Borchers, Andreas; Dietze, Elisabeth; Kuhn, Gerhard; Esper, Oliver; Voigt, Ines; Hartmann, Kai; Diekmann, Bernhard (2015): Sedimentological, mineralogical, biogeochemical and micropaleontological parameters on sediment core PS69/849-2, Burton Basin, MacRobertson Shelf, East Antarctica. PANGAEA, https://doi.org/10.1594/PANGAEA.848478, Supplement to: Borchers, A et al. (2015): Holocene ice dynamics and bottom-water formation associated with Cape Darnley polynya activity recorded in Burton Basin, East Antarctica. Marine Geophysical Research, https://doi.org/10.1007/s11001-015-9254-z
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A multi-proxy study including sedimentological, mineralogical, biogeochemical and micropaleontological methods was conducted on sediment core PS69/849-2 retrieved from Burton Basin, MacRobertson Shelf, East Antarctica. The goal of this study was to depict the deglacial and Holocene environmental history of the MacRobertson Land-Prydz Bay region. A special focus was put on the timing of ice-sheet retreat and the variability of bottom-water formation due to sea ice formation through the Holocene. Results from site PS69/849-2 provide the first paleo-environmental record of Holocene variations in bottom-water production probably associated to the Cape Darnley polynya, which is the second largest polynya in the Antarctic. Methods included end-member modeling of laser-derived high-resolution grain size data to reconstruct the depositional regimes and bottom-water activity. The provenance of current-derived and ice-transported material was reconstructed using clay-mineral and heavy-mineral analysis. Conclusions on biogenic production were drawn by determination of biogenic opal and total organic carbon. It was found that the ice shelf front started to retreat from the site around 12.8 ka BP. This coincides with results from other records in Prydz Bay and suggests warming during the early Holocene optimum next to global sea level rise as the main trigger. Ice-rafted debris was then supplied to the site until 5.5 cal. ka BP, when Holocene global sea level rise stabilized and glacial isostatic rebound on MacRobertson Land commenced. Throughout the Holocene, three episodes of enhanced bottom-water activity probably due to elevated brine rejection in Cape Darnley polynya occured between 11.5 and 9 cal. ka BP, 5.6 and 4.5 cal. ka BP and since 1.5 cal. ka BP. These periods are related to shifts from warmer to cooler conditions at the end of Holocene warm periods, in particular the early Holocene optimum, the mid-Holocene warm period and at the beginning of the neoglacial. In contrast, between 7.7 and 6.7 cal. ka BP, brine rejection shut down, maybe owed to warm conditions and pronounced open-water intervals.
Median Latitude: -67.583794 * Median Longitude: 68.118059 * South-bound Latitude: -67.583830 * West-bound Longitude: 68.117500 * North-bound Latitude: -67.583330 * East-bound Longitude: 68.125330
Date/Time Start: 2007-03-11T08:37:00 * Date/Time End: 2007-03-11T09:46:00
This investigation was funded by Deutsche Forschungsgemeinschaft priority program SPP 1158 through grant DI 655/3-1/-2.
Datasets listed in this publication series
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Age determination of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848470
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Clay minerals of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848474
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Grain size distribution of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848476
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Heavy minerals of sediment cores PS69/849-1 and PS69/849-2. https://doi.org/10.1594/PANGAEA.848471
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Ice rafted debris of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848475
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Relative diatom abundance of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848477
- Borchers, A; Dietze, E; Kuhn, G et al. (2015): Total organic carbon and opal content of sediment core PS69/849-2. https://doi.org/10.1594/PANGAEA.848473