Fine scale sediment structure and geochemical signature between eastern and western North Atlantic during Heinrich events 1 and 2

摘要: Abstract Heinrich iceberg-rafting events 1 and 2 (H1 H2) in the Labrador Sea are identified by their typical nepheloid-flow deposit sedimentary structure, high bulk carbonate, increase iceberg-rafted detritus (IRD), depletion of δ18O surface-dwelling foraminifer, Neogloboquadrina pachyderma (s). H-layers this region have sedimentological characteristics different than those North Atlantic, consist IRD interspersed pelagic sediments. High resolution 14C-AMS dates allowed us to delineate leads lags instability between ice-streams former Laurentide ice-sheet (LIS). Our data suggest that discharge from Hudson Strait ice-stream was followed Cumberland Sound during H1 H2. New radiogenic isotopes ice-proximal surficial sediments greater H0, H2 layers carbonate-rich were only derived Strait, not Baffin Bay. Fine scale structure intervals slope cores is characterized two lithic peaks dominated detrital carbonate grains a single peak central Sea. A similar pattern observed along western European margin. These findings contrast with Atlantic intervals, which grains, quartz volcanic grains. This comparison margin coupling or lack thereof, LIS ice-sheet, related depositional processes occurring margins, as well distance sources ability oceanic currents disperse icebergs. Any significant change dynamics would be recorded close margin, while distal locations record extreme events. We hypothesize discordance reported literature most likely difference upper slope/deep sites Flemish Pass site described contribution but requires vigorous testing.