Geometry and tectonic history of the Northeastern Cévennes Fault System (Southeast Basin, France) : new insights from deep seismic reflection profiles

A new deep seismic reflection survey of the Northeastern Cévennes Fault System (NCFS) reveals its polyphase tectonic history, spanning 320 million years. The study identifies three major phases: initial normal faulting during the Lower Jurassic and Lower Cretaceous, reactivation as a transfer fault zone during Pyrenean shortening in the Upper Cretaceous, and subsequent Oligocene extension. These findings update the geological history of the Vivaro-Cévenol region and constrain structures affecting the Southeast Basin since the Mesozoic. The research provides critical insights for paleoseismological studies following the 2019 Le Teil earthquake (Mw4.9), aiding seismic hazard assessment in the region.

Thomasset, C., Ritz, J.-F., Pouliquen, S., Manchuel, K., & Le-Roux-Mallouf, R. (2024). Geometry and tectonic history of the Northeastern Cévennes Fault System (Southeast Basin, France) : new insights from deep seismic reflection profiles. BSGF - Earth Sciences Bulletin, 195, 17. https://doi.org/10.1051/bsgf/2024016