99650 doi 10.1344/105.000001771 articleid 16965728v10n3p249 eng Balanyá, J.C. Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturales Arc-parallel vs back-arc extension in the Western Gibraltar arc : is the Gibraltar forearc still active? Extremely tight arcs, framed within the Eurasia-Africa convergence region, developed during the Neogene on both sides of the western Mediterranean. A complex interplate deformation zone has been invoked to explain their structural trend-line patterns, the shortening directions and the development of back-arc basins. Updated structural and kinematic maps, combined with earthquake data covering the complete hinge zone of the western Gibraltar arc help us to explore the mode of strain partitioning from 25My ago to present. During the Miocene, the strain partitioning pattern showed arc-perpendicular shortening in the active orogenic wedge –assessed from the radial pattern of tectonic transport directions– accompained by subhorizontal stretching. Structures accommodating stretching fall into two categories on the basis of their space distribution and their relationships with the structural trend-line pattern: i) arc-parallel stretching structures in the external wedge (mainly normal faults and conjugate strike-slip faults); and ii) extensional faults developed in the hinterland zone in which transport directions are centripetal towards the Alborán back-arc basin. Pliocene to Recent deformational structures together with focal solutions from crustal earthquakes (n=167; 1.5 Tots els drets reservats http://www.europeana.eu/rights/rr-f/ Anglès Article de fons Forearc tectonics Strain partitioning Crustal earthquakes Gibraltar arc info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Crespo-Blanc, A. Instituto Andaluz de Ciencias de La Tierra Díaz-Azpiroz, M. Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturales Expósito, I. Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturales Torcal, F. Instituto Andaluz de Geofísica y Prevención de Desastres Sísmicos Pérez-Peña, V. Universidad de Granada. Departamento de Geodinámica Booth-Rea, G. Universidad de Granada. Departamento de Geodinámica Vol. 10, Núm. 3 (setembre 2012), p. 249-263 Geologica acta 1696-5728 18 7997946 http://ddd.uab.cat/pub/geoact/geoact_a2012m9v10n3/geoact_a2012m9v10n3p249.pdf 0249 263 setembre 3 10 geoact_a2012m9v10n3 2012 ARTPUB UAB GEOACT artpubuab oai:ddd.uab.cat:99650 driver