Multi-seismic experiments ALCUDIA which include normal incidence and wide-angle seismic reflection data reveal detailed crustal and lithospheric structure of the central to the southwestern Iberia. The experiments provided an opportunity to analyse the nature and possible origin of the Mohorovicic discontinuity and map in cross-section the distribution of the physical properties across the Central Iberian Massif. The normal incidence deep seismic reflection transect, acquired in summer 2007 provides a detailed image of an intra-continental Variscan orogenic crust (the Central Iberian Zone, CIZ) and its suture zone with the Ossa-Morena Zone in southwest Iberia. This seismic image shows a slightly less reflective upper crust, which has been interpreted to be ~13 km thick. The deformation patterns in the mid-lower crust appear to correspond to ductile boudinage structures, thrusting and an upper mantle wedge. The Mohorovicic discontinuity has been interpreted to be the sharp, sudden decrease in reflectivity identified at 10.5 s TWTT (~31-33 km depth). The velocity structure, P and S waves was constrained by conventional iterative forward model of the travel time picks digitized from the high-resolution wide-angle seismic reflection data acquired in early May 2012. The P wave velocity model reveals significant lateral velocity variations in the upper crust down to ~20 km depth. The mid-lower crust is identified by a sharp gradient in velocity at ~13 km and ~20 km beneath the CIZ in the south and the Madrid Basin in the north, respectively. The base of the crust is well constrained by the high amplitude PmP arrivals and it is located at ~31 km in the southern end and at ~35.5 km below the northern end of the profile. These data provides for the first time a significant piece of evidence for a smooth and gradual increase of crustal thickness beneath the Madrid Basin, Central Iberian Peninsula.

TOPO-Europe 10th Annual Workshop , 2014 Interplay between surface, lithospheric, and mantle processes, 17–19 September 2014, Barcelona