In 1980 a seismic sequence occurred along the Nea Anchialos Fault Zone near the town of Volos in Central Greece. The fault zone constitutes the northern bound of the Almiros Basin which is one of the Neogene tectonic basins of Thessaly. It is filled up by Plio-Pleistocene lacustrine sediments. In the area has been executed an extensive field work with the specific purpose of carring out a detailed neotectonic study. The meso-structural data have been elaborated with computer-aided methodologies to estimate the three principal directions of the paleo-stress field. The results clearly show a pure extensional regime nearly N-S which is consistent with the direction of the T axes computed from the focal mechanisms of the 1980 Volos earthquake. A minor set of data indicates an extension roughly WNW-ESE and is probably due to a local and second order stress field as suggested in the text. Furthermore, during the field work new archeological data have been discovered. Their evident implications with the morphology and the tectonics of the area are discussed. Following some hypothesis it is possible to compute the slip rate occurred in historic time, along the fault zone. Finally, the already existing seismological data are compared with the presented structural and archeological data and all together permit a broader view and a better understanding of the recent (neo- to seismo-)tectonic evolution of the Nea Anchialos Fault Zone.
Recent tectonics along the Nea Anchialos Fault Zone (Central Greece)
CAPUTO, Riccardo
1991
Abstract
In 1980 a seismic sequence occurred along the Nea Anchialos Fault Zone near the town of Volos in Central Greece. The fault zone constitutes the northern bound of the Almiros Basin which is one of the Neogene tectonic basins of Thessaly. It is filled up by Plio-Pleistocene lacustrine sediments. In the area has been executed an extensive field work with the specific purpose of carring out a detailed neotectonic study. The meso-structural data have been elaborated with computer-aided methodologies to estimate the three principal directions of the paleo-stress field. The results clearly show a pure extensional regime nearly N-S which is consistent with the direction of the T axes computed from the focal mechanisms of the 1980 Volos earthquake. A minor set of data indicates an extension roughly WNW-ESE and is probably due to a local and second order stress field as suggested in the text. Furthermore, during the field work new archeological data have been discovered. Their evident implications with the morphology and the tectonics of the area are discussed. Following some hypothesis it is possible to compute the slip rate occurred in historic time, along the fault zone. Finally, the already existing seismological data are compared with the presented structural and archeological data and all together permit a broader view and a better understanding of the recent (neo- to seismo-)tectonic evolution of the Nea Anchialos Fault Zone.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
