| The Ordos basin of North china is an important block in Cenozoic and moderntectonic activity, and it is also locate in the boundary of the North plate, South plateand Qinghai-Tibet plate. Its tectonic activity and the dynamic problems have attractedthe attention of geoscientists. The block is famous for its long-history evolution andstable craton basement, till in the different periods of the Cenozoic, different intensityfault movement occurred on the periphery of Ordos block and this formed theperipheral fault system of the basin. Because the Ordos basin is located in the specifictectonic belt, the dynamics background of these fault system and the relationship ofmutual movement between the basin and its peripheral fault basin have drawn theattention of many scholars, Different structure models were put forward. Differenttectonic model reflected different points of the researchers.The research obeyed the principle of tectonic stress background in differenttectonic period. Through the comprehensive processing and interpretation of gravityand magnetic data, this thesis studied the regional structure of the Ordos basin;described the partition and characteristic of the gravity field and magnetic field;processed the gravity anomaly data and magnetic anomaly data; and extracted thestructure line from processing result data, with combining the existing research. Wecompleted the inferred work of the fault system (distribution and composition) ofOrdos basin, carry out a systematic study of the structure of the Ordos basin.The research mainly contained the following aspects:1) The objective facts were summarized. Then the data of geological,sedimentary formation, tectonic deformation and the existing fault research werecollected and collated. The tectonic dynamic backgrounds of the basin in differentperiods were discussed.2) The gravity and magnetic data processing and integrated interpretation weredone: The appropriate data processing method was selected and the measuredmagnetic anomaly data were processed. The method of comprehensive interpretation was applied in the Ordos basin and the surrounding fault basin to analysis the dataprocessing result. Based on a variety of gravity and magnetic data processing result,the distribution and phases of the fault was deduced using these data processing resultfor the interpretation of the fault.3) Several typical profile across Ordos basin and the surrounding basin wereselect to create the gravity model. The reasonable explanation of the related movingprocesses between the Ordos block and adjacent blocks were given. the view of“Counterclockwise rotation” was supported by the results. |
PDF Full Text Request