Stratigraphic-sedimentological modeling is a valuable tool for testing the role of parameters that can act in the depositional process of sedimentary rocks. The present study on the tectonoestratigraphic evolution of the southwestern portion of the Santos Basin aims to show the unique geological context recorded in the Cenozoic of that basin regarding the rate of subsidence and the anomalous behavior of the relative sea level curve. The Cenozoic-Paleocene interval specifically in the basin is mainly related to tectonic events that occurred in the continental region adjacent to the basin, associated with the evolution of Serra do Mar. These events may explain the anomalous sedimentation recorded in this period, which produces a sedimentary stack that generates a disagreement between the coastal onlap curve and the behavior of the global eustatic level curve, in a condition of constant subsidence. The Dionisos modeling software allowed to test the role of the parameters that acted in the sedimentary process in the Santos basin, by calculating possible deposition scenarios for the platform section in the range of 66 to 56 million years. A variety of scenarios were simulated, but only six are explored in this project. The main objective was to understand the controlling parameters of the formation and evolution of this system, at the time of its genesis, considering the relative variations in sea level, sedimentary input, subsidence with a methodological approach that includes the seismic stratigraphic analysis of the seismic lines, chronostratigraphic data and lithological samples of 20 exploratory wells available, and the construction of stratigraphic models in 2D and 3D dimensions. Scenario two shows a reproduction of the geometry of a given sedimentary package and thus obtaining the variation of the main parameters responsible for its formation expected in agreement with the techno-sedimentary evolution of the study area. The simulations for scenario two carried out in the project were carried out using the forward Subsidence modeling method, changing the sedimentary input with an average of 6325 Km3 / Ma and the river discharge of 3000 m3 / s by placing three sources of input. From the final stratigraphic model in scenario 3, it was then possible to estimate the temporal and spatial variation of the defining parameters of the architectural construction of the studied sedimentary basin as the variation of accommodation and subsidence space, the variation of sedimentary input and fluvial discharge. and migration of sedimentary sources that feed the basin.nter text


  • Adriana Henao, Egberto Pereira