Tectonic Evolution Of The Central Uplift Belt In The Dongying Depression

The Dongying Depression is a fault basin in the southeastern of Bohai Bay Basin.Salt rock,gypsum rock and mudstone are developed in the upper part of Kongdian Formation and the under part of Es₄submember.Due to the disturbance of the plastic rock strata,the seismic data in the deep part of the Central Uplift has chaotic reflection,which leads to controversy about the dynamic mechanism of the diapir structure and the main controlling factors of the formation of the fault in the Central Uplift Belt.This paper,on the basis of previous studies,analyzing the fine tectonics of seismic data and combining with the characteristics of stratigraphic assemblage,designs physical simulation experiments of structures with plastic layer,and links the Balanced cross section technique,and conducts research on tectonic-sedimentary evolution of the Dongying Depression as to explore the deformation characteristics of plastic layer and its interaction with overlying strata under extensional tectonic background and clarify the diapiric dynamic mechanism.Some conclusions have been reached:?1?Diapirs are not only developed in compressive basins,but in extensional basins.The activity of the basement fault and the later deposition will cause the plastic layer to be unevenly pressed,which will eventually cause the plastic layer to migrate and uplift to region where strata is thin,forming diapir structures;?2?The diapir of the Central Uplift belt is related to the occurrence of the basement fault,which controls the diapir position of the Central Uplift belt.?3?The faults in the Central Uplift belt are the result of diapir and regional extension,and the plastic layer provides good detachment layer for fault development.