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Experimental constraints on trace element partitioning between coesite and hydrous silicate melt at 5 GPa and 1500-1750℃

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Science China Earth Sciences 2021年第7期64卷 1171-1183页

作者： Wei YAN Xi LIU Saijun SUN Weidong SUN Dan WU Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education of ChinaBeijing 100871China School of Earth and Space Sciences Peking UniversityBeijing 100871China Center of Deep Sea Research Institute of OceanographyChinese Academy of SciencesQingdao 266071China Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

Trace element partitioning between coesite and hydrous silicate melt has been investigated at 5 GPa and 1500-1750℃.High-P experiments successfully produced large coesite crystals in equilibrium with large silicate melt pools(plus kyanite and corundum crystals in some cases).Scanning electron microscopy and micro-Raman spectroscopy were employed to characterize the phases and the ***-dispersive electron microprobe analyses were performed to quantify conventional major elements,and laser ablation-inductively coupled plasma-mass spectrometry analyses were successfully conducted to quantify trace ***,high-P partition coefficients were obtained for 33 *** general coesite is a very pure *** a few possible exceptions like Sc,Ti,and V,nearly all other trace elements are incompatible in ***,the partitioning behaviors of nearly all trace elements except some 4+cations cannot be readily described by the lattice strain model,presumably implying a minor role for the cation size in the trace-element *** our experimental results with the results in the literature,some T and P effects on the element partitioning behavior have been observed:T seemingly has different effects on different trace elements,but P might negatively correlate with the partition coefficients in all *** to its large modal fraction in some subducted materials such as the continental crustal material,coesite might play an important role in the distributions of some trace elements,Ti for example.

关键词： Partition coefficients High-P experiments LA-ICP-MS coesite Hydrous silicate melt Temperature and pressure dependence

Synthesis of ZrSiO_4 and coesite in SiO_2-ZrO_2 System Under High Pressure

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Chemical Research in Chinese Universities 2008年第2期24卷 135-137页

作者： XUE Yan-feng XU Da-peng ZHANG Guang-qiang ZHOU Xian-feng DING Zhan-hui LIU Xiao-mei SU Wen-hui College of Physics Jilin University Changchun 130012 P. R. China Center for the Condensed-MatterScience and Technology Harbin Institute of Technology Harbin 150001 P. R. China International Center for Materials Physics Chinese Academy of Sciences Shenyang 110015 P. R. China

ZrSiO4 and coesite were obtained under high-pressure and high-temperature from the nano precursor of a-SiO2 and ZrO2. XRD and Raman measurements indicate that ZrSiO4 was formed at a temperature higher than 920 ℃ under a pressure of 3.6 GPa. As the pressure increased to 3.9 GPa, the ZrSiO4 formation temperature was reduced to 815 ℃. The formation temperature for coesite was 990 ℃ under 3.9 GPa. The lower formation temperature for ZrSiO4, as compared to that for coesite, provided an experimental evidence that the coesite in the Earth＇s surface usually occurs as inclusions in ZrSiO4.

关键词： ZrSiO4 coesite High pressure synthesis Mechanical ball milling

Influence of Carbon-doped Content on Formation Conditions of coesite

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Chemical Research in Chinese Universities 2009年第6期25卷 920-923页

作者： WANG De-jun LIU Xiao-mei ZHU Cheng-jun YAN Duan-ting LIU Yi-xin SUN Ying LIU Fu-lin SU Wen-hui State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun 130021 P. R. China Adult Education College Changchun University Changchun 130022 P. R. China Center of the Condensed Matter Science and Technology Harbin Institute of Technology Harbin 150001 P. R. China International Center for Material Physics Chinese Academy of Sciences Shenyang 110015 P. R. China

The mixtures of a-quartz and graphite powder with different mass ratios were, respectively, high-energetically mechanically milled and then treated under high pressure and high temperature. The influences of carbon content on the synthesis conditions of coesite were investigated. The experimental products were characterized by XRD, TEM, and Raman spectrometry. The results show that the existence of carbon can obviously inhibit the formation of coesite, and the higher the carbon content of the initial material, the higher the pressure for forming coesite.

