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Abstract: In tectonically active areas, the landscape response to tectonic forcing is described and possibly quantified by regional topographic and hydrographic features as well as by spatial variation in rates of surface processes. We investigated the recent landscape evolution of the Iberian Chain (NE Spain), an intraplate thrust-belt formed in Cenozoic times and characterized by a dome-shaped topography. In its central sector the landscape is dominated by low relief surfaces, Late Neogene (?) in age, presently standing at an average altitude of 1300m. A recent regional uplift controlled the organization of the present fluvial network and dissection of the landscape. In this framework we investigated the geomorphic responses to tectonic forcing by the calculation of morphometric parameters, focusing on topography (map of local relief, swath profiles) and hydrography (basin hypsometric curve and integral, basin asymmetry factor, river longitudinal profiles and relative indices), and using SRTM DEM. The results of morphometric analysis have been coupled with radiometric uranium-series dating of calcareous tufas lying on fluvial strath terraces. The obtained ages allow the estimation of incision rate along the High Tajo and Martín rivers. Our results indicate that uplift and rock-type erodibility are the main factors influencing landscape evolution of the study area. The incision rates are very similar throughout the central sector of the range, indicating that, despite subtle local variation, the rivers are responding to a main tectonic input: the regional uplift. In conclusion, the Iberian Chain landscape is in a transient state in response to a recent dome-like uplift. Indeed, the fluvial processes that weakly incised this landscape at a rate of ~0.6mm/yr are approaching a radial pattern. On the basis of geological and geomorphic constraints, we hypothesize that the uplift started around or after 3Ma. [Copyright &y& Elsevier]

The Iberian Chain (central–eastern Spain) is characterized by a dome-shaped topography with poorly incised and relatively flat landscape in its interior at an elevation of ~ 1300 m. A recent regional tectonic event started during or after the Late Pliocene, inducing deep valley incision on the flanks of the Iberian Chain. The rate and timing of this deformation, as well as the magnitude of the uplift-induced erosion processes, still lack a quantitative validation. We used 3D (SIGNUM) and 1-D (river profile) numerical models to investigate the landscape evolution of the Iberian Chain from the Late Pliocene to the present and to study the response of topography and rivers to tectonically induced base level lowering. Our model results are supported by geological, geomorphological and geochronological data. The results of the SIGNUM experiments show that the Iberian Chain topography has experienced regional uplift since ca. 3 Ma with rates between 0.25 and 0.55 mm y − 1 . In response to this uplift, rivers have incised at an average long-term incision rate of about 0.22 mm y − 1 and have progressively captured drainage areas from the chain interior. To further validate the results of landscape evolution modeling, we use a 1-D river incision model to explore the incision history of several rivers draining the Iberian Chain. The results constrain the range of values of bedrock erodibility from 5.8 × 10 − 5 to 5.0 × 10 − 4 m 0.4 y − 1 and predict long-term incision rates similar to those from the SIGNUM experiments. [ABSTRACT FROM AUTHOR]