ORIGEM E EVOLUÇÃO TECTÔNICA DA BACIA SANFRANCISCANA

Abstract (English)

This paper presents data about the origin and tectonic evolution of the Phanerozoic cover of the São Francisco Craton, defmed as the Sanfranciscana Basin. The tectonic compartmentation allowed the subdivision in the Abaeté (south portion) and the Urucuia sub-basins (middle-north portion). The stratigraphy and sedimentology of the Phanerozoic successions are as follows: Santa Fé Group (Permo-Carboniferous) - subdivided into the Floresta and Tabuleiro formations. Areado Group (Early Cretaceous) comprising the Abaeté, Quiricó and Três Barras forraations. Mata da Corda Group (Late Cretaceous) composed by the Patos and Capacete formations. Urucuia Group (Late Cretaceous) composed by the Posse and Serra das Araras formations. Chapadão Formation (Cenozoic) represents the sandy, unconsolidated, recent covers of talus, residual or alluvium origin. Paleozoic epyrogenesis characterized the onset of tectonism in the Sanfranciscana Basin. During the Mesozoic the basin has undergone tectonic reactivations fïnishing with neotectonic activity in Cenozoic times. The origin of the basin, as well as its tectonic evolution had been controlled by the São Francisco Craton marginal fold-and-thrust belts (Brasília and Araçuaí belts), by the South Atlantic opening (rift phase) and by transform oceanic fractures (drift phase).