Abstract
According to geological environment, landslids have been classified into three groups: namely, Tertiary Zone, Fractured Zone and Thermal Spring Zone landslides.
Through recent surveys, however, the author has observed that there is a special type of landslide which cannot be included in any typical group of landslide.
The author made investigations of the strata and underground structure, by the earth resistivity method, the strain gage measurement and the boring, and obtained the following results.
1. The landslide movement in Tertiary zone covered with volcanic materials has been conditioned by the products.
2. As the landform due to landslide, the movement is observed at their terminal parts. It is quite different from other landslides in the Tertiary sandstone or mudstone zone without any cover, where the slide can easily happen from upper parts.
There are a little moving blocks with a simple mechanism of motion, while other Tertiary sliding areas have many moving blocks.
3. The landslide motion is slow, begins at the surface materials and shifts to the lower deposits, contrary to that of the sandstone or mudstone zone.
