The Corinth-Patras rift as the initial stage of continental fragmentation behind an active island arc (Greece)

Abstract During the migration of the back arc extension from central to western Greece the Corinth and Patras grabens are being formed. Orthogonal opening of these graben zones is accomplished by WNW listric normal faults and NNE transfer faults which produce an along-axis fragmentation. The listric faults show an increase in the dip of the fault plane westwards as well as a decrease in the maximum extension rate from 50% to the east in the Corinth graben, to 10% to the west in the Patras graben. Similarly, towards the west, Plio-Quaternary deposits become thinner whereas Pliocene sediments thin-out indicating a westward rift propagation.
As the back arc extension migrates westwards it is interacting or is being superimposed above another orthogonal fault system consisting of NNW and ENE normal faults. These faults have been formed during general uplift behind the orogenic front which has been migrating from western Greece to the Ionian islands. The ENE-trending Rio graben which belongs to his orthogonal system connects the Patras graben to the Corinth graben and has subsequently been active as a transfer fault between them.
Plio-Quaternary geodynamic processes in central continental Greece are quite similar to those earlier processes observed in the central Aegean region which reflect the initial stage of continental break-up behind a migrating orogenic front.