Paleogeographic reconstruction of northwestern Amazonian fluvial systems during the Pliocene and Quaternary

• Grant number: 21/14947-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2023
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Fabiano do Nascimento Pupim
• Grantee: Caio Breda
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/23899-2 - Trans-Amazon Drilling Project: origin and evolution of the forests, climate, and hydrology of the South American tropics, AP.PFPMCG.TEM
• Associated scholarship(s): 24/08072-5 - COSMOGENIC NUCLIDES APPROACH TO CONSTRAIN PALEO-EROSION RATES IN THE NORTHEWESTERN AMAZON., BE.EP.DR

Abstract

The Late Cenozoic (Pliocene and Quaternary) is characterized by significant and well-documented environmental changes around the Earth. During this period, tectonic plate convergence events and regional climate changes played a fundamental role in the evolution of the physical landscapes in the Andes-Amazonian system, such as the uplift of the Andes Mountains, the configuration of the drainage network, alteration of terrestrial and floodable habitats and in the diversification of the biota. However, there are still gaps in the chronology of events, the mechanisms and rates of processes that control changes in the Amazon River system over time, especially for the lowlands in the Andean Piedmont and the interfluve of the Amazon and Orinoco River basins, northwestern edge of the Amazon. Based on an integrated approach of dating methods, isotopic and sedimentary provenance techniques, this doctoral project proposes to fill the information gap regarding the evolution of northwestern Amazon paleogeography in the last 5 Ma. Based an integrated approach of dating isotopic and sedimentary provenance techniques, this doctoral project aims to fill this information gap and reconstruct the geological evolution of the fluvial systems and lowlands of the interfluve of the Caquetá (Amazonas) and Guaviare (Orinoco) rivers, Colombia, in the last 5 Ma. The analysis of the following results will allow achieving the proposed objectives: (i) Morphosedimentary map and characterization of sedimentary facies of the Pliocene-Quaternary terrains; (ii) Sediment burial ages by luminescence dating methods and cosmogenic nuclides; (iii) Quantification of paleoerosion rates using cosmogenic nuclides; and (iv) Provenance of sediments by luminescence and U/Pb techniques in detrital sediments. We will answer questions regarding the time and mechanisms that control the landscape evolution of the northwestern Amazon region, known as Arco de Vaupés. Furthermore, these data can support numerical models and provide new insights into the connections between the geological history of the Amazon River system and the evolution and distribution of biota