High- and Low-Angle Normal Fault Activity in a Collisional Orogen: The Northeastern Granada Basin (Betic Cordillera)
Metadatos
Mostrar el registro completo del ítemAutor
Madarieta Txurruka, Asier; Galindo Zaldívar, Jesús; González Castillo, María Lourdes; Peláez, José Antonio; Ruiz Armenteros, Antonio M.; Henares, Jesús; Garrido Carretero, María Selmira; Avilés, Manuel; Gil, Antonio J.Editorial
Wiley Online Library
Materia
Tectonics Betic Cordilleras Cuenca de Granada Active faults Geodesy Seismicity Active tectonics Tectónica Activa
Fecha
2021-06-21Referencia bibliográfica
Madarieta-Txurruka, A., GalindoZaldívar, J., González-Castillo, L., Peláez, J. A., Ruiz-Armenteros, A. M., Henares, J., et al. (2021). High- and low-angle normal fault activity in a collisional orogen: The northeastern Granada Basin (Betic Cordillera). Tectonics, 40, e2021TC006715. https:// doi.org/10.1029/2021TC006715
Patrocinador
Spanish projects DAMAGE. Grant Number: CGL2016-80687-R AEI/FEDER; Evaluación de la Peligrosidad de Inestabilidades de Laderas Asociadas a Terremotos. Grant Number: CGL2015-65602-R AEI-FEDER; Junta de Andalucia; European Regional Development Fund. Grant Numbers: AGORA P18-RT-3275, PAPEL B-RNM-301-UGR18; Programa Operativo FEDER-Andalucia 2014–2020; University of Jaén. Grant Number: POAIUJA 21/22; Junta de Andalucía (Andalusian Board). Grant Numbers: RNM-148, RNM-282, RNM-370Resumen
Understanding active tectonics and seismicity in extensional settings requires the analysis
of high-angle normal faults (HANFs) and the transfer of deformation at depth. The debate surrounds
the role of low-angle normal faults (LANFs) in triggering high magnitude earthquakes. The central Betic
Cordillera is an active seismic zone affected by the NNW-SSE Eurasia-Nubia convergence and orthogonal
extension. The seismicity and present-day stress determined by earthquake focal mechanisms reveals the
activity of a NE-SW extensional system in the shallowest 12 km of the Granada Basin. The structure of
the sedimentary infill, as derived by geological field and gravimetric techniques, suggests the formation
of a half-graben tilted to the N-NE. Seismologic data suggest the activity of HANFs above 6–7 km depth
and a LANF zone around 6–12 km depth, with related earthquakes of up to Mw 4.0 and 20° to 30° fault
dips. High-precision leveling lines highlight the importance of the Granada Fault in the system, with
average vertical displacement rates of 0.35–1.1 mm/yr. These data suggest creep fault behavior at the
surface and increased seismicity at depth. The upper crustal extension in the collisional Betic Cordillera is
accommodated by a top-to-the-WSW extensional detachment related to westward motion and rollback in
the Gibraltar Arc and the gravitational collapse of the cordillera, in a framework of NNW-SSE shortening.
This comprehensive study draws a new scenario that advances understanding of relationships between
HANFs and LANFs.