Sequence Stratigraphy and Continental Margin Development of the Northwestern Shelf of the South China Sea
Sequence Stratigraphy and Continental Margin Development of the Northwestern Shelf of the South China Sea
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DOI：
10.1306/bdff8d76-1718-11d7-8645000102c1865d
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发表时间：
1993-05
期刊：
影响因子：
3.5
通讯作者：
Percy P. H. Chen;Zhi Chen;Qi Zhang
中科院分区：
文献类型：
--
作者：
Percy P. H. Chen;Zhi Chen;Qi Zhang
本文以南海西北陆缘第三系层序地层分析为基础，总结区域构造运动及其对盆地发育的影响，探讨陆缘生长过程中体系域的分布。研究区下方是两个第三纪盆地，被主要盆地边界断层隔开，断层上发育出两种截然不同的盆地结构样式。琼东南盆地具有特征性的断陷构造，与南海的开放密切相关。莺歌海盆地基底上覆有较厚的新近纪单斜岩，无明显裂谷构造。莺歌海的成因与红河缝合带沿线的构造活动有关。边缘发育的特点是沉积物流入不断超出可容纳空间的沉积环境。在这些环境下，高位三角洲经常在陆架边缘附近发育，其中高位三角洲和低位楔形/三角洲垂直堆积的浅水砂体可以产生有利的勘探目标。研究区域的高沉积率可以识别第四纪的四级旋回。区域层序地层对比表明，许多层序边界似乎是同步的，但并非所有边界都存在于中国大陆东部和南部大陆边缘的所有盆地中。边缘是通过低位扇、低位楔、海侵体系域和高位三角洲的反复发育而演变的。上新世之前，陆架主要来自越南和海南岛，因此形成了两个陆架边缘。西南缘在中新世晚期停止生长，而北缘则继续前移，可能通过第四纪红河系统输入额外的沉积物。
Based on the sequence stratigraphic analyses of the Tertiary in the northwestern continental margin of the South China Sea, this paper summarizes the regional tectonics and their influences on the basin developments and discusses the systems tract distributions through the continental margin growth. The study area is underlain by two Tertiary basins separated by a major basin boundary fault across which two distinctly different basin structural styles developed. The Qiongdongnan basin shows characteristic rift structures and is closely related to the opening of the South China Sea. The Yinggehai basin is filled with thick Neogene monoclines overlying basement without apparent rift structures. The Yinggehai's genesis has been linked to the tectonism along the Red River suture zone. The margin development is characterized by depositional environments of sediment influx constantly exceeding accommodation space. Under these environments, the highstand deltas frequently developed near shelf edges, where vertically stacked shallow water sands of both highstand deltas and lowstand wedges/deltas could produce favorable exploration targets. High rates of sedimentation in the study area allow the identification of fourth-order cyclicity in the Quaternary. Regional sequence stratigraphic correlations suggest that many sequence boundaries appear to be synchronous, but not all boundaries exist in all basins along the eastern and southern continental margins of mainland China. The margin evolved through the repeated development of lowstand fans, lowstand wedges, transgressive systems tracts, and highstand deltas. Prior to the Pliocene, the shelf was sourced both from Vietnam and Hainan Island and, as a result, two shelf margins developed. The southwestern margin stopped growing in the late Miocene, and the northern margin continued to prograde with possible additional sediment inputs through the Red River system in the Quaternary.