The Crustal Domains of the Alboran Basin (Western Mediterranean)

26 pages, 15 figures, tables, supporting information https://doi.org/10.1029/2017TC004946.-- All the data used are listed in the references or archived at the Barcelona‐CSI repository at the ICM (TOPOMED, EVENT‐DEEP, and ESCI cruises, http://www.icm.csic.es) and at the UTIG repository (CONRAD cruise, http://www.udc.ig.utexas.edu/sdc/).-- This work has been carried out within Grup de Recerca Consolidat de la Generalitat de Catalunya “Barcelona Center for Subsurface Imaging” (2017 SGR 1662)The Alboran Basin in the westernmost Mediterranean hosts the orogenic boundary between the Iberian and African plates. Although numerous geophysical studies of crustal structure onshore Iberia have been carried out during the last decade, the crustal structure of the Alboran Basin has comparatively been poorly studied. We analyze crustal-scale images of a grid of new and reprocessed multichannel seismic profiles showing the tectonic structure and variations in the reflective character of the crust of the basin. The nature of the distinct domains has been ground-truthed using available basement samples from drilling and dredging. Our results reveal four different crustal types—domains—of the Alboran Basin: (a) a thin continental crust underneath the West Alboran and Malaga basins, which transitions to (b) a magmatic arc crust in the central part of the Alboran Sea and the East Alboran Basin; (c) the North African continental crust containing the Pytheas and Habibas subbasins; and (d) the oceanic crust in the transition toward the Algero-Balearic Basin. The Alboran Basin crust is configured in a fore-arc basin (West Alboran and Malaga basins), a magmatic arc (central and East Alboran), and a back-arc system in the easternmost part of the East Alboran Basin and mainly Algero-Balearic Basin. The North African continental crust is influenced by arc-related magmatism along its edge and was probably affected by strike-slip tectonics during westward migration of the Miocene subduction system. The distribution of active tectonic structures in the current compressional setting generally corresponds to boundaries between domains, possibly representing inherited lithospheric-scale weak structuresThe authors acknowledge support from the Spanish Ministry of Economy and Competitiveness through the Complementary Action ESF TopoEurope TOPOMED (CGL2008‐03474‐E/BTE), national projects EVENT (CGL2006‐12861‐C02‐02), INSIGHT (CTM2015‐70155‐R), FRAME (CTM‐2015‐71766‐R), and COST Action 1301 “FLOWS.” This work was supported by the Spanish Ministry of Education, Culture and Sport through the FPU fellowship 2013–2017 to L. Gómez de la Peña (AP2012‐1579). This publication is funded by the Cluster of Excellence “The Future Ocean,” within the framework of the Excellence Initiative by the Deutsche Forschungsgemeinschaft (DFG) on behalf of the German federal and state governmentsPeer Reviewe