Late Miocene-Pliocene glacial cyclicity in a deep-sea sediment drift on the Antarctic Peninsula continental margin: Sedimentary and diagenetic processes

Abstract

The presented sedimentological, geochemical and paleoceanographical work is intended to improve the understanding of the regional influence of West Antarctic Ice Sheet dynamics and changes in oceanographic conditions on (1) sedimentary processes and (2) the preservation of proxies in the sedimentary record. A crucial feature for interpreting ice sheet dynamics is the understanding of the glacial driven sedimentary transport system across the shelf to the slope and subsequently to deep-sea sediment bodies. Sediment physical and geochemical records, and X-ray images derived from ODP Site 1095 (West Antarctic Peninsula) were used to identify pattern in glacial-interglacial cyclicity and associated sedimentary and diagenetic processes of the late Miocene and Pliocene. A prominent feature is the cyclic loss of the magnetic susceptibility signal at the glacial-to-interglacial transitions, which is related to ice sheet collapses, meltwater formations, high fluxes of organic matter, and temporary suboxic to anoxic near surface sediment conditions at the end of the deglaciation phases. A quantification of the slope failure frequency reflects short and rapid but cyclic ice advances every ~375 yrs.