Reexamination of the river profile change since the Last Glacial in the Tama River, central Japan

Abstract

Several fluvial terraces are distributed in the upstream area of the Tama River, central Japan. The previous studies interpreted the Aoyagi terrace as the fill-top terrace formed during the Last Glacial, and pointed out that the valley filling had continued until MIS4. In this study, heights of the mainstream deposits were measured and the long-profile of the mainstream was reconstructed. Besides, the Hk-TP and KMP tephras were found out from the deposits of the tributaries covering the mainstream deposits. Then, it is suggested that the aggradation of the mainstream finished before MIS4, and that tributaries had supplied sediments until MIS3.