Cenozoic structural deformation and expression of the “Tan-Lu Fault Zone” in the West Sag of Liaohe Depression, Bohaiwan basin province, China  

作　　者：QI JiaFu LI XiaoGuang YU FuSheng YU TianCai 

机构地区：[1]State Key Lab of Petroleum Resources and Prospecting,China Petroleum University [2]Department of Earth Sciences,China Petroleum University [3]Liaohe Oilfield Company of PetroChina

出　　处：《Science China Earth Sciences》2013年第10期1707-1721,共15页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China(Grant No.90914006);Ministry of Science and Technology of China(Grant No.2009ZX05009-001);State Key Lab of Petroleum Resources and Prospecting(Grant No.PRPDX2008-03)

摘　　要：Based on the interpretation of 3D seismic data and structural mapping we analyzed the geometry and kinematics of the fault system and validated the expression of the"Tan-Lu Fracture Zone"in the West Sag of Liaohe Depression,Bohaiwan basin province.The Cenozoic structural deformation within the West Sag of Liaohe Depression can be divided into extensional structure system and dextral structure system.The extensional system is constituted by numerous NNE-NE trending Paleogene normal faults,where the Taian-Dawa fault(F1)is the master boundary fault(MBF)dominating the deposition during Paleogene so that the sag shows a complex half-graben with"boundary fault in the east and overlap in the west".The dextral system is constituted by 2–3 dextral basement faults in NNE-NE trending(F2,F3,F4)and associated structure,and the time of structural action started in Oligocene and continued to Quarternary so that some associated secondary faults of the dextral system cut off the Neogene and Quaternary.Under the influence of the position and attitude of NNE-NE trending basement strike-slip faults,the central north part and the south part of the West Sag show obviously different structural features.The former appears to be a complex"graben"structure limited by the reversed strike-slip fault in the west and bounded by the inverted normal fault in the east,the latter remains the complex half-graben structure with"boundary fault in the east and overlap in the west",and the graben was mildly reconstructed by one or two normal strike-slip faults.The dextral system within the West Sag is the element of the west branch fault of the Tan-Lu Fracture Zone,which is a deep fracture zone extending along the east of the Liaodongwan Gulf.The deep fracture zone branches off into two separate faults within the Liaohe Depression.The east branch goes through from northern part of the Liaodongwan Gulf to the East Sag of Liaohe Depression and links with the Denghua-Mishan Fault near Shenyang,and the west branch passes from northern part of the LiaodoBased on the interpretation of 3D seismic data and structural mapping we analyzed the geometry and kinematics of the fault system and validated the expression of the ＂Tan-Lu Fracture Zone＂ in the West Sag of Liaohe Depression, Bohaiwan basin province. The Cenozoic structural deformation within the West Sag of Liaohe Depression can be divided into extensional structure system and dextral structure system. The extensional system is constituted by numerous NNE-NE trending Paleogene normal faults, where the Taian-Dawa fault （F1） is the master boundary fault （MBF） dominating the deposition during Paleo- gene so that the sag shows a complex half-graben with ＂boundary fault in the east and overlap in the west＂. The dextral system is constituted by 2-3 dextral basement faults in NNE-NE trending （F2, F3, F4） and associated structure, and the time of structural action started in Oligocene and continued to Quarternary so that some associated secondary faults of the dextral sys- tem cut off the Neogene and Quaternary. Under the influence of the position and attitude of NNE-NE trending basement strike-slip faults, the central north part and the south part of the West Sag show obviously different structural features. The former appears to be a complex ＂graben＂ structure limited by the reversed strike-slip fault in the west and bounded by the in- verted normal fault in the east, the latter remains the complex half-graben structure with ＂boundary fault in the east and overlap in the west＂, and the graben was mildly reconstructed by one or two normal strike-slip faults. The dextral system within the West Sag is the element of the west branch fault of the Tan-Lu Fracture Zone, which is a deep fracture zone extending along the east of the Liaodongwan Gulf. The deep fracture zone branches off into two separate faults within the Liaohe Depression. The east branch goes through from northern part of the Liaodongwan Gulf to the East Sag of Liaohe Depression and links with the Denghua-Mishan Fault near Shenyan

关 键 词：extensional structure strike-slip structure CENOZOIC Tan-Lu Fracture Zone West Sag of Liaohe Depression 

分 类 号：P618.13[天文地球—矿床学]