Seismic structure of the northwestern margin of the South China Sea: implication for asymmetric continental extension
Seismic structure of the northwestern margin of the South China Sea: implication for asymmetric continental extension
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南海西北缘地震结构：大陆不对称伸展的意义
DOI：
10.1093/gji/ggz219
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发表时间：
2019-05
影响因子：
2.8
通讯作者：
Tianyao Hao
中科院分区：
文献类型：
--
作者：
Haibo Huang;Xuelin Qiu;Thibaud Pichot;Frauke Klingelhoefer;Minghui Zhao;Ping Wang;Tianyao Hao
南海大陆边缘的演化是讨论大陆裂解和海底扩张时的一个开放性问题。通过对穿越南海西北缘的广角地震剖面（OBS 2011 -1）的数据进行处理，并进行走时建模，获得了地震速度结构。模拟结果表明，地壳厚度从大陆边缘到洋盆呈阶梯状变化。沿中沙海槽，上地壳的拉伸因子比沿着下地壳的估计值高出近一倍。下地壳表现出向海槽中心的不对称上涌，并伴随着由于岩浆的加入而导致的约0.3 kms（-1）的速度增加。在陆块之下，上、下地壳的伸展因子基本相同，表明伸展作用是一致的。西南次海盆共轭边缘的地壳结构表现出相似的速度范围和不同的厚度分布，支持这两个边缘的共同起源和不对称延伸。大洋-大陆过渡带（OCT）在南部（约50 km）比跨越边缘的北方（约25 km）宽得多。我们提出了一个构造模型的共轭边缘和OCT的不对称性，有利于高度拉伸的上地壳，并伴随着上升的韧性中下地壳控制的主要低角度断层。刚性块体也可能对断裂的进一步发展起到阻碍作用，影响OCT的形状。
Evolution of the continental margins of the South China Sea (SCS) is one of the open questions when discussing continental breakup and seafloor spreading. We processed data from a wide-angle seismic profile (OBS2011-1), which passes through the northwestern margin of the SCS, and performed travel time modelling to obtain the seismic velocity structures. The modelling results show a stepwise variation of the crustal thicknesses from continental margin to oceanic basin. Stretching factor of the upper crust is nearly double the estimate of the lower crust along the Zhongsha Trough. The lower crust shows asymmetrical upwelling towards the trough center, accompanied by similar to 0.3 kms(-1) of the velocity increase due to magmatic addition. The upper and lower crusts have almost the same stretching factor beneath continental blocks, indicating a uniform extension. Crustal structures of the conjugate margins of the Southwest Subbasin show similar velocity range and different thickness distribution, supporting the common origin and asymmetric extension of these two margins. The Ocean-Continent Transition zones (OCT) are much wider in the southern part (similar to 50 km) than the northern part (similar to 25 km) crossing the margins. We propose a tectonic model for the asymmetry of both the conjugate margins and the OCTs, favoring the highly stretched upper crust and accompanied by rising of the ductile middle-lower crust controlled by major low-angle faults. The rigid blocks may also act as a kind of hindrance for further evolution of the failed rifts and affect the shape of the OCT.
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影响因子：
2.9
作者：
Y. Pin;Z. Di;Zhao-shu Liu
通讯作者：
Y. Pin;Z. Di;Zhao-shu Liu
影响因子：
5.3
作者：
Guoliang Zhang;Qing Luo;Jian Zhao;M. Jackson;Lishuang Guo;Li-feng Zhong
通讯作者：
Guoliang Zhang;Qing Luo;Jian Zhao;M. Jackson;Lishuang Guo;Li-feng Zhong
DOI：
10.1002/jgrb.50318
发表时间：
2013-08
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
A. Leprêtre;Frauke Klingelhoefer;D. Graindorge;P. Schnurle;M. Beslier;K. Yelles;J. Déverchère;R. Bracène
通讯作者：
A. Leprêtre;Frauke Klingelhoefer;D. Graindorge;P. Schnurle;M. Beslier;K. Yelles;J. Déverchère;R. Bracène
DOI：
10.1007/s11430-011-4324-9
发表时间：
2011
期刊：
Science China Earth Sciences
影响因子：
--
作者：
Zhenli Wu;Jiabiao Li;A. Ruan;Hai Lou;W. Ding;X. Niu;Xibing Li
通讯作者：
Zhenli Wu;Jiabiao Li;A. Ruan;Hai Lou;W. Ding;X. Niu;Xibing Li
DOI：
--
发表时间：
2012
期刊：
Journal of Tropical Oceanography
影响因子：
--
作者：
Zhang Yunfan;Hua Dengke;Wang Wan-yin;Qiu Zhi-yun;L. Fucheng
通讯作者：
Zhang Yunfan;Hua Dengke;Wang Wan-yin;Qiu Zhi-yun;L. Fucheng