A multiproxy palaeoenvironmental reconstruction of Loch Sunart (NW Scotland) since the Last Glacial Maximum

Loch Sunart is located on the northwest coast of Scotland and contains a sedimentary sequence that records Late Glacial to Holocene climatic variations. A 12 m core MD04-2833 was acquired in the main basin of the loch sampling this sequence. We present the palaeoenvironmental data and palaeoclimatical scenario, based on a multiproxy approach, using pollen concentrations, sortable silt variation, lithic fraction and marine benthic foraminifera assemblages. These analyses allow the identification of major climate fluctuations such as cooling events. Global temperature decreases are discriminated from local water temperature decreases due to ice-melting processes by the presence of Elphidium subarcticum and the assemblage of Cassidulina obtusa and Haynesina germanica. Two meltwater pulses (MWP) are distinguished, which respectively correspond to the MWP-Ia (15,500–13,000 cal yr BP) and MWP-Ib (12,200–10,100 cal yr BP). After the maximum water stratification occurred at 7,500 cal yr BP, full marine conditions were established around 6,000 cal yr BP, which correspond to the highest relative sea-level reached in the loch.