5 janvier 2026 à 14h : séminaire international n° 76
Intervenant
Raphaël Tournier
Doctorant, ISTerre, université de Grenoble
Thème
Reconstruction de la paléogéographie africaine entre 30 Ma et 1 Ma : définition des conditions limites pour les modèles éco-évolutionnaires
Large eco-evolutionary studies require realistic and dynamic environmental frameworks, used both as a spatial background and as stress variables (e.g., geographic barriers, water availability, resource distribution, and environmental stability). In this context, we reconstruct the environmental evolution of continental Africa over the past 30 million years using a multi-layered modelling approach. The resulting paleogeography integrates several geodynamic components, including mantle-driven dynamic topography, crustal tectonics history, plate tectonic motions, and volcanic eruptive dynamics. Combining these elements allows us to produce an elevation model for Africa since 30 Ma, continuous in space and time. This elevation model is then also used as a boundary condition for climatic and physiographic simulations, generating a more comprehensive representation of past environments. I then evaluate the spatial and temporal accuracy of these reconstructions by confronting them with field-based evidence. This assessment identifies the scales at which the models are most robust, informing which interrogation can be explored with confidence. It also highlights where the reconstructions correspond with geological, paleoenvironmental, and paleontological data, and where their precision may require refinement.
Lieu
Salle 410, bât. B35 (3ème étage, aile nord), université de Poitiers.