Takashi Nakata

Department of Geography, University of Hiroshima, Hiroshima, 730, Japan

Shuji Iwata

Department of Geography, Tokyo Metropolitan University, Setagaya, Tokyo 158, Japan

Hidetsugu Yamanaka

(Died in a climbing accident in the Japan Alps in February, 1983)

Hiroshi Yagi

Department of Geography, Tohoku University, Sendai 980, Japan

Hideaki Maemoku

Department of Geography, University of Hiroshima, Hiroshima, 730, Japan

Tectonically produced geomorphology along some of the active faults in the Western Nepal Himalayas has been examined in order to clarify the mode, sense and amount of displacement of the late Quaternary faulting. The Talphi Fault of the Main Central active Fault System occurring along the Main Central Thrust zone, shows that vertical slip is down to the north on this high angle reverse fault dipping to the south. The Bari Gad Fault in the Lower Himalayas also shows downthrow to the north with dextral displacement. The Surkhet-Ghorahi Fault of the Main Boundary Fault System is accompanied by a pressure ridge along the straight fault trace and the sense of vertical displacement differs in places. Average rate of uplift across the Main Boundary Fault in West Nepal is much smaller than that known in the Eastern Himalayas. Along the active faults, except those in the Himalayan Front, the mountains have been subsiding during the late Quaternary.