Transcurrent displacement along the median line, South-Western Japan

Abstract

There has been transcurrent displacement along the major fault zone in south-western Japan known as the Median (tectonic) line, despite the former consensus of opinion that only dip-slip displacements have occurred in this zone. In places along and adjacent to this “line”, which is a geologically proved feature, much right-lateral geomorphic offset has been detected. Offsetting of topographic features of the ubiquitous fine-textured feral relief (itself undoubtedly of recent development) is very characteristic; and Californian-type shutter ridges (offset up to 2 km in western Kii) are found, together with numerous offset streams. Thus, at least during the Quaternary, right-lateral transcurrent faulting has obviously been in progress throughout the length of the median line, and activity quite probably dates back to earlier time.