Fundamental study of the paleoseismological survey for active fault systems

Haraguchi, Tsuyoshi*

This report introduce several solutions for paleoseismological survey, especially the surveys for Late Pleistcene- Holocene faulting. One is a basic technique, detail topographical measurement and decide the age of the faulted surfaces. We applied this technique to three cases (Asahi fault on Tokachi active fault system ; Hokkaido, Tarui fault on Miyashiro active fault system; Gifu, Atera fault system; Gifu). On the other hand, we have to consider secondary fault, that is opposed to main trace of active faulting, in all its aspects. We defined back-thrusts as one of the secondary faults, and discuss their characteristics.