Multi-proxy reconstruction of climate changes in the Lower St. Lawrence Estuary, Canada, during the Middle and Late-Holocene

The micropaleontological and palynological content, geochemical isotopic composition of a marine sediment core collected off Pointe-des-Monts in eastern Québec, Canada, reveal regional palaeoclimatic paleoceanographic conditions the Lower St. Lawrence Estuary over last ~8200 years. pollen spore content allows comparison with terrestrial palynostratigraphy, whereas dinoflagellate cysts benthic foraminifera are used to reconstruct sea-surface bottom water properties, respectively. dinocyst-based reconstructions indicate shifts between estuarine oceanic important changes temperature, salinity, primary productivity. Both dinocyst assemblages quantitative estimates highlight distinct transition at ca. 4200 cal years BP. It is notably marked by change towards higher which suggests reduced freshwater discharge, hence lower precipitation watershed, during Late-Holocene. (δ 18 O δ 13 C) centennial millennial frequency variability general trend decreasing temperatures increasing ventilation from beginning Middle Holocene until century. Since then, reverse trends abrupt warming dissolved oxygen have been observed.