Evolution of the Amazon drainage basin: Andean uplift, climate and other geodynamic processes

Abstract

The Andean orogeny had a profound impact on the evolution of the Amazon drainage system, modifying the climate in South America and the influx of sediments to the interior and marginal sedimentary basins. Additionally, the dynamic of the surface processes of erosion and deposition continually sculpted the landscape and guided the drainage pattern on the continents. Therefore, the correct interpretation of the geological evolution of the northern South America during the Cenozoic depends not only on the interior dynamics of the planet but also on the coupling of the Earth's geodynamics with the erosion of the continents, deposition in the sedimentary basins and the interaction with the evolving climate. Due to the great complexity of the different processes involved in the geological evolution of Amazonia, the use of numerical models is a natural way to treat this problem. The aim of this project is to study the formation and evolution of the Amazon drainage system based on numerical scenarios, taking into account surface processes along with geodynamic processes such as Andean uplift, flexure of the lithosphere, and mantle convection. With this coupled numerical model we intend to test different mechanisms proposed in the last decades to explain the formation of the present Amazon drainage system as well as the timing for the main event(s) of drainage reorganization. This project intends to contribute to the discussion about stratigraphic evolution, paleoclimate conditions, and biodiversity impacts in Amazonia. (AU)