Abstract Grain-size analysis of the sediments in borehole M0079A, located in the Corinth Rift, was used to explore hydrodynamic conditions and provenance in the Late Pleistocene Corinth Rift. Grain-size populations that were sensitive to the sedimentary environments were characterized by frequency distribution, particle size–standard deviation and probability cumulative curves. Our results indicate the grain-size population component in the range 0.15–0.25 µm may be used as a sensitive proxy for hyperpycnal flows, which have commonly been triggered by river floods from the southern margin of the rift since c. 0.593–0.613 Ma. The high-density plumes derived from the longer rivers of the southern rift that were prevalent before c. 0.593–0.613 Ma. When sediment is supplied as hemipelagic deposition, the proportion of the total grain-size population that is in the 0.3–0.5 µm range becomes an index for suspension fall-out deposits. The core shows coarser sediments during the marine periods, and this may be linked to the current circulation related to the Ishtmia Strait opening. The study thus illustrates how the establishment of interbasinal straits can influence the details of sedimentary hydrodynamics in the deep-water axis of an adjacent depocentre.

Abstract: The active Corinth rift records hanging-wall migration of faulting and slip-rate acceleration. 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 northward 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 stable 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 established 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.

Abstract The arcuate form of the external western Alps was generated during Tertiary NW-directed collision between the Apulian indentor and the southward-subducting European passive margin. The evolution of peripheral syn-collisional depocentres around this arcuate orogen (in France and Switzerland) is reconstructed using a compilation of stratigraphic and tectonic data. This reveals fundamental changes in the flexural behaviour of the European lithosphere during collision. During early collision (Eocene), an increasingly arcuate, peripheral flexural basin migrated rapidly NW across the European plate. During peak collision (early Oligocene), frontal flexure, recorded in the North Alpine Foreland Basin (NAFB), steepened markedly, while lateral flexure of the European plate, affecting SE France, effectively ceased. Here, Oligocene sedimentation was confined to small thrust-sheet-top basins. Two rift systems initiating in the late Eocene, the West European rift system and the West Mediterranean oceanic basin (that created the Gulf of Lion passive margin), are superimposed in space and time on the outer margins of the alpine flexural depocentres. During waning collision (Mio-Pliocene) the NAFB became overfilled, then uplifted and abandoned while, in SE France, a local depocentre (Digne-Valensole) developed between uplifting blocks and continued to accumulate sediments until the late Pliocene.