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ABUNDANCE AND DISTRIBUTION OF PLATINUM-GROUP ELEMENTS (PGE) IN PERIDOTITE FROM THE DAGZHUKA OPHIOLITE IN TIBET:IMPLICATIONS FOR MANTLE METASOMATISM

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地学前缘 2000年第S1期7卷 99-100页

作者： Xia Bing 1,2.,Yu Hengxiang 1,Mei Houjun 1,Qi Lang 2.(1 guangzhou institute of{2., chinese academy of sciences, guangzhou 510640, China 2.institute of{2., chinese academy of sciences, Guiyang 550002. China)

Information on abundance and distribution of platinum\|group elements (PGE) in peridotite from ophiolite is relevant to understand the nature and evolution of the upper mantle. The ophiolite suite outcropping along the famous suture zone of Yarlung Zangbo River, Tibet, has attracted wide attention of geologists both in China and abroad. The Dagzhuka ophiolite of in the suture zone is thought to display a complete ophiolitic sequence. The peridotite from the Dazhuka ophiolite is composed of fairly fresh or unaltered lherzolite, harzburgite and minor dunite which are the upper mantle residuum formed by 15%～35% partial melting. In this paper we have mainly studied the abundance and distribution of PGE in the harzburgites and lherzolites. The harzburgites and lherzolites preserve total PGE contents of 2. 37×10 -9 ～50 67×10 -9 respectively higher than Primitive mantle or the peridotite from some typical ophiolites and Alpine. They all have fractionated chondrite\|normalized PGE patterns with positive slopes from Ir to Pd (Fig.1), and Pd/Ir=1 13～2.40>1, Pd/Rh=2.2.～7 49>1, and Pd/Pt=0 2.～1 16 (average 0 67) higher than Primitive mantle (1 11, 2.35, 0 57) or CI\|chondrite (1 01, 2.73, 0 53). Consequently, the Dagzhuka peridotite are PGE\|enriched, but otherwise possess residual characteristics arising from a minimum of 15% partial melting. It is suggested that mantle residuum by partial melting have low total PGE contents, fractionated chondrite\|normalized PGE patterns with negative or slightly flat slopes from Ir to Pd, and Pd/Ir<1. But, the total PGE contents, chondrite\|normalized PGE patterns and Pt/Ir, Pd/Rh and Pd/Pt values of the Dagzhuka peridotite are completely inconsistent with a residual origin. Partial melting would have partitioned all sulfide in the source into the melt. In fact, no sulfide or silicate melt remained in the Dagzhuka peridotite. Therefore, PGE in Dagzhuka peridotite are not present in sulfides. The PGE\|enrichment and fractionation of the Dagz

关键词： platinum\|group elements(PGE) peridotites Dazhuka ophioli te Tibet

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Alkalic-type epithermal gold mineralization associated with Tongshi complex in Pinyi County, Shandong Province

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chinese Science Bulletin 1999年第S2期44卷 236-238页

作者： XIONG Xiaolin, ZHAO Zhenhua and WANG Qiang guangzhou institute of{2., chinese academy of sciences, guangzhou 510640, China guangzhou institute of{2. Chinese Academy of Sciences Guangzhou 510640 China

THE alkali-rich subvolcanic complex of Tongshi and the associated gold mineralization are located at thesouth boundary of Pinyi Mesozoic volcanic depression in western Shandong Province. There are morethan 30 gold deposits and mineralization locations around the complex, in which Guilaizhuang gold deposit and Zhuojiazhuang bonanza gold deposit with important economic value are included. This area isbecoming a perspective target of superlarge gold deposit. In the mine area, there crop out Archeangranitic gneisses, Paleozoic carbonates and Jurassic clastic rocks, which was intruded by Tongshi complexwith 30 km. The complex consists of K-high igneous rocks formed by two stages of magmatism. In thefirst stage, the monzonitic dioritic porphyrys, which belong to K-high calc-alkalic rocks, were formed andin the second stage, monzonitic-syenitic porphyrys, which belong to K-high alkalic rocks, were *** Ar-Ar ages are 189 Ma and 188 Ma, respectively. At the end of the second stage, a lot of theexplosive breccias were formed. The gold mineralization in this area is closely associated in time andspace with the second stage monzonitic-syenitic porphyrys. Based on the characteristics of

关键词： epithermal gold mineralization Tongshi complex Pinyi County Shandong Province.

