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

• Published in: Global and Planetary Change
• Main Authors: Jimenez-Ruiz, Francisco, Presti, Massimo, Kuhn, Gerhard, McKay, Robert, Crosta, Xavier, Escutia, Carlota, Lucchi, Renata Giulia, Tolotti, Raffaella, Yoshimura, Toshihiro, Ortega Huertas, Miguel, Macrì, Patrizia, Caburlotto, Andrea, De Santis, Laura
• Other Authors: Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Spain, Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS), Trieste, Italy, Alfred-Wegener-Institut (AWI), Bremerhaven, Germany, Antarctic Research Centre, Wellington, New Zealand, UMR-CNRS, Université de Bordeaux, France, DISTAV, Università degli Studi di Genova, Italy, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan, Universidad de Granada, Spain, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Roma2, Roma, Italia
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Wilkes Land; Glaciation; Antarctic Bottom Water; Redox Manganese; 04.04. Geology; Antarctic; East Antarctica; The Antarctic; Antarc*; Antarctica; Ice Sheet
• Online Access: http://hdl.handle.net/2122/13279; https://doi.org/10.1016/j.gloplacha.2019.103045

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. Published 1A. Geomagnetismo e Paleomagnetismo JCR Journal