Dating faulted terrace surfaces with thin aeolian loess cover by using terrestrial Be-10 depth profiles: an attempt along the Nobi active fault system, central Japan

High-definition digital elevation models (DEMs) from airborne light detection and ranging (LiDAR) are very powerful tools in detecting unknown tectonic-geomorphic features and quantifying cumulative slip from repeated faulting events. The faulted geomorphic features, however, need to be somehow dated to convert the slip to long-term slip rate, and this task still remains as a challenging part of many tectonic geomorphic and paleoseismic studies. The dating is particularly difficult in mountainous and densely vegetated regions, where we are most benefitted from LiDAR DEMs but most often confront challenges in finding datable organic materials in high-energy gravelly deposits. Here we attempted to date left-laterally faulted fluvial terrace surfaces discovered along the Nobi active fault system (NAFS) in the Etsumi Mountains, central Japan, by using a terrestrial cosmogenic nuclide Be-10. In this region, terrace surfaces are covered with thin aeolian loess deposits of