Changes of marine productivity and sedimentary environment recorded by biogenic components in the Antarctica Ross Sea since the last deglaciation

Abstract

Changes in the marine productivity and sedimentary environment since the last deglaciation in the Ross Sea are presented in this paper. Opal has replaced calcium carbonate as the major biogenic component and has a significantly positive correlation with total organic carbon (TOC), which indicates that siliceous phytoplankton controlled the absorption and release of carbon by the biological pump and was the main producer of marine organic matter. Using the AMS 14C age framework, foraminiferal fossils and redox sensitive elements (RSEs), we found that both the sedimentary environment and marine productivity changed clearly in ∼11 cal ka BP, which is more likely related with the melting and retreat of the Ross Ice Shelf. In addition, the increase of marine productivity promoted the sinking of more organic-matter to the seabed. A large proportion of oxygen in the bottom water body was consumed and more carbon dioxide was produced during the decomposition of organic matter, making the bottom water body more soluble to calcium carbonate.