[H-QR05] Quaternary, Diachronic dynamics of human-environment interactions

[HQR05-P07] Stratigraphic verification of the Kokumoto Formation, the Pleistocene Kazusa Group in Tabuchi district, Ichihara City, Chiba Prefecture

*Taro Fuse¹, Yayoi Yamada¹, Hideto Kimura² (1.Paleo-Kanto Great Depth Submarine Basin Geopark Promotion Council, 2.Soilsystem Co.,Ltd.)

Keywords:Global Boundary Stratotype Section and Point, Chiba Section, Byk-A volcanic ash

The outcrop along the Yoro River in Tabuchi district, Ichihara City, Chiba Prefecture is classified as part of the Kokumoto Formation of the Pleistocene Kazusa Group, and is also known as “the Chiba Section(Calabrian - Chibanian boundary)”. In this study, based on the results of previous research, we investigated in detail on outcrop at the Yoro-Tabuchi section (Okada et al. (2017)), which is along the tributary flows into the Yoro River. In addition, by comparing the results of this research with previous papers (such as Suganuma et al. (2021)), we gained some findings that differ from previous studies. For example, the distribution of key beds of volcanic ash such as pumice, as well as the distribution of thin sand beds, differ from previous papers. Here, we report the findings obtained through the geological survey on the outcrop.