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A～6 Ma chemical weathering history,the grain size dependence of chemical weathering intensity,and its implications for provenance change of the Chinese loess-red clay deposit

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A～6 Ma chemical weathering history,the grain size dependenc...

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Shangfa Xiong~*,Zhongli Ding,Yuanjian Zhu,Ru Zhou,Haijian Lu key laboratory of Cenozoic geology and Environment,Institute of geology & Geophysics,Chinese Academy of Sciences,100029 beijing,china

Major element chemical analyses of the Baishui loess—red clay sequence(35°24’ 10"N,106°54’ 43"E, Gansu Province,china) reveal that,the chemical weathering intensities inferred from CIA(chemical index of alteration) values have progressively weakened and increased in amplitude with decreasing age. The general trend of the CIA can be correlated well with the oxygen isotope variations of the deep sea *** of multiple size fractions(20μm and 20—63μm) indicate that the CIA and the major element abundances are strongly grain size *** chemical alternation of all three size fractions is relatively weak,and the long-term variation in chemical composition of the loess—red clay is mainly controlled by the mixing of fresh detritus from different source *** CIA variability of the coarse fractions(5—20μm and 20—63μm) within the section is apparently different from that of the fine fraction(<5μm),implying a different erosion—transportation—deposition—weathering *** 1 Ma onward,CIA values for all size fractions decrease,indicating an increasing input of fresh or poorly weathered detritus in the desert source regions of loess *** variations in the KO/AlO, NaO/AlO,CaO/AlO and MgO/AlO ratios from 4.5 Ma to about 0.6 Ma in bulk and size fractioned samples may reflect provenance change as well as changing chemical weathering processes.

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A calculation method to eliminate gain effect on isotopic measurement using the virtual amplifier multi-collector mass spectrometer

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A calculation method to eliminate gain effect on isotopic me...

中国科学院地质与地球物理研究所2006学术年会

作者： Zhuyin Chu,Yueheng Yang,Guangsheng Qiao State key laboratory of Lithospheric Evolution,Institute of geology and Geophysics,Chinese Academy of Sciences,beijing 100029,china

The virtual amplifier design employed in the ThermoElectron multi-collector mass spectrometers is a novel innovation for high precision isotopic *** the virtual amplifiers,uncertainties of gain factors of amplifiers can be effectively averaged out,so that accuracy and external reproducibility on isotopic measurement can be *** paper presents a new calculation method on isotopic measurement using the virtual amplifier mass spectrometers such as ThermoElectron Triton and *** the calculation method,gain factors of the amplifiers can be completely eliminated out for both raw measured isotopic ratios and normalized isotopic ratios when exponential or power law is used to correct isotope fractionation effect,and therefore,gain calibration is unnecessary even for the high precision measurement purpose.

关键词： Calculation method Gain factor Multi-collector Mass spectrometer isotope measurement

Applications of stable isotopes to study plant-animal relationships in terrestrial ecosystems

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Chinese Science Bulletin 2004年第22期49卷 2339-2347页

作者： WANG Jianzhu1,LIN Guanghui1,2,HUANG Jianhui1 & HAN Xingguo1 1.key laboratory of Quantitative Vegetation Sciences and Research Center for Plant Ecology and Biodiversity Conservation,Institute of Botany,Chinese Academy of Sciences,beijing 100093,china 2.Department of Global Ecology,Carnegie Institution of Washington,Stanford,CA 94305,USA key laboratory of Quantitative Vegetation Sciences and Research Center for Plant Ecology and Biodiversity Conservation Institute of Botany Chinese Academy of Sciences Beijing 100093 China Department of Global Ecology Carnegie Institution of Washington Stanford CA 94305 USA

