Main active faults in the Granada and Guadix-Baza Basins (Betic Cordillera)/Principales fallas activas de las Cuencas de Granada y Guadix-Baza (Cordillera Bética)

• Published in: Journal of Iberian geology Vol. 38; no. 1; p. 209
• Main Authors: de Galdeano, C Sanz, García-Tortosa, F J, Peláez, J A, Alfaro, P, Azañón, J M, Galindo-Zaldívar, J, Casado, C López, Garrido, A C López, Rodríguez-Fernández, J, Ruano, P
• Format: Journal Article
• Language: English
• Published: Madrid Springer Nature B.V 01.01.2012
• Subjects: Basins; Plate tectonics; Seismology; Betic Cordillera; Spain, Andalucia, Betic Cordilleras; Spain, Galicia; Spain, Granada; Spain, Granada, Guadix-Baza Basin
• ISSN: 1698-6180; 1886-7995

The Granada and Guadix-Baza Basins, the largest Neogene-Quaternary intramontane basins of the Betic Cordillera (southern Spain), undergo active deformation with an associated moderate level of seismic activity. This deformation is controlled by a NNWSSE compressive regime and an approximate orthogonal tensional regime. The compression produced N700E to E-W folds of several scales, the Sierra Nevada antiform being the largest one. The tension is accommodated mainly by NW-SE active normal faults, the most notable being the Baza Fault, in the Guadix-Baza Basin, and the Granada, Sierra Elvira-Dílar and Padul-Dúrcal Faults, in the Granada Basin. In addition, other active faults with different orientations also exist, such as the Alfahuara-Botardo and the Galera faults in the Guadix-Baza Basin, and the Huenes, Obéilar-Pinos Puente and N of Sierra Tejeda Faults in the Granada Basin. Moreover, in several sectors, the presence of orthogonal normal fault sets suggests alternating trends or even radial extension. Slip rates of these active faults, based on geologic markers, vary between 0.06 and 0.5 mm/year. Estimates for the maximum expected magnitude of earthquakes caused by these faults vary between MW 6.0 and 7.0. The N of Sierra Tejeda and the Baza Faults, the larg- est faults in the Granada and Guadix-Baza Basins, respectively, have the greatest seismic potential. They could cause events up to a magnitude of14 6.5-7.0, although their reference earthquakes, computed for a return period of 475 years, are on the order ofMw 5.0-5.5. [PUBLICATION ABSTRACT]