Geoscientific studies on the Quaternary faulting and geomorphic processes of the Ryukyu arc, southwestern Japan

Abstract

This paper reviews studies on the Quaternary tectonics and geomorphic processes of the Ryukyu arc, southwestern Japan. The Ryukyu arc lies along the subduction zone between the Eurasia and Philippine sea plates. Many islands of the Ryukyu arc are classified into volcanic islands, accretionary complex islands and uplifted coral reef islands. The Quaternary tectonics forms many strike-slip and normal faults in the Pleistocene limestone (Ryukyu group) originating from coral reef sediments. Mountains and hills consisting of metamorphic and sedimentary rocks are eroded, reflecting the rate of weathering controlled by various environmental conditions. Previous physiographic studies considered several landforms as tropical and subtropical landscapes, whereas such landforms should be reconsidered in terms of geological factors as well as climatic ones. The authors suggest that future studies require a more comprehensive and integrated understanding of the geomorphic processes involving both the climatic and geological factors.