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Magma underplating and Hannuoba present crust-mantle transitional zone composition: Xenolith petrological and geochemical evidence

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Science china Earth Sciences 2005年第8期48卷 1089-1105页

作者： FAN Qicheng1,2. ZHANG Hongfu1, SUI Jianli1, ZHAI Mingguo1, SUN qian2.& LI Ni2.1. {4. of {2. and Geophysics, chinese Academy of Sciences, Beijing 10002., china 2. {4. of {2., china Seismological Bureau, Beijing 10002., china 1. institute of geology and Geophysics Chinese Academy of Sciences 100029 Beijing China 2. institute of geology China Seismological Bureau 100029 Beijing China

On the basis of mineral assemblage, mineralogy, petrology, and major, trace ele-mental and isotopic geochemistry of the underplated granulite- and eclogite-facies accumulate, peridotite and pyroxenite xenoliths entrained in Hannuoba Cenozoic basalts, this work con-strained the petrological constituents for the crust-mantle transitional zone, which is supported by the results of high-temperature and pressure velocity experiments on rocks and geophysics deep survey. Present lower part of lower crust is mainly composed of granulite-facies mafic accumu-lates (dominantly plagioclase websterite) and crust-mantle transitional zone dominantly com-posed of eclogite-facies pyroxenites with or without garnet and spinel lherzolites; Archaean ter-rain granulite is only nominally early lower crust. Magma underplating in the crust-mantle boundary led to the crustal vertical accretion and the formation of the crust-mantle transitional zone, which is a significant mechanism for the chemical adjustment of the crust-mantle boundary since the Phanerozoic.

关键词： magma underplating, xenolith petrology, geochemistry, cust-mantle boundary constituent, Hannuoba.

Si-and alkali-rich melt inclusions in minerals of mantle peridotites from eastern china:Implication for lithospheric evolution

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Science china Earth Sciences 2006年第1期49卷 43-49页

作者： FAN Qicheng1, SUI Jianli2. XU Ping2. LI Ni1, SUN qian1 & WANG Tuanhua1 1. {3. of {2., china Seismological Bureau, Beijing 10002., china 2. {3. of {2. and Geophysics, chinese Academy of Sciences, Beijing 10002., china 1. institute of geology China Seismological Bureau Beijing 100029 China 2. institute of geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Minerals of spinel- and garnet-facies mantle xenoliths entrained in Cenozoicbasalts from eastern china (North china, Northeastern china and Southeastern china coastal area)contains lots of melt inclusions. Studies on these melt inclusions show that the glass inclusionsare rich in SiO_{4.(60%—68%) and alkalis (K_{4.+Na_{4. = 5%—11%, especially for K_{4.) as well asvolatiles such as H_{4. and CO_{4.({4.—7%), which belong to dacites and andesites of the high-K calcicalkali series rocks with few shoshonites. High Al and Ca diopside in melt inclusion is the productof melt crystallization at high temperature and pressure, rather than the product ofdevitrification. Results show that these K-rich (in general K_{4. > 3.) intermediate-acidic silicatemelt inclusions have characteristics of continent without a genetical link to host basalts and theirphenocrystic minerals. Thus, these trapped melt inclusions represent melts of Mesozoic lithosphericmantle-crust interaction and imply that the continental lithospheric mantle beneath eastern chinahad undergone fragmentation and recreation processes during the Mesozoic and Cenozoic periods. Thisresult undoubtly provides important implication for the evolution of sub-continental lithospherebeneath eastern china. We propose that these Si- and alkalis-rich melts should be responsible forthe mantle chemical heterogeneity underneath eastern china.

关键词： Si- and alkali-rich melt inclusion, mantle peridotite, lithospheric evolution, eastern china.

