Paleoenvironmental research of the Antarctic Core Sediment from the Antarctic Polar Front in Drake Passage, based on Diatom assemblage

Abstract

56 diatom species belonging to 21 genera were identified from the core DP00-02, drilled in Drake Passage. Actinocyclus actinochilus, Fragilariopsis kerguelensis, Thalassiosira rentiginosa and Thalassiothrix longissima are the dominant species (56% of the total assemblage) in DP00-02 core sediments. The abundance pattern of diatom assemblages and paleoindicator species at the horizon of 144 ㎝ suggests the position of Antarctic Polar Front migrated to the south of the modern site. Above this horizon, we believe that there is little effect by the sea-ice even in the glacial periods. The presence of neritic species (Stephanopyxis spp, Odontella weisflogii and Cocconeis costata) and reworked species (Dentculopsis hustedtii, D. dimorpha, Fragilariopsis aurica and Thalassiosira striata) due to strong current activity, i.e. Circumpolar Deep Water and Antarctic Bottom Current.