该区张夏组沉积地层记录旋回性明显，反映高频旋回的特点，共划分１个三级旋回层序、４个四级旋回层序、１４个五级旋回层序和５８个六级（米级）旋回层序。各级别旋回层序均由相应的次一级旋回层序向上变浅、变粗、变厚的序列组成，其底部均以相应级别的加深—间断面为界。四级旋回层序具有区域地层对比意义。该时期的海平面具有高频率振荡特点，为一个复合海平面变化旋回。 The recorded sedimentary stratigraphy of Zhangxia Formation in this area is obvious, reflecting the characteristics of high-frequency cycles. There are 1 third-level cycle, 4 fourth-level cycle, 14 fifth-cycle and 58 sixth-level Meter level) gyration sequence. Each level of the sequence of cycles is composed of a series of sequences of shallow, thickening and thickening of the corresponding sub-first-order cycles, all of which are bounded by corresponding deepening-discontinuity at the bottom. The quadruplex sequence has the significance of stratigraphic correlation. The sea level during this period was characterized by high frequency oscillations, cyclically changing for a composite sea level.