The West Sichuan depression is a foredeep developing in western Sichuan Basin since Late Triassic and has experienced multi-stage tectonic movements in Indosinian, Yanshanian and Himalayan. Affected by the Mt. Longmenshan thrust belt on the west side, Mt. Micangshan belt on the north side and Chuandian structural belt on the south side the NE-trending, sub-EW-trending and sub-NS-trending structures developed correspondingly in the West Sichuan depression. The structure formation in the West Sichuan Depression was controlled by three major factors as follows, the basement texture and gypsum-salt layers in Lower-Middle Triassic provided boundary conditions and material base, and the multi-stage and multi-direction structures driven by peripheral structural belts coined eventually the structural framework of zonation, segmentation, delamination and compounding-combination superimposition.
