DEFINING THE ONSET OF ARCTIC-ATLANTIC THROUGHFLOW DURING EARLY HOLOCENE DEGLACIATION OF THE ARCTIC ISLAND CHANNELS USING TRACE METAL RATIOS IN NEOGLOBOQUADRINA PACHYDERMA

The post-glacial opening of channels between the Arctic Ocean and Baffin Bay likely impacted the Atlantic Meridional Overturning Circulation (AMOC) and the productivity of the North Water Polyna, via the transport of freshwater and nutrients, respectively. These routes were blocked by confluent ice sheets until the early Holocene, but the timing of channel opening has not been established. We apply ICP-MS analysis on planktic foraminifera Neogloboquadrina pachyderma (NPS) from radiocarbon dated cores on the southern ends of Perry Channel, Nares Strait, and western Baffin Bay to capture the initial signal of Arctic Surface Water entering Baffin Bay. Zn/Ca and Cd/Ca are of particular interest because they are tracers of dissolved silica and phosphate - key nutrient indicators of Arctic and Pacific waters . Our analysis found nutrient tracer variations coincided with foraminiferal species assemblages, biomarkers, and mineralogical changes indicating throughflow and circulation transitions. Adding the ICP-MS data to this comprehensive multiproxy approach, allows us to identify and date channel opening and entry of Arctic/Pacific waters. By detailing the deglaciation of the area and timing of Arctic throughflow we can gain insight into post-glacial circulation impacts on climate, local productivity, and the AMOC.