Rift migration and lateral propagation: evolution of normal faults and sediment-routing systems of the western Corinth rift (Greece)
Résumé
The active Corinth rift records hanging-wall migration of faulting and slip-rate accel- eration. The rift initiated at approximately 5 – 4 Ma, and older parts are well exposed in the northern Peloponnese. A new correlation of chrono- and lithostratigraphy and structure across the onland central to westernmost rift with offshore data reveals westward rift propagation, as well as north- ward fault migration. Northward fault migration ended first in the east, with the stabilization of major north-dipping faults that now bound the Gulf. The basin then propagated to the WNW in two stages, each involving the initiation of a new fault that propagated east to SE to link to the sta- ble fault system. Extension rates accelerated in distinct steps as the rift opened to the west. The youngest faults in the westernmost rift are associated with high seismicity and highest geodetic extension due to rapid fault growth and linkage at depth.
The early synrift succession infilled substantial inherited palaeo-relief. Antecedent rivers estab- lished vigorous sediment-routing systems that controlled facies distribution throughout rifting, albeit with drainage reorganization during fault-migration events. Multiple deepening events recorded in the stratigraphy can be due to lateral rift propagation. The transition from rift initiation to rift climax is, therefore, diachronous along the rift axis.