At the beginning of the Late Carboniferous, the whole basin subsided, and on the top of the Middle Ordovician limestone, which had been weathered and leveled for a long time, it accepted the transgression from the northeast and began the evolution history of the continental surface sea. The ancient topography is high in the north and low in the south. Yinshan ancient land in the north is a towering mountain range or plateau, which was the main material source at that time. The study area is a lagoon with a small slope and obvious vertical evolution law. Among them, offshore carbonate shelf facies and lagoon facies constitute the lithofacies palaeogeographic sedimentary pattern of this period. Judging from the development of cycles, there are generally four cycles in Kaiping, Jingxing and the southern foot of Yanshan in central Hebei. There are only three cycles in the south of Shijiazhuang; Xingtai area generally has only two cycles; Most of the Fengfeng area is an incomplete cycle, and the offshore carbonate shelf facies is basically undeveloped, indicating that the transgression direction in this period mainly comes from the northeast.
In the Late Carboniferous, the scope of transgression expanded, and limestone was deposited at the bottom of Taiyuan Formation. After that, the direction of transgression changed to southeast. The limestone in Fengfeng area of southern Hebei Province is the best developed, with 4 ~ 5 layers, which decreases northward and gradually becomes marine mudstone, which is a series of first-order seawater advance and retreat cycles of swamp-offshore carbonate shelf-lagoon facies. The general law of vertical evolution of sedimentary environment is that the surface is clear water.
In the early Permian, as the North China Plate continued to thrust northward, it kept retreating. The paleogeography of the study area is dominated by offshore carbonate shelf system and barrier-lagoon system, with 1 ~ 2 layers of limestone (Julia limestone and one layer of limestone, Julia limestone is relatively stable, and only one layer of limestone develops in the peak area). There are basically no limestone deposits in other northern areas, followed by two cycles, and the lower cycle is offshore carbonate shelf-tidal flat-peat swamp. The upper cycle is estuary bar-distributary bay-peat swamp-distributary bay-distributary channel, which represents the evolution process of offshore carbonate shelf system-barrier bar-lagoon system-delta system from bottom to top, and forms a relatively stable 2 # coal seam in the distributary bay environment.
In the Middle Permian, the sea retreated southward in a large area, and the vast area has evolved into a delta plain environment, where distributary channels and flood basins coexist. In Fengfeng-Xingtai area, there are some sub-environments of delta front, which are the continuous development of paleogeography in the early Early Permian. The distributary bay-distributary channel environment of delta front is the main environment, followed by the repetition of distributary channel-natural dike-flood basin, reflecting the continuous migration of distributary channel in delta plain. Flood basins are sometimes partially submerged, forming coal lines.
In the early Late Permian, with the southward movement of the coastline, the lithofacies palaeogeography in this area further evolved. Except for the small delta environment in Fengfeng-Cixian area, most of the other areas are river sediments. Generally speaking, it is an alluvial plain with high north and low south. With the development of regression, the differentiation degree of paleogeographic pattern in the region is getting smaller and smaller, and the vertical evolution law is obvious. From bottom to top, it evolved from riverbank deposition to flood basin, which represented a complete drainage sedimentary cycle and constituted all the contents of the vertical evolution of the environment in this period. However, Fengfeng area is still in the delta plain environment, and the seawater from the south can occasionally flood into the coastal delta plain area, bringing normal marine life to the land, forming a thin layer of siliceous mudstone with sponge spicules in the low-lying area, which is located at the top of the third member of Shangshihe Formation and becomes a good indicator layer for stratigraphic correlation in this area.
In the late Late Permian, there were still rivers and lakes in Fengfeng and Xingtai areas of the study area, and the early flood basins were transformed into lakes. There are thin freshwater limestone or marl deposits in lakes in Fengfeng area, which indicates that the early lacustrine facies deposits have a trend of development and expansion.