2:15 PM - 2:30 PM
*Mitsuhiro Nagata1, Ouhiko Miyawaki1, Tatsuo Kanamaru1, Sota Niki2, Takafumi Hirata3, Shinji Takeuchi1 (1.Department of Earth and Environmental Sciences, College of Humanities and Sciences, Nihon University, 2.Division for Chronological Research, Institute for Space-Earth Environmental Research, Nagoya University, 3.Geochemical Research Center, The University of Tokyo)