The study will extend previous work on the global circulation of the Miocene deep ocean. Previous work has centered on the Pacific Ocean and that work will be expanded to include the Indian and Atlantic Oceans. The deep paleo-circulation patterns will be inferred from stable isotopic analyses and benthic foraminiferal assemblages in DSDP and ODP cores. The results of this study will provide an important link in reconstructing the response of the ocean to major climatic changes that occurred as the modern ocean regime was initiated.