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现代地质 ›› 2025, Vol. 39 ›› Issue (03): 704-714.DOI: 10.19657/j.geoscience.1000-8527.2024.042

• 机器学习与矿物学应用 • 上一篇    下一篇

稀土元素对褐帘石晶体结构的精细影响研究

徐晶晶1,2(), 李林1,2,*(), 杨小男3   

  1. 1.中国地质大学(北京)科学研究院,北京 100083
    2.中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京 100083
    3.中国地质博物馆,北京 100034
  • 出版日期:2025-06-10 发布日期:2025-07-03
  • 通信作者: *李 林,男,副教授,1984年出生,主要从事高温高压矿物学方面研究工作。Email:clark.li@cugb.edu.cn
  • 作者简介:徐晶晶,女,硕士研究生,1997年出生,主要从事矿物学方面研究工作。Email:1959812527@qq.com
  • 基金资助:
    国家自然科学基金-基金委重大计划培育项目(28832020004)

Research on the Atomic Level Structure Effects by Rare Earth Elements Substitutions in Allanite of Different Occurrence

XU Jingjing1,2(), LI Lin1,2,*(), YANG Xiaonan3   

  1. 1. Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China
    2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
    3. The Geological Museum of China, Beijing 100034, China
  • Published:2025-06-10 Online:2025-07-03

摘要:

褐帘石作为花岗岩、矽卡岩以及花岗伟晶岩中常见的副矿物,是岩浆中轻稀土元素(LREE)、Th、U和Sr等微量元素的重要载体,在俯冲带的临界温度范围内褐帘石能够很好的控制LREE含量,其成分对结构变化所产生的影响对地球科学研究具有非常重要的指示作用。本文通过单晶X射线衍射、粉晶X射线衍射、LA-ICP-MS等一系列系统的结构和化学成分对比分析了不同地质环境中褐帘石族矿物单晶的晶胞参数特征,并在此基础之上深入讨论了帘石族矿物中稀土元素对晶体结构微调的过程。根据实验数据的比较随着REE3+替代Ca2+占据A2占位使得帘石族矿物晶体的abcV各个晶胞参数得到了相应程度增大,其中晶胞体积的变化较为明显由457.92 Å3增大至479.93 Å3,体积增大接近4.8%;褐帘石的(110)、( 31 1 ¯)、(222+123+114)、(322+ 42 4 ¯)和(307)等面网可以间接指示褐帘石中稀土元素的含量和占位情况。本研究通过分析褐帘石的晶体结构和化学成分,揭示了稀土元素替代Ca2+对其晶体结构的调控机制及其地球化学意义。

关键词: 褐帘石, 稀土元素, 晶体结构, 晶胞参数, 多面体体积

Abstract:

Allanite is a common accessory phase in granite, skarn and granite pegmatite. As the major carrier of light rare earth elements (LREE) and trace elements such as Th, U and Sr, allanite can control LREE content well within the critical temperature range of the subduction zone. The effect of changes that its composition to structure have directive influence to the research of earth science. This paper summarise the characteristics of the cell parameters of the three epidote group minerals contain allanite, epidote and zoisite through a series systematic structural and chemical compositional analyses. Such as single-crystal X-ray diffraction (XRD), powder X-ray diffraction, and LA-ICP-MS. We discuss the effects of composition on the structure in the epidote group minerals on the basis of the series of analyses. According to experimental data comparisons, as REE3+ substitutes for Ca2+ and occupies the A2 site, the unit cell parameters a, b, c and V of the epidote-group minerals exhibit corresponding increases. The change in unit cell volume is particularly significant, expanding from 457.92 Å3 to 479.93 Å3, representing a volume increase of approximately 4.8%. Additionally, the (110), ($31\overline{1}$311¯), (222+123+114), (322+$42\overline{4}$424¯), and (307) lattice planes of allanite can indirectly reflect the content and occupancy of REEs within the mineral structure.This study investigates the crystal structure and chemical composition of allanite, revealing the regulatory mechanism of rare earth elements (REEs) substituting for Ca2+ and its geochemical significance.

Background collection

Key words: allanite, REE, crystal structure, cell parameters, polyhedral volume

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