Geology and radioralian fossils of the Misogawa Complex of the eastern Mino Terrane in the Kaida area, Nagano Prefecture

Hiroaki HAKOIWA; Atsushi MATSUOKA

Presentation information

Oral

Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS30] Evolution of the Pelagic Realm

Tue. May 26, 2015 11:00 AM - 12:45 PM 304 (3F)

Convener:*Atsushi Matsuoka(Department of Geology, Faculty of Science, Niigata University), Toshiyuki Kurihara(Graduate School of Science and Technology, Niigata University), Yasuhiro Kato(Department of Systems Innovation, Graduate School of Engineering, University of Tokyo), Tetsuji Onoue(Earth and Environmental Sciences, Graduate School of Science and Technology, Kumamoto University), Katsunori Kimoto(Japan Agency for Marine-Earth Science and Technology), Tatsuo Nozaki(Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology), Hayato Ueda(Department of Geology, Niigata University), Kenta Kobayashi(Department of Geology, Faculty of Science, Niigata University), Takashi Hasegawa(Division of Global Environmental Science and Engineering, Graduate School of Natural Science and Technology, Kanazawa University), Chair:Tetsuji Onoue(Earth and Environmental Sciences, Graduate School of Science and Technology, Kumamoto University), Atsushi Matsuoka(Department of Geology, Faculty of Science, Niigata University)

12:26 PM - 12:29 PM

[MIS30-P03] Geology and radioralian fossils of the Misogawa Complex of the eastern Mino Terrane in the Kaida area, Nagano Prefecture

3-min talk in an oral session

*Hiroaki HAKOIWA¹, Atsushi MATSUOKA¹ (1.Department of Geology, Niigata Univeristy)

Keywords:Sawando Complex, Shimashima Complex, Misogawa Complex, Late Triassic, radiolaria

The Sawando, Shimashima and Misogawa Complexs are exposed in the eastern part of the Mino Terrane. The Sawando and Misogawa Complexs are regarded to be formed by off-scraping accretion. On the other hand, the Shimashima Complex distributed between the Sawando Complex and the Misogawa Complex is considered to be formed by different processes. In this study, we intended to clarify whether the Shimashima Complex exists around the boundary between the Sawando Complex and the Misogawa Complex in the Kaida area, Nagano Prefecture.
The study area is composed by the A, B and C formations. The A formation is dominated by siliceous rocks, forming an imbricate structure. Cherts in the A formation yielded radiolarian fossils indicative of the Middle Norian to Early Rhaetian. The B formation is dominated by sandstone and alternating beds of sandstone and mudstone. The C formation is dominated by mudstone. These lithologic features are similar to those of the Misogawa Complex. No geological unit similar to the Shimashima Complex in lithology has been found in the Kaida area.