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Tectonic implications of the isotopic geochemical steep zone in eastern Yunnan, China

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chinese Science Bulletin 1999年第S2期44卷 195-196页

作者： DONG Yunpeng, ZHU Bingquan and CHANG Xiangyang guangzhou institute of{2., chinese academy of sciences, guangzhou 510640, China guangzhou institute of{2. Chinese Academy of Sciences Guangzhou 510640 China

THE studies on geology, geochemistry and geophysics of mantle and crust show that there exist distinctvertical and lateral heterogenetics of the composition and structures of lithosphere. Especially, continentallithosphere possesses a complex rheological structure, which is one of the important factors controlling thedeformation and evolution of continent. Recently, the comprehensive studies in China and other countries suggest that the geochemical mapping and provincial division is a reliable method to reveal the heterogenetics, and Pb isotopic compositionhaving strong tectonic and regional characteristics. Therefore, Pb isotopic mapping is a key to revealingthe structure, formation and evolution of the lithosphere. Based on Pb isotopic mapping in South Chinacontinent, it has been revealed that there exists a Pb isotopic geochemical steep zone between Yangtzeblock and Cathaysia

关键词： tetonics isotopic steep zones Yunnan.

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Modern microbialites and their environmental signifi-cance,Meiji reef atoll,Nansha (Spratly) Islands,South China Sea

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Science China Earth sciences 2008年第4期51卷 608-617页

作者： SHEN JianWei1 & WANG Yue1,2.1 Department of Marine Geology, South China Sea institute of Oceanology Key Laboratory of Marginal Sea Geology, South China Sea institute of Oceanology and{2. institute of geochemistry, chinese academy of sciences,{2. 510301, China 2.Graduate University of the chinese academy of sciences, Beijing 100049, China Department of Marine Geology South China Sea Institute of Oceanology Guangzhou China Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou

Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, South China Sea, consists of an annular reef rim surrounding a central lagoon. On the atoll rim there are either protuberant 'motu' (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encrustation, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2. on massive colonies of Galaxea fascicularis, (3) on dead Montipora digitata, and (4) on dead Acropora teres, some hairy microbialite growing around broken coral branches. This study demonstrates that microbial carbonates are developed in coral reefs of South China Sea and indicates that microbial processes may be important in the construction of modern reef systems. The results have significance in the determination of nature and composition in microorganisms implied in the formation ancient microbialites, and permit evaluation of the importance of microbial deposits in mo-dern coral reefs and of 'microbialites' in biogeochemical cycles of modern coral reef systems. The re-sults also provide evidence of modern analogues for ancient microbialites in shallow-water settings, and combine with sedimentological studies of ancient microbialites to understand their controls.

关键词： Microbialite Meiji reef Nansha Island South China Sea

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On deposits controlled by tectonic lenses

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Science China Earth sciences 2004年第12期47卷 1095-1101页

作者： WANG Jincao 1 ,XIA Bin 1 & JI Shaocheng 2.1.guangzhou institute of{2.,chinese academy of sciences,guangzhou 510640,China 2.Department of Civil,Geological and Mining Engineering,Montreal institute of Technology,P.O.Box6079,Station Centre-ville Montreal,Canada 1. chinese academy of sciences Guangzhou Institute of Geochemistry 510640 Guangzhou China 2. Department of Civil Geological and Mining Engineering Montreal Institute of Technology Station Centre-ville Montreal P. O. Box 6079 Canada

By study of the typical tectonic lenses controlling some ore deposits, the tectonic lens boundaries may be classified into fuzzy boundaries, sharp boundaries and complex boundaries, and the metallostructures in tectonic lenses may be classified into vein-type, stock- work-type and breccia-type. After studying their metallostructures, we suggest the conception on tectonic lenses as an ore-forming system, realizing that the compact-function ore-forming system is made up of the lenticular weak-strain domain(Q) and its outside linear strong-strain belt(P). The ore-forming system, which is composed of four subsystems that coupled with each other and exert their system functions to the full, includes the dual-dynamical system made up of tectonic and fluid dynamics, the metallotectonic system controlled by hydrofracturing, the ore-source system made up of multi-substances and the mineral transportation system contacted by tectonic network. Deformational partitioning, hydrofracturing and tectonic pumping operate the consid- erable function while the system function practises. Finally, the significance of metallotectonics on the tectonic lenses is discussed in the paper.

