Kinematics and rifting processes of the Liguro-Provençal Basin, Western Mediterranean

The Liguro-Provençal Basin, situated at the junction of the Northern Apennines and the Western Alps, formed due to the rollback subduction of the Adriatic-African plate underneath Europe and the subsequent upper plate extension in the Oligocene to early Miocene time. The opening of this basin was accompanied by the counter-clockwise rotation of the Corsica-Sardinia block relative to Europe until 16 Ma, with the basin widening towards southwest. It is yet unclear if the extension ever reached seafloor spreading with the production of oceanic crust, or whether it led to anomalously thin continental crust and/or to mantle exhumation. Although considered as tectonically inactive today, the Liguro-Provençal Basin shows active seismicity, indicating compression and potential basin inversion. Thus, it is crucial to better understand the opening of the basin and the tectonic inheritance due to rifting in order to better interpret the present-day seismicity. To this end, we compile existing geological and geophysical data, including recent data from the 4DMB project (“Mountain Building Processes in Four Dimensions”), to constrain the crustal and sedimentary thicknesses throughout the basin. We also focus specifically on two profiles in the NE (Corsica-Provence) and SW (Sardinia-Gulf of Lion) parts of the basin and compare these with the results of coupled thermo-mechanical and surface process modelling using Aspect and Fastscape codes. Finally, we discuss the effect of differences in various parameters, such as pre-rift crustal thickness, rift velocities and sediment supply, on rifting processes in the Liguro-Provençal Basin.