Fold structure of Changle semi-submersible monoclinal fault depression

It is mainly composed of Wutu nationality, and there are two main types. One is the northwest axis, which is the result of extrusion in different directions in the basin after the formation of Wutu Group. It developed in two stages, such as Wutu syncline, which was formed in Paleogene after the formation of Wutu Group. The second phase, such as Qiaoguan syncline, has a NNE axis and is superimposed on the first fold. The formation time is also from Paleogene to Quaternary after the formation of Wutu Group, which is a drag fold formed by the activity of Yishu fault zone.