热带海洋学报 ›› 2026, Vol. 45 ›› Issue (5): 128-145.doi: 10.11978/2026040CSTR: 32234.14.2026040

• 海洋地质学 • 上一篇    下一篇

基于数值模拟的环礁形成与发育演化研究

刘金龙1,2(), Jody Webster3, Tristan Salles3, 王淑红1,2, 马一开4, 徐维海1,2, 黎刚1,2, 颜文1,2,5()   

  1. 1 热带海洋环境与岛礁生态全国重点实验室(中国科学院南海海洋研究所), 广东 广州 510301
    2 中国科学院南海海洋研究所边缘海与大洋地质重点实验室, 广东 广州 510301
    3 悉尼大学地球科学学院, 澳大利亚 悉尼 2006
    4 国家海洋局南海标准计量中心, 广东 广州 510300
    5 中国科学院大学, 北京 100049
  • 收稿日期:2026-03-02 修回日期:2026-03-23 出版日期:2026-09-10 发布日期:2026-10-13
  • 通讯作者: 颜文
  • 作者简介:

    刘金龙(1987—), 男, 山东省德州市人, 副研究员, 从事珊瑚礁发育演化和海底冷泉与天然气水合物研究。email:

  • 基金资助:
    国家重点研发计划项目(2021-06); 国家自然科学基金专项项目(L2424234); 中国科学院国防科技创新专项重点部署项目(KGFZD-145-26-36)

The formation of atolls: new insights from numerical simulations

LIU Jinlong1,2(), Jody Webster3, Tristan Salles3, WANG Shuhong1,2, MA Yikai4, XU Weihai1,2, LI Gang1,2, YAN Wen1,2,5()   

  1. 1 State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
    2 Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
    3 School of Geosciences, the University of Sydney, Sydney 2006, Australia
    4 South China Sea Standards and Metrology Center, State Oceanic Administration, Guangzhou 510300, China
    5 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2026-03-02 Revised:2026-03-23 Online:2026-09-10 Published:2026-10-13
  • Contact: YAN Wen
  • Supported by:
    National Key Research and Development Program of China(2021-06); Special Funds of the National Natural Science Foundation of China(L2424234); Key Program of National Defense Science and Technology Innovation of the Chinese Academy of Sciences(KGFZD-145-26-36)

摘要:

目前已有沉降理论、冰期控制理论、岩溶理论和改进的岩溶理论解释环礁形成机制。尽管冰期的喀斯特岩溶和间冰期礁体周缘的相对快速生长常被用以解释环礁形成过程, 但岩溶和礁体周缘上相对较快的礁体生长分别在环礁形成过程中的角色与作用尚未基于数值模拟研究予以明确。文章基于2018年采集南海美济礁北缘钻岩芯(长度2020.20m)探测数据, 对美济礁的第四纪发育演化过程开展了三维数值模拟研究。模拟结果表明, 环礁形成很可能是由于礁体周缘区域和中部区域之间的空间差异性岩溶(即周缘区域弱、中部区域强), 而非平顶型台地周缘区域上相对较快的礁体生长(即礁体在平顶型台地的周缘区域生长快、中部区域生长慢)。假如平顶型台地周缘区域上相对较快的礁体生长作用足够强, 以至于能够形成明显的中央潟湖或环礁地形, 则其无法在潟湖中形成顶面接近平均海平面的点礁。礁体周缘隆起区域上相对较厚的礁体沉积地层, 主要源于空间差异性岩溶作用形成的中部区域凹陷、周缘区域隆起的先存地形。假如不存在基底沉降, 礁体沉积地层的厚度会显著减少, 但中央潟湖和环礁形态的形成情况很可能与平均沉降速率68m·Ma-1时的情况几乎相同。潟湖中地形高点上的水深或高度若与周缘隆起区域的水深或高度接近, 则潟湖中地形高点上的礁体生长速度可与周缘隆起区域上的礁体生长速度相当, 从而在潟湖中形成与平均海平面接近的点礁。综上所述, 礁体周缘区域和中部区域之间的空间差异性岩溶(即周缘区域弱、中部区域强)是环礁和中央潟湖形成的关键驱动因素。

关键词: 环礁成因, 珊瑚礁生长, 岩溶, 数值模拟

Abstract:

Several theories have been proposed to explain atoll formation. While karst dissolution during glacial periods and preferential coral reef accretion along raised bank margins during deglaciations and interglacials have been invoked to explain atoll formation, the respective roles of karst dissolution and reef margin construction in atoll formation have not been adequately evaluated by simulations. In this study, we conducted three-dimensional numerical simulations of the Quaternary development of Meiji Atoll in the southern South China Sea based on interpreted data from a 2020.20-m-deep borehole drilled on its northeast rim in 2018. Our results suggest that the origin of atolls is more likely due to spatially differential dissolution across margin and interior areas (i.e., minimal along margins and maximal in bank centers) rather than preferential reef accretion along margins of flat-topped banks. Preferential reef accretion along margins of flat-topped banks that can result in central lagoons and atoll morphology can hardly result in the formation of lagoonal patch reefs that reach mean sea level. Preferential reef accretion along margins is mainly predicated on the karst-induced morphology that has a central depression surrounded by raised rims, i.e., using antecedent karst morphologies. If no subsidence or uplift occurred, that is, only sea-level change occurred since 2.65 Ma (million years ago), the thickness of the reef rims became significantly less, but the occurrence of the central lagoons and atoll morphology was almost the same as that with an average subsidence rate of 68 m·Ma-1. If topographic highs in the lagoon are similar in elevation to the margins, reef accretion on these topographic highs can be similar to that observed on the margins, resulting in lagoonal patch reefs that reach mean sea level. Our simulation shows that spatially differential dissolution across margin and interior areas is a critical driver of global central lagoons and atoll formation.

Key words: atoll origin, coral reef accretion, karst dissolution, numerical simulation

中图分类号: 

  • P737.11