Rifting and thermal evolution of the Northwestern Mediterranean

Abstract

The structural setting of the Northwestern Mediterranean stems from tectonothermal processes which reflect on the nature of the crust. The Oligocene to Present evolution is here analysed with a thermal model which takes into account the significant extension of the continentallithosphere before the onset of sea-floor spread- ing in the bathyal zone. Subsidence data were used to set the boundaries of the oceanic realm which was com- pared with previous reconstructions inferred from other geophysical evidence. The thermal features of the transitional crust that lies between the oceanic crust and the stretched continental margins were also outlined. The Ligurian-Proven~al basin is a marginaI basin, whereas only the continental crust is expected in the Valen- cia trough. An evolutionary sketch of the study area that accounts for the observed subsidence and heat flux is proposed.