Hidetsugu Yamanaka
(Died in a climbing accident in the Japan Alps in February, 1983)
Hiroshi Yagi
Institute of Geography, Tohoku University, Sendai 980, Japan
Six levels of fluvial terraces are identified in the Dun: the Highest, Higher, Middle, Lower I, II and III terraces in descending order. They are filltop terraces, except for the Lower II and III, composed of thick deposits. The relative height of the terraces above the present river bed increase toward the mountain foot of the Mahabharat Lekh (range). It is believed that the geomorphological development of the Dun is directly related to the late Quaternary intermittent supply of detritus and the crustal movement.