Detrital zircon provenance record of the Oligocene Zhuhai Formation in the Pearl River Mouth Basin, northern South China Sea
Detrital zircon provenance record of the Oligocene Zhuhai Formation in the Pearl River Mouth Basin, northern South China Sea
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南海北部珠江口盆地渐新统珠海组碎屑锆石物源记录
DOI：
10.1016/j.marpetgeo.2018.08.032
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发表时间：
2018
影响因子：
4.2
通讯作者：
Liang Xirong
中科院分区：
文献类型：
--
作者：
Wang Ce;Wen Shunv;Liang Xinquan;Shi Hesheng;Liang Xirong
渐新统珠海组是南海北方珠江口盆地的主要储层之一，但其物源问题一直存在争议。本文通过对珠海组碎屑锆石U-Pb分析，系统研究了渐新世珠海组的物源，探讨了渐新世珠海组的沉积物源，建立了渐新世珠海组物源变化的格架。研究表明，不同构造单元中的碎屑锆石显示出明显的年龄组成空间差异，这与来源的变化有关。盆地西部和东部的碎屑沉积物的年龄组成表明，有一个显着不同的物源。盆地西部总体上具有相对复杂的年龄谱，具有多峰分布的特征，表明主要物源来自华南地块南缘。相反，东部盆地显示了一个占主导地位的人口范围从131至142马，这意味着沉积物主要是从附近的源侵蚀。研究表明，珠江口盆地在渐新世的物源主要来自华夏陆块腹地和盆内物源。此外，海南岛和越南中部（印度支那地块东部）似乎并不是重要的来源，而吕宋岛和北方巴拉望在同一时期可能提供了微不足道的贡献盆地。
The Oligocene Zhuhai Formation has been proven to be one of the main reservoirs in the Pearl River Mouth Basin in the northern South China Sea but its sedimentary provenance remains uncertain and controversial. Here we conducted a systematic study by U-Pb analysis of detrital zircon of the Zhuhai Formation in order to identify the source terrane, investigate the sedimentary source, and establish the framework for the provenance variation during the Oligocene. The study suggests that the detrital zircon in the different structural units reveal marked spatial differences in their age compositions that correlate with the changing sources. The western and eastern parts of the basin have a significantly different provenance manifested by the age compositions of the detrital sediments. The western basin generally has a relatively complex age spectrum and is characterized by a multi-peak distribution, suggesting that the main source was derived from the southern margin of the South China Block. In contrast, the eastern basin displays a dominant population ranging from 131 to 142 Ma, which implies that the sediments were mainly eroded from a nearby source. Our data demonstrate that the Cathaysia Block hinterland and the intrabasinal sources provided dominant provenance contributions to the Pearl River Mouth Basin during the Oligocene. Additionally, Hainan Island and Central Vietnam (eastern Indochina Block) do not appear to have been important sources, whereas Luzon Island and northern Palawan probably provided negligible contributions to the basin during the same time period.