A singular association of deformation structures that have disturbed terrains up to Quaternary age, has beendetected along the rocky coast of Vendicari (south-eastern Sicily). These structures are soft sedimentdeformations consisting of autoclastic breccias, diapyr-like injections and thixotropic wedges, as well as fractures, generally opened and filled by sediments. Both soft and brittle deformations can be due either to trigger mechanisms internal to the sedimentary environment or to external causes. In order to define the deformation mechanisms affecting the deposits, the local paleo-environmental reconstruction and detailed deformation structure investigations have been performed. Moreover, fractures have been analysed by a mesostructural study and the examination of the microscopic features of the filling materials, to highlight possible relationships with the stress field induced by regional tectonics. The multi-theme analysis allowed us to discard internal trigger mechanisms as responsible of the deformations and to reasonably infer thesedeformation structures as being seismically induced. This interpretation is also supported by similarities with structures studied in other areas worldwide and commonly interpreted as seismites. The link between these records of seismic activity and the eastern Sicily seismicity is set into evidence by the analysis of the historicalaccounts which report the occurrence of structures similar to those detected at Vendicari, in several sites close to the study area. A major result of the present study is to improve the catalogue of deformation features, recorded in sedimentary units, attributed to earthquakes.

Analysis of deformation structures in Pliocene and Quaternary deposits of the Hyblean Plateaux (south-eastern Sicily)

PIRROTTA, CLAUDIA;BARBANO, Maria Serafina
2011-01-01

Abstract

A singular association of deformation structures that have disturbed terrains up to Quaternary age, has beendetected along the rocky coast of Vendicari (south-eastern Sicily). These structures are soft sedimentdeformations consisting of autoclastic breccias, diapyr-like injections and thixotropic wedges, as well as fractures, generally opened and filled by sediments. Both soft and brittle deformations can be due either to trigger mechanisms internal to the sedimentary environment or to external causes. In order to define the deformation mechanisms affecting the deposits, the local paleo-environmental reconstruction and detailed deformation structure investigations have been performed. Moreover, fractures have been analysed by a mesostructural study and the examination of the microscopic features of the filling materials, to highlight possible relationships with the stress field induced by regional tectonics. The multi-theme analysis allowed us to discard internal trigger mechanisms as responsible of the deformations and to reasonably infer thesedeformation structures as being seismically induced. This interpretation is also supported by similarities with structures studied in other areas worldwide and commonly interpreted as seismites. The link between these records of seismic activity and the eastern Sicily seismicity is set into evidence by the analysis of the historicalaccounts which report the occurrence of structures similar to those detected at Vendicari, in several sites close to the study area. A major result of the present study is to improve the catalogue of deformation features, recorded in sedimentary units, attributed to earthquakes.
2011
Fractures; Sedimentary dykes; Soft sediment deformations; Liquefaction; Seismites; Quaternary
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/21659
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