The marine record of deglaciation from the continental margin off Nova Scotia

摘要: Continental margin sediments off Nova Scotia accumulate at high rates (up to 360 cm kyr−1) and contain a history of millennial-scale environmental changes which are dominated by the proximity Laurentide ice sheet during latest Quaternary. Using stable isotope ratios oxygen, accelerator mass spectrometer radiocarbon dating, micropaleontology, sedimentology, we document these in six piston cores ranging water depth from ∼450 ∼4300 m. We find that maximum δ18O N. pachyderma occurred about 15 ka preceded abundance this species ∼1000 years. Between 13 14 second peak pachyderma, minimum δ18O, two pulses rafting. The sediment lithology supports terrestrial studies indicate there was general withdrawal beyond upper Paleozoic Mesozoic red beds southeastern Canada, so rafting events between probably reflect stream activity St. Lawrence valley. Younger Dry as event is recognized (dated ∼11.3 ka), but meltwater discharge Gulf either too small or over long time leave distinct Scotia. At 7.1 ka, middle Holocene warming, third another no interpret data evidence late-occurring which, if correct, could have originated Great Lakes, Labrador-Ungava region, both. final phenomenon onset “Neoglaciation,” marked increased % beginning 5 kyr ago.