ANALYSIS ON THE TYPICAL STRUCTURAL STYLES AND DEFORMATION MECHANISM OF THE KELASU TECTONIC ZONE IN THE KUQA DEPRESSION OF THE TARIM BASIN

The Kelasu tectonic zone located in the Kuqa Depression of the Tarim Basin is rich in natural gas.Affected by salt-bearing measures,the structural deformation of salt-above layers is not consistent with that of salt-under layers,and it has the features of dual thrust structures.The thrust-nappe-typed drag structre with gentle or deep dipping angles,and the mass-upthrusting structure with deep dipping angles were developed in salt-above layers.And salt under layers are characterized by developing superimposed thrust structures.According to the analysis of lithomechanical properties,the occurrence of thrust faults and the change of structural patterns in salt-above layers are related to the developing thickness and distributive range of plastic saltrock layers.Meanwhile,as saltrock layers are high quality caprocks for natural gas,their thickness and continuous changes are also key factors to result in the differential accumulation of natural gas in the Kela 2 and Kela 3 structures.