Sponge spicules in phosphorites of the Early Cambrian Gezhongwu Formation,Zhijin,Guizhou

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Progress in Natural Science:Materials International 2004年第10期14卷 56-62页

作者： YANG Ruidong 1 ,qian Yi 2.,ZHANG Jie 1 ,ZHANG Weihua 1 ,JIANG Lijun 1 and GAO Hui 1 (1.Guizhou University of Technology,Guiyang550003.china 2.{2. of geology and Paleontology,chinese Academy of Sci-ences,nanjing2.0008,china) Guizhou Univ Technol Guiyang 550003 Peoples R China chinese Acad Sci Inst Geol & Palaeontol Nanjing 210008 Peoples R China

Phosphorites occurring at the bottom of the Cambrian system contain abundant small shelly fossils,which are the prod-uct of the first episode of life explosion in the *** was previously reported that the small shelly fossils are dominated by hy-olithids,olivooids,zhijinitids,conodontomorphs,yubelichitids,camenitids and algae,with minor amounts of sponge *** amounts of sponge spicules,diverse in form,have been found for the first time in the Gezhongwu Formation phosphorites at Shixing,Zhi-jin County,Guizhou Province,of which such spicules as diaxon-triactins,diaxon-tetractins,pentaxon-pentactins and hexon-hexactins ac-count for3.%.These spicules constitute the sponge clastic phosphorites made up of sponge ***,it is also expected that the radiation and diversity of sponge animals started as early as in the earliest Early *** and burying environment of sponge animal are discussed in the paper.

关键词： sponge animal Gezhongwu Formation Early Cambrian Guizhou

Structural and Chemical Characterization of the Ediacaran Embryo-Like Fossils via the Combination of 3.-XRM and FIB-SEM Approaches

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Journal of Earth Science 2024年第4期35卷 1204-1214页

作者： qian Chen Weichen Sun Suping Wu Zongjun Yin State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing210008China University of chinese Academy of Sciences Nanjing211135China

The three-dimensional(3.)morphology,anatomy,and in-situ chemical composition analysis of fossils are crucial for systematic paleontology and determining their phylogenetic *** electron microscopy(SEM)coupled with energy-dispersive X-ray spectroscopy(EDS),offers valuable structural and chemical information for the analysis of ***,its primary limitation is the restriction to two-dimensional surface data,which limits the exploration of fossils’3. ***,3. X-ray microscopy(3.-XRM),also known as a novel form of micro-computed tomography(micro-CT)facilitates the non-destructive 3. reconstruction of fossil ***,it lacks the capability to provide in-situ compositional *** the constraints inherent in these individual techniques,and in response to the evolving requirements of paleontological research,this study introduces an integrated approach that combines 3.-XRM with EDS-coupled focused ion beam scanning electron microscopy(FIB-SEM).This innovative strategy is designed to synergize the advantages of both techniques,thereby addressing challenges that conventional methods *** enables the rapid identification of regions of interest(ROI)within fossil specimens at micrometer ***,this method collects detailed data on both 3. structures and chemical compositions at the nanometer scale for the identified *** integrated approach represents a significant advancement in paleontological and geological research methodologies,promising to meet the increasing demands of these fields.

关键词： Embryo-like microfossils structural and chemical characterization 3.-XRM FIB-SEM 3. reconstruction

RECONSIDERATION OF THE PHYLOGENETIC AFFINITIES OF ZHIJINITIDS

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微体古生物学报 2000年第3期 313-316页

作者： qian Yi Zhu Mao yan Li Guo xiang (nanjing {2. of {3. and Palaeontology, {4. Academy of Sciences, nanjing 2.0008) Chen Meng’e ({2. of {3., {4. Academy of Sciences, Beijing 10002.)

This discovery of complete body fossils of Halkieria and Microdictyon, two problematical taxa originally erected on the basis of isolated sclerites from Cambrian konservt lagersttte, sheds new light on our understanding of the Early Cambrian small shelly fauna. Based on comparisions of the morphology and preservation of nail shaped sclerites of zhijinitids, Hallucigenia and Onychodictyon, we propose that Zhijinites and Parazhijinites may have been closely related to tardipolypods, a diverse group of Early Cambrian metazoans.

关键词： small shelly fossils scleritome zhijinitids tardipolypods Early Cambrian

Scientists eager for Chang’e-6 lunar farside samples to bring new discoveries

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The Innovation 2024年第5期5卷 5-6页

作者： Wei Yang Yuyang He Yuqi qian Zongyu Yue Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Earth Sciences&Laboratory for Space Research The University of Hong KongHong Kong 999077China

The tidal locking effect keeps the Moon consistently presents its one side—the near side—to Earth,rendering the other side—the far side—inaccessible for people standing on ***,the far side of the Moon remained shrouded in mystery for human observers until the onset of space *** 1959,the Soviet Union’s Luna 3.spacecraft returned the first views ever of the far side of the *** the blurriness of the photo by contemporary standards,the stark contrast between the near side and far side of the Moon was *** then,a growing number of orbital probes have revealed significant differences between the two sides of the Moon,including lunar crust thickness,magma activities,and ***,the origins of these differences remain unexplained.

