Neogene to Quaternary rifting, sedimentation and uplift in the Corinth Basin,Greece

Abstract

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.