华北其他地区一样,仅发育有寒武系及奥陶系中、下统。上奥陶统、志留系、泥盆系在本区全部缺失。 寒武系在本区发育较全,可分为三统七组,奥陶系下、中统共有四个组,地层系统及主要岩性见表1。寒武系沉积总厚在全区一般为550—650米,奥陶系因遭受剥蚀,残余最大厚度为680米。各剖面地层厚度数据见表2。 As in other parts of North China, only the Cambrian and Ordovician middle and lower reaches are developed. The Upper Ordovician, Silurian and Devonian are all missing in this area. Cambrian developed more in this area can be divided into three groups and seven groups, the Ordovician system, the Central Plains total of four groups, the formation system and the main lithology in Table 1. Cambrian sedimentary total thickness in the region is generally 550-650 meters, due to erosion of Ordovician, residual maximum thickness of 680 meters. The thickness of each section of formation data in Table 2.