[B-PT05] [EJ] Decoding the history of Earth: From Hadean to Modern

[BPT05-P15] Lithological and geochemical features of the Permian-Triassic boundary at the Gujo-Hachiman section in the Mino-Tamba belt, central Japan

*Moei Yano¹, Koichiro Fujinaga^2,1, Kazutaka Yasukawa^1,2, Tatsuo Nozaki^3,1,4, Junichiro Kuroda⁵, Kiyoko Kuwahara⁶, Yasuhiro Kato^1,2,3 (1.School of Engineering, The University of Tokyo, 2.Ocean Resources Research Center for Next Generation, Chiba Institute of Technology, 3.JAMSTEC, 4.Graduate School of Science, Kobe University, 5.Atmosphere and Ocean Research Institute, The University of Tokyo, 6.Ashiya University)

Keywords:Permian-Triassic boundary, black shale, chert, Gujo-Hachiman, ocean anoxia

The most significant mass extinction event in the Phanerozoic era occurred across the Permian-Triassic boundary (PTB; ca. 252 Ma). However, the entire picture of this global environmental crisis has not reached a consensus, as well as a culprit that invoked the catastrophe. The PTB sections in the Japanese accretionary complex were primarily deposited in the deep-sea of the superocean Panthalassa, hence it is very likely to have recorded signatures of the global-scale environmental change. Therefore, a number of geological, geochemical, and paleontological researches have targeted them to deduce a series of environmental shift during the event (Isozaki, 1997; Kato et al., 2002; Takahashi et al., 2009). The Gujo-Hachiman section located in the Mino-Tamba belt, central Japan, has a continuous outcrop across the PTB (Kuwahara et al., 1998; Yao et al., 2001). In the present study, to decipher the marine environmental change across the PTB, we report the lithological and geochemical features on the basis of thin-section descriptions and chemical analyses of total organic carbon and bulk chemical compositions of the Gujo-Hachiman section.