Formative Process of Fluvial Terraces during the Late Quaternary along the Hidakahorobetsu and Motoura Rivers in Southern Hidaka, Hokkaido

Abstract

Fluvial terraces distributing extensively along the Hidakahorobetsu and Motoura Rivers in southern Hidaka, Hokkaido were investigated by the tephrochronological and geomorphological method to reveal their formative periods and processes. Based on the data obtained and on the river profile sreconstructed from terrace surfaces and the present river-bed, the change in the river response to sea-level and climatic change during the Late Quaternary was discussed, focusing on the period from 20 to 60 kyr.B.P.