Cycladophora davisiana Stratigraphy in Plio-Pleistocene Cores from the Antarctic Ocean (Atlantic Sector)

Examination of absolute and relative abundance curves of Cycladophora davisiana from Plio-Pleistocene sediment cores (time interval Brunhes Chron to Gauss/Matuyama Chron) recovered in the Atlantic sector of the Southern Ocean (south and north of the Polar Front) supports the stratigraphic significance of this radiolarian species. Beside already defined abundance peaks in the uppermost Pleistocene other stratigraphically useful C. davisiana peaks can be determined in the lower Brunhes Chron, near the Brunhes/Matuyama and the Matuyama/Gauss Chron boundary. The correlation of the C. davisiana abundance curve to the abundance curve of the diatom species Eucampia balaustium for the last glacial interval supports the hypothesis that C. davisiana is a deep-dwelling species and thus the C. davisiana abundance fluctuations reflect changes in deep water masses rather than in surface water.