The Lower Jurassic Baitianba Formation in western Sichuan foreland basin has four main sediment types: alluvial fan, meandering river, lacustrine delta, and lacustrine. Alluvial fans are found in various areas and transition into river, delta, and lake sediments. The study used well logs, outcrops, and cores to understand the sedimentary facies and palaeogeography of the formation.