Neogene paleoclimate development of the Antarctic Weddell Sea region: organic geochemistry

Abstract

Stable carbon and nitrogen isotopic compositions as well as organic carbon and total nitrogen contents of cored material are reported for the Weddell Sea, Ocean Drilling Program Sites 689 and 690 (Maud Rise), Site 693 (continental margin) and Site 694 (abyssal plain). In general, the results indicate large changes in the types and amounts of carbon and nitrogen preserved in the sediments of the Weddell Sea region during the past 25My, with an especially important and dramatic event coinciding with the western Antarctic ice-sheet becoming a semi-permanent or permanent feature ~5Ma. The overall results may be correlated with the onset of major ice-sheets on West Antarctica, stabilization of the ice-sheet in the Pliocene and the intensified recycling of organic carbon and total nitrogen, which is possibly the result of increased ice cover. -from Authors