RELATIONS BETWEEN QUATERNARY FLUVIAL DYNAMIC AND RELIEF CONFIGURATION IN THE BRAZILIAN CENTRAL PLATEAU: ANALYSES BASED ON DEPOSITIONAL AND MORPHOLOGICAL FLUVIAL ARCHIVES

Abstract

Fluvial dynamics play a key role in shaping the relief of humid tropical zones. This study aims to investigate the impacts of Quaternary fluvial dynamics on the hydrography, fluvial archives, and relief of the southeastern portion of the Brazilian Central Plateau. The Espírito Santo River basin, focus of this research, is located in the southern portion of the Central Plateau, featuring significant geological diversity but with gaps in knowledge about local fluvial archives. The study included office-based activities, such as analyzing geomorphic features using satellite imagery and valley floor characteristics in digital elevation models developed within a Geographic Information System. Additionally, fieldwork was conducted to identify fluvial depositional levels, and a sample was collected for dating using Optically Stimulated Luminescence. The analysis revealed that the basin underwent a stream piracy process, altering the hydro-sedimentary balance and causing infilling in the lower valley areas since the Pleistocene-Holocene transition. This process led to the formation of a resistant detrital pavement responsible for riverbed armouring. These events created a unique relief configuration in the Espírito Santo River basin compared to neighboring basins.