Sediment provenance and erosion rates in the Andes-Amazon fluvial system: a study using luminescence and cosmogenic nuclides technics

Continental sedimentary deposits are essential geological records for understanding landscape evolution over time. In this context, the “modern analog” approach is employed in the Andes-Amazon system to deepen the understanding of past changes and the factors influencing them. This methodology involves studying contemporary fluvial deposits using advanced techniques and methods to identify how natural processes shape the current landscape. The main objective of this study is to determine the spatial variability and environmental controls of the sediment provenance and the erosion rates in modern deposits of the Ucayali, Maranõn, Napo, Madre de Dios, Huallaga, and Solimões rivers in the Andes-Amazon fluvial system. This approach will involve luminescence sensitivity signatures of quartz and feldspar grains, which can indicate grain source and transport process; the latitudinal gradient of erosion rates using in situ cosmogenic nuclides; the relationship between sedimentary variability and tectonic, topographic, lithologic, and climatic controls using Geographic Information Systems (GIS). The new cosmogenic nuclide and luminescence data will be used together to evaluate the compatibility of these methods in analyzing sediment provenance and erosion rates. This comparison will assess whether these methods and approaches can be consistently integrated, contributing to a more comprehensive understanding of sedimentary and erosive processes in the Andes-Amazon fluvial system. (FAPESP #2023/16318-1)