Active faulting in the Betic External Zones (SE, Spain)
Evidence of active faulting is presented from a fault in the eastern Betic External Zones (SE Spain). New fault data are provided for the Alcoy Fault Zone, a structure whose Quaternary activity is currently under debate. This study includes a detailed structural and geomorphic characterization, alon...
| Autores: | , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2026 |
| País: | España |
| Recursos: | Universitat Autònoma de Barcelona |
| Repositório: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglês |
| OAI Identifier: | oai:ddd.uab.cat:326386 |
| Acesso em linha: | https://ddd.uab.cat/record/326386 https://dx.doi.org/urn:doi:10.1344/GeologicaActa2026.24.4 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Fault characterization Active tectonics Tectonic geomorphology Palaeoseismology Betic external zones |
| Resumo: | Evidence of active faulting is presented from a fault in the eastern Betic External Zones (SE Spain). New fault data are provided for the Alcoy Fault Zone, a structure whose Quaternary activity is currently under debate. This study includes a detailed structural and geomorphic characterization, along with a preliminary palaeoseismological analysis. This fault is ca. 13 km long, and two main sectors are defined based on its surface geometry: a SW sector striking N060E formed by a border fault strand, and a NE sector striking N040E to N065E, formed by a border and an intrabasinal fault strands. The Alcoy Fault Zone displays oblique kinematics, with a predominant left-lateral and a subordinate dip-slip component. Quaternary fault activity is evidenced by a qualitative and quantitative geomorphic analysis, where three geomorphic indices were applied (Smf, Vf, and Bs). The fault presents a marked mountain front with low sinuosity. Cross-fault streams, which are deflected in a left-lateral sense, exhibit knickpoints that coincide with the fault traces and display highly incised valleys. Moreover, the morphology of their watersheds is consistent with an ongoing tectonic uplift in the area. Additionally, the palaeoseismological analysis performed in deformed colluvial deposits suggests a Holocene surface rupture history involving two events during the last ca. 1160 years. The results of this work represent the first step for the seismogenic characterization of the Alcoy Fault Zone and the base for further seismic hazard assessment studies in the External Zones of the eastern Betic Cordillera. However, additional seismicity studies will be required to determine whether the fault is basement-involved or represents a decoupled structure controlled by the Triassic evaporitic layer between the Variscan basement and the pre-Neogene Betic rocks. |
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