[S-CG50] Dynamics in mobile belts

[SCG50-P08] Analysis of fault kinematics and internal structure of fracture zone at ISTL

*HIBIKI CHIBA¹, Kenta Kobayashi¹, Keita Takahashi¹ (1.Gradate School of Science and Technology Niigata University)

Keywords:Itoigawa Shizuoka Tectonic Line, Fault rock, Yokokawa Fault

Purpose of this study is to elucidate the activity history of the Yokokawa fault in FMP, And we carried out geological reconnaissance, structure observation of fault rocks, X-ray diffraction measurement and Rf/φstrain analysis.

From the above results and considerations, we estimated formation process of Yokokawa fault and displacement of fault gouge. We used numerical expressions of displacement (Scholz, 1987). As a result, the amount of displacement was 4.7-470m. This result was smaller than displacement of Nechi-Ono Belt which was estimated by Shiraishi (2003). For this reason, we estimated that Yokokawa fault is connected to Nechi-Ono Belt.

Reference

Nagamori, H., Takeuchi, M., Furukawa, R., Nakazawa, T. and Nakano, S., 2010, Geology of the Kotaki district, Quadrangle Series, 1:50,000, Geological Survey of Japan, AIST, p.31-35, 66-69, 130

Scholz, C.H., 1987, Wear and gouge formation in brittle faulting, Geology, 15, p.493-495

Shiraishi, S., 2003, Geology of Itoigawa Spa and Itoigawa-Shizuoka Tectonic Line, Bulletin of the Fossa Magna Museum, No. 2, p.1-13