[O-02] Poster presentations by senior high school students

[O02-P11] The formation process of the Late Cretaceous of the middle Southern Hyogo Prefecture

*Kana Fukushima¹, *Sachi Ishii¹, Kohei Usui¹, Amane Takemoto¹, Aiko Tanaka¹, Kenta Hojo¹, Takumi Ookido¹, Koki Okamoto¹, Mana Okuda¹, Hiroto Kubo¹, Ryoga Toda¹, Ryusei Saito¹, Akihiro Sakamoto¹, Mutsuki Shinoda¹, Akane Tanaka¹, Toru Nakahashi¹, Tomo Murakami¹ (1.Hyogo Prefectural Nishiwaki Senior High School, Earth Science Club)

Keywords:caldera lake, modal composition, magnetic susceptibility, chemical composition

1. Motivation and Purpose
Some of the authors were received several flood damages of Kakogawa River in the school area. Last year, in order to clarify the cause of the flood, we conducted a geological survey of Nishiwaki region east and west 20km, over the north and south 18km. We analyzed 85 samples and created a detailed geological map. We elucidated the cause of the flood and formation process of the Southern Hyogo Prefecture (Hyogo Prefectural Nishiwaki Senior High School Earth Science Club, 2014).
We were continued the research, we observed the inclusion of tuff rock fragments. We noticed errors in the discussion which was announced last year. So, we went a geological survey 160km longitudinal north-south direction of Hyogo Prefecture, from the Sea of Japan to the Seto Inland Sea. After observation of 146 samples with the naked eye, we analysed modal composition, magnetic susceptibility, and chemical composition.

2. The formation process of the Late Cretaceous of the Middle-Southern Hyogo Prefecture