Active faulting at the western tip of the Gulf of Corinth, Greece, from high-resolution seismic data

Abstract

International audienceThe Gulf of Corinth is one of the fastest-spreading intra-continental rifts on Earth. GPS data indicate that the rift is currently opening in a NNE-SSW direction, with a rate of extension reaching up to 16 mm yr (super - 1) in its westernmost part. Although the rest of the offshore rift has been well studied, the western tip of the rift is still poorly explored. We present an accurate map of submarine faults in this area based on two high-resolution seismic reflection surveys (single-channel sparker). In the eastern part of the studied area, the sedimentary infill is affected by the known North Eratini, South Eratini, and West Channel faults. Further to the west, the seafloor is mostly flat and is bounded to the north by the normal, south-dipping, Trizonia fault. To the north, the shallower part of the Gulf shows to the east a diffuse pattern of normal and strike-slip deformation, which is replaced to the west by a 7.5 km long SE striking strike-slip fault zone, called the Managouli fault zone. To the westernmost tip of the Gulf, in the Nafpaktos Basin, two fault sets with different strikes are encountered; the one with a NE-SW strike exhibits a clear strike-slip component. The western tip of the Gulf of Corinth is the only part of the Corinth Rift where convincing evidence for strike-slip movement has been found. This fault pattern is likely related to the complex deformation occurring at the diffuse junction at the western tip of the Rift between three crustal blocks: Continental Greece, Peloponnese, and the Ionian Island-Akarnania block

Influence of bottom currents on the sedimentary processes at the western tip of the Gulf of Corinth, Greece

“…The rifting was initiated~5 Ma ago, to the south and east of the present gulf, and then shifted northward to the present gulf area probably at the beginning of the Quaternary (Ori, 1989;Ford et al, 2009). The Gulf of Corinth basin is affected by numerous active faults, mainly located on the southern coastline, but also offshore and along the northern coast (e. g. Stefatos et al, 2002;Bell et al, 2008Bell et al, , 2009Taylor et al, 2011;Charalampakis et al, 2014;Beckers et al, 2015). The fault network controls the overall morphology of the Gulf described in the previous section at the scale of the whole Gulf as well as at the scale of the study area, at its western tip.…”

“…1D). The northern flank of the canyon is a tectonic scarp while the southern flank encompasses fault scarps and Gilbert-type deltas (Beckers et al, 2015). East of the Trizonia Island meridian, the deep gulf widens and forms the so called Delphic Plateau, at a depth of about −400 m ( Fig.…”

Patterns of Quaternary uplift of the Corinth rift southern border (N Peloponnese, Greece) revealed by fluvial landscape morphometry

“…Many seismic reflection studies contributed in the last decade toward an improved mapping of active offshore faults (e.g., Stefatos et al, 2002;Lykousis et al, 2007;Bell et al, 2008;Taylor et al, 2011;Beckers et al, 2015). The mostly north-dipping faults of the southern margin are grouped in several parallel lines of right-stepping en-échelon faults, both on-and offshore.…”

Recent Sedimentary Processes in the Western Gulf of Corinth, Greece: Seismic and Aseismic Turbitides

“…Based on the interpretation of the pattern of turbidites in the canyon, Beckers (2015) has proposed two periods of seismic quiescence; 1740-1890 AD in the western part of the canyon and 1500-1700 AD in the eastern one. This coincident rather well with the findings of the present work.…”

“…This canyon has been formed by the tectonic subsistence of the north-dipping Psathopyrgos-Lambiri-Helike faults and the south-dipping Trizonia fault (Zelilidis, 2003) and is associated with gravitative mass movements during the late Quaternary (Heezen et al, 1966). For this canyon, Beckers (2015) has proposed different sedimentation rates ranging between 2.1-2.6 mm/yr in the western part and 0.8-1.6 mm/yr in the eastern part, based on radiocarbon dates from four sediment cores and two unsupported 210 Pb activity profiles.…”