Efforts to model the equable global climate during Paleogene times (~66-35 Ma) are hampered by a lack of detail in our knowledge of temperature patterns and ocean circulation during this interval. Drs. Zachos and Lohmann at the Univ. of Michigan and their colleague Dr. Stott at Univ. of S. Calif. have been awarded funds to analyze samples from 21 DSDP and ODP sites from three time slices during this interval. They will measure delta O18 and delata C13 values in planktonic and benthic forams to establish sea surface temperatures, thermal structure of the mixed layer/thermocline, and intermediate water characteristics. Age control will be based on integrated bio- and Sr-isotope stratigraphies. They intend to reconstruct latitudinal temperature gradients from these locations across the Indian and adjacent Southern Ocean, and will evaluate the hypothesis that deep-ocean circulation during the Paleogene was driven by salinity gradients created by especially intense low-latitude evaporation.
