[B-PT05] [EJ] 地球史解読：冥王代から現代まで

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

*矢野 萌生¹、藤永 公一郎^2,1、安川 和孝^1,2、野崎 達生^3,1,4、黒田 潤一郎⁵、桑原 希世子⁶、加藤 泰浩^1,2,3 (1.東京大学・工学系研究科、2.千葉工業大学・次世代海洋資源研究センター、3.海洋研究開発機構、4.神戸大学・理学研究科、5.東京大学・大気海洋研究所、6.芦屋大学・臨床教育学部)

キーワード：ペルム紀/トリアス紀境界、黒色頁岩、チャート、郡上八幡、海洋無酸素化

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.