PLIOCENE UPLIFE OF THE EASTERN IBERIAN MARGIN - INFERENCES FROM QUANTITATIVE MODELING OF THE VALENCIA TROUGH

We present the results of quantitative modelling of subsidence in the Valencia Trough and associated uplift in the Catalan Coastal Ranges and the Balearic Islands. Basement subsidence, Moho depth and gravity anomalies are calculated for different effective elastic thicknesses (eet) and durations of rifting, along two profiles constrained by recently collected multichannel seismic and gravity data. The tectonic evolution of the Catalan Coastal Ranges cannot be explained with traditional two-layer lithospheric stretching models for the Valencia Trough, but is consistent with a thermomechanical model invoking lithospheric necking, combined with a late-stage uplift event. The modelling of the topography of the Balearic Islands suggests an interaction of extension in the Valencia Trough with extension in the South Balearic Basin. Our study supports a rifting model with low values for the flexural rigidity, an intermediate level of necking and one finite duration stretching event propagating from the northeast towards the southwestern part of the Valencia Trough. The modelling provides constraints on the magnitude of a large-scale Pliocene uplift of the eastern margin of the Iberian Peninsula.