Revision of the upper Pliocene-Pleistocene diatom biostratigraphy for the northern belt of the Southern Ocean

摘要

Previous diatom biostratigraphic results for the southern high-latitude late Pliocene and Pleistocene are revised. Consid- ering new biostratigraphic results and the ranges of acme intervals, an improved diatom zonation for the last ca. 26 Ma is proposed. Guided by magnetostratigraphic events, the diatom zonation provides a time resolution of ca. 200-300 kyrs. Considering the latitudinal Control on diatom distribution during the last 2.6 Ma in the Southern Ocean, the zonation should only be used in sediments deposited North of the present Polar Frontal Zone. The paper a;so includes the taxonomic transfer of stratigraphically useful Southern Ocean diatom Taxa from the genus Nitzschia Hassal to Fragilariopsis Hustedt, and the description of Fragilariopsis matuyamae Gersonde et Barcena Sp. Nov. And F. Matuyamae var. Heteropola Gersonde et Barcena var. Nov.