Complicated crustal deformation beneath the NE margin of the Tibetan plateau and its adjacent areas revealed by multi-station receiver-function gathering
Complicated crustal deformation beneath the NE margin of the Tibetan plateau and its adjacent areas revealed by multi-station receiver-function gathering
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多站接收函数采集揭示青藏高原东北缘及邻区复杂地壳形变
DOI：
10.1016/j.epsl.2018.06.010
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发表时间：
2018-09
影响因子：
5.3
通讯作者：
Qifu Chen
中科院分区：
文献类型：
--
作者：
Xiaoming Xu;Fenglin Niu;Zhifeng Ding;Qifu Chen
对于阵列中的每个台站，我们收集了该台站及其附近台站记录的所有接收函数，这些台站位于一个半径为0.5°的圆内。我们将H-κ叠加技术和联合反演方案应用于总共654个站簇，分别测量（H, κ）和（φ, τ）。测得的莫霍深度从中北部高原下方67 km的峰值到东北部周围地块下方39-45 km的峰值不等。边缘下增厚的地壳也有很低的Vp/Vs，表明地壳主要由长英质矿物组成。超过三分之一的站点集群（221个）的分裂时间显著大于0.2 s。221次测量的平均分裂时间为0.68s，与SKS/SKKS （XKS）相的平均分裂时间（0.94 s）相当。边界内台站群记录的Moho p和XKS相估算的快速方向非常相似，也与该地区主要断层、缝合线和逆冲锋面的走向大致平行。较低的Vp/Vs比值，再加上从Moho Ps和XKS阶段观测到的快速极化方向，表明整个岩石圈垂直于挤压方向的缩短可能是导致观测到的地壳在边缘增厚的主要原因。此外，银川盆地和河套盆地西部的Moho p和XKS各向异性差异很大，这可能表明两个盆地下的地壳和地幔具有不同的变形模式。
We use a multi-station stacking method to analyze receiver function data recorded by a large-scale dense seismic array covering the northeastern (NE) margin of the Tibetan plateau and its adjacent regions to estimate crustal thickness (H), Vp/Vs ratio (κ) and crustal anisotropy (fast polarization direction φ and splitting time τ). For each station of the array, we gathered all the receiver functions recorded by the station and its nearby stations located inside a circle with a radius of 0.5°. We applied the H-κ stacking technique and the joint inversion scheme to a total of 654 station clusters to measure the (H, κ) and (φ, τ), respectively. The measured Moho depth varies from a peak value of 67 km beneath the northern-central plateau to 39-45 km beneath the surrounding blocks in the northeast. The front of the depressed Moho beneath the plateau margin exhibits a complicated geometry, which suggests that when the Tibetan plateau encroached upon the surrounding terrenes, the front expanded unevenly depending on the strength of the encountering terranes. The thickened crust beneath the margin also has a very low Vp/Vs ratio, indicating that the crust is composed largely of felsic minerals. More than one third of the station clusters (221) have a splitting time significantly larger than 0.2 s. The average splitting times of the 221 measurements is 0.68s, which is comparable to those measured from the SKS/SKKS (XKS) phases (0.94 s). The fast directions estimated from the Moho Ps and XKS phases recorded by the station clusters within the margin are very similar, and are also approximately parallel to the strikes of major faults, sutures and thrust fronts in the area. The low Vp/Vs ratio, together with the observed fast polarization directions from the Moho Ps and XKS phases, suggests that shortening of the entire lithosphere orthogonal to the compressional direction is likely the main cause for the observed crustal thickening occurring at the margin. We also found that the Moho Ps and XKS recorded by stations inside the western Hetao basin and the Yinchuan basin present very different anisotropy, which may suggest that the crust and mantle beneath the two basins have very different deformation patterns.
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远震接收函数数据约束的青藏高原东北缘地壳结构与变形
影响因子：
2.8
作者：
Wang Q;Niu F L;Gao Y;Chen Y T
通讯作者：
Chen Y T
影响因子：
5.3
作者：
Weilai Wang;Jianping Wu;L. Fang;Guijuan Lai;Y. Cai
通讯作者：
Weilai Wang;Jianping Wu;L. Fang;Guijuan Lai;Y. Cai
DOI：
10.1002/cjg2.1330
发表时间：
2009
期刊：
Chinese Journal of Geophysics
影响因子：
--
作者：
Yufen Zhang;Chang‐An Li;Liang Chen;Chunguo Kang;Sihui Hu;Junzhou Huo;Lingling Yan;Xuemei Cheng
通讯作者：
Yufen Zhang;Chang‐An Li;Liang Chen;Chunguo Kang;Sihui Hu;Junzhou Huo;Lingling Yan;Xuemei Cheng
根据S接收函数和SKS分裂测量推断青藏高原东北部岩石圈厚度和上地幔变形
影响因子：
2.8
作者：
Zhang, Hongshuang1, 2;Teng, Jiwen2;Tian, Xiaobo2;Zhang, Zhongjie2;Gao, Rui1;Liu, Jiaqi2
通讯作者：
Liu, Jiaqi2
影响因子：
2.8
作者：
KENNETT, BLN;ENGDAHL, ER
通讯作者：
ENGDAHL, ER