Elastic thickness, mechanical anisotropy and deformation of the southeastern Tibetan Plateau
Elastic thickness, mechanical anisotropy and deformation of the southeastern Tibetan Plateau
复制标题
青藏高原东南部的弹性厚度、力学各向异性与变形
DOI：
10.1016/j.tecto.2014.09.007
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发表时间：
2014-12
期刊：
影响因子：
2.9
通讯作者：
Jinsong Du
中科院分区：
文献类型：
--
作者：
Bo Chen;Jianxin Liu;Mikhail K. Kaban;Ya Sun;Chao Chen;Jinsong Du
它包含一个平缓倾斜的长波长边缘，并以强烈的变形和活跃的地震活动为特征。岩石圈的机械强度是控制任何地区变形和演化的参数之一。特别是强度的各向异性对于理解构造过程与岩石圈变形之间的关系具有重要意义。岩石圈有效弹性厚度Te可以作为岩石圈强度的空间分布和各向异性的表征。本文基于地形和布格重力异常资料，利用扇小波相干性方法确定了其各向异性变化。这也暗示了岩石圈变形的样式是连续的，并且可能以下地壳流动为主。这可能表明由于印度-欧亚板块的辐合和四川盆地的刚性阻力，高原内部形成了碰撞后的挤压构造。而在云南和印度支那北部，各向异性反映了高原外大约WNW-ESE方向的伸展应力，这可能与缅甸板块的俯冲过程有关。
The southeastern Tibetan Plateau (SE Tibet), located between the Eastern Himalayan Syntaxis and Sichuan Basin, is a heterogeneous structure combining different tectonic regimes. It encompasses a gently sloping long-wavelength margin, and is characterized by intense deformation and active seismicity. Mechanical strength of the lithosphere is one of the parameters that controls deformation and evolution of any region. In particular, anisotropy of the strength is important for understanding the relation between tectonic processes and lithosphere deformation. As a proxy, the effective elastic thickness of the lithosphere (Te) can be used to study both spatial distribution and anisotropy of the lithospheric strength. Here we use the fan wavelet coherence method to determine variations of Teand its anisotropy based on the topography and Bouguer gravity anomaly data. The coherence analysis shows that low Te(5–30 km) and high Teanisotropy are widespread in SE Tibet, indicating a weak and highly mechanical anisotropic lithosphere. This also implies that the style of lithospheric deformation is continuous, and may be dominated by lower crustal flow. Compared with the crustal stress and lithospheric strain indicators, we find that the Teanisotropy is predominantly governed by the present-day tectonic stress in SE Tibet. This may indicate a post-collision compression tectonics within the plateau due to the India–Eurasia plate convergence and a resistance by the rigid Sichuan Basin. However, the anisotropy reflects extension stresses in approximately WNW–ESE direction in Yunnan and northern Indochina off the plateau, which may relate to the Burma plate subduction processes. We infer that the present-day tectonic stresses and mantle processes associated with the India–Eurasia collision continuously modify and rework the mechanical structure, and both govern the lithospheric deformation in SE Tibet.
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影响因子：
64.8
作者：
BECHTEL, TD;FORSYTH, DW;GRIEVE, RAF
通讯作者：
GRIEVE, RAF
影响因子：
2.3
作者：
Lili Xu;S. Rondenay;R. Hilst
通讯作者：
Lili Xu;S. Rondenay;R. Hilst
DOI：
10.1016/0012-821x(95)00095-t
发表时间：
1995-08
期刊：
--
影响因子：
--
作者：
A. Watts;S. Lamb;J. Fairhead;J. Dewey
通讯作者：
A. Watts;S. Lamb;J. Fairhead;J. Dewey
影响因子：
5.3
作者：
F. Simons;R. Hilst
通讯作者：
F. Simons;R. Hilst
DOI：
10.1017/9781139027748
发表时间：
2001-10
期刊：
--
影响因子：
--
作者：
A. Watts
通讯作者：
A. Watts