塔北隆起中西部新近纪末构造应力场数值模拟

The plane and profile geological models at the end of Neocene in the midwest of Tabei uplift are established on the basis of seismic data of oil field and tectonic analysis,and the numerical simulation results of tectonic stress field in the area are obtained using linear elastic finite element method.Modeling results indicate that N-S regional compressive stress dominates the stress field of the whole area at that time,as well as that all faults of Yaha,Luntai,Hongqi,Yingmai 7 are compresso-shear structures with sinistral strike slip,while Kalayuergun fault is right lateral,and Yangtake fault is pure compressive thrust.In the condition of regional compressive stress,local stress field is formed,and affected by the main faults,which controlles the generation of secondary structures.In the modeling results of profile stress field,the orientation of the major principal stress change from horizon to incline in the middle of the uplifting area and the vertical stress component becomes bigger,which is the main factor to control the development of the compressional and subtuberant structures.