocks confining the Paraíba do Sul Rift valley (Almeida 1976), which was filled by Paleogene continental sediments with a couple of 100 meters thick. Along the CSF southern margin, the end of this morphotectonic event is recorded by the formation of Sao Joao del Rei Rift Zone-SJRRZ (Saadi 1991), which exhibits fluvio-lacustrine sediments with more than 120 meters thick. Analysis of pollens extracted from lignite indicates an Oligocene-early Miocene age (R. Maizzato - UFOP, 1998), similar to the sediments of Tertiary basins on the east part of Quadrilátero Ferrífero (Gorceix 1889). The main part of these morphotectonic features results from a morphogenesis under hot-humid climate and compressive tectonics characterized by Saadi (1991) for the Minas Gerais State and Costa et al. (1998) for its southern portion. Basseto & Szatmari (1997) describe compressive structures into the ocean crust of the southeastern Brazilian margin compatible with the continental evolution presented here. Their sedimentary data indicates the development of this structure since the Oligocene until today.
*Supported by FAPEMIG and PRPQ/UFMG