Salween River much of its length, the Salween's course is nearly parallel to that of the much larger Mekong in the east. Although the commonly accepted name is Salween, the river is known by a handful of other names regionally: "Nu" in China, "Thanlwin" in southern Burma, and "Salawin" on the border of Thailand and Burma. Several major sub-continental drainage basins border on the Salween. The Mekong basin forms nearly the entire eastern boundary of the watershed, while the Irrawaddy River flows southwards on the west side of the basin. The smallest boundary is formed by the Yangtze to the extreme north.
Geology of Myanmar India and the Eurasia Plate led to the formation of the Himalayan Orogeny. On the eastern margin of the India plate, high oblique subduction occurs between the boundary of India and the Burma-micro plate. Between late Eocene to Miocene, the Burma and Shan-Thai block rotated 30° to 40° clockwise, to accommodate the major collision along the plate boundary. This resulted in the trend of arc shifting from east-west to the north-south direction. The subduction boundary forms an accretionary prism and eventually with thrusting and folding forms the Indo-Burma Range. In late Miocene to Pliocene, the slab detachment of Burma-microplate beneath