The article discusses the rocks and sediments found in a specific area in Chongqing, China, from the Upper Triassic period. The researchers studied the layers of sandstone, shale, and mudstone, along with coal seams and plant remains. They found evidence of a shallow-water delta environment, with different sub-environments like delta plains and channels. The layers show how the environment changed over time, from the delta plain to the delta front and prodelta.