Thermal Equation of State of Natural F-Rich Topaz up to 29 GPa and 750 K  

作　　者：Yungui Liu Xiang Li Haipeng Song Jingui Xu Dongzhou Zhang Junfeng Zhang Xiang Wu 

机构地区：[1]State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China [2]College of Gems and Materials,Hebei GEO University,Shijiazhuang 050031,China [3]Hawai'i Institute of Geophysics and Planetology,School of Ocean and Earth Science and Technology,University of Hawaii at Manoa,Honolulu HI 96822,USA

出　　处：《Journal of Earth Science》2023年第3期758-766,共9页地球科学学刊（英文版）

基　　金：financial support from the National Science Foundation of China(No.41827802);supported by the National Science Foundation-Earth Sciences(No.EAR-1634415);the Department of Energy,Geosciences(No.DE-FG0294ER14466);supported by DOE-BES(No.DE-AC0206CH11357);supported in part by COMPRES under NSF Cooperative Agreement EAR-1661511。

摘　　要：Subducting oceanic sediments and crusts,originating from the Earth's surface and descending into its deep interior,are important carriers of volatiles.The volatiles have significant effects on materials cycling and the dynamic evolution of the subduction zones.A simplified Al_(2)O_(3)-SiO_(2)-H_(2)O(ASH)ternary system models the relationship of minerals in the hydrated and alumina-silica rich sedimentary layer.Topaz Al_(2)SiO_(4)(F,OH)_(2)is an important mineral in the ASH system and comprises two volatiles:H_(2)O and fluorine(F).In this study,the thermoelasticity of a natural F-rich topaz was investigated using synchrotron-based single-crystal X-ray diffraction combined with diamond anvil cells up to 29.1 GPa and 750 K.The pressure-volume-temperature data were fitted to a third-order Birch-Murnaghan Equation of state with V_(0)=343.15(7)Å3,K_(0)=166(1)GPa,K_(0)'=3.0(1),(∂K_(0)/∂T)P=-0.015(9)GPa/K andα_(0)=3.9(5)×10^(-5)K^(-1).The isothermal bulk modulus increases with the F content in topaz,and the various F contents present significant effects on its anisotropic compressibility.Our results further reveal that the isothermal bulk modulus K_(0)of the minerals in ASH system increases with density.F and H contents in hydrous minerals might greatly affect their properties(e.g.,compressibility and stability),providing more comprehensive constraints on the subduction zones.

关 键 词：TOPAZ hydrous mineral water FLUORINE subduction zones 

分 类 号：P736.3[天文地球—海洋地质]