Late Pleistocene oceanographic and depositional variations along the Wilkes Land margin (East Antarctica) reconstructed with geochemical proxies in deep-sea sediments

Water masses and depositional environments over the last 500 ka were reconstructed using absolute and relative abundances of lithogenous, biogenous and redox-sensitive elements in four sediment cores from two channel-levee systems of the Wilkes Land continental slope (East Antarctica). Sediments old...

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Bibliographic Details
Published in:Global and Planetary Change
Main Authors: Jimenez-Espejo, Francisco J., Presti, Massimo, Kuhn, Gerhard, Mckay, Robert, Crosta, Xavier, Escutia, Carlota, Lucchi, Renata G., Tolotti, Raffaella, Yoshimura, Toshihiro, Ortega Huertas, Miguel, Macrì, Patrizia, Caburlotto, Andrea, De Santis, Laura
Format: Article in Journal/Newspaper
Language:unknown
Published: 2020
Subjects:
Antarctic
East Antarctica
The Antarctic
Wilkes Land
Antarc*
Antarctica
Ice Sheet
Online Access:https://epic.awi.de/id/eprint/50542/
https://doi.org/10.1016/j.gloplacha.2019.103045
https://hdl.handle.net/10013/epic.606d0978-26d0-4bbf-9ade-f315c133fc50
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Summary:Water masses and depositional environments over the last 500 ka were reconstructed using absolute and relative abundances of lithogenous, biogenous and redox-sensitive elements in four sediment cores from two channel-levee systems of the Wilkes Land continental slope (East Antarctica). Sediments older than the Mid-Bruhnes event (MBE, 430 ka BP) show reduced glacial/interglacial variability in the abundance of elements associated to the terrigenous mineral phases (i.e. Al, Ti, Fe and partly Si). This suggests minor ice-sheet size changes occurred in the Antarctic margin during the pre-MBE “lukewarm” interval. Post-MBE sediments record instead a high variability between glacial and interglacial periods in the concentration of terrigenous and biogenous (i.e. Ca, Ba) elements suggesting larger amplitude changes in both ice-sheet size and ocean conditions toward the gradual establishment of last glacial cycle conditions. Moreover, a marked increase of Mn during the glacial to interglacial transitions, indicates a post-depositional migration of the redox front and re-oxidation of the surface sediment layers linked to major changes in bottom water oxygen conditions associated to Antarctic Bottom Water formation along the margin at the onset of deglaciations.

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