The Longmenshan Fault (Chinese: 龙门山断层) is a thrust fault which runs along the base of the Longmen Mountains in Sichuan province in southwestern China. The strike of the fault plane is approximately NE. Motion on this fault is responsible for the uplift of the mountains relative to the lowlands of the Sichuan Basin to the east. Representing the eastern boundary of the Qinghai-Tibet Plateau, it is a border formation between the Bayan Kola block in the Plateau and the South China block in the Eurasian Plate.