Sedimentation and subsidence rate in the Gulf of Corinth: what we learn from the Marion Dufresne's long-piston coring

Abstract

Long-piston coring in the central Gulf of Corinth Basin was performed in 2001 on board the RSS Marion Dufresne , enabling the recovery of lacustrine sediments buried at 12–13.5 mbsf below Holocene marine sediments. The lacustrine sequence consists of varve-like muddy, organically rich, layers interbedded with silty and fine sand turbidites. AMS dating determined the age of the marine-lacustrine interface at 13 kyr BP. Vertical fault slip rates were measured by using fault offsets of correlated reflectors. The maximum subsidence rate of the depocentre (3.6 mm yr −1 ) exceeds the maximum sedimentation rate by 1.8 mm yr −1 , which, consequently, corresponds to the rate of deepening of the basin floor. Data on the water level during the last glacial period indicate that the Corinth–Lake level was about 80 m lower than the present sea level. Inflow of seawater through the Rio–Antirio sill, as a consequence of the last eustatic sea level rise, may have caused catastrophic marine flooding phenomena in the Gulf of Corinth, similar to the one reported from the Black Sea.