Sedimentation and pedogenesis in Cretaceous continental sequences of the Bauru, Sanfranciscana, Parecis and Neuquén basins.

Abstract

The Bauru, Sanfranciscana and Parecis basins in Brazil, and Neuquén Basin in Argentina, shelter Cretaceous continental sequences, whose evolution were conditioned to tectonic and climatic events following rupture of Gondwana. This project aims to identify the sedimentary relationship between these basins, as well as environmental and pedogenic conditions and to establish the continental paleogeographic and climate of the Upper Cretaceous of South America. From the results obtained in FAPESP project 2010/19787-2 "Stratigraphic Correlation and Paleogeography the Upper Cretaceous Bauru, Sanfranciscana and Parecis basins", this project aims to advance the issue, including specific studies in Bauru Sanfranciscana and Parecis basins, in Brazil, adding information about the Cretaceous sequence of the Neuquén Basin in Argentina. The correlation will be based on facies analysis, architectural elements and characterization of paleosols. Facies analyses will be based on lithological characteristics and allow interpreting the paleodepositional processes. The characterization of paleosols will be analyzed by macro and micromorphological features, geochemistry of major elements and trace fossils. The integration of these methods allow develop some considerations on paleoclimate, paleogeomorphic and paleobiological conditions. With this study we intent to elaborate the analogous models for hydrocarbon reservoirs. The relationship between depositional and pedogenetic cycles, as well as the pattern of stratigraphic stacking in each basin will be analyzed according to the stratigraphic base level concepts or ratio of accommodation space and sediment supply (A / S), allowing set sedimentary cycles in different orders of magnitude. Finally, we intend to develop a paleogeographic model for the continental Upper Cretaceous of South America. (AU)