关键词： rendering striking Earth

Geological Characteristics and Its Metallogenesis of Daolundaba Copper Polymetallic Deposits,Inner Mongolia

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矿物学报 2011年第S1期31卷 86-87页

作者： PAN Xiao-fei1,HOU Zeng-qian1,WANG Shuo2.TONG Ying1,XUE Huai-min1,ZHOU Xi-wen1,XIE Yu-ling3.1.institute of {2.,chinese Academy of Geological Sciences,Beijing 10003.,china 2.Inner Mongolia Geological Prospecting Limited Company,01002.,china 3.University of Science and Tectonlogy Beijing,Beijing 10002.,china)

1 geology Daolundaba copper polymetallic deposit occurs in West Ujimqin Banner,the Xilin Gol League of Inner Mongolia,along the west side of South part of Daxinganling ore belt,whose tectonic position just lies at the junction of Siberian Block in the south part,North china Block in the north and Songliao block in the *** Daolundaba copper polymetallic deposit is hosted by the Lower Proterozoic Baoyintu group of biotite-plagioclase gneiss(Pt1by),upper Permian Linxi formation of sandy slate(P2.),and the Hercynian {2.jinchang pluton of biotite granite.

关键词： In Geological Characteristics and Its Metallogenesis of Daolundaba Copper Polymetallic Deposits,Inner Mongolia Pb

Temporal and spatial variations hydrochemical components and driving factors in Baiyangdian Lake in the Northern Plain of china

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Journal of Groundwater Science and Engineering 2024年第3期12卷 293-308页

作者： Tian-lun Zhai qian-qian Zhang Long Wang Hui-wei Wang Hebei and china Geological Survey Key Laboratory of Groundwater Remediation Institute of Hydrogeology and Environmental GeologyChinese Academy of Geological SciencesShijiazhuang 050061China

Understanding the temporal and spatial variation of hydrochemical components in large freshwater lakes is crucial for effective management and *** this study,we identify the temporalspatial characteristics and driving factors of the hydrochemical components in Baiyangdian Lake using geochemical methods(Gibbs diagram,Piper diagram and End-element diagram of ion ratio)and multivariate statistical techniques(Principal component analysis and Correlation analysis).16 sets of samples were collected from Baiyangdian Lake in May(normal season),July(flood season),and December(dry season)of *** indicate significant spatial variation in Nat,ci,SO and NO,,suggesting a strong influence of human *** concentrations exhibit greater seasonal variation in the dry season compared to the flood season,while the concentrations of the four anions show inconsistent seasonal changes due to the combined effects of river water chemical composition and human *** hydrochemical type of Baiyangdian Lake is primarily HCO,***,Mg*and HCO,originate mainly from silicate and carbonate rock dissolution,while Kt,Nat and CI originate mainly from sewage and salt dissolution in ***4.0}may mainly stem from industrial wastewater,while NO,primarily originates from animal feces and domestic *** the use of Principal Component Analysis,it is identified that water-rock interaction(silicate and carbonate rocks dissolution,and dissolution of salt in sediments),carbonate sedimentation,sewage,agricultural fertilizer and manure,and nitrification are the main driving factors of the variation of hydrochemical components of Baiyangdian Lake across three hydrological *** findings suggest the need for effective control of substandard domestic sewage discharge,optimization of agricultural fertilization strategies,and proper management of animal manure to comprehensively improve the water environment in Baiyangdian Lake.

关键词： Hydrochemical variation Sources Human activities Water-rock interaction Multivariate statistical techniques

REMNANTS OF EARLY ARCHEAN (CIRCA 3.5 GA) SEAWATER AND IMPLICATION OF LIFE IN BIFS (BANDED IRON FORMATION) FROM CAOZHUANG FORMATION, qian'AN COUNTY, HEBEI PROVINCE,NORTH china

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REMNANTS OF EARLY ARCHEAN (CIRCA 3.5 GA) SEAWATER AND IMPLIC...