The region of the Sao Francisco river valley in eastern Brazil encompasses two main components of the geologic framework of the South American continent: the Sao Francisco craton and its marginal orogenic belts. Cratons, as the oldest, differentiated and relatively stable pieces of the continental lithosphere, preserve a substantial part of the Earth's memory. Orogenic belts, on the other hand, record collisional processes that occurred during a limited time span. Because of their topographic relief, mountain belts developed along craton margins provide however access to rock successions not...