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Anatexis in Himalayan crust:Evidence from geochemical and chronological investigations of Higher Himalayan Crystallines

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Science china earth sciences 2005年第9期48卷 1347-1356页

作者： yang Xiaosong1, JIN Zhenmin2 & MA Jin1 1. State Key Laboratory of earthquake Dynamics, Institute of Geology, china earthquake Administration, Beijing 100029, china 2. faculty of earth sciences, china university of geosciences, wuhan 430074, china State Key Laboratory of earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China faculty of earth sciences China University of Geosciences Wuhan China

Migmatization in Higher Himalayan Crystallines (HHC) results from anatexis. The widely distributed migmatites in HHC are an important clue to investigate the relationship be- tween anatexis and the origins of Higher Himalayan leucogranites (HHL), and to understand the effect of anatexis on crustal evolution during the post-collision period. We studied in detail the chemical features of three basic constituent parts of the migmatites, i.e. leucosome, mesosome and melanosome, and determined the K-Ar ages of leucosomes. Our studies indicate that type-I leucosome is the product of crystallization of melt generated by partial melting of mesosome at source region, but type-II leucosome and HHL probably underwent crystallization differentiation of plagioclase during melt aggregation and migration. The age of 22.67 Ma of Type-I leucosome, which is a little older than the beginning of MCT movement, indicates that anatexis may have played an important role in the formation of MCT. That the ages of type-II leucosome (ranging from 14.82 to 18.37 Ma) are consistent with that of HHL provides new chronological evidence for the relationship between migmatization and HHL. We obtained a very young age of 6.23 Ma of Type-II leucosome that provides new time constraint on magma activity in the central segment of Higher Himalayas.

关键词： Higher Himalayan Crystallines, migmatite, anatexis, leucosome, K-Ar age.

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Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

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Science china earth sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2, ZHAO Zhidan1,2, zhang Hongfei3, zhang Benren3 & CheN Yuelong2 1. State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences, Beijing 100083, china 2. School of earth Science and Mineral Resources, china university of geosciences, Beijing 100083, china 3. faculty of earth sciences, china university of geosciences, wuhan 430074, china State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China School of earth Science and Mineral Resources China University of Geosciences Beijing China faculty of earth sciences China University of Geosciences Wuhan China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.27). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-YX3 tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143)Nd/^(144)Nd (0.512955-0.512978). Pb isotopes are in the rangeof ^(206)Pb/^(204)Pb (18.054-20.562), ^(207)Pb/^(204)Pb (15.537-15.743) and ^(208)Pb/^(204)Pb(38.068-38.530). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

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Sm-Nd and zircon SHRIMP U-Pb dating of Huilanshan mafic granulite in the Dabie Mountains and its zircon trace element geochemistry

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Science china earth sciences 2005年第12期48卷 2081-2091页

作者： HOU Zhenhui1, LI Shuguang1, CheN Nengsong2, LI Qiuli1 & LIU Xiaoming3 1. School of earth and Space sciences, university of Science and Technology of china, hefei 230026, china 2. The Key Laboratory of Continental Dynamics of the Ministry of Education, Northwest university, Xi’an 710069, china 3. faculty of earth sciences, china university of geosciences, wuhan 430074, china School of earth and Space sciences University of Science and Technology of China Hefei China The Key Laboratory of Continental Dynamics of the Ministry of Education Northwest University Xi’an China faculty of earth sciences China University of Geosciences Wuhan China

The mafic granulites from Huilanshan are outcropped on the center of the Luotian dome in the northern Dabie Mountains. The Sm-Nd isochron defined by granulite-facies meta-morphic minerals (garnet + clinopyroxene + hypersthene) yields an age of 136 ± 18 Ma indicating the early Cretaceous granulite-facies metamorphism. The cathodoluminescence (CL) images of zircons from the granulite show clearly core-mantle-rim structures. The zircon cores are charac-terized by typical oscillatory zoning and highly HREE enriched patterns, which suggests their magma origin. Some zircon cores among them with little Pb loss give SHRIMP U-Pb ages rang-ing from 753 to 780 Ma, which suggests that the protolith of Huilanshan granulite is Neopro-terozoic mafic rocks. The zircon mantles usually cut across the oscillatory zone of the zircon cores have 3―10 times lower REE, Th, U, Y, Nb and Ta contents than the igneous zircon cores but have high common Pb contents. These characteristics suggest that they were formed by hydrothermal alteration of the igneous zircons. The part of zircon mantles with little Pb loss give a similar SHRIMP U-Pb age (716―780 Ma) to the igneous zircon cores, which implies that the hydrothermal events occurred closely to the magmatic emplacement. In view of the strong early Cretaceous magmatism in the Luotian dome, consequently, the Huilanshan mafic granulite was formed by heating of the Neoproterozoic mafic rocks in mid-low crust, which caused the granu-lite-facies metamorphism underneath the Dabie Mountains. The similarity between the granulite metamorphic age (136 ± 18 Ma) defined by Sm-Nd isochron and K-Ar age of 123―127 Ma given by amphible from the gneiss in Luotian dome suggests a rapid uplifting of the Luotian dome, which may result in further exhumation of the ultrahigh pressure metamorphic rocks in the Dabie Mountains.