As natural tracers, stable isotopes have been extensively used in plant physiological, ecological and envi- ronmental research. Recently, animal physiological ecologists have also applied stable isotope techniques to study plant- animal relationships. The isotopic compositions of animal body generally reflect and integrate their diets over a time period ranging from hours to years to the lifetime of an indi- vidual. When animal living habitat changes or animals move to a new environment, the animal isotopic compositions will shift accordingly. Thus, stable isotope signatures of an ani- mal can truly reflect its food sources, habitat, distribution and movement patterns during a given time period. More- over, by analyzing animal-tissue isotopic compositions at different temporal scales, we can improve our understanding of animal adaptation to environmental changes. Stable iso- tope technique also provides an ideal tool to study animal foodweb relationship and community structure because of isotopic fractionation during the processes of nutrient as- similation by animals. Stable isotope technique can continu- ously measure animal trophic position in a foodweb, which can eventually reveal the predator-prey relationship and its role in determining matter balance and energy flow in the entire ecosystem. Stable isotope technique has been one of the most important and efficient tools in studying plant-animal relationship. In this paper, we first review recent advances in the application of stable isotope techniques to plant-animal relationship research then evaluate their advantages and disadvantages, and finally discuss some future directions associated with stable isotope applications to plant-animal relationship research.

关键词：稳定同位素植物-动物关联性食物来源营养水平动物迁移

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Pb isotope geochemistry of lead, zinc, gold and silver deposit clustered region, Liaodong rift zone,northeastern china

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Science china Earth Sciences 2005年第4期48卷 467-476页

作者： CHEN Jiangfeng1, YU Gang1, XUE Chunji2, QIAN Hui1, HE Jianfeng1, XING Zhi1 & ZHANG Xun1 1. School of Earth and Space Sciences, University of Science and Technology of china, Hefei 230026, china 2. Department of geology, Chang’an University, Xi’an 710054, china 1. School of Earth and Space Sciences University of Science and Technology of China 230026 Hefei China 2. Department of geology Chang’an University 710054 Xi’an China

Pb isotopic analyses were reported for sulfide and hydrothermal carbonate minerals and marble of the Xiquegou lead-zinc, the Zhenzigou zinc-lead and the Gaojiapuzi silver deposits from the Qingchengzi ore field and the Beiwagou zinc-lead deposit in the west, Proterozoic Liaodong rift zone. Pb isotopic ratios of the marble from the Qingchengzi ore field range from 18.24 to 30.63 for 206 Pb/204Pb, 15.59 to 17.05 for207Pb/204Pb and 37.43 to 38.63 for 208Pb/204Pb. The marble gives a Pb-Pb isochron age of 1822±92 Ma, which is interpreted as the age of the metamorphism of the marble. Ore Pb, including Pb of sulfide and hydrothermal car- bonate minerals, from the Qingchengzi ore field shows limited variation with 206 Pb/204Pb=17.66- 17.96, 207 Pb/204Pb=15.60-15.74 and 208Pb/204Pb=37.94-38.60. In contrast, ore Pb from the Beiwagou deposit gives different Pb isotopic ratios with 206Pb/204Pb=15.68-15.81, 207 Pb/204Pb= 15.34-15.45 and 208Pb/204Pb=35.30-35.68. Pb of all deposits from the Liaodong rift zone is derived from the upper crust. Ore Pb of the Qingchengzi deposits is derived from a young upper crust. The model Th/U ratios of 4.40 to 4.74 for ore Pb are significantly different from that of 1.7 to 4.4 given by the marble of the Qingchengzi ore field, suggesting that marble is not the source of the ore Pb. Ore Pb of the Beiwagou deposit is extracted from its source and the deposit is formed at the Paleoproterozoic era. Different Pb isotopic ratios of the Qingchengzi ore field and the Beiwagou deposit are due to different ages of the deposits and suggest that the two types of deposits are derived from different sources and are possibly formed by different ore-forming processes.

关键词： Pb isotopes, source(s) of the ore-forming materials, origin of ore deposits, Liaodong rift zone.

