Transition from collision to subduction in Western Greece: the Katouna–Stamna active fault system and regional kinematics
Abstract
Transition from subduction to collision occurs in Western Greece and is accommodated along the downgoing plate by the Kefalonia right-lateral fault that transfers the Hellenic subduction front to the Apulian collision front. Here we present an active tectonic study of Aitolo-Akarnania (Western Greece) that highlights how such a transition is accommodated in the overriding plate. Based on new multi-scale geomorphic and tectonic observations, we performed an accurate active fault trace mapping in the region, and provide evidence for active normal and left-lateral faulting along the Katouna–Stamna Fault (KSF), a 65-km-long NNW-striking fault system connecting the Amvrakikos Gulf to the Patras Gulf. We further show that the Cenozoic Hellenide thrusts located west of the KSF are no longer active, either in field observation or in GPS data, leading us to propose that the KSF forms the northeastern boundary of a rigid Ionian Islands-Akarnania Block (IAB). Cosmic ray exposure measurements of ^(10)Be and ^(36)Cl were performed on a Quaternary alluvial fan offset along the KSF (~50 m left-lateral offset). A maximum abandonment age of ~12–14 ka for the alluvial fan surface can be determined, giving an estimated KSF minimum geological left-lateral slip rate of ~4 mm year^(−1), in agreement with high GPS slip rates (~10 mm year^(−1)). Despite this high slip rate, the KSF is characterized by subdued morphological evidence of tectonic activity, a gypsum-breccia bedrock and a low level of seismicity, suggesting a dominantly creeping behavior for this fault. Finally, we discuss how the IAB appears to have been progressively individualized during the Pleistocene (younger than ~1.5 Ma).
Additional Information
© 2016 Springer-Verlag Berlin Heidelberg. Received: 9 July 2015; Accepted: 28 May 2016; Published online: 29 June 2016. This research work has been funded by the Laboratoire de Géologie de l'Ecole Normale Supérieure, Paris (PSL Research University). We thank V. Guillou, L. Léanni, L. Benedetti, G. Aumaître, K. Keddadouche, M. Arnold, and F. Chauvet for their warm welcome and help during chemistry preparation and AMS measurements at CEREGE. The AMS measurements were performed at the ASTER AMS national facility (CEREGE, Aix-en-Provence), which is supported by the INSU/CNRS, the ANR through the "Projets thématiques d'excellence" program for the "Equipements d'excellence" ASTER-CEREGE action, IRD and CEA. We are very grateful to Mary Ford for the English syntax corrections in the manuscript, and her very careful review. We thank Laurent Jolivet for valuable comments in his review. Both reviewers significantly improved the final version of this work. We also thank Leigh Royden and two anonymous reviewers for critical reviews of a previous version of this work.Attached Files
Supplemental Material - 531_2016_1345_MOESM1_ESM.docx
Supplemental Material - 531_2016_1345_MOESM2_ESM.pdf
Supplemental Material - 531_2016_1345_MOESM3_ESM.pdf
Files
Additional details
- Eprint ID
- 77365
- Resolver ID
- CaltechAUTHORS:20170511-074920797
- Laboratoire de Géologie de l'Ecole Normale Supérieure
- Created
-
2017-05-12Created from EPrint's datestamp field
- Updated
-
2023-10-25Created from EPrint's last_modified field