大巴山
The Sichuan Basin forms the rigid northwest edge of the Yangtze tectonic plate. The Yangtze Plate's complex relationship with the surrounding Eurasian Plate is evidenced at its margins. Orogeny formed by the Indian Plate's collision with Eurasia has compressed against the Sichuan Basin's western edge, most notably along the Longmenshan Fault, the epicenter of the 2008 Sichuan Earthquake. The basin's rigidity withstands much of the Tibetan Plateau's eastern movement, but dramatic folds have formed within the Yangtze Plate along the Sichuan Basin's eastern edges. Here, ancient faults interact with the Daba Mountains, themselves a result of pressure between the Yangtze and Eurasian Plates in a perpendicular direction.