Early onset of Pyrenean collision (97-90 Ma) evidenced by U-Pb dating on calcite (Provence, SE France)

Early Late Cretaceous uplift of Provence gave rise to the Durance Isthmus. In the present study, U-Pb dating on calcite of compressional structures related to Pyrenean foreland compressional deformation in Provence shows that N-S shortening occurred coeval with emersion of the Durance Isthmus, through the development of combined top-to-the-North to NW thrusts between 97 and 90 Ma. This large-scale event, recorded from the Pyrenees to the Middle-East regions is interpreted as a far-field internal plate precursor of the Africa-Europe plates reorganization. Furthermore, the change in tectonic style and amount of shortening between Provence and Pyrenees was accommodated by sinistral reactivation of the NE-SW Cevennes and Nimes faults, acting as transform boundaries in this incipient collisional context.

Automated summary

The uplift of Provence in the early Late Cretaceous led to the formation of the Durance Isthmus. Through U-Pb dating of calcite in compressional structures related to Pyrenean foreland compression in Provence, it is found that north-south shortening occurred at the same time as the emersion of the Durance Isthmus, with top-to-the-North to northwest thrusts developed between 97 and 90 million years ago. This large-scale event, observed from the Pyrenees to the Middle-East regions, is interpreted as a precursor to the reorganization of the Africa-Europe plates. The change in tectonic style and shortening amount between Provence and Pyrenees is attributed to the sinistral reactivation of the NE-SW Cevennes and Nimes faults, acting as transform boundaries in this early collisional context.