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Normal faulting, regional uplift and glacio-eustacy have controlled patterns of sedimentation on a variety of scales during the active rift history of the Corinth Basin. Extensive sections through 800 m of early rift deposits are exposed in the north of the basin. These are overlain by andesites dated at 3.62 ± 0.18 and 4.00 ± 0.40 Ma. Early in the rifting process, basin relief controlled by normal faulting determined broad environmental conditions. Slope gradients determined transport process within an east-west asymmetric graben. Palaeoflow and provenance data allow lateral and axial sediment dispersal systems to be distinguished, and indicate that the Corinth basin was separated by a drainage divide from the larger Gulf of Corinth basin, to the west, during the Lower Pliocene. Sedimentary facies and thickness changes across faults, and the distribution of unconformities and soft-sediment deformation features define active tectonism at this time. As such, the Corinth Basin provides a model for the recognition of syn-rift unconformities and associated depositional patterns in other extensional basins. Since the mid-Pliocene, a combination of regional, crustal uplift and of more localized, fault-controlled, extensional subsidence have determined basin form. In the north of the basin, Lower Pliocene and Quaternary marine sediments have been uplifted up to 300 m above present-day sea-level. Normal faulting during the same episode separated successive intrabasinal depocentres from emergent highs that were subject to erosion. The competition between uplift and extensional subsidence has important implications for the back-arc evolution of the central Aegean area. The uplift suggests that crustal underplating by the subducted Mediterranean plate may have advanced as far north as northern Peloponessus and Corinth by the Upper Pliocene-Lower Pleistocene.

No abstract

The Büyük Menderes and Gediz graben of western Turkey developed during Miocene to Recent extension in the Aegean region. New mapping of structures and sedimentary lithofacies in exhumed basin-fill strata is used to reconstruct the evolution of the graben. Field evidence shows that extension was primarily accommodated by tilted fault-blocks 0.2–0.8 km wide, bounded by planar faults, with some modification by antithetic faulting. The basins are faulted on both margins, although they are highly asymmetric, with dominant 'footwall' margins characterized by steeper topography and greater thicknesses of exhumed strata. Within exhumed graben-fill sequences, lacustrine, axial fluvial, and laterally-derived sedimentary facies can be identified. Palaeocurrent orientations, divergent wedge geometries and intra-basin unconformities all indicate that exposed sediments are syn-tectonic. The present day map patterns demonstrate that the position of graben-bounding faults has migrated basinward with time. As a result, large-scale erosion and recycling of the uplifted basin fill have created extensive footwall-derived alluvial fans. These displace the axial drainage towards the hanging-wall margins, away from the locus of greatest subsidence.