%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Uagoda, R.
%A Siame, L. L.
%A Garnier, J.
%A Leanni, Laetitia
%A Caldeira, D.
%A Braucher, R.
%A Freydier, R.
%A Seyler, Patrick
%T Decoding surface processes from escarpment to watershed : insights from karst landscapes using cosmogenic nuclides and geochemical data
%D 2025
%L fdi:010093510
%G ENG
%J Geomorphology
%@ 0169-555X
%K Cosmogenic nuclides ; Fluvio-karst systems ; Sediment dynamics
%K BRESIL
%M ISI:001485056400001
%P 109794 [16 ]
%R 10.1016/j.geomorph.2025.109794
%U https://www.documentation.ird.fr/hor/fdi:010093510
%> https://www.documentation.ird.fr/intranet/publi/2025-06/010093510.pdf
%V 482
%W Horizon (IRD)
%X Tropical karst landscapes are marked by complex sediment dynamics resulting from the interplay between geomorphic processes and sediment transport. In the Vermelho Watershed (Brazilian savanna), we use paired cosmogenic nuclides (10Be and 26Al) to quantify denudation rates, burial durations, and sediment mixing. The spatial distribution of Al-Be ratios reveals rapid erosion and prolonged burial on escarpments, in contrast to the more stable conditions of flatter areas, where erosion is subdued, and sediment residence time is longer. Comparisons with Iraquara and Serra das Mesas emphasize the influence of topography and sediment sources on nuclide inventories. Downstream increases in freshly eroded material point to fluvial mixing, while discrepancies between cosmogenic burial and OSL ages (Tarimba Cave) suggest partial burial and pre-depositional histories. The integration of cosmogenic, geochemical, and geomorphic data underscores the complexity of tropical karst systems, where vertical mixing and uneven erosion are key processes. These results contribute to a broader understanding of landscape evolution and offer a comparative basis for interpreting cosmogenic signals in fluviokarst environments worldwide.
%$ 064 ; 021