Paleogeographic reconstruction of the middle Negro River during the Quaternary: a geomorphological-geochronological approach

• Grant number: 23/10430-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2023
• End date: April 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Physical Geography
• Principal Investigator: Fabiano do Nascimento Pupim
• Grantee: Renan Cassimiro Brito
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/03007-5 - From sand grains to mountain chains: linking recent Andean orogenesis and climate changes to the assembly of lowland Amazonia (PAALE), AP.PNGP.PI
• Associated scholarship(s): 24/07848-0 - Using feldspar luminescence methods for dating Middle Pleistocene fluvial deposits of the Negro River, Amazonia, BE.EP.MS

Abstract

the most biodiverse ecosystems on Earth. The growing acknowledgement of role of the fluvial dynamic in the evolution of the Amazonian landscape contrasts with the absence of information about the evolution of fluvial systems throughout time. This knowledge gap results from the lack of absolute ages for the sedimentary deposits that would allow the paleohydrologic reconstruction of the rivers and associated wetlands. This research project aims at reconstructing the geological evolution of the middle Negro River during the late Quaternary (<250 ka), based on new geomorphological and sedimentary data, and optically stimulated luminescence (OSL) dating. From this integrated approach, it is expected to generate one of the most detailed geochronological records of the landscape evolution for the Negro River, which is the most important affluent draining the northwestern Amazonian watershed. This record will allow refining the interpretations about the Negro River evolution and the possible causal correlations with climate changes and tectonics occurred during the Quaternary. Understanding these connections between the landscape evolution and external forcing is crucial to feed predictive models about future impacts of climate and/or anthropogenic changes in the Amazonian biome. This project is part of an international collaboration, and the results will contribute to better understand of how the evolution of the fluvial systems impacted the structure and functioning of the forests, which are key factors in the richness and biodiversity.