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

• Main Authors: Jiménez Espejo, Francisco J., Presti, Massimo, Kuhn, Gerhard, McKay, Robert M., Crosta, Xavier, Escutia, Carlota, Lucchi, Renata G., Tolotti, Raffaella, Yoshimura, Toshihiro, Ortega Huertas, Miguel, Macrì, Patricia, Caburlotto, Andrea, De Santis, Laura
• Other Authors: Ministerio de Ciencia e Innovación (España), European Commission
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier BV 2020
• Subjects: Wilkes Land; Glaciation; Antarctic bottom water; Redox; Manganese; Antarctic; East Antarctica; The Antarctic; Wega; Antarc*; Antarctica; Antartide; Ice Sheet
• Online Access: http://hdl.handle.net/10261/213021; https://doi.org/10.1016/j.gloplacha.2019.103045; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100004837

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. All scientific participants are thanked for shipboard collaboration in the data collection and post-cruise discussions and sample management. U1361 samples were provided by the Integrated Ocean Drilling Programme, Expedition 318. WEGA and MOGAM core samples were provided by the Italian “Programma Nazionale di Ricerche in Antartide”, Antarctic Expeditions 2000 and 2006. MD03-2603 core samples were provided by the Images X-CADO programme. MP acknowledges the EC Human Resources and Mobility Activity - Marie Curie European Re-Integration Grant (ERG) “HoloSed”, Contract 039566. CE and FJJE acknowledge funding from the Ministry of Science and Innovation Grants CTM2017-89711-C2-1-P co-financed by the European Regional Development Fund (FEDER). FJJE acknowledges ...