关键词： tectonic lenses, boundary type of tectonic lenses, type of metallostructures, tectonic lens as an ore-forming system.

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Noble gas and cosmic-ray exposure age of Juancheng chondrite

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chinese Science Bulletin 1999年第12期44卷 1142-1143页

作者： WANG Daode and WANG Ruitian guangzhou institute of{2., chinese academy of sciences , guangzhou 510640, China Heze Bureau of Seismology, Shandong Province , Heze 2.402., China guangzhou institute of{2. Chinese Academy of Sciences Guangzhou China Heza Bureau of Seismology Shandong Province Heze China

The analytical results of noble gase in recently fallen Juancheng chondrite indicate that cosmic-ray ages of cosmogenic nuclei of 3He, 2.Ne and 38Ar are 5.1, 5.0 and 5.8 Ma, respectively, averaging 5.3 Ma. The gas retention ages radiogenic nuclei of 4He and 40Ar are 32.0 and 4 2.0 Ma, respectively. The average cosmic-ray age shows that it has occurred at breakup of the meteoroid from its parent body by impact before 5.3 Ma.

关键词： noble gas cosmic-ray exposure age chondrite Juancheng Shandong.

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Experimental study of ore gabbro liquid immiscibility

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Science China Earth sciences 2005年第4期48卷 496-505页

作者： SANG Zunan1,2. XIA Bin1, ZHOU Yongsheng3 & JIN Zhenmin4 1. guangzhou institute of{2., chinese academy of sciences, guangzhou 510640, China 2. Wuhan University, Wuhan 430072. China 3. institute of Geology, China Seismological Bureau, Beijing 10002., China 4. Faculty of Earth sciences, China University of Geosciences, Wuhan 430074, China 1. guangzhou institute of{2. Chinese Academy of Sciences 510640 Guangzhou China 2. Wuhan University 430072 Wuhan China 3. institute of Geology China Seismological Bureau 100029 Beijing China 4. Faculty of Earth sciences China University of Geosciences 430074 Wuhan China

In this paper, the authors present the results of a preliminary experimental study on partial melting of fine-grained gabbro, Panzhihua, Sichuan Province, China. Experiments were conducted under (confining) pressure ranging from 450 to 500 MPa and temperature of 900— 12.0℃. The results show that the initial melt is distributed along grain boundaries and triple junctions. Liquid immiscibility phenomena are noted in the melt with two compositional different melt phases, i.e. matrix and sphere phases. The matrix phase is relatively rich in Si, Al and K, and is depleted in Mg, Fe, Ca, Na and Ti, whereas the sphere phase shows opposite trends. The calculation of the melt free energy indicates that the liquid immiscibility is governed by the rule of thermodynamics, as the liquid immiscibility would result in the decrease in free energy of the melt system. The field relationships suggest that the liquid immiscibility may have played an important role in the generation of ore magma of Panzhihua V-Ti magnetite ore deposit. This study thus provides experimental constraints on the mechanism of the formation of V-Ti magnetite deposite.

关键词： partial melting, experimental study, gabbro, liquid immiscibility, ore formation mechanism.

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Geochemical constraints from hydrothermal fluid inclusions of altered deformation zone type Au(Ag)deposits in Yunkai area, South China

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chinese Science Bulletin 1999年第S2期44卷 230-232页

作者： WANG Zuwei~1, ZHANG Haihua~2. YAO Dongliang~2.and ZHOU Yongzhang~3 1. Department of Geography, Tianjin Normal University, Tianjin 300071, China 2. guangzhou institute of geochemistry, chinese academy of sciences,{2., China 3. Department of Earth sciences, Zhongshan University, guangzhou 5102.5, China eeszhou@*** Department of Geography Tianjin Normal University Tianjin 300071 China guangzhou institute of{2. Chinese Academy of Sciences Guangzhou 510640 China Department of Earth sciences Zhongshan University Guangzhou 510275 China

