The Key Technology Research In Deep Seismic Reflection Profiling Data Processing And Its Application In Quinling Oregen

The deep seismic reflection technology has been recognized as the effected means to probe lithospheric fine structure, continental base and deep geological issues.The deep seismic reflection technology was developed from the conventional seismic reflection method, and their principles are same. Their principle that the elastic wave reflects lineups when it meets different physical property boundaries is to describe the geological structural features, e.g. interfaces and faults. The seismic data processing is the intermedia that connect the field data observation with the indoor information interpretation and inversion, and its quality directly determined the precise and reliability of the subsequent interpretation and inversion. The differences of the explored target layers and parameter acquisition results in the large differences between the deep seismic reflection data processing and the petroleum reflection seismic data. The frequency of the deep seismic reflection data is low, the aanalytical precision of the middle and lower crust velocity is poor, and the deep imaging is difficult. Considering the above characteristics, in this thesis I carried out a few of studies on the key skills, for example the suppressing the deep seismic surface wave interference, deep reflection, wide angel reflection, jointly acquire the deep velocity structure through refraction travel time, constraining the deep structure by sub-vertical one-time cover section. And I applied these key skills to process the deep seismic reflection data of Qinling and obtained the structural framework and the deformational features of Dabashan-South Qinling crust and upper mantle. The research results and understandings I obtained were listed as follows:1. The surface wave attenuation technology to discriminate anomaly amplitude: under the condition that the low-frequency signals were not damaged, to make the energy of surface wave attenuated to the same level with the valid signal. On the basis of the energy features of the surface wave, preliminarily decomposed data into surface wave and valid signal in frequency domain, then to discriminate and collect the surface wave amplitude and the valid signal amplitude in the T-X domain through ZAP skill. The abnormal amplitude that was discriminated will be discomposed in multi-domain through gauss-seidel. The scale factor of the answer attenuated the surface wave in the shot domain and geophone domain. Finally, the attenuated surface wave data overlaid with valid signal; 2. Building the seismic sounding/deep seismic reflection and measuring line strata velocity technology:using CVI method, I established the initial velocity model through collect the superficial layer velocity structure that were overlaid velocity and the structure of the deep seismic sounding. Adopting delamination, I repeatedly iterated to successively simulate that the every layers velocity structure of self-excitation and self-receive section, common reflected points set, common shot channel set respectively from shallow to deep through the reflecting tomography update rate model and the ray tracing technology. The velocity of this layer was used to offset before the iteration or to conduct time-depth conversion on the stacked sections. Through verifying the model data and deep seismic reflection section of Liupanshan, the results were preferable.3. The one-time cover section technology of the sub-vertical reflection big shot: it is strong that the reflectional energy of the deep seismic reflection big shot and frequency band is wide. The scope of the sub-vertical reflection area was determined by predicting the velocity, dominant frequency, travel time of Moho. According to the sub-vertical reflection area of the big shot, the one-time cover section was established. However, the section must be along the deep seismic reflection measuring line and reflect deep structure. The one-time cover section will provide the quality control to the successively processing on the deep data. The one-time cover section technology of the sub-vertical reflection was applied to the Moho imaging of the deep seismic reflection on Liupanshan and Qinling area, and the preferable results have been achieved.4. For imaging the data of the deep seismic reflection section collected from the Qinling, a few of corresponding processing technologies were adopted. Through processing section, the structural framework of the deep seismic reflectional measuring line of the Qinling was attained. The evidence that the Sichuan Lithosphere subduct under the Qinling Lithosphere was captured. The evidence revealed the correlation between the Daba Mountain and the thrust faults of upper crust of the South Qinling. In addition, it demonstrated an angular unconformity plane between upper and lower crust of the South Qinling.