Quantitative Pleistocene calcareous nannofossil biostratigraphy: preliminary results from the IODP Site U1385 (Exp 339), the Shackleton Site

In order to explore the effects of Mediterranean Outflow Water (MOW) on North Atlantic circulation and climate, Integrated Ocean Drilling Program (IODP) Expedition 339 (Mediterranean Outflow) cored a series of sites in the Gulf of Cadiz slope and off West Iberia (North East Atlantic). Site U1385 (37°48'N, 10°10‧W, 3146 m water depth) was selected and drilled in the lower slope of the Portuguese margin, at a location close to the so-called Shackleton Site MD95-2042 (in honor of the late Sir Nicholas Shackleton), to provide a marine reference section of Pleistocene millennial-scale climate variability. Three holes were cored at Site U1385 using the Advanced Piston Corer (APC) to a depth of ~151 meters below seafloor in order to recover a continuous stratigraphic record covering the past 1.4 Ma. Here we present preliminary results of the succession of standard and alternative calcareous nannofossil events. Our quantitative study based on calcareous nannofossils shows well-preserved and abundant assemblages throughout the core. Most conventional Pleistocene events were recognized. Moreover, our quantitative investigations provide further data on the stratigraphic distribution of some species and groups, such as the large Emiliania huxleyi (>4 μm), the small Gephyrocapsa group, and Reticulofenestra cisnerosii. A preliminary calibration of the calcareous nannofossil events with the paleomagnetic and astronomical signal, estimated by comparison with geophysical and logging parameters is also presented. *IODP Expedition 339 Scientists: Bahr, A., Ducassou. E., Flood, R., Furota, S., Jimenez-Espejo, F., Kim, J. K., Krissek, L., Kuroda, J., Llave, E., Lofi, J., Lourens, L., Miller, M., Nanayama, F., Nishida, N., Roque, C., Sloss, C., Takashimizu, Y., Tzanova, A., Williams, T.