Kerguelen Plateau ODP748 Eocene-Oligocene Nannofossil Isotope Data Villa, G.; Fioroni, C.; Pea, L.; Bohaty, S.M.; Persico, D. Villa, G. Fioroni, C. Pea, L. Bohaty, S.M. Persico, D. earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,calcareous nannofossil,null,per mil VPDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,million years ago,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,calcareous nannofossil,null,per mil VPDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP748>LATITUDE -58.441>LONGITUDE 78.9981) A major deterioration in global climate occurred through the Eocene-Oligocene time interval, characterized by long-term cooling in both terrestrial and marine environments. During this long-term cooling trend, however, recent studies have documented several short-lived warming and cooling phases. In order to further investigate high-latitude climate during these events, we developed a high-resolution calcareous nannofossil record from ODP Site 748 Hole B for the interval spanning the late middle Eocene to the late Oligocene (~42 to 26 Ma). The primary goals of this study were to construct a detailed biostratigraphic record and to use nannofossil assemblage variations to interpret short-term changes in surface-water temperature and nutrient conditions. The principal nannofossil assemblage variations are identified using a temperate-warm-water taxa index (Twwt), from which three warming and five cooling events are identified within the middle Eocene to the earliest Oligocene interval. Among these climatic trends, the cooling event at ~39 Ma (Cooling Event B) is recorded here for the first time. Variations in fine-fraction d18O values at Site 748 are associated with changes in the Twwt index, supporting the idea that significant short-term variability in surface-water conditions occurred in the Kerguelen Plateau area during the middle and late Eocene. Furthermore, ODP Site 748 calcareous nannofossil paleoecology confirms the utility of these microfossils for biostratigraphic, paleoclimatic, and paleoceanographic reconstructions at Southern Ocean sites during the Paleogene. STUDY NOTES: Stable isotope data on calcareous nannofossils from marine sediments sampled in Kerguelen Plateau ODP Core 748, for the Eocene and Oligocene (~42 - ~23 MYrBP). NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Villa, G. Investigator : Fioroni, C. Investigator : Pea, L. Investigator : Bohaty, S.M. Investigator : Persico, D. 2011-08-19 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/11923 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.xls English https://www.ncdc.noaa.gov/paleo/study/11923 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/villa2008/villa2008.xls Villa, G., C. Fioroni, L. Pea, S.M. Bohaty, and D. Persico. 2008. Middle Eocene - late Oligocene climate variability: calcareous nannofossil response at Kerguelen Plateau, Site 748. Marine Micropaleontology, Vol. 69, Issue 2, pp. 173-192, October 2008. doi:10.1016/j.marmicro.2008.07.006 START YEAR: 42520000 cal yr BP * END YEAR: 23151000 cal yr BP 78.9981 -58.441 78.9981 -58.441