白云岩成因研究方法:回顾与展望
- 收稿日期:
2025-03-28
- 网络出版日期:
2025-09-04
摘要: 摘 要 【意义】困扰几代地质学家的“白云岩问题”历久弥新,其成因机制不仅涉及沉积成岩理论突破,更对碳酸盐岩油气储层预测具有重要指导意义。【进展】传统岩石学-地球化学研究手段在白云岩成因研究中具重要作用:(1)X射线衍射、阴极发光和扫描电镜的矿物表征技术,可有效获取白云石晶体结构、有序度及微区形貌特征;(2)红外光谱与拉曼光谱通过分子振动模式识别,实现白云石与方解、高镁方解石的高精度鉴别,并检测矿物离子的微观结合形式;(3)主微量元素及稀土元素分析为判别成岩流体性质、氧化还原条件及物质来源提供重要地球化学依据;(4)碳氧同位素耦合分析可示踪流体混合过程并重建成岩古温度,锶同位素体系约束流体来源及演化路径。然而,传统技术手段难以精准解译白云岩形成过程的关键参数。近年来,新兴技术为白云岩成因研究提供了新视角,推动研究向微观、定量、动态过程解析转变:微区及原位分析技术(如LA-ICP-MS、EPMA)通过亚微米级空间分辨率(<10 μm)突破了全岩分析的局限,实现多期白云石化过程的精细刻画;镁同位素数值模拟定量约束白云岩形成过程的关键参数及镁离子来源;碳酸盐团簇同位素(Δ47)与U-Pb定年技术的发展,为白云石形成过程的温度和时间提供定量约束。【结论与展望】未来白云岩成因研究中需持续关注:晶体微观结构定量分析技术、同位素示踪联用技术、原位、微区元素分析技术、大数据融合分析技术,构建涵盖矿物结构解析-元素地球化学示踪-同位素年代学标定的成因研究方法体系,通过多尺度技术协同、多源数据融合与智能模型驱动,共同推动白云岩成因研究范式的革新与理论突破。
Current methodologies and emerging trends in dolomite research: Review and Perspectives
- Received Date:
2025-03-28
- Available Online:
2025-09-04
Abstract: Abstract: [Significance] The enduring ‘dolomite problem’, which has puzzled geologists for generations, remains a cornerstone of geoscientific inquiry. Its formation mechanisms not only drive breakthroughs in sedimentary diagenetic theories but also play a crucial role in predicting carbonate hydrocarbon reservoirs. [Progress] Traditional petrological-geochemical approaches remain pivotal in dolomite researches: (1) Mineral characterization techniques, including X-ray diffraction, cathodoluminescence, and scanning electron microscopy, effectively reveal dolomite crystal structures, ordering degrees, and microtextural features; (2) Infrared and Raman spectroscopy facilitate high-precision differentiation dolomite from calcite and high-Mg calcite through molecular vibration pattern recognition, while also identifying microscopic bonding configurations of ions; (3) Major-trace elements and rare earth elements analyses provide crucial geochemical constraints for deciphering dolomitizing fluid properties, redox conditions, and Mg sources; (4) Carbon and oxygen isotopic analysis traces fluid mixing processes and reconstructs paleotemperatures, complemented by strontium isotopic systems that constrain the evolution pathways of paleoseawater. However, traditional approaches have been proved to be insufficient for precisely unraveling fluid evolution sequences during dolomitization due to the complexities caused by multistage diagenetic overprinting and uncertainties in reconstructing paleoseawater geochemical compositions. Recent technological advancements have provided novel insights, promoting the research to micro, quantitative, and dynamic process analysis. Magnesium isotopes enable quantitative modeling of Mg2+ transport pathways, while microscale in-situ techniques (e.g., LA-ICP-MS, EPMA) achieve submicron spatial resolution (<10 μm), overcoming the limitation of bulk-rock methods to characterizing multiphase diagenetic events. Concurrently, carbonate clumped isotope (Δ47) thermometry and U-Pb geochronology provide unique advantages in constraining temperature and absolute timing of dolomitization processes. [Conclusions and Prospects] Future research should place a high priority on the following areas: quantitative crystallographic analysis, multi-isotope systematics tracing techniques, in-situ and microanalytical elemental mapping, and machine learning-driven big data fusion. Establishing a multidisciplinary framework that combines mineralogical characterization, elemental geochemical tracing, and isotopic chronostratigraphy will be essential. By integrating multiscale analytical techniques, multi-source data fusion, and intelligent modeling approaches, it is possible to refine the paradigm of dolomite research and achieve significant theoretical advancements.