Quaternary sedimentary record of Parnaíba river basin, Piauí, Northeastern Brazil: a multi-proxy study for climate changes research

Abstract

The Serra da Capivara National Park (UNESCO World Heritage Site) region has great archaeological record left by one of the earliest human occupations in the Americas, as well as paleontological ones, related to the abundant remains of the Pleistocene megafauna.Researches on these themes have been developed in the region since the creation of the park in the 1970s. The semi-arid climate of the region, as it is currently described, has motivated disbelief regarding the antiquity of the human occupation (over 20,000 years old) in the area.However, few studies have focused on climatic and environmental evolution throughout the Late Quaternary, the scenario of this human occupation. Therefore, the purpose of this project is to use a multi-proxy approach to study the Quaternary record of lacustrine and fluvial deposits, within the park boundaries and also on a larger scale, including the marine deposits of the Piauí continental shelf, in order to reconstitute the evolution of the regional depositional systems and paleoclimate as completely as possible.Granulometry, heavy minerals, LOE sensitivity, stable isotopes and palynomorphs are the principal among the various environmental indicators to be explored. It is expected that this reconstitution allows interpretations of archaeology and Quaternary paleontological remains, helps improve existing models of climate evolution in South America and serves as a basis for the planning of socio-economic activities and the management of this drought-beset region.