关键词： Dabie orogen, granulite, zircon U-Pb ages, Sm-Nd age.

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Differentiation of Natural and Irradiated Blue Topaz by Cathodoluminescence(CL) Properties

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地学前缘 2009年第S1期16卷 169-170页

作者： Ying Song~(1,2),Xinqiang Yuan~2 1.faculty of earth Resources,china university of geosciences(wuhan),wuhan 430074,china. 2.Gemmological Institute,china university of geosciences(wuhan),wuhan 430074,china

Blue colored topaz is one of the most recognized gemstones ***,it is rarely found in the field and the products have been made mostly in laboratory using gamma,neutron and electron irradiation or combinations of these *** of the blue color in topaz remains not well understood, largely due to a lack of nondestructive way in idnetifying the blue *** we report a compari-

关键词： cathodoluminescence natural blue topaz irradiated blue topaz

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Analytical method of Cr stable isotope and its application to water pollution survey

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Chinese Science Bulletin 2010年第7期55卷 664-669页

作者： GAO YongJuan 1,2,3,MA Teng 4,5,LING WenLi 1,2,LIU CunFu 4,5 & LI Li 4,5 1faculty of earth Science,china university of geosciences,wuhan 430074,china 2State Key Laboratory of Geological Processes and Mineral Resources,china university of geosciences,wuhan 430074,china 3 Graduate School,china university of geosciences,wuhan 430074,china 4 Biogeological and Environmental Geology Laboratory of Ministry of Education(china university of geosciences) ,wuhan 430074,china 5 Sino-Hungary Joint Laboratory of Environmental sciences and health,china university of geosciences,wuhan 430074,china faculty of earth Science China University of Geosciences Wuhan China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Graduate School China University of Geosciences Wuhan China Biogeological and Environmental Geology Laboratory of Ministry of Education (china university of geosciences) Wuhan China Sino-Hungary Joint Laboratory of Environmental sciences and health China University of Geosciences Wuhan China

High Cr(VI) concentration is a potential serious risk to environment and ecologic ***,it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend.A new method of in-situ tracer technique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this *** on documented literatures,an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry(TIMS) are *** samples collected around a chemical factory in Hubei Province were analyzed by this *** samples showδ53Cr values ranging from-1.7‰to 7.3‰and an elevating trend with an increasing in distance from the sampling site to pollution source.A functional correlation following Rayleigh fractionation law was established between sample'sδ53Cr value and its extent of Cr *** study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water *** is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation.

关键词：铬(VI) 水污染调查稳定同位素应用同位素分析供水系统演变趋势示踪技术

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Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

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Science china earth sciences 2006年第8期49卷 862-871页

作者： yang Ruiyan1,2, MA Dongsheng2, BAO Zhengyu3, PAN Jiayong2, CAO Shuanglin2 & XIA Fei2 1. School of Mathematics and Physics, china university of geosciences, wuhan 430074, china 2. State Key Laboratory for Research of Mineral Deposits, Nanjing university, Nanjing 210093, china 3. faculty of earth sciences, china university of geosciences, wuhan 430074, china School of Mathematics and Physics China University of Geosciences Wuhan China State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China faculty of earth sciences China University of Geosciences Wuhan China

The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, china, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2―0.4 m/a.

关键词： ore-forming fluid, numerical simulation, geothermal field, geofluid transport, Xikuangshan, antimony deposits.

