| ABSTRACT | The sedimentary sequence of Aliakmon River delta (core S1) in north Aegean Sea is investigated to provide information about the mid-Holocene (8500 – 4500 cal yr BP) climate variability of northeastern Mediterranean (NEM). A synthetic age-depth model was constructed from 4 radiocarbon dates and through correlations with lithostratigraphic profiles and magnetic susceptibility (MS) stratigraphy of proximal to S1 cores. The mid-Holocene part of the core (450cm) represents lacustrine and floodplain fine (silt and clay) sediments with successive layers of coarser (coarse silt, sand and fine gravel) interbedded material. Clay minerals are represented by kaolinite and chlorite. The layers of coarse sediment correspond to peaks in the MS profile and to low percentages of weight loss-on ignition (LOI) and are interpreted as periods of increased flood activity. Decreases in LOI coincide with decreases in total organic carbon (TOC) from Lake Dorjan (70km to the northeast) sediments (core Col260), while peaks in Aliakmon River MS profile correspond to increased sand, kaolinite and chlorite concentrations in north Aegean Sea sediments (core SL-148), suggesting a regional signal of environmental change across NEM region. The results show significant centennial-scale climatic variability during mid-Holocene with periods enhanced flooding activity alternating rather abruptly with short periods of low flooding activity centered at at 8.04, 7.6, 7.25, 6.7, 6.25, 5.83, 5.4, 4.85, 4.4 cal. yr BP respectively. The successive periods of increased flooding occur at approximately 500 years for the mid-Holocene part of the record and may reflect changes of similar period in North Atlantic Deep Water (NADW) circulation. |