Rifting of the West Galicia continental margin: a review

The west Galicia margin (Spain) is a typical passive margin. During the Mesozoic, the continental crust of the margin experienced several episodes of extension. The main stage was during the Berriasian-late Aptian interval (140-114 Ma). The stretching of the lithosphere resulted in (a) the thinning of the continental crust, testified by superficial extensional structures (normal faults, tilted fault blocks) and rapid subsidence, and (b) the emplacement of mantle rocks (peridotite) at the continental rift axis. The crustal thinning and the final emplacement of peridotite onto the seafloor are explained by asthenosphere diapirism succeeded by uniform, normal, simple shear of the thinned continental lithosphere