Figure 14. Cartoon, illustrating an initial, simplified model for the extension of the lithosphere controlled by detachment faulting during rifting on the Iberia Abyssal Plain margin. During synrift I, lithospheric extension may have been accommodated by detachment faulting and accompanied by consequent upwelling, melting, and intrusion of gabbro into the lower crust at about l36 Ma (see Féraud et al., this volume). Subsequently, during synrift II, block-faulting cuts the upper plate into tilted blocks, dismembering the detachment system and the lower plate. The resulting crustal cross section shows an oceanward deepening of lithospheric level, consistent with the results of Leg 149.