Geochemical characteristics of biogenic barium in sediments of the Antarctica Ross Sea and their indication for paleoproductivity

Abstract

In this paper, the biogenic Ba of Column R11 in the Antarctic Ross Sea and its implications to the paleo oceanographic productivity since the late of Late Quaternary were discussed, combined with the organic carbon, opal and biogenic calcium carbonate. The biogenic Ba contents ranged from 51.8 to 508.4 μg/g overall, exhibiting a gradually rising trend from the bottom to the top. It highly correlated both with TOC and opal, revealing that on one hand biogenic Ba can be used to study the change of productivity in the Ross Sea; and on the other hand, the marine productivity gradually increased since the late Pleistocene. The new productivity based on Francois model varied from 0.40 to 233.90 gC/(m²•a). The high values were mainly concentrated at the depth from 32 to 48 cm, but the new productivity values of the bottom were lower. It was inferred that the change in marine productivity in the Ross Sea was possibly affected by the ice cover since the late Pleistocene.