Soft-sediment deformation structures interpreted as seismites in lacustrine sediments of the Prebetic Zone, SE Spain, and their potential use as indicators of earthquake magnitudes during the Late Miocene
Lacustrine formations of Late Miocene age in the Prebetic area, SE Spain, show several types of deformational structures that are interpreted as seismites. They are present in both marginal and deep lacustrine facies. Seismites formed in marginal lake environments comprise sand dikes, pillows and in...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2000 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/60443 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/60443 |
| Access Level: | acceso abierto |
| Palabra clave: | 551.24 Seismites Earthquake magnitudes Lacustrine deposits Late Miocene Spain Geodinámica 2507 Geofísica |
| Sumario: | Lacustrine formations of Late Miocene age in the Prebetic area, SE Spain, show several types of deformational structures that are interpreted as seismites. They are present in both marginal and deep lacustrine facies. Seismites formed in marginal lake environments comprise sand dikes, pillows and intruded and fractured gravels. In deep lacustrine facies, the seismites are represented by pseudonodules, mushroom-like silts protruding into laminites, mixed layers, disturbed varved lamination and loop bedding. The measured orientations of these structures are consistent with the orientations of the main faults limiting the basins, showing that their origin is clearly related to the tectonic stress field that prevailed in the region during the Late Miocene. The magnitudes of the earthquakes that deformed the sediments have been estimated after published data from both ancient and recent lake deposits accumulated in tectonic active regions elsewhere. A rank of earthquake magnitudes with two end-members, i.e. the lowest magnitudes recorded by loop bedding in laminites and the highest magnitudes represented by intruded and fractured gravels, is proposed. |
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