地学前缘 ›› 2025, Vol. 32 ›› Issue (5): 165-189.DOI: 10.13745/j.esf.sf.2025.3.71

• 沉积时空再造 • 上一篇    下一篇

从晶体成核—生长热动力学剖析白云岩成因问题的新进展

高和婷1(), 李茜1, 朱光有1,*(), 李生1, 王瑞林1, 侯佳凯1,2, 张杰志1, 郑凯航1   

  1. 1.南方复杂页岩油气地质与开发湖北省重点实验室, 长江大学, 湖北 武汉 430100
    2.中国石油勘探开发研究院, 北京 100083
  • 收稿日期:2024-09-02 修回日期:2025-03-21 出版日期:2025-09-25 发布日期:2025-10-14
  • 通信作者: 朱光有
  • 作者简介:高和婷(1997—),女,博士研究生,矿产普查与勘探专业。E-mail: geoght@126.com
  • 基金资助:
    国家自然科学基金项目(42230812)

A review of dolomite genesis analysis based on crystal nucleation-growth thermodynamic and kinetic

GAO Heting1(), LI Xi1, ZHU Guangyou1,*(), LI Sheng1, WANG Ruiling1, HOU Jiakai1,2, ZHANG Jiezhi1, ZHENG Kaihang1   

  1. 1. Hubei Key Laboratory of Complex Shale Oil and Gas Geology and Development in Southern China, Yangtze University, Wuhan 430100, China
    2. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
  • Received:2024-09-02 Revised:2025-03-21 Online:2025-09-25 Published:2025-10-14
  • Contact: ZHU Guangyou

摘要:

“白云岩问题”已持续困扰了地质学家200余年,无疑是地质学上争议最长久的难题之一。为推进白云岩成因问题的研究,本文借助晶体结构分析对白云岩晶体结构特征进行差异性研究,明确其形成环境及演化特征,进而为揭示其成因机制提供依据。由于晶体结构和成核-生长动力学之间存在相互影响和制约的关系,本文将晶体结构研究与成核-生长热动力学理论相结合,深入剖析白云岩的形成机制和条件。晶体结构分析表明,晶体结构控制了白云石的晶体类型、成核-生长速率、生长方向和其晶体最终形态,并决定了其热力学和动力学性质。热力学研究表明,现代海水具有析出白云石的热力学倾向,白云化反应可以在标准状态下进行,然而现代海水白云石的沉积量非常有限,建立新的热力学模型解释白云岩成因问题仍需结合实际加以验证可行性。动力学研究表明,海水中低温无机白云石形成困难的动力学因素包括Mg2+的水合作用、硫酸盐、阳离子有序化过程、$\mathrm{CO}_{3}^{2-}$的活性、溶液过饱和度和成核位点的有无等。但对于这些因素研究的认识仍然存在分歧,并没有解决低温无机白云石形成的关键问题。白云岩的形成和有序化是在地质时期内溶解-重结晶的结果,白云岩早期阶段可能受成核动力学控制,产物以亚稳定中间相为主,而后主要是受生长动力学控制。高新技术的发展与应用,使矿物学研究向分子、原子尺度深入,为白云石形成机制的研究提供方向。因此,合理利用高新技术,结合晶体结构分析和晶体成核-生长热动力学理论,从原子尺度探索白云石晶体生长机制,以期为研究白云岩成因提供新视角,进而为解开白云岩成因之谜提供重要的理论和实验基础。

关键词: 白云岩成因, 晶体结构, 晶体成核-生长, 热力学, 动力学

Abstract:

The “Dolomite Problem” has been a source of contention among geologists for over two centuries and remains one of the most contentious issues in the field. To advance research on dolomite genesis, this paper employs crystal structure analysis to investigate its structural characteristics, formation environment, and evolutionary characteristics, thereby providing a basis for revealing its formation mechanism. Given the mutual influence and constraints between crystal structure and nucleation-growth kinetics, the study combines crystal structure analysis with nucleation-growth thermodynamics to analyze dolomite’s formation mechanism and conditions in detail. Results demonstrate that the crystal structure controls the mineral type, nucleation-growth rate, growth direction, and final morphology of dolomite, thus determining its thermodynamic and kinetic properties. Thermodynamic studies indicate that modern seawater exhibits a thermodynamic tendency to precipitate dolomite, and the dolomitization reaction can proceed under standard conditions. However, actual dolomite deposition in modern seawater is minimal, and the feasibility of establishing a new thermodynamic model to explain dolomite genesis requires verification through experimentation. Kinetic studies reveal that factors impeding low-temperature inorganic dolomite formation in seawater include Mg2+ hydration, sulfate effects, cation ordering processes, $\mathrm{CO}_{3}^{2-}$ activity, solution supersaturation, and the presence or absence of nucleation sites. Nevertheless, current understanding of these factors remains inconclusive and does not fully resolve the pivotal issue of low-temperature inorganic dolomite formation. Dolomite formation and ordering result from dissolution-recrystallization processes over geological time. In the initial stages, dolomite formation is likely controlled by nucleation kinetics, with metastable intermediate phases predominating. As the process advances, growth kinetics becomes the primary control. The development and application of advanced analytical techniques have facilitated mineralogical research at the molecular and atomic scales. Such analysis provides direction for studying dolomite formation mechanisms. We therefore recommend utilizing advanced techniques rationally, integrating crystal structure analysis and nucleation-growth thermodynamic theory, to explore dolomite crystal growth mechanisms at the atomic scale. This approach aims to furnish novel perspectives on dolomite genesis research and provide a robust theoretical and empirical foundation for potentially unraveling the enigma of dolomite formation.

Key words: dolomite genesis, crystal structure, crystal nucleation-growth, thermodynamics, kinetics

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