Fallas de salto en dirección en el basamento de la cuenca de antepaís del Guadalquivir
- V. Tendero-Salmerón 1
- J. Galindo-Zaldívar 1
- J.A. Peláez 2
- M. Martínez-Martos 3
- J. Henares 2
- C. Marín-Lechado 4
- A.J. Gil-Cruz 2
- A.C. López-Garrido 1
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1
Instituto Andaluz de Ciencias de la Tierra
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2
Universidad de Jaén
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3
Universidad de Granada
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4
Instituto Geológico y Minero de España
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ISSN: 1576-5172
Year of publication: 2021
Issue Title: X Congreso Geológico de España
Issue: 18
Pages: 854
Type: Article
More publications in: Geotemas (Madrid)
Abstract
Several seismic swarms have affected the Eastern Guadalquivir Basin, located into the basement, which should be non-defor- med as the foreland of the Betic Cordillera. The most recent of them (2016-2018) is in the Guadiana Menor Valley, reaching a m bLg 4.1 event. Focal mechanisms are strike-slip solutions, and seismicity is distributed in a N-S elongated cluster. In addition to seismic analysis, other studies including surface researches, electric resistivity tomographies (ERT) and gra- vity prospecting have been carried out. Signs of active tectonics are scarce, but there are minor N-S vertical faults over the shallowest earthquakes (northern part of the cluster). ERT evidences the continuity of these faults. On the other hand, gravity anomaly models show a sedimentary infill that increases its thickness eastwards, in coherence with a foreland basin. Basement surface does not present big steps, scarps nor structures. Altogether supports that the origin of the seismicity is a NNE-SSW sinistral fault nucleated in the Iberian basement that may be propagating upwards. At regional scale, the generation of this fault has significant implications: this fault is not coherent with a strain partitioning or transfer fault models because of the absence of the geometry of the fault system. We propose a model of an incipient tecto- nic indentation in the Iberian basement, similar to the Palomares fault, associated to the Aguilas Arc.