古地理学报 ›› 2020, Vol. 22 ›› Issue (4): 775-784. doi: 10.7605/gdlxb.2020.04.052

• 第四纪古地理学及沉积学 • 上一篇    下一篇

南海北部深海盆地上中新统浊积砂体物源分析*

周俊燊1, 邵磊1, 乔培军1, 崔宇驰1, 孙珍2, 侯元立1, 杨逸凯1   

  1. 1 同济大学海洋地质国家重点实验室,上海 200092;
    2 中国科学院南海海洋研究所边缘海地质重点实验室,广东广州 510301
  • 收稿日期:2020-02-07 修回日期:2020-03-20 出版日期:2020-08-01 发布日期:2020-08-10
  • 通讯作者: 邵磊,男,1960年生,博士,同济大学教授,主要从事沉积学和沉积地球化学研究。E-mail: lshao@tongji.edu.cn。
  • 作者简介:周俊燊,男,1995年生,同济大学海洋与地球科学学院硕士研究生,海洋科学专业。E-mail: zjs@tongji.edu.cn。
  • 基金资助:
    *国家自然科学基金项目(标号: 41576059),国家科技重大专项(编号: 2016ZX05026004-002)以及国家重点研发计划项目(编号: 2018YFE0202400)联合资助

Provenance analysis of the Upper Miocene turbidite sand-bodies in deep-sea basin of northern South China Sea

Zhou Jun-Shen1, Shao Lei1, Qiao Pei-Jun1, Cui Yu-Chi1, Sun Zhen2, Hou Yuan-Li1, Yang Yi-Kai1   

  1. 1 State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China;
    2 CAS Key Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology, Chinese Academy of Sciences,Guangzhou,510301 China
  • Received:2020-02-07 Revised:2020-03-20 Online:2020-08-01 Published:2020-08-10
  • Contact: Shao Lei,born in 1960,Ph.D., is a professor of Tongji University. He mainly specializes in sedimentology and geochemistry. E-mail: lshao@tongji.edu.cn.
  • About author:Zhou Jun-Shen,born in 1995,is a master degree candidate of Tongji University. He majors in ocean science. E-mail: zjs@tongji.edu.cn.
  • Supported by:
    National Natural Science Foundation of China(No.41576059),the National Science and Technology Major Project(No.2016ZX05026004-002)and the National Key Research and Development Program of China(No.2018YFE0202400)

摘要: IODP367/368航次在南海北部深海盆地多个站位发现上中新统厚达数百米的大规模深海浊积岩。采用碎屑锆石U-Pb年龄谱系分析方法对U1500站上中新统浊积砂体进行源汇对比分析。研究结果表明U1500站上中新统浊积岩碎屑锆石年龄谱系与其西侧琼东南盆地和北侧珠江口盆地中新世沉积物特征类似。多维排列分析(MDS)结果也显示,该站位样品与珠江口盆地、琼东南盆地沉积物关系密切,表明南海北部深海盆地内厚达数百米的上中新统浊积砂体为南海北部物源和南海西部物源混合堆积形成。南海西部陆源输入物质以浊流搬运的方式,沿中央峡谷从西到东搬运至南海东部深海盆地;南海北部珠江物源以重力流的形式,经南海北部陆坡峡谷搬运至深海盆地中,两种来源的沉积物在深海盆地发生混合沉积,形成U1500站厚达数百米的浊积砂体。南海北部深海盆地厚层浊积砂体物质来源的准确识别,对深刻理解南海新生代盆地的构造演化、沉积物充填过程、物源演变以及古地理特征均具有重要意义。

关键词: 南海, 浊积岩, IODP, 碎屑锆石定年, 物源

Abstract: The International Ocean Discovery Program (IODP) Expedition 367/368 reported massive Upper Miocene deep-sea turbidite in the northern South China Sea basin. The Upper Miocene turbidite sand-bodies at Site U1500 were examined with detrital zircon U-Pb dating to conduct the source-to-sink analysis. This study shows that the U-Pb age spectrums of Site U1500 sample are similar to those detrital zircons from the Miocene Qiongdongnan Basin and the Pearl River Mouth Basin. Multidimensional scaling (MDS) plot also shows that the turbidite sand-bodies at Site U1500 are closely related to the sediments in the Pearl River Mouth Basin and Qiongdongnan Basin. It is likely that the thick deep-sea turbidite succession in the deep-water basin of northern South China Sea was formed by a mixed provenance pattern during the late Miocene. On the one hand, terrigenous sediments from the west of the South China Sea were transported along the Central Canyon to the eastern South China Sea deep-sea basin in the form of turbidity current. On the other hand, terrigenous sediments were also transported from the Pearl River through the slope canyon system to the northern South China Sea in the form of gravity flow . Those mixed sediments from two different source areas have collectively deposited at the deep-sea basin and thus, give rise to turbidite sequence of hundred meters. Provenance analysis of the thick turbidites sand-bodies in the deep-sea basin is of great significance to the profound understanding of the tectonic evolution, filling processes, provenance evolution, and the palaeogeographic characteristics of the Cenozoic basins of the South China Sea.

Key words: South China Sea, turbidite, IODP, detrital zircon dating, provenance

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