Actividad neotectónica de la Falla de Alentejo-Plasencia en Extremadura (Macizo Hespérico)
Signs of recent tectonic activity are found at the Extremadura sector of Alentejo-Plasencia fault. This fault was active during the alpine compressional period as a sinistral strike-slip fault at the foreland of a collisional zone and presents sorne activity from the Miocene to the Quaternary. Upper...
| Autores: | , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 1996 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | español |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/102253 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/102253 |
| Access Level: | acceso abierto |
| Palabra clave: | 551.24 Alentejo-Plasencia fault Neotectonic activity Alluvial terraces Raña Slip rate Paleoseismicity Geodinámica 2507 Geofísica |
| Sumario: | Signs of recent tectonic activity are found at the Extremadura sector of Alentejo-Plasencia fault. This fault was active during the alpine compressional period as a sinistral strike-slip fault at the foreland of a collisional zone and presents sorne activity from the Miocene to the Quaternary. Upper «Raña» deposits of Early Villafranquian age, present an around-2-meter-vertical-displacement at the north border of Alburquerque granitic massif. Clase to this point old fluvial terraces of unknown age are folded and faulted, and low terraces (3 m above present river course) are jointed. In the tertiary Cañaveral pull-apart basin, at the Alcantara reservoir border, the fault disrupts a Tagus river fluvial terrace, which lies 80 m above the river course and has a probable Middle Pleistocene age. All these observations imply a vertical displacement which could be related to a slip rate less than 0.001 mm/year. lf this fault is compared with other active faults of the Hesperian Massif, such as the Bragança-Manteigas one, it becomes clear that Alentejo-Plasencia fault is less active. There are though paleoseismicity structures associated to the Alentejo-Plasencia fault, such as liquefaction features. |
|---|