抄録
Xray diffraction examination in Anabara Landslide has revealed clay-mineralogical differences in some samples which are megascopically same grade hydrothermal alteration.
Frequently, landslides occurs in hydrothermal alteration zone (so-called hot spring-landslide). But the relationship between hydrothermal alteration and occurence of Anabara landslide suggests that landsliding depends on high ratio of smectite in clayfraction but not on grade of hydrothermal alteration.
Xray diffraction examination is a effective method for these study and a quantitative interpretation may be worked out by Watanabe's model.