Climate variability during MIS 20–18 as recorded by alkenone-SST and calcareous plankton in the Ionian Basin (central Mediterranean)

• Published in: Palaeogeography, Palaeoclimatology, Palaeoecology
• Main Authors: Marino M., Girone A., Gallicchio S., Herbert T., Addante M., Bazzicalupo P., Quivelli O., Bassinot F., Bertini A., Nomade S., Ciaranfi N., Maiorano P.
• Other Authors: Marino, M., Girone, A., Gallicchio, S., Herbert, T., Addante, M., Bazzicalupo, P., Quivelli, O., Bassinot, F., Bertini, A., Nomade, S., Ciaranfi, N., Maiorano, P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Coccolithophore; Lower-Middle Pleistocene; Marine biomarker; MIS 19; Planktonic foraminifera; Southern Italy
• Online Access: http://hdl.handle.net/11586/334110; https://doi.org/10.1016/j.palaeo.2020.110027

This study shows the first Mediterranean high-resolution record of alkenone-derived sea surface temperature (SST) in the marine sediments outcropping at the Ideale section (IS) (southern Italy, central Mediterranean) from late marine isotope stage (MIS) 20 - through early MIS 18. The SST pattern evidences glacial-interglacial up to submillennial-scale temperature variation, with lower values (~13 °C) in late MIS 20 and substage 19b, and higher values (up to 21 °C) in MIS 19c and in the interstadials of MIS 19a. The SST data are combined with the new calcareous plankton analysis and the available, chronologically well-constrained carbon and oxygen isotope records in the IS. The multi-proxy approach, together with the location of the IS near the Italian coasts, the lower circalittoral-upper bathyal depositional setting, and high sedimentation rate allow to document long-and short-term paleoenvironmental modifications (sea level, rainfall, inorganic/organic/fresh water input to the basin), as a response to regional and global climate changes. The combined proxies reveal the occurrence of a terminal stadial event in late MIS 20 (here Med-HTIX), and warm-cold episodes (here Med-BATIX and Med-YDTIX) during Termination IX (TIX), which recall those that occurred through the last termination (TI). During these periods and the following ghost sapropel layer (insolation cycle 74, 784 ka) in the early MIS 19, high frequency internal changes are synchronously recorded by all proxies. The substage MIS 19c is warm but quite unstable, with several episodes of paleoenvironmental changes, associated with fluctuating tropical-subtropical water inflow through the Gibraltar Strait, variations of the cyclonic regime in the Ionian basin, and the southward shift of westerly winds and winter precipitation over southern Europe and Mediterranean basin. Three high-amplitude millennial-scale oscillations in the patterns of SST and calcareous plankton key taxa during MIS 19a are interpreted as linked to changes in temperature as well as in ...