热带海洋学报 ›› 2026, Vol. 45 ›› Issue (5): 80-93.doi: 10.11978/2025246CSTR: 32234.14.2025246

• 海洋地质学 • 上一篇    下一篇

南沙群岛新近纪碳酸盐台地中的微体化石及其意义*

苏翔1,2(), 向荣1,2(), 易亮3, 张强1,2, 张亚南4, 秦国权5, 万随1,2, 颜文1,2,6()   

  1. 1 中国科学院南海海洋研究所, 热带海洋环境与岛礁生态全国重点实验室, 广东 广州 511458
    2 中国科学院南海海洋研究所, 边缘海与大洋地质实验室, 广东 广州 511458
    3 同济大学海洋地质全国重点实验室, 上海 200092
    4 中国科学院广州地球化学研究所, 深地过程与战略矿产资源全国重点实验室, 广东 广州 510640
    5 中国海洋石油总公司南海东部石油公司, 广东 广州 510240
    6 中国科学院大学, 北京 100049
  • 收稿日期:2025-12-20 修回日期:2026-02-07 出版日期:2026-09-10 发布日期:2026-10-13
  • 通讯作者: 向荣, 颜文
  • 作者简介:

    苏翔(1984—), 男, 副研究员, 主要从事微体化石与古海洋学研究。email:

    * 感谢贵州省地质矿产局115地质调查大队、中国科学院南海海洋研究所岛礁中心及其同事、中国科学院南京地质古生物研究所祝幼华研究员和李保华研究员对本研究样品采集、实验方法和数据处理的贡献和支持。

  • 基金资助:
    国家重点研发计划项目(2021-06); 国家重点研发计划项目(2022-24); 国家自然科学基金面上项目(42476066)

Microfossils in the Neogene carbonate platform of Nansha Islands and their significance*

SU Xiang1,2(), XIANG Rong1,2(), YI Liang3, ZHANG Qiang1,2, ZHANG Yanan4, QIN Guoquan5, WAN Sui1,2, YAN Wen1,2,6()   

  1. 1 South China Sea Institute of Oceanology, Chinese Academy of Sciences, State Key Laboratory of Tropical Oceanography, Guangzhou 511458, China
    2 South China Sea Institute of Oceanology, Chinese Academy of Sciences, Laboratory of Ocean and Marginal Sea Geology, Guangzhou 511458, China
    3 State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
    4 Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, State Key Laboratory of Deep Earth Processes and Resources, Guangzhou 510640, China
    5 CNOOC South China Sea Eastern Petroleum Corporation, Guangzhou 510240, China
    6 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2025-12-20 Revised:2026-02-07 Online:2026-09-10 Published:2026-10-13
  • Contact: XIANG Rong, YAN Wen
  • Supported by:
    National Key Research and Development Program of China(2021-06); National Key Research and Development Program of China(2022-24); National Natural Science Foundation of China(42476066)

摘要:

生物礁是生产力水平最高、生物多样性最丰富的生态系统之一, 对全球碳循环至关重要。南海发育了西太平洋最大的碳酸盐台地, 在南沙群岛美济环礁上钻取的全取心井——南科1 (NK-1)井, 为评估南海生物礁的长期演化提供了良好机会。为了揭示南沙群岛的演化历史及其控制因素, 需要对NK-1井建立更可靠的年龄约束。文章提供了NK-1井生物礁碳酸岩中微体化石(钙质超微化石、有孔虫和放射虫)丰度和多样性的新记录, 基于微体化石组合, 在NK-1井序列中识别出7个生物地层事件, 揭示了从早中新世到更新世的连续沉积序列。通过结合古地磁年代数据, 重建了南沙群岛碳酸盐台地的发育和演化。NK-1井生物礁序列的底界年龄估计为(23.03±1.06)Ma, 接近渐新世/中新世边界。新的年代地层格架揭示了3个短暂的沉积间断(3.6—2.4Ma、11.1—10.0Ma和 13.5—11.9Ma), 它们分别与210.3m、464.6m和561.6m处的显著暴露面良好对应。通过与南沙和西沙群岛生物礁深钻岩心的地层和堆积速率记录对比, 揭示了南海自新近纪以来极其相似的碳酸盐台地演化历史。结果表明, 南海碳酸盐台地的发育经历了晚渐新世/早中新世初始阶段、早—中中新世快速生长阶段、中—晚中新世侵蚀阶段、中新世—上新世稳定发育阶段和第四纪快速生长阶段, 主要受全球海平面变化、环境因素和区域构造运动(如南海海盆扩张、沙巴造山运动和东沙运动)的影响。

关键词: 碳酸盐台地, 微体化石, 构造运动, 海平面变化, 南海

Abstract:

Biogenic reefs are among the most productive and biodiverse ecosystems, and are critical to global carbon cycling. The South China Sea (SCS) has developed the largest carbonate platforms in the Western Pacific. The fully-cored Well NK-1, drilled through the reef complex on the Meiji Atoll, Nansha Islands, offers a good opportunity for assessing the long-term evolution of biogenic reefs in the SCS. To reveal the evolution history of Nansha Islands and their controlling factors, more credible age constraints on core NK-1 are needed. This research presents new records of microfossils (calcareous nannofossils, foraminifera and radiolarians) abundances and diversities in the biogenic reef carbonates of core NK-1. Based on the assemblages of the microfossils, seven biostratigraphic events are recognized from the sequence of core NK-1, revealing a general continuous succession of the Early Miocene to Pleistocene age. Combined with the magnetostratigraphic data, the development and evolution of carbonate platform in the Nansha Islands are reconstructed. The bottom age of the biogenic reef sequence of NK-1 is estimated at (23.03 ± 1.06) Ma, close to the Oligocene/Miocene boundary. The new chronostratigraphic framework highlights three short hiatuses of 3.6—2.4 Ma, 11.1—10.0 Ma, and 13.5—11.9 Ma, which are well correlated with the prominent exposed surfaces at 210.3 m, 464.6 m and 561.6 m, respectively. These records reveal a remarkably similar evolutionary history of carbonate platforms in the SCS since Neogene, by comparison with stratigraphic records and growth rates from deep drilling cores on isolated coral reefs in Nansha and Xisha Islands. The results show that carbonate platform development in the SCS experienced five phases: Late Oligocene / Early Miocene initiation phase, Early-Middle Miocene rapid growth phase, Middle-Late Miocene erosion phase, Miocene-Pliocene stable development phase, and Quaternary rapid growth phase, which were mainly influenced by global sea-level changes, environmental factors and regional tectonism such as the SCS basin spreading, the Sabah Orogeny and the Dongsha Movement.

Key words: carbonate platform, microfossils, tectonic movement, sea-level change, South China Sea

中图分类号: 

  • P736.221