GYIG OpenIR  > 研究生
Alternative TitleEquation of state of epidote-group minerals at high pressure and high temperature
Thesis Advisor范大伟
Degree Grantor中国科学院研究生院
Place of Conferral北京
Degree Name硕士
Degree Discipline地质工程
Keyword含水矿物 绿帘石 状态方程 同步辐射 x 射线衍射 拉曼光谱

Hydrous minerals play an important role in transporting and storing of water in the deep Earth. The study of physical and chemical properties of hydrous minerals is important to understand the mode of existence of water, the mineral composition and structural behavior in the subduction zone, and also can help us properly understand the subduction dynamics. Epidote-group minerals are common hydrothermal alteration minerals in the basalt and one of the major hydrous minerals and an important carrier of water in the Earth’s interior. Therefore, the studies on the structure and thermoelastic properties of the epidote-group minerals have great significance in geology. The author have studied the PV/VT/PVT equation of state (EoS) of epidote, clinozoisite and zoisite by using external resistance heating diamond anvil cell combined with synchrotron radiation power X-ray diffraction method and Raman spectroscopy. Combined with previous studies, we discussed the effect of the isomorphous substitution on the unit-cell volume, bulk modulus and other physical parameters in epidote-group mineral. The experimental results suggest that:1. By analyzing the PV EoS of epidote and clinozoisite, we found that the bulk modulus of epidote-clinozoisite solid solution decreases with the increasing composition of iron. The possible reason for this phenomenon is that the radii of Fe3+ cation (0.645 ?) is bigger than Al3+ cation (0.535 ?), the volume of MO6 octahedron increases with increasing radii of M3+, and then more easy to be compressed. In the zoisite-clinozoisite homogenous two-phase variants, is the bulk modlus has no linear correlation with the composition of iron. In addition, the zoisite is easier to be compressed than clinozoisite.2. Researching for epidote VT EoS at high temperature gets the coefficient of thermal expansion (α0). In addition, according to the PVT EoS of epidote, we also obtained the temperature derivative of the bulk modulus (dK/dT)P and thermalexpansivity coefficient (α0) of epidote. Comparing the two experimental results, we found that the thermal expansivity coefficient (α0) at simultaneously high pressure and high temperature is obviously larger than the value obtained at high temperature.3. We also completed the high pressure Raman spectroscopy studies on epidote and clinozoisite. With increasing pressure, the pressure coefficient of M-O modes and Si-O modes in epidote is obviously larger than clinozoisite, which can also prove the conclusion that epidote is easier to be compressed than clinozoisite.4. Using the EoS data in this study combined the EoS experimental results of other hydrous minerals from previous studies to calculate the densities of epidote, zoisite, clinozoisite, brucite, serpentine and chlorite under different geothermal gradient in subduction zone. And then, it is presumed that epidote with higher iron content contribute to subduction plate into deep mantle. 

Other Abstract

含水矿物作为水的运输和储存的主要载体,其热物理化学性质的研究对精确 了解水在俯冲带中的存在形式,俯冲带中的物质组成与结构状态以及俯冲动力学 过程具有重要意义。绿帘石族矿物是玄武岩中最常见的热压蚀变矿物,也是地球 内部重要的含水矿物之一,是水在地球内部的重要携带者,因此,高温高压条件 下对绿帘石族矿物结构及热弹性性质的研究具有较为重要的地学意义。作者利用 金刚石压腔实验装置,结合常规 X 射线衍射技术,同步辐射 X 射线粉末衍射技 术以及拉曼光谱散射实验技术,在常温高压、常压高温以及高温高压条件下,对 黝帘石、斜黝帘石、绿帘石进行了较为系统的 PV/TV/PVT 状态方程研究。结合 前人研究成果,讨论了类质同像置换对绿帘石族矿物晶胞体积、体弹模量等物性 参数的影响。获得了以下研究结果:1)对绿帘石、斜黝帘石进行了常温高压 PV 状态方程研究,发现绿帘石-斜黝帘 石固溶体系列的体弹模量值总体上随着 XEp 含量的增加而减小,随着 XEp 含 量增加,矿物更容易被压缩。其原因为在绿帘石-斜黝帘石固溶体系列矿物中, 离子半径较大的 Fe3+离子(0.645 ?)对 M3(1)位置上的 Al3+离子(0.535 ?) 的替代会导致 M3(1)八面体体积变大,从而导致矿物容易被压缩。而在黝帘 石-斜黝帘石同质二相变体中 Fe 含量与体弹模量没有明显的线性关系,但黝帘石比斜黝帘石更容易被压缩。2)在常压高温条件下获得了通过VT 状态方程获得了绿帘石的热膨胀系数值。 并在高温高压条件下通过 PVT 状态方程获得了绿帘石的体弹模量的温度导 数值((dK/dT)P)以及热膨胀系数值(α0)等热弹性参数值。对比后发现,高 温高压条件下获得的热膨胀系数值明显比常压高温条件下获得的热膨胀系数 值大。3)常温高压条件下对绿帘石、斜黝帘石进行拉曼光谱实验,发现在高压下,绿 帘石的 M-O 键与 Si-O 键振动频率随压力的变化相对于斜黝帘石更为明显, 同样证明了绿帘石较容易被压缩的结论。4)利用本论文获得的状态方程数据,结合前人对其他含水矿物状态方程的研究成果,计算了绿帘石、斜黝帘石、黝帘石、水镁石、蛇纹石和绿泥石在俯冲带不同地温梯度下的密度值,认为绿帘石的含铁量越高越利于俯冲板片进入深部地幔。

Document Type学位论文
Recommended Citation
GB/T 7714
匡云倩. 高温高压条件下绿帘石族矿物状态方程研究[D]. 北京. 中国科学院研究生院,2017.
Files in This Item:
File Name/Size DocType Version Access License
高温高压条件下绿帘石族矿物状态方程研究.(4010KB)学位论文 开放获取CC BY-NC-SAView Application Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[匡云倩]'s Articles
Baidu academic
Similar articles in Baidu academic
[匡云倩]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[匡云倩]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: 高温高压条件下绿帘石族矿物状态方程研究.pdf
Format: Adobe PDF
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.