The study looked at the Yanchang Formation in the Ordos Basin, focusing on how different sediment layers were formed over time. By analyzing the rock layers, the researchers found that the area went through different cycles of sedimentation, creating various types of environments like rivers and lakes. They also discovered that the sandstone reservoirs in the area were formed by different processes like underwater channels and river bars. The researchers found that changes in the lake level affected how sediment was deposited in the area, leading to different patterns of sediment distribution.