Sediment record of Deglacial Sea-Level from the SWERUS-C3 Expedition 2014, western Arctic Ocean

Abstract:

We analyzed micropaleontologic assemblages [benthic and planktic foraminifera and ostracodes] and reconstructed deglacial sea level from a depth transect of gravity and piston cores [120 to 964 mwd] on the continental shelf and upper slope in the Eastern Siberian Sea from Leg 2 of the 2014 SWERUS-C3 Expedition. Radiocarbon dates on mollusks and benthic foraminifera indicate that sediments were deposited during the late deglacial from at least 13 ka to about 10 ka. The dominant foraminiferal species include Buccella frigida, Cassidulina reniforme, Elphidium spp., and Islandiella teretis; ostracodes include Acanthocythereis dunelmensis, Cytheromorpha macchesneyi, Sarsicytheridea punctillata and Paracyprideis pseudopunctillata. These species generally represent shallow, inner continental shelf environments signifying deposition during the last deglacial sea-level rise. The relatively sparse occurrence of planktic foraminifera (Neogloboquadrina pachyderma] supports the interpretation of a shallow water environment. Changes in microfaunal assemblages and associated patterns in sediment physical properties will be discussed in terms of rates of deglacial regional sea-level rise during the Younger Dryas climate reversal and the early Holocene [Preboreal] period. Combined with sea-level records from the Laptev Sea, results provide new interpretations of the disintegration of Arctic Ocean ice cover after the Last Glacial Maximum and regional glacio-isostatic response.