Japan Geoscience Union Meeting 2018

Presentation information

[EJ] Oral

H (Human Geosciences) » H-CG Complex & General

[H-CG24] Earth surface processes related to deposition, erosion and sediment transport

Sun. May 20, 2018 10:45 AM - 12:15 PM A04 (Tokyo Bay Makuhari Hall)

convener:Koji Seike(Geological Survey of Japan, AIST), Naofumi Yamaguchi(Center for Water Environment Studies, Ibaraki University), Hajime Naruse(京都大学大学院理学研究科, 共同), Hideko Takayanagi(Institute of Geology and Paleontology, Graduate School of Science, Tohoku University), Chairperson:Seike Koji, Yamaguchi Naofumi

11:20 AM - 11:35 AM

[HCG24-08] Formation process for spherical carbonate and iron concretions

*Hidekazu Yoshida1, Koshi Yamamoto1, Hitoshi Hasegawa2, Nagayoshi Katsuta3, Sin-iti Sirono1, Ippei Maruyama1, Masayo Minami1, Yoshihiro Asahara1, Yasushi Yamaguchi1, Shoji Nishimoto4, Niiden Ichinnorov5, Richard Metcalfe6 (1.Nagoya University, 2.Kochi University, 3.Gifu University, 4.Nagoya City Science Center, 5.Institute of Paleontology and Geology, Mongolian Academy of Science, Mongolia, 6.Quintessa Limited, UK)

Keywords:Spherical carbonate concretion, Spherical iron oxides concretion, Formation process

Spherical carbonate concretions are observed widely varying geological ages in marine sediments throughout the world. In particular, it has commonly spherical shape with highly enriched in CaCO3, and are hardened and isolated from the surrounding sedimentary rock matrices by sharp boundaries. This feature is reason why isolated carbonate concretion as it is identical in sedimentary rocks and fascinated simply persuade people to think why such rounded concretion in there. It is also known that the concretions often have various kinds of well-preserved fossils at their centres. Here we have describe the formation process and also extesively we have fund the formation of Fe spherical concretions is related on the carbonate spherical concretion. In the presentation, we will introduce those evidences.