Open AccessBarium accumulation in the Atlantic sector of the Southern Ocean: Results From 190,000‐year records
Author(s) -
Nürnberg C. C.,
Bohrmann G.,
Schlüter M.,
Frank M.
Publication year - 1997
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/97pa01130
Subject(s) - polar front , geology , deglaciation , oceanography , barium , glacial period , interglacial , last glacial maximum , holocene , sedimentary rock , isotopes of oxygen , climatology , paleontology , geochemistry , inorganic chemistry , chemistry
Extensive investigations of sedimentary barium were performed in the southern South Atlantic in order to assess the reliability of the barium signal in Antarctic sediments as a proxy for paleoproductivity. Maximum accumulation rates of excess barium were calculated for the Antarctic zone south of the polar front where silica accumulates at high rates. The correspondence between barium and opal supports the applicability of barium as a proxy for productivity. Within the Antarctic zone north of today's average sea ice maximum, interglacial vertical rain rates of excess barium are high, with a maximum occurring during the last deglaciation and early Holocene and during oxygen isotope chronozone 5.5. During these periods, the maximum silica accumulation was supposedly located south of the polar front. Glacial paleoproductivity, instead, was low within the Antarctic zone. North of the polar front, significantly higher barium accumulation occurs during glacial times. The vertical rain rates, however, are as high as in the glacial Antarctic zone. Therefore there was no evidence for an increased productivity in the glacial Southern Ocean.