Sediment deposition in response to the glacial-interglacial changes on the continental slope of eastern Pennell-Iselin Bank in the Ross Sea, Antarctica

• Main Authors: Sandbeom, Ha, Khim, Boo-Keun, Colizza, Ester, Marci, Patrizia, Sagnotti, Leonardo, Caricchi, Chiara, Langone, Leonardo, Giglio, Federico, Kuhn, Gerhard
• Format: Conference Object
• Language: unknown
• Published: SCAR 2017
• Subjects: Iselin Bank; Ross Sea; Antarc*; Antarctica
• Online Access: https://epic.awi.de/id/eprint/46230/; https://epic.awi.de/id/eprint/46230/1/PAIS17_Ha_et_al_1A.pdf; https://hdl.handle.net/10013/epic.9a670842-fb7e-4af7-a2d6-0b4a09c23744

In order to understand the growth and retreat of glaciers in response to the glacial-interglacial changes, subglacial marine sedimentary sequences have been studied extensively in the continental shelf areas of the Ross Sea. The purpose is to comprehend the glaciomarine sedimentation change on the continental slope of eastern Pennell-Iselin Bank in the Ross Sea, using three gravity cores (C1, C2, C3) and three box cores (BC1, BC2, BC3) collected from sites (RS14-1, 2, 3), respectively, across the continental slope to the eastern side of the Pennell-Iselin Bank during XXIX° (2014) PNRA expedition (Rosslope Ⅱ project). Several sedimentological (grain size, magnetic susceptibility), elemental (XRF), geochemical (biogenic opal, total organic carbon, total nitrogen, C/N ratios, CaCO3), and isotopic (δ13C and δ15N of organic matter) parameters were measured along sediment cores with AMS 14C dating of bulk sediments. Core-sediments consist mostly of hemipelagic sandy clay or silty clay with scattered IRDs (Ice-Rafted Debris). A comparison of sediment properties between box cores and the top of gravity cores reveals that the loss of sediment during sampling is trivial. Sediment colors of gravity cores alternate between brown and gray downward. Based on the variation patterns of sediment properties, sediment lithology was divided into different units (A and B), and subunits (B1 and B2). AMS 14C dates and sediment properties assign Unit A, Unit B1, and Unit B2 to interglacial, deglacial, and glacial conditions, respectively. Unit A represents the Holocene and interglacial sediments deposited mainly by the suspension settling of biogenic particles with IRDs in the open marine condition. Unit B1 reflects the deglacial sediments with an increase in IRDs showing the transition of sediment properties from Unit B2 to Unit A by the retreat of subglacial ices. Unit B2 is characterized by different sediment properties, mainly supplied by the continuously lateral melt-water plume or distal part of debris flow originating from the ...