Evidence of climatic changes in the Venetian Coastal Plain (Northern Italy) during the last 40,000 years.

Borehole ARS-S1 sampled sediments down to 40 m under the coastal city of Venice with the aim of reconstructing climatic variations during the last 40,000 years. Seven sedimentary facies belonging to continental and littoral depositional systems have been identified and dated. An age-depth model gives a mean sedimentation rate of 1.6 mm yr-1 between 40 and 22.5 cal ka BP. A general change in sedimentation rate occurred around 29 cal ka BP, indicating an increased accumulation during the Last Glacial Maximum. The main climatic changes during the last 40,000 years have been identified through pollen analyses. From the deepest core depth to-5 m the pollen sequence indicates a long glacial period characterized by open steppe vegetation with pine and low concentrations of arboreal pollen grains. Fluctuations of mountain elements and the occurrence of Quercetum elements indicate the presence of the main interstadials and interglacial phases of the Middle Weichselian-Holocene interval. This framework results from comparison with European palyno-chronostratigraphic records and Atlantic stadial and interstadial chronologies, and confirms the evolution of the Venetian Plain under global climatic pulses.