Segmentation Characteristics And Genetic Simulation Of Central Structural Belt In Linhe Depression,Hetao Basin

The Hetao Basin is distributed in a narrow and elongated arc between the Bayan Ula Mountain Langshan structural belt,the Yinshan fold belt,and the Ordos Basin.The Linhe Depression is the largest first level negative structural unit in the Hetao Basin,which can be further divided into three secondary structural units: Jilantai Depression,Bayannur Depression,and Wuyuan Depression.Among them,Bayannur Depression includes third level structural units such as Naoxi Depression,Central Structural Belt,and Eastern Depression.Recent exploration results show that large oil fields with accumulated Proven reserves of more than 100 million tons have been found in different sections and structural traps of the central structural belt.Therefore,it is of theoretical value to carry out research on deformation characteristics and genesis of different structural sections to further implement structural traps and deepen exploration.On the basis of literature research and based on the theory of structural analysis in oil regions,this article has achieved the following cognitive results through seismic profile interpretation,field outcrop investigation,structural physical simulation,and numerical simulation research.(1)The central structural belt of the Linhe Depression in the Hetao Basin can be divided into three parts: the southern Nalinhu structural belt,the central Zage structural belt,and the northern Xinglong structural belt,which are separated by a northwest trending transformation structural belt.(2)The southern Nalin Lake structural belt develops non parallel conjugate fault combinations,accompanied by lateral fold structures;The central Zage tectonic zone develops a segmented growth and connection style of co directional inclined faults;In the northern Xinglong structural belt,there are segmented growth and connection styles of anticlinal and opposite inclined faults and Rollover anticlines structures.(3)The results of physical and numerical simulations demonstrate that the connection characteristics of the same dip fault are the most common and obvious;If the opposite inclined fault wants to be connected,it needs to have greater displacement,and there are no adjacent co directional faults that can interact.After successful connection,it shows a connection feature of sedimentation and diffusion towards both ends centered around the intersection of two faults;The connection characteristics of opposite inclined faults are relatively vague,making them the most difficult fault connection system to generate in naturally stretched strata.Two faults restrict each other’s development and instead connect with distant faults in the same direction.After successful connection,it is manifested as a connection feature of sedimentation and diffusion towards each fault direction centered around the intersection of two faults.(4)The main controlling factors of non parallel conjugate faults are related to the dip angle,top width,and cover thickness of the pre existing basement horst faults.When the cover thickness exceeds the height of the vertical intersection of the conjugate faults,a graben horst superimposed structure is formed.When the cover thickness is less than the height of the vertical intersection of the conjugate faults,a horst horst superimposed structure is formed.