3.4.3. Constraints on vertical motions

Large parts of Iberia are presently elevated to 750–1000m, with mountain chains reaching heights of up to 1500m in areas that were affected by Late Eocene to Early Miocene compression. Apatite fission-track (AFT) studies carried out on the Mediterranean and Atlantic margins of Iberia (Stapel et al., 1996), on the Central System (De Bruijne and Andriessen, 2000; De Bruijne and Andriessen, 2002), as well as on the Betics (Zeck et al., 1992) and the Pyrenees (Fitzgerald et al., 1999), provided evidence for a rapid post-Miocene cooling phase (uplift and erosion). For the Central System these data show that Late Eocene to Early Oligocene compressional uplift was followed by significant Middle Miocene (15 My) cooling and subsequently by a pronounced cooling acceleration starting in the Early Pliocene (5 My; De Bruijne and Andriessen, 2000). From the Sierra Guadarrama, which forms the eastern part of the Central System, a rock column of 6km was eroded during Pliocene and Quaternary times (De Bruijne and Andriessen, 2000; Ter Voorde et al., 2004).

Preliminary data indicate that during Pliocene and Quaternary times the Atlantic sea board of Portugal was uplifted by some 1000m, the Betic Cordillera by up to 1200m and the Pyrenees by some 500m (Cloetingh and Cornu, 2005b). Moreover, numerous paleoseismic features occur in the Tagus Basin (De Vicente et al., 2007).

TOPO-EUROPE plans to assess the neotectonic uplift/subsidence pattern of entire Iberia by combining geomorphologic studies and geodetic data with additional AFT studies. In order to quantify the seismic hazard potential of the Iberia area, combined paleoseismic and modelling studies are required.