Geochronology of the Sencelles fault scarp and its relationships with the AD 1851 Mallorca Earthquake (Baleares Islands, Spain)
- P.G. Silva 1
- E. Roquero 2
- T. Bardají 3
- R. Pérez-López 4
- M.A. Rodríguez-Pascua 4
- J.L. Giner 5
- M.A. Perucha 4
- 1 Universidad Salamanca
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2
Universidad Politécnica de Madrid
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3
Universidad de Alcalá
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- 4 Instituto Geológico y Minero de España (IGME)
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5
Universidad Autónoma de Madrid
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ISSN: 1576-5172
Any de publicació: 2016
Títol de l'exemplar: IX CONGRESO GEOLÓGICO DE ESPAÑA
Número: 16
Pàgines: 653-656
Tipus: Article
Altres publicacions en: Geotemas (Madrid)
Resum
The Sencelles fault constitutes the main extensional structure of the Mallorca Island tentatively linked to the AD 1851 Palma earthquake (VII EMS.) The SE termination of the fault (Sta. Eugenia Segment) is featured by a linear bedrock fault scarp of a maximum of 3.15 m height. The last 840 m of this rocky scarp display a significant horizontal banding, with up to five bands differentially weathered and colonized by lichens. The lichenometric analysis is based on the measurement of 125 specimens of “Aspicilia calcarea” and “Aspicilia radiosa”in tombstones and funerary monuments (with inscribed dates) of the cemeteries of Sta. Eugenia and Sta. María del Camí, to obtain the lichen growth rates (LGR) for the zone. The application of the resulting LGR on the banded fault scarp indicates that the basal ribbon (10-13 cm) responds to ground leveling works developed in the zone during the middle 20th century (c. 1956-1953). The second fault ribbon (23-47 cm) can be related to the AD 1851 Palma Earthquake, since LGR results here in exposure dates of 1853±18 AD (A.radiosa) and 1855±59AD (A. calcarea). The associated displacements cannot be interpreted as surface faulting, but as secondary or sympathetic ground ruptures (secondary earthquake effects).