Broadland Seismological Research And Deep Structure From Fuyun To Kuerle

Tianshan orogen, which is away from the plate collision boundary, is one ofIntra-continental collision orogen rifting from Triassic Period up to the present. Themechanism of uplift and curst incrassation will provide dynamics evidence atlithosphere scale for the formation and evolvement of Tianshan orgoen and its controlto formation and distribution of dominant metal mineral resources. The thesis achievessome new apperception by using teleseismic receiver function migrated images aboutcrust and upper mantle structure, especially the spatial variation of the Moho along atight array apanning from Kuerle to Fuyun. The main points consists:1. On the basis of fully understanding the effect of lower velocity layer at thesurface, the real "incidence" angle of P wave at the free surface is obtained accordingto the rule that the amplitude of Q component in L,Q,T coordinate system at time ofP arrive is zero. The frequency band is selected to eliminate the effect of phasicmigration. A program based on Matlab platform is accomplished by adopting theprocessing schemes designed by Kosarev et al.2. The collision between India plate and Eurasia plate not only brings upQinghai-Tibet plateau but also has large effect on the development of Tianshan orogenfar away from collision belt. Crust and lithosphere in Tianshan region take placerupture, overlap and intersect just because of jiostling from north and south.3. The complicated region in structure with large depth and overlap Mohoconverters is just about the modern seismic activity belt. The depth of the structureactivity belt is about 100km. Lithosphere structure presents stratum under the depth100km. Moreover, the image in north part of the profile gives some evidence ofunderthrusting of lithosphere to north under Altai.4. A number of steep angle deep faults were deduced according to thediscontinous converters. We do not connect them with the faults seen in the earth'ssurface for there are not enough earthquake data in depth. Steep angle deep faults atleast indicate structure difference created by asymmetry stress that results indiscontinuous distribution of all kinds of converters in each region.5. The tomography results under west Tianshan obviously reveal the northdipping of high velocity material of Tarium basin to the deep part of North Tianshanand south dipping with large angle of high velocity material of Junggar basin. Uplift ofTianshan and its corresponding incidence extend to about 200km. That is to say,structure actuality in west Tianshan is stronger than that in the region of this profile.