Crustal structure beneath the Dabie orogenic belt from ambient noise tomography
Crustal structure beneath the Dabie orogenic belt from ambient noise tomography
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环境噪声层析成像显示大别造山带下方的地壳结构
DOI：
10.1016/j.epsl.2011.11.004
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发表时间：
2012
影响因子：
5.3
通讯作者：
Yang Y.
中科院分区：
文献类型：
--
作者：
Luo Y.,;Xu Y.;Yang Y.
中国中东部的秦岭—大别—苏鲁造山带是世界上最大的高压和超高压变质带。大别山是华北克拉通与扬子克拉通之间造山带的中段。这项工作研究大别造山带下方的地壳结构性质，以更好地了解造山运动。为此，我们利用 2008 年 1 月至 2009 年 12 月期间中国国家地震台网 (CNSN) 40 个台站的环境噪声数据，对大别造山带应用环境噪声层析成像。我们通过对大多数台站对之间的环境噪声数据进行互相关来检索高信噪比 (SNR) 瑞利波，然后使用谱方法从这些互相关中提取相速度色散测量值。通过这些色散测量，我们获得了 8-35 秒周期的高分辨率相速度图。通过反演瑞利波相速度图，构建了大别造山带地壳的高分辨率三维剪切速度模型。由此产生的 3D 模型揭示了与造山运动相关的有趣的地壳特征。高剪切波速度在 HP/UHP 隐喻带下方 9 公里以下的深度处成像，表明 HP/UHP 隐喻岩石主要集中在上地壳。在高速HP/UHP变质带之下，在中地壳中观察到低剪切速度，可能代表在HP/UHP变质岩折返过程中形成的韧性剪切带和/或脆性断裂带。中地壳北大别杂岩体下方存在较强的高速，可能与碰撞后岩石圈拆沉和随后的岩浆作用导致中地壳侵入火成岩的冷却和结晶有关。大别东部地区出露了北倾的莫霍面，最深的莫霍面出现在大别杂岩体北部之下，这与三叠纪扬子克拉通向北俯冲到华北克拉通之下的模式一致。
The Qinling–Dabie–Sulu orogenic belt in east-central China is the largest high and ultrahigh pressure (HP and UHP) metamorphic zone in the world. The Dabie Mountains are the central segment of this orogenic belt between the North China and Yangtze cratons. This work studies the nature of the crustal structure beneath the Dabie orogenic belt to better understand the orogeny. To do that, we apply ambient noise tomography to the Dabie orogenic belt using ambient noise data from 40 stations of the China National Seismic Network (CNSN) between January 2008 and December 2009. We retrieve high signal noise ratio (SNR) Rayleigh waves by cross-correlating ambient noise data between most of the station pairs and then extract phase velocity dispersion measurements from those cross-correlations using a spectral method. Taking those dispersion measurements, we obtain high-resolution phase velocity maps at 8–35 second periods. By inverting Rayleigh wave phase velocity maps, we construct a high-resolution 3D shear velocity model of the crust in the Dabie orogenic belt. The resulting 3D model reveals interesting crustal features related to the orogeny. High shear wave velocities are imaged beneath the HP/UHP metaphoric zones at depths shallower than 9km, suggesting that HP/UHP metaphoric rocks are primarily concentrated in the upper crust. Underlying the high velocity HP/UHP metamorphic zones, low shear velocities are observed in the middle crust, probably representing ductile shear zones and/or brittle fracture zones developed during the exhumation of the HP/UHP metamorphic rocks. Strong high velocities are present beneath the Northern Dabie complex unit in the middle crust, possibly related to cooling and crystallization of intrusive igneous rocks in the middle crust resulting from the post-collisional lithosphere delamination and subsequent magmatism. A north-dipping Moho is revealed in the eastern Dabie with the deepest Moho appearing beneath the Northern Dabie complex unit, consistent with the model of Triassic northward subduction of the Yangtze Craton beneath the North China Craton.
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DOI：
10.1017/cbo9780511573088.002
发表时间：
1995
期刊：
--
影响因子：
--
作者：
R. Coleman;X. Wang
通讯作者：
R. Coleman;X. Wang
俯冲上大陆地壳的命运：一项实验研究
影响因子：
5.3
作者：
Fei, Yingwei;Jin, Zhenmin;Liu, Xiaoyang;Wu, Yao
通讯作者：
Wu, Yao
影响因子：
2.8
作者：
T. Yanovskaya;P. Ditmar
通讯作者：
T. Yanovskaya;P. Ditmar
影响因子：
3.4
作者：
H. Day;J. Liou;Lu Liangzhao
通讯作者：
H. Day;J. Liou;Lu Liangzhao
影响因子：
5.2
作者：
P. Xu;Futian Liu;Qingchen Wang;B. Cong;Hui Chen
通讯作者：
P. Xu;Futian Liu;Qingchen Wang;B. Cong;Hui Chen