THE altered deformation zone type Au (Ag) deposits share an important part from the precious metallicore deposits in the Yunkai area, South China. Their formation is a history of poly-stage evolution. Pre- liminary source strata, Calidoniam metamorphism, Indosinian-Yanshanian ductile shear deformation andassociated hydrotheraml alteration all play certain roles in the history. This note discusses the geochemical conditional of the hydrothermal fluids during mineralization. Two representative ore deposits, the Pangxidong Ag(Au) deposit and Hetai Au deposits are selectedfor this study. They are hosted in altered ductile shear zones. Wall-rock hydrothermal alteration is bothspatially and temporally associated with the development of the ductile shear system. Silicification occurred throughout the whole alteration process. There are three groups of quartz: thepredeformational quartz, the early stage hydrothermal quartz, and the late stage hydrothermal quartz asso-

关键词： precious metallic deposit fluid inclusions mineralizing fluid South China.

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PREPARATION AND PROPERTIES OF ETHYL-CYANOETHYL CELLULOSE/POLYACRYLIC ACID COMPOSITE FILMS WITH REFLECTION COLORS

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chinese Journal of Polymer Science 2001年第3期19卷 277-282页

作者： Yong Huang institute of Chemistry, chinese academy of sciences, Beijing 100080 China Laboratory of Cellulose and Lignocellulosics Chemistry{2. institute of Chemistry chinese academy of sciences,{2. 510650, China 中科院化学所北京

Ethyl-cyanoethyl cellulose [(E-CE)C]/acrylic acid (AA) becomes a cholesteric liquid crystalline solution withvivid colors when the (E-CE)C concentration is 42.wt%～52.wt%. (E-CE)C/polyacrylic acid (PAA) composites withcholesteric structure were prepared by polymerzing AA in (E-CE)C/AA liquid crystalline solutions. The layers of orderedpolymer chains in the cholesteric phase were inclined during polymerization and the degree of the inclination depended onthe polymerization temperature and the concentration of the solution before polymerization. The cholesteric structure in thecomposites could not be changed when temperature was lower than 100℃. Cross-linking of the PAA in compositesimproved their water-resistance. The cholesteric order of the composites without cross-linking was destroyed when theywhere immersed in water. The color derived from the selective reflection of the cholesteric phase of the cross-linkedcomposites turned from blue to red after the composites absorbed water. The color of the composites could be returned to theoriginal one when the absorbed water was removed from the swollen composites.

关键词： Cholesteric structure Composites Selective reflection Liquid crystalline solutions

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Summary of the 11th Conference on Magnetic Confined Fusion Theory and Simulation

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Plasma Science and Technology 2024年第10期26卷 1-7页

作者： guangzhou HAO Jianqiang XU Youwen SUN Zhibin GUO Organizing Committee of the 11th Conference on Magnetic Confined Fusion Theory and Simulation Southwestern institute of Physics Chengdu 610041People’s Republic of China institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People’s Republic of China State Key Laboratory of Nuclear Physics and Technology Fusion Simulation CenterSchool of PhysicsPeking UniversityBeijing 100871People’s Republic of China 不详

This conference report summarizes recent progress in plasma theory and simulation that was presented in contributed papers and discussions at the 11th Conference on Magnetic Confined Fusion Theory and Simulation(CMCFTS)held in Chengdu,China,2.–30 October,*** in various fields has been *** example,results on zonal flow generation by mode coupling,simulations of the key physics of divertor detachment,energetic particle effects on magnetohydrodynamic(MHD)modes in addition to ion-and electron-scale turbulence,physics of edge coherent modes and edge-localized modes,and the optimization of ion heating schemes as well as confinement scenarios using advanced integrated modeling are presented at the *** this conference,the scientific research groups were organized into six categories:(a)edge and divertor physics;(b)impurity,heating,and current drive;(c)energetic particle physics;(d)turbulent transport;(e)MHD instability;and(f)integrated modeling and code development.A summary of the highlighted progress in these working groups is presented.

关键词： magnetic confined fusion(MCF) theory and simulation modeling tokamak

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