Abstract
The periodicity of landslide is able to consider in landslide area. Because the landslide has usually occurred at one part of the former landslide area.
The ages of buried woods in landslide areas in the eastern part of Toyama Pref. have dated by C14 dating method as follows:
Kurombo-ike, Tateyama-machi 1350±110Y.B.P. Gak. 6154
Awarada, Kamiichi-machi 1050±90 Y.B.P. GaK. 6155
Locality A. near Kama-ike, Kamiichi-machi 1250±85 Y.B.P., Gak. 4 121
1050±90 Y.B.P., Gak. 4122
The history of Fujiyasuuchi shrine, Nyuzen-machi also has written that this shrine removed from hill to this place on 830 A.D. occurring landslide. Above mentioned ages converged into 1100-1200 Y.B.P. The climate of 1100-1200 Y.B.P. was rather cool than one of present day by pollen analysis at locality A. Perhaps land slides had tend to occur easily by havy snow and rain at that time. These 1100-1200Y.B.P. perhaps have suggested the periodicity of landslide in the eastern part of Toyama Prefecture.
