Tectonic setting and stratigraphic architecture of an Early Cretaceous lacustrine carbonate platform, Sugar Loaf High, Santos Basin, Brazil

Abstract

Abstract The Sugar Loaf High is an extensive basement structure within the Santos Basin, offshore Brazil, in which all of the elements of the pre-salt hydrocarbon play are present. Following a clastic-dominated early synrift phase, the later synrift and sag phases are characterized by an extensive non-marine carbonate platform over the basement high. The study area within this new 3D seismic dataset contains carbonates stratigraphically equivalent to the reservoirs within the Lula and Sapinhoá fields. Analysis of the 3D seismic data shows that the pre-salt carbonates onlap the basement of the Sugar Loaf High and form aggradational geometries on a platform that has a proximal to distal width of about 100 km and an interpreted relief of some 900 m. The carbonate platform has an aggradational and mounded basinward-facing gullied margin with slope deposits. Progradational units are imaged on the platform top that may be either carbonate or clastic in composition. The platform is preserved beneath evaporites that form the regional seal within the Santos Basin. Platforms of this size are previously unknown from lacustrine settings outside the pre-salt stratigraphy of the Santos and Campos Basins, Brazil.