Interplay between subsidence and sediment flux in the filling of the North Pyrenean retro-foreland basin during the Eocene (Corbières, France)

External forcings, such as climate and tectonics, influence sedimentary basin fills. In turn, sedimentary archives provide key information on variations in accommodation and sediment flux over time, which record paleoclimate and tectonic conditions. However, the impacts of accommodation and flux on sedimentation must be disentangled before understanding their specific influence on surface processes. This study focuses on the Talairan Syncline (Corbières area, France) in the northeastern Pyrenean retro-foreland during the Early Eocene. This basin is filled with continental deposits coeval with the initiation of the major tectonic pulse of the Pyrenean orogeny and the Early Eocene Climatic Optimum. Therefore, the Talairan Syncline enables the characterization of the impact of flux and subsidence on the filling of a tectonically active area during climate changes. Detailed mapping and facies analyses led to the identification of four depositional sequences marked by clear erosional surfaces and syn-tectonic growth strata. The evolution of the stratigraphy over time indicates a progradation of the gravel front, accompanied by a net decrease in the downstream grain size fining rate. This change is linked to an enhanced imprint of sedimentary flux on sedimentation compared to subsidence. These results suggest a clear influence of subsidence in the early stages of the North Pyrenean retro-foreland's development, followed by an increased influence of flux, resulting in a larger depositional area and an increased export of sediments downstream. Referencing these settings enables the identification of the interplay between subsidence and flux over time, paving the way for further studies to define the impact of climate and tectonics on flux variations.