Бентосные фораминиферы как индикаторы проникновения атлантических вод в Арктический бассейн в конце позднего плейстоцена – голоцене

The distribution of the tests of Atlantic water index species Cassidulina neoteretis and several other common benthic foraminiferal species in the Postglacial and Holocene sediments is analysed in marine sediment cores recovered in the Arctic and North Atlantic. The following key regions located on the pathway of Atlantic waters were selected: the western continental slope of the Great Britain, the eastern Fram Strait and the Laptev Sea continental slope. The occurrence of C. neoteretis in the studied sections gives evidence for the inflow of subsurface Atlantic waters to the Arctic since the onset of deglaciation period. The similar pattern of the predominance of C. neoteretis in the cores during the early deglaciation since the end of the Heinrich 1 event about 16,5 cal.ka until 13–12 cal.ka gives evidence for a strong inflow of subsurface Atlantic waters with the Fram Strait Branch under meltwater induced stratified conditions. During the time period between 13–12 to 7 cal.ka the relative abundance of C. neoteretis decreases in the cores from the Fram Strait and the Laptev Sea, probably in relation to the onset of deep convection and the reduction of freshwater influence in the Nordic seas. The growing representation of C. neoteretis after 7 cal.ka manifests an increase in the subsurface Atlantic water influence under modern-like sea-level position, growing climate cooling trend, sea-ice cover expansion and enhanced water stratification.