The Candeias sediments were deposited between two time lines. The A blanket sand lays in the base, bounded by th e R-9.l and R-9.2 biozones. The top of the Candeias is the marker 50, coincident with the top of R-B biozone. The stratigraphic division in early and late Candeias appears consistent in regional terms. The lithology and fauna of the early Candeias (marker 60 - A sand) is indicative of widespread lacustrine conditions. The basin, in this time, was tectonically stable, and its geographical limit wider than the present limit. The marker 60 to marker 50 is coincident with the range of R-8 biozone defining the late Candeias time, when strong structural transformations, under synsedimentary conditions occur. The Salvador High, the present limit of the basin, accumulated a thick clastic wedge derived from nearby uplifted basement rocks. Within the basin the Quiricó stable platform received a substantially smaller thircknrss of sediments than did the Araçás-Miranga-Brejo Preto surrounding through locus of maximum subsidence. The structural differentiation of the Quiricó platform was the key factor for oil accumulations in the Sergi and A sandstones.The Candeias sediments were deposited between two time lines. The A blanket sand lays in the base, bounded by th e R-9.l and R-9.2 biozones. The top of the Candeias is the marker 50, coincident with the top of R-B biozone. The stratigraphic division in early and late Candeias appears consistent in regional terms. The lithology and fauna of the early Candeias (marker 60 - A sand) is indicative of widespread lacustrine conditions. The basin, in this time, was tectonically stable, and its geographical limit wider than the present limit. The marker 60 to marker 50 is coincident with the range of R-8 biozone defining the late Candeias time, when strong structural transformations, under synsedimentary conditions occur. The Salvador High, the present limit of the basin, accumulated a thick clastic wedge derived from nearby uplifted basement rocks. Within the basin the Quiricó stable platform received a substantially smaller thircknrss of sediments than did the Araçás-Miranga-Brejo Preto surrounding through locus of maximum subsidence. The structural differentiation of the Quiricó platform was the key factor for oil accumulations in the Sergi and A sandstones.