Tropical regions are a major source of heat to mid- and high-latitudes. The Atlantic Ocean-Atmosphere system is unique as it is the only system that currently transports heat across the equator. Therefore, accomplishing accurate global climate reconstructions, documentation and implementation of Atlantic climates in large-scale climate models is essential. This, however has been hampered for most of the Cenozoic due to the lack of sufficient low-latitude sediment records. Here we will investigate paleoceanographic changes across the Cenozoic driven by longer and shorter term forcings from the Eocene greenhouse to icehouse conditions in the Quaternary, through the reconstruction of atmospheric, oceanographic and biological processes. The Brazilian Equatorial Margin (BEM) is a passive and stable continental margin that developed following the opening of the central Atlantic Ocean in the mid-Cretaceous. A peculiar aspect of this margin is that it remained tectonically “passive” and approximately at the same equatorial latitude since its formation until present. Such conditions are unique and provide great potential if added with extended, potentially continuous, and well-preserved sedimentary archives of inter-tropical environments. This project will take advantage of these unique attributes for obtaining high-quality sedimentological, paleoclimatic, and paleoceanographic data for the Cenozoic. We propose to drill transects across the BEM from the uppermost part of the continental slope to the abyssal plain near Fortaleza (Ceará and Potiguar Basins). The expected stratigraphic continuity along these transects will allow the detailed study of the fundamental relation between pCO2, sea-level and climate changes throughout the Cenozoic. Moreover, it will be possible to detect the low-latitude climatic response to the major Cenozoic climatic events such as the Paleogene transient global warming events, (i.e. the Paleocene-Eocene Thermal Maximum), the onset of the Antarctic glaciation during the Eocene-Oligocene, the warm mid-Miocene and Pliocene phases, the cooling during the mid-Miocene Transition and the onset of the Northern Hemisphere glaciation in the Plio-Pleistocene. Sediments are expected to yield calcareous and organic fossils, which not only will allow for studying the response of tropical ecosystems to these climatic events, but also provide independent substrates for climate and carbon cycle reconstructions. The new data should establish a landmark for high-resolution Cenozoic tropical climate reconstructions, which will provide the following outcomes: 1) detail the relationship between tropical climate (temperature), sea-level and atmospheric pCO2; 2) evolution of the Atlantic Meridional Overturning Circulation driven by longer (tectonic) and shorter term (solar input) forcings.

Leading PI: Prof. Luigi Jovane (University of Sao Paulo).