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Oxygen and carbon isotope composition from the UHP Shuanghe marbles, Dabie Mountains, China

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Science China Earth Sciences 1999年第1期42卷 88-96页

作者：王清晨 Douglas Rumble geophysical laboratory Carnegie Institution of Washington 5241 Broad Road N. W. Washington DC 20015-1305 U. S. A.

Investigations on the oxygen and carbon isotope compositions from the ultrahigh-pressure (UHP)-metamorphosed Shuanghe marbles, that occur as a member of a UHP slab, show that the δ18 O values range from +11.1% to+20.5% SMOW, and δ13 C from+1.0% to+5.7% PDB, respectively. The variations in isotope compositions show a centimeter scale of homogeneity and a heterogeneity of regional scale larger than 1 meter.In contrast to the eclogite marbles from Norway, the Shuanghe marbles have inherited the carbon isotope compositions from their sedimentary precursor. The δ13C shows positive correlation to the content of dolomite. The depletion in18O, compared with the pmtolithic carbonate strata, might result from three possible geological processes: 1) exchanging oxygen isotope with meteoric water before the UHP metamorphism, 2) decarbonation during the UHP metamorphism, and 3) exchanging oxygen isotope with country gneiss at local scale during retrograde metamorphism.It seems that the advection of fluid in the orogenic belt was very limited during subduction and exhumation of UHP rocks.

关键词： oxygen and carbon isotope UHP metamorphism Shuanghe marble Dabie Mountains of China.

Synchrotron radiation X-ray diffraction in situ study of fine-grained minerals in shock veins of Suizhou meteorite

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Science China Earth Sciences 2005年第6期48卷 815-821页

作者： XIE Xiande1, SHU Jinfu2 & CHEN Ming1 1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 2. geophysical laboratory, carnegie institution of washington, washington, dc, 20015, USA Correspondence should be addressed to Xie Xiande 1. Guangzhou Institute of Geochemistry Chinese Academy of Sciences 510640 Guangzhou China 2. geophysical laboratory Carnegie Institution of Washington 20015 Washington DC USA

The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added twomore examples of successful utilization of synchrotron radiation X-ray diffraction technique for insitu investigations of fine-grained (0.5―30 μm in size) minerals in very thin shock melt veins othe Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrixminerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrixIt has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineratuite has also been successfully obtained. The result of present investigations has enriched thecontent of dynamic high-pressure mineralogy and that of Earth’s mantle geochemistry.

关键词： synchrotron radiation, X-ray diffraction, fine-grained minerals, Suizhou meteorite.

A New Method for Experimental Determination of Compressional Velocities in Rocks and Minerals at High-pressure

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Chinese Physics Letters 2000年第12期17卷 924-926页

作者： LIU Yong-Gang XIE Hong-Sen GUO Jie ZHOU Wen-Ge XU Ji-An ZHAO Zhi-Dan Institute of Geochemistry Chinese Academy of SciencesGuiyang 550002 geophysical laboratory The Carnegie InstitutionWashingtonDC 20015USA Department of Geology China Univercity of GeosciencesBeijing 100083

A transmission-reflection-combined new method is presented for measuring elastic velocities of rocks and minerals at elevated temperature and pressure,which resolves the problems of gradients of temperature and pressure existing in original sample assembly with a pyrophyllite *** room temperature and pressure up to 3 GPa,single-crystal quartz and eclogite were used to provide samples under test,*** results of this work agree with the previous measurements very well within the error *** the use of this new technique,more precise and reasonable data of elastic properties of rocks and minerals at elevated temperature and pressure can be achieved.

关键词： minerals quartz elevated

Deep Volatiles as the Key for Energy and Environments of the Four-Dimensional Earth System

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Engineering 2019年第3期5卷 393-394页

作者： Ho-Kwang Mao Craig M. Schiffries Center for High Pressure Science and Technology Advanced Research (HPSTAR) Shanghai 201203 China geophysical laboratory Carnegie Institution for Science Washington DC 20015 USA

Carbon, hydrogen, oxygen, nitrogen, sulfur, and their compounds are volatile components that dominate the thin and fragile atmosphere, hydrosphere, and biosphere on Earth’s habitable surface. However, the vast majority of these volatiles are hidden in the deep interior, where the high pressure–temperature conditions drastically and categorically alter the physics and chemistry of the volatiles. Like the bloodstream of an organism, the circulations and interactions of volatiles in the deep Earth modulate climate, resources, energy, natural hazards, and other factors that define the Earth as a unique living and changing planet.

