Hydration Effect on Equations of State for Minerals in the Peridotite System:Implication for Geotherms in the Mantle

作     者：Yu Ye Joseph R.Smyth Guangchen Chen Yu Ye;Joseph R.Smyth;Guangchen Chen

作者机构：State Key Laboratory of Geological Processes and Mineral ResourcesChina University of GeosciencesWuhan 430074China Department of Geological SciencesUniversity of ColoradoBoulderCO80309USA 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2022年第33卷第5期

页      面：1124-1144页

核心收录：

学科分类：0709[理学-地质学] 070801[理学-固体地球物理学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 0708[理学-地球物理学] 

基　　金：supported by the National Natural Science Foundation of China(No.42072050) the Science Fund for Distinguished Young Scholars of Hubei Province(No.2020CFA104) 

主　　题：equation of state DHMS phases nominally anhydrous minerals thermodynamic Grüneisen parameters adiabatic geotherm subduction slab mantle transition zone mineralogy 

摘      要：Water in the deep Earth’s interior has important and profound impacts on the geodynamical properties at high-temperature(T)and high-pressure(P)conditions.A series of dense hydrous Mg-silicate(DHMS)phases are generated from dehydration of serpentines in subduction slabs below the lithosphere,including phase A,chondrodite,clinohumite,phase E,superhydrous phase B and phase *** the other hand,olivine and its high-P polymorphs of wadsleyite and ringwoodite are dominant nominally anhydrous minerals(NAMs)in the upper mantle and transition zone,which could contain significant amount of water in the forms of hydroxyl group(OH-)*** water solubilities in wadsleyite and ringwoodite are up to about 3 weight percent(wt.%),making the transition zone a most important layer for water storage in the *** can significantly affect the pressure-volumetemperature equations of state(P-V-T EOSs)for the DHMS and NAM phases,including the thermal expansivities and isothermal bulk *** this work,we collected the reported datasets for the DHMS and NAM phases,and reconstruct internally consistent ***,we further evaluated the thermodynamic Grüneisen parameters,which are fundamental for constraining the temperature distribution in an isentropic process,such as mantle *** adiabatic temperature profiles are computed for these minerals in the geological settings of normal mantle and subduction zone,and our calculation indicates that temperature is the dominant factor in determining the gradient of a geotherm,rather than the mineralogical composition.