Climatically Linked Carbon-Isotope Variation during the Past 430,000 Years in Southern-Ocean Sediments

TitleClimatically Linked Carbon-Isotope Variation during the Past 430,000 Years in Southern-Ocean Sediments
Publication TypeJournal Article
Year of Publication1995
AuthorsSinger, AJ, Shemesh, A
JournalPaleoceanography
Volume10
Issue2
Pagination171-177
Date PublishedApr
ISSN0883-8305
Accession NumberWOS:A1995RD38200002
Abstract

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 C-13 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.

DOI10.1029/94pa03319