Structural Characteristics And Deformation Mechanism Of Cenozoic Fold And Thrust Belt In Eastern Section Of The Piedmont Of West Kunlun

Using sesmic datas,combing with surface geological survey and remote sensing image、well data,this thesis constructued structural model of Keliyang—Fusha structure and eastern section of the piedmont of West Kunlun,analyzed deformation time of Hetian—Kekeya thrust belt、evolutionary process and deformation mechanism.Keliyang—Fusha strcture located in western section of Hetian-Kekeya thrust belt,from Sangzhu river to Fusha.Keliyang section in the eastern section of Keliyang—Fusha strcture developed Kedong structure and Heshitage anticline from south to north,but Fusha section in the western section developed Fudong structure,Kekeya anticline and Guman anticline from south to north.Tiekelike fault is boundary fault of West Kunlun mountain and Yecheng—Hetian sag,Keliyang—Fusha fault was through Kedong structure and Fudong structure, it involved steep belt which continued from Jurassic to Pliocene in outcrop at Keliyang section. Kedong structure and Fudong structure were basement involved strctures,but Kekeya anticline、Heshitage anticline、 Guman anticline were low relief anticlines, their displacement transformed to Mazrtagh structure。Fudong structure was pinch—out towards Kedong structure,Kekeya anticline converged with Kedong structure eastwardly.Transverse fault didn’t developed between Keliyang section and Fusha section.Kedong structure and Kekeya anticline were lateral growth and converged,they were hard linkage. Aqike(Keliyang) structure (located in western section of Fudong structure) deformed from Miocene;the deformation of Kedong structure and the blind fault below backlimb of Kekeya anticline started at Early Pliocene; at Late Pliocene, Kekeya anticline strated deforming,Kedong structure continued deforming,they developed by break—forward sequence.Hetian—Kekeya thrust belt located in southern margin of Cenozoic fold and thrust belt in eastern section of the piedmont of West Kunlun, extend about270Km from Hetian to Kekeya. Mazartagh structural belt is leading edge of Hetian—Kekeya structural belt,the Cenozoic compressive deformation of Hetian—Kekeya along the gypsum—mudstone of Aertashi Formation of Paleogene slided to Mazartagh and transformed to Fault—propagation—folds,leaded obvious topographic rise in Tarim basin.Madong structure which located at east and Qunkuqiake structure、 Bashituopu structure which located at west didn’t involved this deformation.The taper wedge angle of this fold and thrust belt is less than those active orogenies,it’s means the gypsum—mudstone of Aertashi Formation and the shape of Cenozoic deposition are key factors, the gypsum—mudstone controls a of taper wedge,the shapes of basement and depositive wedge control β of taper wedge.Growth strata of Hetian—Kekeya structural belt deposited from Miocene. So,Hetian—Kekeya structural belt deoformed from Miocene.Combineing with wedge shape sediment of Cenozoic fold and thrust belt in eastern section of the piedmont of West Kunlun,Western Kunlun mountain uplift from Miocene.