The researchers studied the Jurassic rocks in the western Sichuan foreland basin by looking at surface outcrops, drilling cores, well logs, and seismic profiles. They identified 13 sequence boundaries and divided the basin into 13 sedimentary sequences. They found four main types of depositional systems: alluvial, lakes, fan delta, and delta. The distribution of these systems changes from west to east in the basin, with alluvial fans and plains in the west and deltas and shallow lakes in the east.