Distributed normal faulting in the tip zone of the South Alkyonides Fault System, Gulf of Corinth, constrained using 36Cl exposure dating of late-Quaternary wave-cut platforms

Robertson, J., Roberts, G.P., Iezzi, F., Meschis, M., Gheorghiu, D.M. , Sahy, D., Bristow, C. and Sgambato, C. (2020) Distributed normal faulting in the tip zone of the South Alkyonides Fault System, Gulf of Corinth, constrained using 36Cl exposure dating of late-Quaternary wave-cut platforms. Journal of Structural Geology, 136, 104063. (doi: 10.1016/j.jsg.2020.104063)

Abstract

The geometry, rates and kinematics of active faulting in the region close to the tip of a major crustal-scale normal fault in the Gulf of Corinth, Greece, are investigated using detailed fault mapping and new absolute dating. Fault offsets have been dated using a combination of 234U/230Th coral dates and in situ 36Cl cosmogenic exposure ages for sediments and wave-cut platforms deformed by the faults. Our results show that deformation in the tip zone is distributed across as many as eight faults arranged within ~700 m across strike, each of which deforms deposits and landforms associated with the 125 ka marine terrace of Marine Isotope Stage 5e. Summed throw-rates across strike achieve values as high as 0.3–1.6 mm/yr, values that are comparable to those at the centre of the crustal-scale fault (2–3 mm/yr from Holocene palaeoseismology and 3–4 mm/yr from GPS geodesy). The relatively high deformation rate and distributed deformation in the tip zone are discussed in terms of stress enhancement from rupture of neighbouring crustal-scale faults and in terms of how this should be considered during fault-based seismic hazard assessment.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gheorghiu, Dr Delia M

Creator Roles

Gheorghiu, D.M.: Investigation

• Authors: Robertson, J., Roberts, G.P., Iezzi, F., Meschis, M., Gheorghiu, D.M., Sahy, D., Bristow, C., and Sgambato, C.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Journal of Structural Geology
• Publisher: Elsevier
• ISSN: 0191-8141
• ISSN (Online): 1873-1201
• Published Online: 21 April 2020
• Copyright Holders: Copyright © 2020 Elsevier Ltd.
• First Published: First published in Journal of Structural Geology 136: 103062
• Publisher Policy: Reproduced in accordance with the publisher copyright policy