关键词： coesite High pressure Mechanical ball-milling α-SiO2 Graphite

Synthesis of Small-sized coesite Under Lower Pressure

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Chemical Research in Chinese Universities 2010年第3期26卷 352-354页

作者： WANG De-jun LIU Xiao-mei ZHU Cheng-jun YAN Duan-ting LIU Fu-lin SU Wen-hui State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun 130021 P R. China Adult Education College of Changchun University Changchun 130022 P. R. China Center of the Condensed Matter Science and Technology Harbin Institute of Technology Harbin 150001 P R. China International Centre for Materials Physics Chinese Academy of Sciences Shenyang 110016 P. R. China

With the help of high-energy mechanical milling and a-SiO2 as the initial material, we investigated the synthesis of coesite at a high temperature and high pressure under the condition of adding a certain amount of hard Fe filling. The synthetic samples were measured by XRD and Raman spectroscopy. The results show that a small amount of small-sized coesite can be obtained under 2.5 GPa and 973 K.

关键词： coesite High temperature and high pressure High-pressure micro-area a-SiO2

A first-principles study of helium diffusion in quartz and coesite under high pressure up to 12GPa

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Geoscience Frontiers 2021年第2期12卷 1001-1009页

作者： Hong Liu Lingling Wang Shuchen Li Yaochun Yang Hua Tian Fengxia Sun Chaowen Xu Lei Liu Yi Li Yueju Cui Ying Li Jijun Zhao United Laboratory of High-Pressure Physics and Earthquake Science Key Laboratory of Earthquake PredictionInstitute of Earthquake ForecastingCEABeijing 100036China Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Dalian University of Technology)Ministry of EducationDalian 116024China College of Information Engineering and Computer Science(Tai Yuan University of Technology) Taiyuan 030024China

Helium diffusion in mantle minerals is crucial for understanding mantle structure and the dynamic processes of Earth's *** this paper,we report helium incorporation and the mechanism of its diffusion in perfect crystals of quartz and *** diffusion pathways,activation energies(Ea),and frequency factors of helium under ambient and high pressure conditions were calculated using Density Functional Theory(DFT)and the climbing image nudged elastic band(CI-NEB)*** calculated diffusive coefficients of He in the quartz in different orientations are:D[100]=1.24×10^(−6)exp.(−26.83 kJ/mol/RT)m^(2)/s D[010]=1.11×10^(−6)exp.(−31.60 kJ/mol/RT)m^(2)/*** in the coesite:D[100]=3.00×10^(−7)exp.(−33.79 kJ/mol/RT)m^(2)/s D[001]=2.21×10^(−6)exp.(−18.33 kJ/mol/RT)m^(2)/*** calculated results indicate that diffusivity of helium is anisotropic in both quartz and coesite and that the degree of anisotropy is much more pronounced in *** diffusion behavior in coesite under high pressures was *** activation energies increased with pressure:Ea[100]increased from 33.79 kJ/mol to 58.36 kJ/mol,and Ea[001]increased from 18.33 kJ/mol to 48.87 kJ/mol as pressure increased from0 GPa to 12 *** calculations showed that helium is not be quantitatively retained in silica at typical surface temperatures on Earth,which is consistent with the findings from previous *** results have implications for discussion of the Earth's mantle evolution and for recognition thermal histories of ultra-high pressure(UHP)metamorphic terranes.

关键词： Helium Diffusion Quartz coesite High pressure

Subduction of Continental Crust in the Early Palaeozoic North Qaidam Ultrahigh-Pressure Metamorphic Belt, NW China:Evidence from the Discovery of coesite in the Belt

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Acta Geologica Sinica(English Edition) 2002年第1期76卷 63-68页

作者：杨经绥许志琴宋述光张建新吴才来史仁灯李海兵 Maurice BRUNEL Paul TAPPONNIER Institute of Geology Chinese Academy of Geological Science 26 Baiwanzhuang Rd. Beijing 100037 China Department of Earth Sciences University of Montpellier II Montpellier France Institut de Physique du Globe 75252 Paris Cedex 05 France

coesite was discovered as inclusions in zircon separates from pelitic gneissassociated with a large eclogite body in the North Qaidam ultrahigh-pressure (UHP) terrane. Somegraphite inclusions were also found. This finding suggested the occurrence of in-situ UHPmetamorphism and that the terrane was most likely recrystallized at pressures below the diamondstability field. It supported other previous indirect UHP evidence, such as polycrystalline quartzinclusions in eclogitic garnet, quartz lamellae in omphacite and P-T estimates for both eclogite andgarnet peridotite. The U-Pb and Sm-Nd ages of the North Qaidam eclogite indicated that subductionof continental crust occurred in the Early Palaeozoic, which probably recorded a collision betweenthe Sino-Korean and Yangtze plates.

