Using travertine deformations to characterize paleoseismic activity along an active oblique-slip fault: the Alhama de Murcia fault (Betic Cordillera, Spain)

[EN] A preliminary paleoseismic study of travertine deposits cut by an active oblique-slip fault is presented. The Alhama de Murcia fault a ffects late Pleistocene and Holocene trave rtine deposits along the Lorca-Totana segment. Travertines along oblique-slip (reverse - sinistral) active faults hav...

Descripción completa

Detalles Bibliográficos
Autores: Hernández-Enrile, J. L., Martínez-Díaz, J. J.
Tipo de recurso: artículo
Fecha de publicación:2001
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/5312
Acceso en línea:http://hdl.handle.net/10261/5312
Access Level:acceso abierto
Palabra clave:Palepseismicity
Travertine
Alhama de Murcia fault
Descripción
Sumario:[EN] A preliminary paleoseismic study of travertine deposits cut by an active oblique-slip fault is presented. The Alhama de Murcia fault a ffects late Pleistocene and Holocene trave rtine deposits along the Lorca-Totana segment. Travertines along oblique-slip (reverse - sinistral) active faults have not been reported. On the Alhama de Murcia fault, CaCO3 rich springs are linked to an extensional step-over and to releasing fault junctions in a reverse-sinistral fault zone. The sampling methodology for U/Th dating employed to avoid contamination (by choosing material from a geochemical closed system) is described. A petrographic analysis is necessary to ensure the quality of the samples. Terrace - mound, fissure-ridge, eroded sheets and range-front trave rtine deposits occur in the Alhama de Murcia fault zone. At Carraclaca a 15 m amplitude monocline fold was formed by the reverse movement of this fault which has been active since the late Pleistocene. The first available absolute ages for deformed and undeformed trave rtines yield a ve rtical slip rate of 0.08 mm/yr. It is possible to estimate 4818 yr of recurrence time for the northern branch given the slip per event on alluvial deposits in the southern branch of the Alhama de Murcia fault.