2014 Volume 65 Issue 3-4 Pages 45-55
Recently, undulating topographies have been revealed at the base of the Alluvium under the coastal lowlands of Japan. These topographies are reconstructed on the basis of spatial interpolation of the basal depth of the Alluvium interpreted from numerous numbers of borehole logs. However, the undulating topographies have been ignored in previous studies because they have been considered as a result of defective description of borehole logs. The age of the Basal Gravel of the Alluvium and the sealevel curve, which are recently reported, suggest that the undulating topographies are natural features, and they have been formed as a result of overlap of incised valleys and buried terraces of the several Marine Isotope Stages.
