Paleoenvironmental changes in the Corinth Rift area (eastern Mediterranean) during MIS 1-5 based on benthic foraminifera and geochemical proxies

The Gulf of Corinth is a relatively young (<5 Ma) and active continental rift zone in the eastern Mediterranean Sea, with a length of ca. 120 km. The Gulf is currently connected to the Ionian Sea through a shallow sill (Rion sill; 60 m of depth) and to the Aegean Sea via the Corinth Canal (Isthmus; 6 km-wide). The eastern part is divided by the Perachora Peninsula into the Lecheon Gulf in the South, and the Alkyonides Gulf in the North, where core MOO80 is located. The closed drainage system and the high sedimentation rates (approx. 0.5-3 mm/yr) make the study area a natural laboratory for the investigation of the complex interaction between sedimentary input, tectonics and climate through the basin’s evolution. In this study, we investigate paleoenvironmental changes recorded in IODP Expedition 381 core M0080A during MIS 1-5 (0-36.5 mbsf), through benthic foraminiferal abundance and composition integrated with a multiproxy dataset (grain size, organic and inorganic carbon content, XRF, benthic foraminifera oxygen and carbon isotopes).

The benthic foraminiferal record is highly variable during the Holocene and the Last Interglacial complex (22.8-25.5 mbsf and 30-35.8 mbsf). Infaunal foraminiferal species characterize these assemblages with high abundances of Hyalinea balthica, Bolivina spathulata, Melonis affinis, Bulimina aculeata, Bulimina marginata and Cassidulina carinata, indicating mesotrophic to eutrophic marine conditions, likely occurring during high sea-levels. During glacial and interstadial intervals, benthic foraminifers are very low in numbers or even absent, suggesting a sea-level drop below sill level and the subsequent (semi-)isolation of the basin. The inorganic carbon content varied following the interpreted sea-level fluctuations, with higher values occurring during intervals of low sea-level. The beginning of the Holocene is characterized by the re-establishment of marine conditions as the sea-level rised above the sill level and the basin re-connected to the Mediterranean Sea.

Ongoing high-resolution studies and a refinement of the age model will improve our understanding of paleoenvironmental changes in the Gulf of Corinth during glacial and interglacial stages and allow us to define the factors driving changes in this unique active rift of the eastern Mediterranean.

This study is funded through project GR 5285/3-1 “Late Quaternary dynamics of marine paleoenvironments and ecosystems in the Gulf of Corinth (eastern Mediterranean)” of the Deutsche Forschungsgemeinschaft (DFG).