Pleistocene paleoclimates and foraminiferal biostratigraphy in subantarctic deep-sea cores

Middle and upper Pleistocene cores from the subantarctic region of the South Pacific can be divided on the basis of the upward sequential appearance of planktonic Foraminifera into three faunal zones. Correlation of this sequence with established radiolarian zones and paleomagnetic stratigraphy are supported by radiometric dates. Alternations of cold and warm water planktonic foraminiferal faunas delimit 8 intervals of climatic warming during the last 1·2-1·3 × 10 ⁶-yr B.P. The relative magnitude of climatic warmings were considerably greater during the last 0·5 × 10 ⁶-yr, than between 0·5 and 1·3 × 10 ⁶-yr B.P. when conditions were generally cooler. Conditions were only once significantly warmer than the Recent, i.e., during the interval between 0·4 and 0·5 × 10 ⁶-yr B.P. Paleoclimatic trends for polar areas can be correlated rather closely with those of tropical areas ( ERICSON and WOLLIN, 1968).