Neogene globorotaua lineages in the tropical Indian ocean: their paleoceanographic implications

Abstract

The evolutionary bioscries within the Neogene globorotaliids, Fokselk, Menardellat Globoromlla and Truncorotalia, have been traced from the tropical Indian Ocean, DSDP sites 214, 216A, 219 and 237. The Fohsella lineage forms the basis for the Middle Miocene biozonation, whereas Menardella, Gbborotaiia and Truncorotatla lineages are useful for the biostratigraphic subdivisions of the Late Neogeno sequences. The study suggests that the evolutionary accelerations within the Neogene globorotaliids are closely linked with the major cooling events and the resultant paleoceanographic changes.