The study looked at different types of sediment found in a specific area called the Xujiahe Formation in Sichuan Basin. By analyzing the rocks, fossils, and structures in the area, researchers identified four main types of sediment: semi-arid flooded basin, delta, beach bar-lagoon, and lake. The delta and beach bar-lagoon sediments were the most common. These sediments can tell us about how the basin formed and changed over time, and can help us understand the history of the area and where to look for oil and gas resources.