关键词： UHP metamorphism coesite eclogite Qinghai-Tibet plateau North QaidamMountains

Calculation of the Model of coesite Inclusions and Analysis of Their Retrometamorphic Paths

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Acta Geologica Sinica(English Edition) 2004年第1期78卷 166-169页

作者： MENGDawei DINGXiaokun WUXiuling FacultyofMaterialsScienceandChemicalEngineering ChinaUniversityofGeosciencesWuhanHubei430074 TestingCentre ChinaUniversityofGeosciencesWuhanHubei430074

The process and path of retrometamorphism of coesite have great significance to our understanding of the P-T tracks of the exhumation of ultrahigh-pressure metamorphic rocks. Most of the coesites in the eclogite from Shima, Anhui Province, the Dabie Mountains, China, are found degraded to quartz partly or wholly, with ruptures occurring in the shells, outside which include the coesite and quartz. According to the microscopic observation, the sample of coesite inclusion is composed of garnet, quartz and coesite, based on which we have built a three-shelled composite sphere model to compute the transition of coesite. Based on the crystal growth formulas and pressure conditions of the ruptures in the garnet, we have calculated the radius of the quartz sphere, which depends on temperature, and eventually drawn the different retrometamorphic paths for different retrometamorphism rates.

关键词： ultrahigh-pressure metamorphic rocks coesite model calculation retrometamorphic path Dabie Mountains

coesite-bearing eclogite breccia:implication for coseismic ultrahigh-pressure metamorphism and the rate of the process

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Coesite-bearing eclogite breccia:implication for coseismic u...

coesite eclogite facies metamorphic tectonite:evidence for ultrahigh pressure deformation

中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： Jian-Jun Yang Meng-Xi Huang Qian-Yi Wu Hao-Ran Zhang State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

A coesite-bearing eclogite breccia is reported here for the first time at Yangkou in the Chinese Su–Lu ultrahigh-pressure(UHP)metamorphic *** is thrusted over a coesite-bearing coronitic eclogite and is gradational to a foliated eclogite at the *** coronitic eclogite is characterized by garnet coronas between fine-grained high-pressure mineral aggregates forming pseudomorphs after plagioclase,ilmenite,biotite,and pyroxene in a gabbroic *** breccia consists of fine-grained cataclastic eclogite fragments(garnet+omphacite+coesite/quartz±phengite±kyanite)and a coarser-grained matrix schist(garnet+quartz+phengite+kyanite).The foliated eclogite consists of intercalating bands of the cataclastic eclogite and a schist similar to the fragments and the matrix,respectively,in the *** igneous fabric of the eclogitized gabbro is increasingly obliterated from the coronitic eclogite through the foliated eclogite to the *** amoeboid garnet containing numerous inclusions of omphacite and other high-pressure minerals is characteristic of eclogite facies pseudotachylytes and suggests flash melting and rapid *** the breccia and foliated eclogite,quartz+K-feldspar±albite aggregates are included in garnet or form strings cutting across the *** some aggregates,quartz grains are cemented by K-feldspar and vesicular albite,also implying crystallization from melts in a rapid cooling and decompression process from the UHP *** field context,the locally preserved igneous fabric in the breccia,the similar whole-rock compositions,as well as the complementary mineral assemblages in the fragments and the matrix with respect to the coronitic eclogite,suggest that the breccia was formed by cataclasis and segregation of minerals in a former coronitic eclogite in response to a sudden pressure *** coesite is found only in the eclogite cataclasites and may have survived via the rapid cooling event,as

关键词： Cataclasis coesite Earthquake Eclogite breccia Quenching Yangkou

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Coesite eclogite facies metamorphic tectonite:evidence for u...