关键词： Four-Dimensional Earth System Deep Volatiles

Xieite,a new mineral of high-pressure FeCr_2O_4 polymorph

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Chinese Science Bulletin 2008年第21期53卷 3341-3345页

作者： CHEN Ming SHU JinFu MAO Ho-kwang Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China geophysical laboratory Carnegie Institution of Washington 5251 Broad Branch Road NW 20015 Washington DC USA

Xieite,a new mineral,occurs in the shock vein of the Suizhou *** mineral has an ortho-rhombic structure and its space group is *** cell parameters are a = 9.462(6),b = 9.562(9),c = 2.916(1).The crystal-chemical formula is(Fe0.87Mg0.13Mn0.01)1.01(Cr1.62Al0.25Ti0.08V0.02)1.97O4,or simply formula *** X-ray diffraction lines are [d(),I/Io]:(2.675,100),(2.389,20),(2.089,10),(1.953,90),(1.566,60),(1.439,15),(1.425,15),(1.337,40).Xieite is a high pressure polymorph of FeCr2O4 and formed by solid-state transformation of chromite under shock-induced high pressure and tem-perature,in association with other high-pressure minerals including ringwoodite,majorite,lingunite and *** P-T condition for the formation of xieite is estimated to be 18―23 GPa and 1800―1950℃,*** has recently been approved by the Commission on New Minerals,Nomenclature and Classification of the International Mineralogical Association(IMA 2007-056).The mineral name,xieite,is named after Xiande Xie.

关键词：络铁矿高压环境基因多态性矿物

Development of High-Pressure Multigrain X-Ray Diffraction for Exploring the Earth’s Interior

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Engineering 2019年第3期5卷 441-447页

作者： Li Zhang Hongsheng Yuan Yue Meng Ho-Kwang Mao Center for High Pressure Science and Technology Advanced Research (HPSTAR) Shanghai 201203 China HPCAT X-Ray Science Division Argonne National Laboratory Argonne IL 60439 USA geophysical laboratory Carnegie Institution of Washington Washington DC 20015 USA

The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.

关键词： High pressure Synchrotron X-ray Multigrain Diamond anvil cell Minerals Petrology Earth’s interior

The Deep Carbon Observatory: A Ten-Year Quest to Study Carbon in Earth

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Engineering 2019年第3期5卷 372-378页

作者： Craig M. Schiffries Andrea Johnson Mangum Jennifer L. Mays Michelle Hoon-Starr Robert M. Hazen geophysical laboratory Carnegie Institution for Science Washington DC 20015 USA

1. Overview The Deep Carbon Observatory (dcO) is a ten-year research program to investigate the quantities, movements, forms, and origins of carbon in Earth. More than 90% of Earth’s carbon may reside in the planet’s deep interior, and dcO’s overarching mission is to understand Earth’s entire carbon cycle—beyond the atmosphere, oceans, and shallow crustal environments, which have drawn most previous research attention—to include the deep carbon cycle [1,2]. A decade of focused research has led to major discoveries by dcO scientists on the physical, chemical, and biological roles of carbon in Earth.

关键词： Deep Carbon Earth

Structural stability of methane hydrate at high pressures

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Geoscience Frontiers 2011年第1期2卷 93-100页

作者： I.-Ming Chou Russell J.Hemley Ho-kwang Mao 954 National Center U.S.Geological SurveyRestonVA 20192USA geophysical laboratory Carnegie Institution of WashingtonWashingtonDC 20015USA

The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil ceils. The diffraction data for types II （slI） and H （sH） were refined to the known structures with space groups Fd3m and P63/mmc, respectively. Upon compression, sl methane hydrate transforms to the sll phase at 120 MPa, and then to the sH phase at 600 MPa. The slI methane hydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methane hydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3m structure and ice VII （Pn3m）. The results highlight the role of guest （CH4）-host （H2O） interactions in the stabilization of the hydrate structures under pressure.

关键词： Methane hydrate Structural stability High pressure

Shift current bulk photovoltaic effect in polar materials—hybrid and oxide perovskites and beyond

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npj Computational Materials 2016年第1期2卷 58-69页

作者： Liang Z Tan Fan Zheng Steve M Young Fenggong Wang Shi Liu Andrew M Rappe The Makineni Theoretical Laboratories Department of ChemistryUniversity of PennsylvaniaPhiladelphiaPAUSA Center for Computational Materials Science United States Naval Research LaboratoryWashingtonDCUSA geophysical laboratory Carnegie Institution of ScienceWashingtonDCUSA

The bulk photovoltaic effect(BPVE)refers to the generation of a steady photocurrent and above-bandgap photovoltage in a single-phase homogeneous material lacking inversion *** mechanism of BPVE is decidedly different from the typical p-n junction-based photovoltaic mechanism in heterogeneous ***,there has been renewed interest in ferroelectric materials for solar energy conversion,inspired by the discovery of above-bandgap photovoltages in ferroelectrics,the invention of low bandgap ferroelectric materials and the rapidly improving power conversion efficiency of metal halide ***,as long as the nature of the BPVE and its dependence on composition and structure remain poorly understood,materials engineering and the realisation of its true potential will be *** this review article,we survey the history,development and recent progress in understanding the mechanisms of BPVE,with a focus on the shift current mechanism,an intrinsic BPVE that is universal to all materials lacking inversion *** addition to explaining the theory of shift current,materials design opportunities and challenges will be discussed for future applications of the BPVE.

关键词： mechanism effect ferroelectric