Upper mantle anisotropy beneath North China from shear wave splitting measurements
Upper mantle anisotropy beneath North China from shear wave splitting measurements
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剪切波分裂测量华北地区上地幔各向异性
DOI：
10.1016/j.tecto.2011.12.009
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发表时间：
2012-02
期刊：
影响因子：
2.9
通讯作者：
Ding, Zhifeng
中科院分区：
文献类型：
--
作者：
Chang, Lijun;Wang, Chun-Yong;Ding, Zhifeng
利用远震资料的偏振分析方法，确定了部署在北中国克拉通的52个临时和永久宽带地震台网的SKS快偏振方向和快、慢剪切波之间的延迟时间。分析采用了Silver和Chan(1991)和堆积分析方法。用这种方法得到了NCC内上地幔各向异性的图像。快速极化方向在东部和中部地块沿WNW-ESE方位旋转，在西部地块沿NNW-SSE方位旋转。东、中地块和西地块的平均快极化方向分别为107±9°和153±12°。东区和中区平均延迟时间为0.98±0.19s，西区为0.75±0.17s。在东部和中部地块，快速极化方向与绝对板块运动(APM)方向一致，表明APM驱动的WNW向软流圈地幔流动对东部和中部地块下观测到的上地幔各向异性起主要作用，使上地幔橄榄岩晶格的排列平行于变形方向，从而一致地产生WNW方向的快速极化方向。然而，在稳定的西部地块，观测到的弱各向异性可能归因于冻结在古克拉通NCC厚岩石圈中的“化石”各向异性。
Polarization analysis of teleseismic data was used to determine the SKS fast polarization directions and the delay times between the fast and slow shear waves for each of the 52 seismic stations from both temporary and permanent broadband seismograph networks deployed in the North China Craton (NCC). The analysis employed both the Silver and Chan (1991) and stacking analysis methods. In this way, an image of upper mantle anisotropy in the NCC was acquired. The fast polarization directions are oriented along a WNW–ESE azimuth in the Eastern and Central Blocks and rotate to a NNW–SSE azimuth in the Western Block. The average fast polarization directions in the Eastern and Central Blocks and the Western Block are 107±9° and 153±12°, respectively. The average delay time in Eastern and Central Blocks is 0.98±0.19s, whereas it is 0.75±0.17s in the Western Block. In the Eastern and Central Blocks, the fast polarization direction is consistent with the absolute plate motion (APM) direction, implying that the WNW-trending asthenospheric mantle flow driven by the APM plays a major role in observed upper mantle anisotropy beneath the Eastern and Central Blocks, and makes the alignment of upper mantle peridotite lattice parallel to the deformation direction, and thus generates consistently the WNW-trending fast polarization direction. However, in the stable Western Block, the weak anisotropy observed is possibly attributed to the “fossil” anisotropy frozen in the thick lithosphere of ancient cratonic NCC.
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DOI：
10.1002/cjg2.694
发表时间：
2005-05
期刊：
Chinese Journal of Geophysics
影响因子：
--
作者：
Wen-yao Xu;Zigang Wei;G. Xia
通讯作者：
Wen-yao Xu;Zigang Wei;G. Xia
DOI：
10.1086/422668
发表时间：
2004-09
期刊：
The Journal of Geology
影响因子：
--
作者：
Yigang Xu;Sun‐Lin Chung;Jinlong Ma;Lanbin Shi
通讯作者：
Yigang Xu;Sun‐Lin Chung;Jinlong Ma;Lanbin Shi
影响因子：
3
作者：
L. Vinnik;V. Farra;B. Romanowicz
通讯作者：
L. Vinnik;V. Farra;B. Romanowicz
影响因子：
5.3
作者：
Zhouchuan Huang;Liangshu Wang;Dapeng Zhao;N. Mi;Mingjie Xu
通讯作者：
Zhouchuan Huang;Liangshu Wang;Dapeng Zhao;N. Mi;Mingjie Xu
影响因子：
3.8
作者：
Guochun Zhao;S. Wilde;Peter A. Cawood;M. Sun
通讯作者：
Guochun Zhao;S. Wilde;Peter A. Cawood;M. Sun