The control of the superimposition effect of the original tectonic framework in different tectonic evolution stages on the development and transformation of buried hills- Taking Yidong Buried Hill in Jiyang Depression as an Example

Abstract: The superimposition relationship of the multi-stage tectonic evolution of the Mesozoic and Cenozoic controls the development process and formation mechanism of buried hills. The formation of Yidong buried hill includes two stages: the hill-forming period and the burial period. The hill-forming period was mainly controlled by three groups of faults in the NW-, NE- and NEE-striking, and the burial period was mainly controlled by the regional geological background of the NNW-SSE extension since the Cenozoic. According to the method of equilibrium profile and active fault analysis, the matching relationship between different buried hills in Yidong area is determined, and then the buried hills in Yidong area are divided into four categories: (1) Yigu 271 buried hill, its formation went through the NW-striking fault-controlled hill in the Mesozoic hill-forming period, the NE-striking fault-controlled hill in the Paleogene hill-forming period, and the Neogene-Quaternary buried period. (2) Yigu 103 buried hill, its formation was controlled by NW-striking faults in the Mesozoic hill-forming period, NE-striking faults in the Kongdian Formation- the third member of Shahejie Formation hill-forming period, and NW-striking and NE-striking faults in the first member of Shahejie Formation-Dongying Formation period. Controlled together into hills, and the Neogene-Quaternary buried period. (3) Yigu 20 buried hill, its formation was controlled by NW-striking faults in the Mesozoic hill-forming period, the Kongdian Formation-Essential Formation NW-striking and NE-striking faults in the hill-forming period jointly controlled the hills, and the third member of Shahejie Formation-Dongying Formation was NE-striking in the hill period The fault is controlled into a hill, and the Neogene-Quaternary buried period. (4) Shaogu 3 buried hill, it was formed in the Paleogene hill-forming period, NE-striking and NEE-striking faults jointly controlled the hill, and the Neogene-Quaternary buried period. The research on the development and superimposition process of Yidong buried hill provides important support for the study of tectonic evolution in Yidong area.