Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS15] Evolution of Pelagic Realm

Mon. May 27, 2019 3:30 PM - 5:00 PM 302 (3F)

convener:Atsushi Matsuoka(Department of Geology, Faculty of Science, Niigata University), Katsunori Kimoto(Japan Agency for Marine-Earth Science and Technology), Toshiyuki Kurihara(Graduate School of Science and Technology, Niigata University), Tetsuji Onoue(Earth and Environmental Sciences, Graduate School of Science and Technology, Kumamoto University), Chairperson:Atsushi Matsuoka, Toshiyuki Kurihara

4:15 PM - 4:30 PM

[MIS15-04] Triassic marine Os isotope record reconstructed from a pelagic chert succession, Sakahogi section, Mino Belt, southwest Japan

★Invited Papers

*Tatsuo Nozaki1,2,3,4, Takashi Nikaido5, Tetsuji Onoue6, Yutaro Takaya7,1,2,4, Keiko Sato1, Jun-Ichi Kimura8, Qing Chang8, Daisuke Yamashita6, Honami Sato4,1, Katsuhiko Suzuki1, Yasuhiro Kato2,4, Atsushi Matsuoka5 (1.JAMSTEC/R&D CSR, 2.Univ. of Tokyo, 3.Kobe Univ., 4.ChibaTech, 5.Niigata Univ., 6.Kumamoto Univ., 7.Waseda Univ., 8.JAMSTEC/D-SEG)

Keywords:Chert, Re-Os isotope, Triassic, Accretionary complex, Mino Belt, Southwest Japan

Pelagic cherts preserved in accretionary complexes represent former seafloor sediment that can retain geochemical evidence of paleoceanographic conditions that predate the oldest extant oceanic crust. The ratio of Os isotopes in seawater, in particular, is of wide interest as a source of insight into notable geologic events such as oceanic anoxic events, rapid global warming episodes, and eruption of large igneous provinces, but marine Os isotope records from before 80 Ma are scarce. We present a record of secular variations of marine Os isotope ratios from a thick, continuous succession of Middle and Upper Triassic pelagic chert in the Sakahogi section of the Mino Belt accretionary complex.