[M-IS02] Evolution and variability of the Asian Monsoon and Indo-Pacific climate during the Cenozoic Era

[MIS02-P05] Evaluation of synchrony in coiling direction change of planktonic foraminifera Pulleniatina in the central and western tropical Pacific

*Takuya Sagawa¹, MISAKI URAKAMI², Shungo Kawagata³, Yoshimi Kubota⁴ (1.Institute of Science and Engineering, Kanazawa University, 2.Graduate School of Natural Science & Technology, 3.Yokohama National University, 4.National Museum of Nature and Science)

Keywords:Tropical Pacific, Sea surface temperature, planktonic foraminifera

Coiling directions of planktonic foraminifera Pulleniatina have changed over time, and its timings are synchronized in the tropical Pacific and Indian Oceans. For this reason, the coiling direction change has been used as a tool for stratigraphic correlation since the late 1970’s. Because age estimates at that time relied on magnetic polarity boundary, the synchrony in coiling direction change has not been evaluated on the glacial-interglacial time-scale. Here, we investigated the coiling direction change of Pulleniatina in two sediment cores from the western and central tropical Pacific for the last 2.2 Myr. The cores are dated by oxygen isotope stratigraphy, allowing us to evaluate the synchrony of coiling direction change events. The pattern and timing of events in two cores are generally similar, with a few exceptions. The results of this study confirm the validity of coiling direction change as a stratigraphic correlation tool.