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 relativeabundances of lithogenous, biogenous and redox-sensitive elements in four sediment cores from two channelleveesystems of the Wilkes Land continental slope (East Antarctica). Sediments older than the Mid-Bruhnesevent (MBE, 430 ka BP) show reduced glacial/interglacial variability in the abundance of elements associated tothe terrigenous mineral phases (i.e. Al, Ti, Fe and partly Si). This suggests minor ice-sheet size changes occurredin the Antarctic margin during the pre-MBE “lukewarm” interval. Post-MBE sediments record instead a highvariability 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 gradualestablishment of last glacial cycle conditions. Moreover, a marked increase of Mn during the glacial to interglacialtransitions, indicates a post-depositional migration of the redox front and re-oxidation of the surfacesediment layers linked to major changes in bottom water oxygen conditions associated to Antarctic BottomWater formation along the margin at the onset of deglaciations.