Active extensional faults in the central-eastern Iberian Chain, Spain

Abstract

Among the conspicuous extensional structures that accommodate the onshore deformation of the Valencia Trough at the centraleastern Iberian Chain, a number of large faults show evidence of activity during Pleistocene times. At the eastern boundary of the Jiloca graben, the Concud fault has moved since mid Pliocene times at an average rate of 0.07-0.08 mm/y, while rates from 0.08 to 0.33 mm/y have been calculated using distinct stratigraphic markers of Middle to Late Pleistocene age. A total of nine paleoseisms associated to this fault have been identified between 74.5 and 15 ka BP, with interseismic periods ranging from 4 to 11 ka, estimated coseismic displacements from 0.6 to 2.7 m, and potential magnitudes close to 6.8. The other master faults of the Jiloca graben (Calamocha and Sierra Palomera faults) have also evidence of Pliocene to Late Pleistocene displacement, with average slip rates of 0.06 and 0.11-0.15 mm/y, respectively. At the eastern boundary of the Teruel graben, the Sierra del Pobo fault has been active since Late Miocene times, at slip rates of 0.06-0.11 mm/y. Quaternary activity its better constrained for the Teruel fault, which offsets two fluvial terraces, with an estimated slip rate of 0.12 mm/y since 76 ka BP. A widespread, NNE-SSW trending fault system extends over the easternmost Iberian Chain (Maestrat sector), with abundant proofs of activity during Early to Middle Pleistocene s.l. times. Nevertheless, such proofs are mainly geomorphologic, while dated stratigraphic markers allowing precise assessment of slip rates are absent.

Plio-Quaternary uplift of the Iberian Chain (central–eastern Spain) from landscape evolution experiments and river profile modeling

“…Most of the irregularities in the Mijares River profile are partially due to NNE-SSW normal faults, related to the opening of the Valencia Through started in the Oligocene. These faults generated small depressions filled with alluvial deposits (Simón et al, 2012 and references therein; Fig. 11a).…”

“…It is low to moderate and mostly concentrated in the intermontane basins (Gutiérrez et al, 2009(Gutiérrez et al, , 2012Lafuente et al, 2011b;Simón et al, 2012) and along the western margin of the Valencia Through (Perea et al, 2012;Simón et al, 2013).…”

“…The lower values are found in the chain interior, but they increase slightly on the flanks. The highest values of local relief are in the eastern sector of the Iberian Chain, along the Mediterranean coast, where active or recent extensional faults are located (Simón et al, 2012). Scotti et al (2014) analyzed several rivers that drain the Iberian Chain arranged in a radial pattern as a consequence of the dome-like uplift.…”

Geophysical characterization of buried active faults: the Concud Fault (Iberian Chain, NE Spain)

“…Several paleoseismic studies in trenches along the Concud Fault have been conducted mainly by our team (Lafuente et al 2011(Lafuente et al , 2014Simón et al 2012Simón et al , 2015Ezquerro et al 2015), but also for other research groups (Gutiérrez et al 2008). These studies have characterized the paleoseismic history of the fault, which includes eleven paleo-events since ca.…”

Tethyan versus Iberian extension during the Cretaceous period in the eastern Iberian Peninsula: insights from magnetic fabrics

“…9. Detailed geological map of the study area modified from Simón et al (2012) andGEODE (2013). Magnetic lineations per site, spatially oriented after restoring bedding to horizontal, are superimposed on the geological map.…”