Processos, ambientes deposicionais e geocronologias das coberturas superficiais sobre aplainamentos neogênicos e terraços fluviais na bacia do Ribeirão Araquá, Depressão Periférica Paulista

Abstract

The complex interpretation of the Quaternary geomorphological dynamics in the Paulista Peripheral Depression is related to both the neotectonic dynamics and the intensity of weathering of the humid tropical regions. Therefore, the analysis of the surface coverages might support qualitatively and quantitatively the understanding of the environmental events that have occurred during the Quaternary. In this context, we propose to correlate the geochronology of the erosive-depositional processes - responsible for the spacialization of surface coverings over the landforms in the Araquá river basin - with Quaternary climatic events. The studied area is in the Paulista Peripheral Depression whose dynamics comprises Neogene Surfaces, Pleistocene and Holocene Fluvial Terraces. In order to establish the environments features and the geochronology of erosive-depositional events, we perform Optical Stimulated Luminescence (OSL) dating, size grain and morphoscopic analysis. The main findings suggest that the Quaternary overlay of these geomorphic forms are associated with erosive-depositional processes, resulting from neotectonic reactivations and Pleistocene climatic changes, as well as short-term Holocene climatic cycles (climate pulsations).