Sedimentology and age models of cores from the Antarctic continental margin in the eastern Weddell Sea

• Main Authors: Grobe, Hannes, Mackensen, Andreas
• Format: Dataset
• Language: English
• Published: PANGAEA 1992
• Subjects: ANT-I/2; ANT-III/3; ANT-IV/3; ANT-V/4; ANT-VI/3; Atka Bay; AWI_Paleo; Camp Norway; gcmd1; Giant box corer; GKG; Gravity corer (Kiel type); Kapp Norvegia; MUC; MultiCorer; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS01; PS01/132; PS06/246; PS06 SIBEX; PS08; PS08/333; PS08/356; PS08/361; PS08/364; PS08/366; PS08/367; PS08/368; PS08/371; PS08/374; PS08/486; PS10; PS10/688; PS10/694; PS1006-1; PS12; PS12/302; PS12/492; PS12/536; PS1265-1; PS1367-2; PS1380-1; PS1380-3; PS1385-3; PS1386-1; PS1386-2; PS1388-1; PS1388-3; PS1389-1; Antarctic; Atka; Norway; The Antarctic; Weddell; Weddell Sea; Antarc*; Berichte zur Polarforschung; Ice Sheet; Ice Shelves; NADW; North Atlantic Deep Water; North Atlantic; Polar Research; Polarforschung; Reports on polar research; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.588236; https://doi.org/10.1594/PANGAEA.588236

To reveal the late Quaternary paleoenvironmental changes at the Antarctic continental margin, we test a lithostratigraphy, adjusted to a stable isotope record from the eastern Weddell Sea. The stratigraphy is used to produce a stacked sedimentological data set of eleven sediment cores. We derive a general model of glacio marine sedimentation and paleoenvironmental changes at the East Antarctic continental margin during the last two climatic cycles (300 kyr). The sedimentary processes considered include biological productivity, ice-rafting, current transport, and gravitational downslope transport. These processes are controlled by a complex interaction of sea-level changes and paleoceanographic and paleoglacial conditions in response to changes of global climate and local insolation. Sedimentation rates are mainly controlled by ice-rafting which reflects mass balance and behaviour of the Antarctic ice sheet. The sedimentation rates decrease with distance from the continent and from interglacial to glacial. Highest rates occur at the very beginning of interglacials, i.e. of oxygen isotope events 7.5, 5.5, and 1.1, these being up to five times higher than during glacials. The sediments can be classified into five distinct facies and correlated to different paleoenvironments: at glacial terminations (isotope events 8.0, 6.0, and 2.0), the Antarctic cryosphere adjusts to new climatic conditions. The sedimentary processes are controlled by the rise of sea level, the destruction of ice shelves, the retreat of sea-ice and the recommenced feeding of warm North Atlantic Deep Water (NADW) to the Circumpolar Deep Water (CDW). During peak warm interglacial periods (at isotope events 7.5, 7.3, 5.5., and 1.1), the CDW promotes warmer surface waters and thus the retreat of sea-ice which in turn controls the availability of light in surface waters. At distinct climatic thresholds local insolation might also influence sea-ice distribution. Primary productivity and bioturbation increase, the CCD rises and carbonate dissolution ...