摘要
超硅石榴石作为地幔过渡带的重要组成部分,对于理解地球内部的物理化学特性和相平衡十分重要。本研究通过数值迭代方法,并结合前人已发表的实验数据,研究了在较大温度和压力范围内,超硅石榴石的单晶体积和弹性性质,尤其是包括热膨胀系数、等压热容、熵和Grüneisen参数在内的热力学性质。研究发现,随着压力的升高,超硅石榴石的热膨胀系数、等压热容、熵和Grüneisen参数与压力呈现非线性的负相关。其中,热膨胀系数、等压热容和Grüneisen参数对压力的一阶导数分别在温度达到约470、860和1050K时达到峰值,随后逐渐降低,而压力对熵的影响则在研究的温度范围内持续增强。本研究为了解地球内部物质组成特征,特别是地幔过渡带的相变提供了重要的参考。
Majoirte is one of the significant components in the Earth′s mantle transition zone.It is of significance for understanding the physical and chemical properties as well as phase equilibria of the Earth’s interior.Based on the application of an iterative numerical approach and the combination of previously published experimental data from the literatures,in this paper,we have studied the self-consistent unit-cell volume and elastic properties,especially the thermodynamic properties including the thermal expansion coefficient,isobaric heat capacity,entropy,and Grüneisen parameter,of majorite over a wide range of temperatures and pressures.The results indicate that the thermal expansion coefficient,isobaric heat capacity,entropy,and Grüneisen parameter of majorite are nonlinearly and negatively correlated with the increase of pressure.Also,the first derivatives of the thermal expansion coefficient,isobaric heat capacity,and Grüneisen parameter with respect to pressure reached the peak values at temperatures of about 470 K,860 K,and 1050 K,respectively,and then gradually decreased with the temperature,while the influence of pressure on entropy will be generally and continuously increased with the temperature within our investigated temperature range.This work provides a fundamental reference for understanding the mineral composition of the Earth’s interior,especially the phase transition of the Earth’s mantle transition zone.
作者
苏畅
宋伟
杨光
刘永刚
SU Chang;SONG Wei;YANG Guang;LIU Yonggang(School of Earth Sciences,Institute of Disaster Prevention,Sanhe Hebei 065201,China;Key Laboratory of High Temperature and High Pressure Study of the Earth’s Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang Guizhou 550081,China;School of Information Engineering,Institute of Disaster Prevention,Sanhe Hebei 065201,China;Hebei Key Laboratory of Earthquake Dynamics,Sanhe Hebei 065201,China)
出处
《矿物学报》
北大核心
2025年第2期204-215,共12页
Acta Mineralogica Sinica
基金
国家自然科学基金(批准号:42404114)
河北省自然科学基金(批准号:D2022512007)。
关键词
超硅石榴石
石榴石
地幔转换带
热力学性质
高温高压
Majorite
Garnet
mantle transition zone
thermodynamic properties
high temperature and high pressure
作者简介
第一作者:苏畅,女,1989年生,副教授,博士,从事地球内部物理方面研究工作。E-mail:suchang@cidp.edu.cn;通信作者:刘永刚,E-mail:liuyonggang@vip.gyig.edu.cn。
