Tectonic Geomorphology and Late Pleistocene Activity of Western Marginal Faults of the Suzuka Mountains, Central Japan

Consistency of Small Tectonic Scarps and Subsurface Geological Structures Revealed by Seismic Reflection Surveys

Abstract

 Small-scale tectonic landforms are identified from detailed aerial photograph interpretations, in order to clarify evidence of faulting since the late Pleistocene period along the marginal fault zone at the western foot of the Suzuka Mountains, central Japan. Surface fault traces at least 9-km long are recognized in the central part of this fault zone. Along the Uso River, small tectonic scarps are recognized on young fan terraces where assumed faults were identified previously by seismic reflection profiling. These scarps suggest that the most recent movement at the fault occurred during or after the late Pleistocene period. Progressive vertical displacement is recognized in the subsurface structure of Kobiwako Group, indicating that the fault zone has been active since the Plio-Pleistocene period. This fault may extend further to the north and south in the western foot area of the Suzuka Mountains.