Geomorphological Development of Hidaka Coast

Abstract

The author surveyed the landform of marine terraces under 400 m along the coast of Hidaka to analyse chronological relationships between Erimo volcanic sand and the formation of terraces.
The terraces may be classified as follows:
Pleistocene
Level-I (upper erosion surface) : mostly destroyed by erosion
Level-II (middle erosion surface) : mostly destroyed by erosion
Level-III (lower erosion surface) : mostly destroyed by erosion
Level-IV (upper marine terrace)
Level-V (lower marine terrace, upper river terrace)
Holocene
Alluvial terraces
Alluvial plain
These surfaces were mainly formed by transgression and regression repeated in the Pleistocene. There were two glacial stages lowering the sea level, namely Poroshiri and Tottabetsu ice-stages. In the author's opinion, Level-IV and Level-V of the Pleistocene surfaces are correlated with these two glacial stages.
The development of landforms in this region is summarized and correlated in the table 3.