The researchers studied the rock layers in Nuqing area to understand how they were formed. They used data from seismic scans and well logs to analyze the different types of rocks and layers. They found that the rock layers in Nuqing area were formed in a specific order, with different stages of water levels. The researchers identified when the water levels rose and fell, and divided the rock layers into different sections based on these changes. Overall, they discovered that the rock layers in Nuqing area were formed in a sequence, with distinct patterns of water levels changing over time.