Paleocirculation and paleoproductivity variations on the Brazilian equatorial margin during mid and late Holocene

Abstract

The Holocene stratigraphic record contains important details of phenomenon that occurred during this geologic epoch. In the modern scenario of interest for climate change, the better understanding of processes triggered in the Holocene is of great importance. The ocean plays a very important role on climate control mainly through termohaline circulation and primary production. Therefore, reconstructions of paleocirculation and paleoproductivity during the Holocene feature great relevance for scientific studies, and proxies as carbon stable isotopes in benthic foraminifera have been widely used. This method appliance is possible because foraminifera organisms calcify their tests from the surrounding water of their living depth and because the isotopic composition of the dissolved inorganic carbon in seawater is directly related to the processes that affect the global carbon cycle, as circulation and productivity. This project aims to identify paleocirculation and paleoproductivity variations during the Holocene on the Brazilian equatorial margin slope, a region of great importance for the comprehension of the mechanisms involved in heat and mass transfer that occur between hemispheres. The material that will go through stable isotopic analyses was obtained from a corer located at 1210m water depth in the continental slope of the Amazon Continental Margin, which was collected during the AMADEUS cruise - "Response of Amazon sedimentation to deforestation, land use and climate variability" -, which is a cooperation project between University of São Paulo and the University of Bremen, Germany.