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SHRIMP zircon U-Pb age and significance of Early Paleozoic volcanic rocks in East Kunlun orogenic belt, Qinghai Province, china

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Science china earth sciences 2006年第1期49卷 88-96页

作者： ZHU Yunhai1, LIN Qixiang1, JIA Chunxing2 & WANG Guocan1 1.faculty of earth Science, china university of geosciences, wuhan 430074, china 2.Regional Geological Survey Academy of Qinghai, Xining 800003, china faculty of earth Science China University of Geosciences Wuhan China Regional Geological Survey Academy of Qinghai Xining China

Early Paleozoic volcanic rocks in Nuomuhong area occurred as basalt slice and meta-volcanic slice. SHRIMP zircon U-Pb dating of the basalt slice and the meta-volcanic slice show that the age of the basalt slice is 419±5 Ma, and that of the meta-volcanic slice is 401± 6 Ma. These ages directly testify that there existed Early Paleozoic ocean-continent transform in East Kunlun, the basalt slice was formed in an extensional mid-ocean ridge setting and the meta-volcanic rock slice was formed in an extrusion subduction and collision setting. The inherited zircon age of 1734 Ma in volcanic rocks reflects that the base of East Kunlun may be Middle Proterozoic.

关键词： volcanic rocks, SHRIMP zircon U-Pb age, Early Paleozoic, East Kunlun orogenic belt.

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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 Geochemistry, Chinese Academy of sciences, Guangzhou 510640, china 2. wuhan university, wuhan 430072, china 3. Institute of Geology, china Seismological Bureau, Beijing 100029, china 4. faculty of earth sciences, china university of geosciences, wuhan 430074, china Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China wuhan university Wuhan China Institute of Geology China Seismological Bureau Beijing China faculty of earth sciences China University of Geosciences 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— 1200℃. 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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Water in peridotite xenoliths from South china

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Science china earth sciences 2011年第10期54卷 1511-1522页

作者： WANG Rong 1,2,3 & zhang BaoMin 3 1 faculty of Land Resource Engineering, Kunming university of Science and Technology, Kunming 650093, china 2 State Key Laboratory for Mineral Deposits Research, Nanjing university, Nanjing 210093, china 3 faculty of earth Science, china university of geosciences, wuhan 430074, china faculty of Land Resource Engineering Kunming University of Science and Technology Kunming China State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing China faculty of earth Science China University of Geosciences Wuhan China

The water contents of nominally anhydrous clinopyroxene （cpx）, orthopyroxene （opx） and olivine （ol） in peridotite xenoliths hosted by Cenozoic basalts from Yingfengling, zhangchouchun, Fujitian and Lindi, South china, were measured by Micro- FTIR. All cpx and opx grains contained a certain amount of water, which was indicated by the presence of hydroxyls in the crystal structure. The water contents （H20, ppm） of cpx and opx from peridotite xenoliths of the study areas were 293-981, 183-752, 73-586 and 51-423 ppm, and 82-471, 74-571, 53-170 and 9-135 ppm, respectively. No prominent OH absorption bands were detected for any ol grains, indicating that the water contents were below the detection limit （approximately 2 ppm）. The entire rock contents recalculated according to mineral volume proportions were 49-163, 48-168, 21-111 and 8-40 ppm, respectively. Combined with previously reported data describing the water contents of peridotite xenoliths worldwide, the results presented here suggest that water distribution in the continental lithospheric mantle is spatially heterogeneous at a global scale. The lithospheric mantle of South china is much richer in water than that of the North china Craton, and is close to that typical of off-craton localities, such as the Basin and Range Province, and Massif Central.

关键词： FTIR water peridotite xenoliths South china

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Genomics,metagenomics,and microbial oceanography—A sea of opportunities

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Science china earth sciences 2011年第4期54卷 473-480页

作者： FANG JiaSong 1,2 &zhang Li 3 1 State Key Laboratory of Marine Geology,Tongji university,Shanghai 200092,china 2 College of Natural and Computational sciences,Hawaii Pacific university,Kaneohe,HI 96744,USA 3State Key Laboratory of Geological Processes and Mineral Resources,faculty of earth sciences,china university of geosciences,wuhan 430074,china State Key Laboratory of Marine Geology Tongji University Shanghai China College of Natural and Computational sciences Hawaii Pacific University Kaneohe USA State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan China

Microbial oceanography is an emerging discipline resulted from the interaction,cross-fertilization and integration of life science and ocean *** oceanography integrates the principles of marine microbiology,microbial ecology and oceanography to study the role of microorganisms in the biogeochemical dynamics of natural marine *** application of genomics tools to study marine microbes is resulting in rapid advancements in microbial oceanography that has important implications in global carbon cycle,climate change,and ecosystem *** we review the application of genomics and metagenomics in microbial oceanography and suggest future directions in microbial oceanography research.

关键词： microbial oceanography genomics metagenomics genes biomass bacteria archaea eukarya phylogeny physiology metabolism ecology biogeochemistry microbiology ecosystem function

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