Abstract
This paper presents a stratigraphic and depositional systems review to the Phanerozoic cover of the Sao Francisco Craton, defined as the Sanfranciscana Basin. The Phanerozoic cover is composed mainly of sedimentary continental rocks and minor explosive volcanic rocks. The stratigraphy and sedimentology of the Phanerozoic successions are summarized as follows: Santa Fe Group (Carboniferous-Permian) -divided into Floresta and Tabuleiro formations. This glaciogenic sequence represents the gondwanan glaciation record in the Sanfranciscana Basin. These sediments are preserved in valleys excavated in the basement and crop out in most of the basin . Areado Group (Early Cretaceous) -constituted by the Abaete, Quirico and Tres Barras formations, characterized by lateral and vertical interfingerings. The Abaete Formation was deposited by braided stream and the in southern area by alluvial fans; the Quirico Formation records a lacustrine sedimentation. and the Tres Barras Formation, was deposited in the fluvial, fluviodeltaic and aeolian environments. The Areado Group is thick in southern portion of the basin (200 meters); it is less than 60 meters and discontinous in the central-northern areas. Mata da Corda Group (Late Cretaceous) -composed by the Patos and Capacete formations. The Patos Formation is composed by alkaline volcanic rocks. The Capacete Formation represents the distai epiclastic sediments with important aeolian sand contribution. It is present only in the southern sector of the basin. Urucuia Group (Late Cretaceous) - composed of sandstones, divided into Posse (with Facies l e 2) and Serra das Araras formations, respectively interpreted as dry field dune deposits, braided stream of channelized deposition and braided stream deposited by sheet flows. It is present in the entire basin. In the southern portion of the basin, it is recovered by volcaniclastic sediments, and in the northern area it becomes the most important unit. Chapadao Formation (Quaternary), represents the recent sandy, unconsolidated, covers of talus, residual or alluvium origin. Provenance studies show the following transportation vectors and source areas: Santa Fe Group - NE to S W transport, with source areas in Northern Espinhaco Range and in the Bambui Group; Areado Group - transport from the adjacent elevated blocks, showing important axial flow; Urucuia Group - transport from NEE to SWW, with sources in the northest Sao Francisco Craton and the Capacete Formation - showing two directions of transport: volcanic rocks from South to North and aeolian sand from NE to SW.
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