The Southeast France basin during Late Cretaceous times: The spatiotemporal link between Pyrenean collision and Alpine subduction

We present and discuss the Late Cretaceous evolution of the Southeast France Basin (SEFB) owing to the Pyrenean and Alpine belts. The available geological data (isopachs maps, boreholes and field data) were integrated in 3D GeoModeller software to build a 3D model of the geometry of the Cenomanian to Campanian sedimentary series of the Late Cretaceous period. Maps, 3D block diagrams and cross-sections extracted from the 3D model reveal a significant eastward marine regression during the Late Cretaceous with an average velocity of 0.5 to 1 cm per year. According to the location of the Late Cretaceous depocenters, two sub-basins are recognized in the SEFB and correspond to “en-échelon” synclines filled by syn-buckling sediments. These events are related to the sub-meridian “Pyrenean-Provence” crustal shortening. During Campanian time, the deepening and the tilting of the SEFB are interpreted as a consequence of the subduction of the Alpine Tethys. The Late Cretaceous SEFB is the prolongation on the European foreland of the Alpine subduction trench.