Abstract:It is an important method to understand basin-range evolution in studying depositional provenances. Five depositional provenances are found to exist in conglomerate clasts, sandstone framework grains and detrital heavy minerals, respectively, the middle- north part of Longmenshan, the Dabashan, the south part of Longmenshan, the South-East to Sichuan Basin and the South to Sichuan Basin. The clastic depositional provenances are characterized by the recycled orogen type dominating the middle-north part and the south part of Longmenshan, and the continental plate type representing the characteristics of the South-East and the South to Sichuan Basin. The recycled orogen type can be subdivided into the collision orogen and mixed orogenic sandstones types with distribution in the north and the south of Longmenshan. The distribution of depositional provenances diversifies in different stages. In the early stage, depositional provenances came from the middle-south part of Longmenshan and Dabashan mainly, with limited deposits coming from the South-East and the South to Sichuan Basin. In the late stage, because of periodic tectonic activity of circumferential plate, the south-east and south to Sichuan Basin provided more sediment increasingly, leading to balanced distribution of depositional provenances. During Late Triassic, Longmenshan has suffered NW —SE directional compression, uplift, and denudation, with the intensity manifesting circular evolutionary sequences. During the sedimentary period of member 2 of Upper Triassic, Longmenshan area began suffering compression, uplift, and denudation, providing substantive sediments to Sichuan Basin. During the sedimentary period of member 4 of Upper Triassic, with intensive tectonic activity, Longmenshan suffered compression and uplift continually, leading to transference of depocenter from NW to SE. Afterwards,the denudation area advances from NW to SE continually, with tectonic intensity weakening gradually.