The Gulf of Corinth (GoC), derived from a geologically young active rift, offers a unique opportunity to study changes in environmental conditions during the Quaternary period in a region where long sequences are few. Due to periods of isolation during Quaternary lowstands, the water conditions were not favorable for the occurrence of conventional palaeoceanographical proxies such as planktonic foraminifera. We present here the first almost continuous record of phytoplankton proxies (dinoflagellate cysts) and freshwater palynomorphs (green algae) for the past 1.1 Myr aiming to provide a comprehensive insight into palaeoceanographic variability between glacial and interglacials cycles. Core M0078A retrieved during the IODP expedition 381 contains a rich and diverse dinoflagellate cyst assemblage, sorted into two major ecogroups, representing alternations between marine and brackish conditions. Our results allow for the first time the reconstruction of the Gulf environmental history of connection and disconnection from marine conditions from late Pleistocene to Holocene (1.1Ma – present). Dinocysts and other palynomorphs (NPPs) suggest that the GoC was repeatedly isolated and reconnected to the Mediterranean Sea during global sea-level lowstands associated with glacial intervals. These combined proxies suggest that marine water flowed into the GoC during the eustatic highstands associated with interglacial intervals. The dinocyst assemblages show a close affinity to modern assemblages from the Black, Caspian, and Marmara Seas.

Agia Bay is located on the southeastern coast of Lemnos Island. The coastal area today is characterized by aeolian sandy deposits (dunes). The systematic investigation of a 15.5-m long sediment core from the coastal plain of Agia Bay aimed to shed light to the paleoenvironmental evolution of the area that prehistoric groups occupied. The exhaustive study of the faunal and floral remains of the deposits including benthic foraminifera, ostracods, mollusks, pollen, and dinoflagellate cysts as well as plant remains was further supported by sedimentological, micromorphological, and elemental analyses, magnetic susceptibility measurements, ERT, and absolute dating. Four main evolutionary stages have been identified since the Late Glacial. At the base of the sequence, the fluvial activity dominated the sedimentation in the area forming a small shallow wetland, while after 12,500 cal BP, a marine signal was observed at the wetland. At 7500 cal BP, the wetland increased in size and depth, whereas at 6000 up to 4000 cal BP, a connection of the wetland to the sea was established, and an inner lagoon formed. After 4000 cal BP, a nearshore environment developed due to the sea-level rise. Pollen assemblages record the occurrence of a mixed deciduous oak forest in the island interior around 6000 cal BP, while after 5000 cal BP, an expansion of Mediterranean vegetation, shaped by human activity, is inferred.