Stratigraphic and spatial distribution of Cenozoic contouritic deposits in the South Atlantic

Abstract

Identifying how continental margins have been affected during geological variations in climate and sea level, is essential for paleoenvironmental reconstruction and for predicting the effects that current climate changes will have on margins in the near future. The tropical regions are the most important source of heat for the mid and high latitudes. The Atlantic Ocean-Atmosphere system is unique, it is the only system that currently, transports heat across the equator through ocean currents. Therefore, it is essential to perform accurate climate reconstructions, documentation, and implementation of Atlantic climates in large-scale climate models. This, however, has been made difficult for most of the Cenozoic due to the lack of sufficient low-latitude sediment records.Here we propose to investigate paleoceanographic changes throughout the Cenozoic driven by long- and shorter-term forcings, from high greenhouse gas conditions in the Eocene to glaciations in the Quaternary, by reconstructing oceanographic processes, in particular ocean currents and the contouritic sedimentary deposits that are associated with these currents. Within this context, this project aims to report and detail the contouritic sedimentary deposits on the Brazilian Continental Shelf during the Cenozoic, especially during the Quaternary, in order to verify how the Quaternary climate and sea level transitions affected the evolution of the Brazilian equatorial continental shelf.For that, this project will employ a new high-resolution seismic system (7000J sparker + multichannel hydrophone array) combined with the sampling and analysis of piston and gravity cores from three locations across the Brazilian Shelf aboard the research vessels Alpha Crucis e Alpha Delphini. This proposal is part of the multidisciplinary thematic project FAPESP (16/24946-9), sea-level changes, and Global Monsoon System - Clues from marine cores in Brazil. (AU)