Late Quaternary evolution of the southern Brazilian Atlantic coast

Fossil interdital and foreshore deposits are important geological sea-level proxies which preserve key information to reconstruct past changes in sea level. Such data are useful for inferring the volume of the ice sheets during past Interglacials. In particular, the Last Interglacial (LIG; Marine Isotope Stage 5e, ~ 125 ka) is considered a process analogue for understanding the current interglacial because during the LIG higher temperatures than the pre-industrial era led to an increase in the global sea level and decrease in ice sheets volume. The work here presented is part of the WARMCOAST Project funded by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovative Program (Grant Agreement No. 802414), and is aimed at getting new geological sea-level proxies on the western Atlantic Brazilian coast. The studied area spans between Rion Grande do Sul to São Paulo. A classical geological and geomorphological approach on the field was carried out in order to collect samples for OSL, granulometric and micropaleontological analysis. Such samples come from shallow-water marine sand outcropping up to a few metres above sea level. The local geoid model (MAPGEO2015) has been used to refer to the elevation of the proxies measured through a GNSS RTK station. The elevation error bar is in the order of a few centimetres. The field campaign results along the southern coast of Brazil are reported in this work, and the new data are interpreted in terms of Glacio-Isostatic-Adjustment processes that have affected the coasts since the Last Interglacial.