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在大别造山带深地震测深剖面H维P波地壳速度结构的基础上,从地震记录的水平分量得到S波地壳速度结构,并用P波和S波的资料共同约束地壳的组成.剖面上大多数炮点的记录均显示了清晰的Sg和SmS震相.在埠塔寺炮和金拱炮的记录上还较清晰地显示出莫霍界面的反射转换震相PmS,表明在相应的范围内莫霍界面是一级间断面.在Pn和SmS震相都比较强的记录截面图上缺少相应的Sn震相,表示在上地幄顶部泊松比随深度急剧增大,在这一深度上物质可能存在局部熔融状态.剖面的地壳泊松比模型表明,上地壳在深度10km以内泊松比为025左右,仅北淮阳弧后复理石带较低,为0.23；扬子板块和华北板块的下地壳泊松比为0.26-0.27；在大别选山带,上地壳下部泊松比为0.22-0.24,而下地壳泊松比为0.27-0.30,其中超高压变质带最高.P、S波速度和泪松比表明超高压变质带下地壳主要由基性麻粒岩组成.大别造山带中、下地壳组成的横向不均匀性反映了在三叠纪造山作用期间扬子板块向华北板块俯冲,以及存在与地慢物质相联系的岩浆侵入体.
Based on the H-dimensional P-wave crustal velocity structure of the deep seismic sounding profile in the Dabie orogenic belt, the S-wave crustal velocity structure is obtained from the horizontal components of the seismic record, and the composition of the crust is constrained by P-wave and S-wave data. The records of most of the shots showed a clear Sg and SmS phase.The PmS reflectance phase PmS was also clearly shown on the port pagoda and gold dome guns, indicating that within the corresponding range The Nemo-Moho interface is a first-order discontinuity, and the corresponding Sn-phase is absent on the recording profiles with strong Pn and SmS phases, indicating that the Poisson’s ratio increases sharply with depth at the top of the Shangdihu area. At this depth The material may exist locally melted.The Poisson’s ratio model of the crust shows that the Poisson’s ratio of the upper crust is about 025 in the depth of 10km and only 0.23 after the Beihuaiyang arc only 0.23.The Yangtze plate and the North China In the Dabie Mountains, the Poisson’s ratio of the lower crust is 0.22-0.24, while that of the lower crust is 0.27-0.30, in which the UHP metamorphic belt is the highest, P, The S-wave velocity and tearing ratio show that the crust beneath the UHPM metamorphic belt is mainly composed of the basic granulite The horizontal heterogeneity of the lower crust in the Dabie orogenic belt reflects the subduction of the Yangtze plate to the North China plate during the Triassic orogeny and the magmatic intrusion associated with the slow materials.