Formation of the Late Triassic western Sichuan foreland basin of the Qinling Orogenic Belt, SW China: sedimentary and geochronological constraints from the Xujiahe Formation

•The Late Triassic western Sichuan Basin was a foreland basin at the southern front of the Qinling Orogenic Belt.•The Late Triassic western Sichuan foreland basin formed at 228–208 Ma.•The depocentres migrated southward along the direction perpendicular to the Qinling orogen.•The proto-type basin of the Late Triassic western Sichuan foreland basin was elongated along the E-W direction.