Japan Geoscience Union Meeting 2024

Presentation information

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS11] Mountain Science

Mon. May 27, 2024 3:30 PM - 4:45 PM 201B (International Conference Hall, Makuhari Messe)

convener:Yoshihiko Kariya(Department of Environmental Geography, Senshu University), Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chiyuki Narama(Niigata University, Program of Field Research in the Environmental Sciences), Motoshi Nishimura(Interdisciplinary Cluster for Cutting Edge Research, Institute for Mountain Science, Shinshu University), Chairperson:Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chiyuki Narama(Niigata University, Program of Field Research in the Environmental Sciences)

3:30 PM - 3:45 PM

[MIS11-06] Study of gravitational deformation in the Hida Mountains

★Invited Papers

*Hidehisa Nagata1 (1.Fu-Sui-Do Company Limited)

Keywords:gravitational deformation, topographic development, structural geology, Hida Mountains

Most of the multiple ridges and linear depressions which were once interpreted as ones of periglacial landforms were formed by gravitational deformation. This concept became accepted in Japan in the 70s, and then studies progress in various areas. In this presentation, I explain our result about the gravitational deformation in the mountain range to the southeast of Kamikochi, provide an overview of the gravitationally deformed landforms in various areas in the Hida Mountains, and represent the significance and the assignment of study in this region.
Multiple ridges and linear depressions continue 12 km long on the ridge from Mt. Chogatake to Tokugo Pass, southeast of Kamikochi. Topographic interpretation using maps made from a 1-m-mesh airborne LiDAR DEM demonstrates that the northwestward gravitationally deformed bodies are recognized by the distribution and arrangement of micro-landforms and the development process of differentiation. Furthermore, geologic investigation in this area revealed an S-shaped structure caused by buckling or viscous flow on the cataclinal slope.
Many other landforms by gravitational deformation are developed in the Hida Mountains. Not only the sedimentary rocks, granitoids (Mt. Nishi-Hotaka, Mt. Eboshi) and volcanic rocks (Tateyama) are to be bedrock. Glacial, periglacial landforms and active faults are also distributed in the Hida Mountains, which makes it possible to distinguish gravitationally deformed landforms from them and to analyze the time and spatial relationship between them. This can be said to be the significance of studying in the Hida Mountains region. Furthermore, structural analysis of deformed body as another issue should contribute to structural geology and rock mechanics.