Comparison of Glacial and Interglacial Oceanographic Conditions in the South Atlantic from Variations in Calcium Carbonate and Radiolarian Distributionsc

Abstract

Temperature estimates produced by a radiolarian-based transfer function, factor distributions of radiolarian assemblages, and variations in calcium carbonate were used to reconstruct the oceanographic conditions in the South Atlantic during the last glacial maximum (18,000 yr B.P.). This study suggests that while the position of the Subtropical Convergence at 18,000 yr B.P. was very similar to its present position, the Antarctic Polar Front shifted northward 1° to 3° of latitude in the eastern South Atlantic and 3° to 5° of latitude in the western South Atlantic. The largest temperature changes occurred in the subantarctic region and along the eastern portion of the Subtropical Gyre.