Reassessing two contrasting Late Miocene-Holocene stratigraphic frameworks for the Pearl River Mouth Basin, northern South China Sea
Reassessing two contrasting Late Miocene-Holocene stratigraphic frameworks for the Pearl River Mouth Basin, northern South China Sea
复制标题
重新评估南海北部珠江口盆地两个对比鲜明的晚中新世-全新世地层框架
DOI：
10.1016/j.marpetgeo.2018.12.034
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发表时间：
2019
影响因子：
4.2
通讯作者：
Cheng-Shing Chiang
中科院分区：
文献类型：
--
作者：
Ming Su;Tiago Marcos Alves;Wei Li;Zhibin Sha;Kan-Hsi Hsiung;Jinqiang Liang;Zenggui Kuang;Nengyou Wu;Boda Zhang;Cheng-Shing Chiang
利用高分辨率二维/三维地震和生物地层资料，对南海北部珠江口盆地北坡晚中新世—全新世两个对比地层格架（SFI和SFII）进行了重新评价。SFII和SFII形成的主要地层边界（t1基第四纪和t2基上新世）深度不同。根据主要界线估计了晚中新世至第四纪的平均沉积速率趋势，以突出这两个格架之间的差异。地震资料表明，海底通道和体运沉积是南海北部及其他大陆边缘晚中新世—全新世盆地发育的有效地层标志。神狐地区水合物钻探点沉积物由两个岩性和粒度相似的异质沉积单元组成：a)底部为细粒浊积岩，b)顶部为细粒海底滑坡。由于中下陆坡上广泛存在的物质损耗，相对较小的纳米化石组合可能会被重新加工。本研究的一个关键结果是，基于地震和层序地层资料的地层格架更适合于整个北坡的地层对比。研究结果为重建PRMB的构造-沉积演化以及解决研究区晚中新世-全新世地层格架的不确定性提供了坚实的基础。
High-resolution 2D/3D seismic and biostratigraphic data are used to reassess two contrasting Late Miocene-Holocene stratigraphic frameworks (SFI and SFII) for the northern slope of the Pearl River Mouth Basin (PRMB), northern South China Sea. The major stratigraphic boundaries (T1-base Quaternary and T2-base Pliocene) derived from SFI and SFII are different in depth. The trends of average sedimentation rates from Late Miocene to Quaternary were estimated according to the major boundaries in order to highlight the differences between these two frameworks. The seismic reflection terminations as erosional and truncation features were recognized through the seismic data implying that the submarine channels and mass-transport deposits are valid stratigraphic markers of Late Miocene-Holocene basin development on the northern South China Sea margin and other continental margins. The sediments from hydrate drilling sites in the Shenhu Area consist of two allochthonous sedimentary units with similar lithology and grain sizes: a) fine-grained turbidites at the bottom, and b) fine-grained submarine landslides at the top. Nannofossil assemblages with relatively minute sizes were likely to be reworked due to the setting of widespread mass wasting on the middle to lower continental slope. A key result of this study is that the stratigraphic framework based on a combination of seismic and sequence stratigraphic data is more suitable for stratigraphic correlations across the northern slope of the PRMB. Our findings provide a robust foundation to rebuild the tectono-sedimentary evolution of the PRMB and also resolve the uncertainties in the Late Miocene-Holocene stratigraphic frameworks of the study area.