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本文利用北京大学在华北克拉通西部布设的一条东西方向流动地震观测台阵记录的远震资料,提取各台站P波接收函数,然后通过倾斜叠加(H|κ)、共转换点叠加(CCP)和偏移成像获得了横跨华北克拉通西部鄂尔多斯块体和祁连块体下方地壳和上地幔速度间断面的形态分布.研究结果显示,Moho面从东向西逐渐加深,与地形大致呈镜像关系,东部华北克拉通内部(鄂尔多斯地块)的地壳厚度为~40km,而最西部青藏高原内部(柴达木盆地)的地壳厚度为~65km.在祁连块体下方出现了剧烈地Moho面阶跃,我们推断这是因为柴达木盆地受到南北方向印度板块对欧亚板块的挤压,从而导致垂直方向上厚度的增加.对于上地幔660km速度间断面的成像显示,在30°~32°N|100~102°E范围内出现了加深,这可能与存在低温物质有关.通过对比其他学者利用体波成像和接收函数所获得的结果,我们推测660km速度间断面的加深可能是受印度板块在对应深度上的残留俯冲块体的影响所致.
In this paper, the teleseismic data recorded by an east-west mobile seismic observation array deployed by Peking University in the western part of North China Craton are used to extract the P wave reception functions at each station. Then, the P wave reception functions at each station are extracted, ) And offset imaging obtained the morphological distribution of velocity discontinuities between the Ordos block and the Qilian block beneath the western North China Craton.The results show that the Moho surface deepens gradually from east to west, The crustal thickness in the eastern North China Craton (Ordos block) is ~ 40 km, while that in the western part of the Qinghai-Xizang (Qaidam Basin) is ~ 65 km.At the lower part of the Qilian block, a dramatic Moho We conclude that this is because the Qaidam Basin was squeezed by the north-south India plate to the Eurasian plate, resulting in an increase in thickness in the vertical direction.For imaging of the 660km velocity upper mantle, 32 ° N | 100 ~ 102 ° E, which may be related to the existence of cryogenic materials.Comparing with other scholars using the body wave imaging and receiver functions obtained results, we speculate 660km speed Deepen cross-section of the body may be affected due to the Indian plate remains on the block corresponding to the depth of the dive.