A comparison of crustal stretching characteristics between northern and southern slopes of the South China Sea
A comparison of crustal stretching characteristics between northern and southern slopes of the South China Sea
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发表时间：
2012
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通讯作者：
Zhang Yunfan;Hua Dengke;Wang Wan-yin;Qiu Zhi-yun;L. Fucheng
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作者：
Zhang Yunfan;Hua Dengke;Wang Wan-yin;Qiu Zhi-yun;L. Fucheng
南中国海共轭大陆边缘不仅具有丰富的油气储量，而且记录了南中国海的扩张过程。本文选取了5条北坡和南坡的长深水多道地震反射剖面，根据不同的初始地壳流变结构，计算了沿该剖面的伸展因子。通过将计算结果与数值模拟得到的陆缘的相关/各自的地壳演化过程进行对比，我们认为：首先，北坡的地壳伸展强于南坡，代表了中生代以来两者不同构造的可证明性，后者也可能与南缘的后挤压和碰撞有关。其次，地震剖面分别横跨南北斜坡的珠江盆地和礼乐盆地具有不同的初始地壳结构，在南中国海共轭边缘的形成过程中两者的演化历史不一致。此外，南坡的地壳伸展因子向南增大，与盆地扩张原理不符，这可能是古南中国海板块向南俯冲的标志。
The conjugate continental margins of the South China Sea are being studied increasingly not only for their reserves of oil and gas but also for the data that recorded the processes of expansion of the South China Sea.In this study,five long deep-water multi-channel seismic reflection profiles from both northern and southern slopes are selected to calculate the stretching factors along the profiles based on various initial crustal rheological structures.By comparing the results and the related/respective crustal evolution processes of the margins from the numerical simulation,we propose the following.First of all,the crustal extension of the northern slope is stronger than the southern slope,representing provability of different tectonics between the two since the Mesozoic Era,the latter of which could also be related to the post-extrusions and collisions on the southern margin.Secondly,the Pearl River Basin and Liyue Basin on the northern and southern slopes,respectively, crossed by the seismic profiles,had different initial crustal structures and in turn the evolution histories of the two were inconsistent during the formation of the South China Sea conjugate margins.Moreover,the crustal stretching factor of the southern slope becomes greater toward south,showing no compliment with the principle basin expansion theories.This could be indicative to the southward subduction of the paleo-South China Sea plate.