Organic carbon abundance and stable isotope record of sediment core RC13-259 (Table 1), supplement to: Singer, Alex; Shemesh, Aldo (1995): Climatically linked carbon isotope variation during the past 430,000 years in Southern Ocean sediments. Paleoceanography, 10(2), 171-178

• Main Authors: Singer, Alex, Shemesh, Aldo
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 1995
• Subjects: DEPTH, sediment/rock; AGE; Carbon, organic, total; δ13C, organic carbon; δ13C, standard deviation; Piston corer; RC13; Robert Conrad; Antarctic; Southern Ocean; The Antarctic; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.1594/pangaea.52708; https://doi.pangaea.de/10.1594/PANGAEA.52708

We use the isotopic composition of carbon from organic matter enclosed within diatom frustules as a proxy for paleoproductivity and paleo-dissolved carbon dioxide concentrations in ocean surface waters. A Southern Ocean record from south of the Antarctic Polar Front and spanning 430,000 years of carbon isotopic variation in diatomaceous organic matter is presented for the first time. The most refractory diatomaceous organic matter fraction was extracted and analyzed to avoid problems associated with diagenesis. The results clearly indicate cyclic changes in organic carbon isotopic ratios, with 13C depleted values associated with all of the last five glacial periods, reflecting changes in surface water properties and primary productivity. Changes in dissolved carbon dioxide concentrations are the most probable cause of these cycles, but the possible effect of seawater pH changes cannot be excluded. : Age based on Eucampia antarctica stratigraphy (Burckle and Cooke, 1983) correlated to oxygen isotopic stages (Imbrie et al., 1984)