Attempt to date Pleistocene normal faults of the Corinth-Patras Rift (Greece) by U/Th method, and tectonic implications

The Rift of Corinth is a major intra-continental rift controlled by a Pleis tocene and still active detachment fault. Its hangingwall contains normal f aults which have migrated as evidenced by geomorphologic studies and by the geometrical relations of the sedimentary series that they controlled succe ssively. However, because of the lack of paleontological data in the contin ental synrift sediments, the timing of this migration is unknown. Therefore , we attempted to date directly the faults using the U/Th method on calcite crystallizations. Preliminary results reveal that this method may be a use ful tool in neotectonics. In this first attempt, we studied the Xylokastro- Loutro fault and the Valimi fault. The age obtained on post-tectonic calcit e of the first fault shows that it locked at least 112.4 +/- 0.4ka ago. Syn tectonic calcite of the Valimi fault yields an age of 382.0 +/- 31.1 ka, sh owing that the fault was still active at that time. Tectonic implications o f these results are discussed.