Optimizational Data Processing Of Deep Reflection Seismic Data And The Tectonic Significance Of Deep Reflection "Bright Spots" In Qiangtang Terrane

The deep reflection seismic profile technology has the advantages of high imaging precision and reliable detection information,and it is the pioneer technology to study the large-scale earth structure.Nowadays,more and more deep reflection seismic profiles were applied into the study of the fine structure of the continental crust.Since the introduction of the deep reflection seismic profile in the 1950 s,Chinese geophysicists have continued to study and apply this technology.The implementation of the national deep detection of special technology pushes the application of this technology to a new height.With the continuous improvement of deep reflection seismic imaging technology,the successful application of artillery seismic data acquisition technology,as well as geophysicist dig deeper into Qinghai-Tibetan Plateau research,more and more meaningful phenomena were constantly discovered,made a lot about the new understanding of the earth science of the Qinghai-Tibet Plateau.The Qiangtang terrane is located in the central Tibet.It is considered as the frontier areas of the collision between India and the Eurasian plate.The strong tectonic activity since the Mesozoic-Cenozoic makes its crustal structure very complicated.In the deep reflection seismic exploration of the Qiangtang terrane,geophysicist found that there are strong reflections in the upper and middle crustcalled "bright spots" of the deep reflections,these discoveries are important for the geological processes in the formation of the thick crust of the Qinghai-Tibetan Plateau.And it is essential to do some further research about these deep reflection "bright spots".In this paper,the data of the deep reflection seismic section in the south of Qiangtang terrane which is collected in 2004 are re-processed,and carefully analyzed the characteristicsof the original data.Through the optimization of the technology and the experiment of the parameters,we obtain a new treatment result profile,which greatly improved the signal-to-noise ratio compared with the old profile,and then we summed up a set of suitable fine data processing technology portfolio and processing programs for the Qinghai-Tibetan Plateau hinterland which has complex surface geological conditions,these researches lay a foundation for deep reflection "bright spots".Through the analysis of the strong reflection "bright spots" in the crust,we found that the phenomenon of "strong amplitude" and "polarity reversal".According to the fact of local "S wave attenuation" and Cenozoic volcanic rocks research results,this paper presents the basic viewpoints of the strong reflection "bright spots" structure in the southern part of the Qiangtang terrane and the magmatic activity in the process of crustal thickening,which promoted the Qinghai-Tibetan Plateau continental collision theory of deepening research,in a certain extent.