Upper Cretaceous-Paleogene stratigraphy of ODP Sites 113-689 and 113-690

This contribution summarizes the biostratigraphy of planktonic foraminifers, calcareous nannofossils, and benthic foraminifers, in combination with the magnetostratigraphy, carbon and oxygen isotope stratigraphy of benthic foraminifers, and CaCO3 stratigraphy for the Maestrichtian through Paleogene calcareous sequences recovered at Sites 689 and 690 on Maud Rise (at about 65°S, eastern Weddell Sea, Antarctica). These data represent the southernmost calciumcarbonate record available for that interval, and thus extend the biostratigraphic and isotopic database to higher latitudes. Sites 689 and 690 form the southernmost anchor of a north-south transect through the Atlantic Ocean for Paleogene biostratigraphy and chemostratigraphy.

Paleogene calcareous nannofossil stratigraphy of ODP Leg 120 sites

Calcareous nannofossils are abundant in the Paleogene sediments recovered during Ocean Drilling Program Leg 120. Although no continuous Paleogene section was obtained, Sites 747 through 751 complemented each other so as to provide a virtually complete composite stratigraphic section. The calcareous nannofossil biostratigraphy at Sites 747, 748, and 749 is discussed. Correlation of calcareous nannofossil biozones and magnetozones at these sites suggests some diachrony with low-latitude areas, as well as on a regional basis. Changes in calcareous nannofossil diversity throughout the Paleogene are analyzed and interpreted as reflecting major paleoclimatic events.