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Origins and fates of CO2 in the Dongying Depression of the Bohai Bay Basin

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Origins and fates of CO2 in the Dongying Depression of the B...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Liuping zhang~(1*),Aiguo Wang~1 and Zhijun Jin~2 ~1key laboratory of Petroleum Resource,Institute of geology and Geophysics, Chinese Academy of Science,beijing 100029,china. ~2Research Institute of Petroleum Exploration and Development,SINOPEC, beijing 100083,china

Co gas reservoirs have been found in a series of rift basins in East *** objective of this study is to reveal origins and fates of CO in the Dongying Depression in East china by using isotopic(He and C) and molecular ***/He,CO/He andδC(CO)),values indicate that the CO gases with CO>79%in the deep fault belts in the depression are predominantly *** contrast,CO in most gases in the relative stable areas,where source rocks are developed,is less than 10%.Based on helium isotope andδC(CO))O/He diagram,it was found that 10-30%of these CO gases is mantle-derived,28%to 68%is limestone-decomposed and 18%to 54% sedimentary organic in the relative stable *** mantle-derived and limestone-decomposed CO in the relative stable areas indicates that the mantlederived geo-fluid met the source *** hydrocarbons can be generated via its heat influence. As the previously published model is not suitable for study of C0 fates at least in the case of thermogenic CO addition,we proposed two models for CO addition and loss:modelⅠfor CO loss and limestone-decomposed CO addition and modelⅡfor CO loss and addition of sedimentary organic CO,based on aδC(CO))～CO/He *** using the new models,it was revealed that the loss rates of mantle-derived CO can be as high as 50-99.99%for most gases in the depression,the addition rates of limestone-decomposed CO range from 18%to 150%,and the addition rates of sedimentary organic CO from 11%to 230%.From this study,it was revealed that more *** entered the Dongying Depression than previously recognized.

关键词： Carbon dioxide Origin Fate Helium Carbon isotope

Climatic changes documented by stable isotopes of sedimentary carbonate in Lake Sugan, northeastern Tibetan Plateau of china,since 2 kaBP

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Science Bulletin 2005年第17期 116-125页

作者： QIANG Mingrui1,2, CHEN Fahu2, ZHANG Jiawu2, GAO Shangyu1 & ZHOU Aifeng2 1. china Center of Desert Research at beijing Normal University and key laboratory of Environmental Changes and Natural Disaster, Ministry of Education of china, beijing Normal University, beijing 100875, china 2. Center for Arid Environment and Paleoclimate Research (CAEP), National laboratory of Western china’s Environmental System, Min-istry of Education of china, Lanzhou University, Lanzhou 730000, china

Lake Sugan at the northern edge of the Qaidam Basin was selected as the research object. The temporal se-quence of sedimentary cores retrieved from Lake Sugan since 2 kaBP was reconstructed using the 210Pb, AMS 14C and conventional 14C dating methods. Carbon and oxygen iso-topes of carbonate in the fine-grained lake sediments were analysed. Combined with the changes of δ 18O values of sur-face water and air temperature observation data in the study area, it might be thought that the δ 18O value of the carbon-ate indicates effective moisture, and the changes in δ 13C val-ues are related to annual freeze-up duration of the lake and indirectly indicate air temperature changes in winter half year. From the above, the sequence of climatic changes in the region since 2 kaBP was established. The climatic changes experienced five stages: Warm-dry climate during 0-190 AD; cold-dry climate during 190-580 AD; warm-dry cli-mate during 580-1200 AD (MWP); cold-wet climate during 1200-1880 AD (LIA); cold-dry climate during 1880-1950 AD; and climate warming since 1950s. The air temperature changes in winter half year reflected by carbon isotope since 2 kaBP are in good agreement with the historical literature records and other geologic records, which shows that the climate changes recorded by the stable isotopes from Lake Sugan since 2 kaBP are of universal significance.

关键词： Lake Sugan carbonate stable isotope climatic changes.

Deformation and 40Ar/39Ar thermochronology on the mylonites from south Tan-Lu fault:The geological significance

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Deformation and 40Ar/39Ar thermochronology on the mylonites ...

第九届全国固体核径迹学术研讨会

作者： X.Y.YANG~(1,2) 1.CAS key laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University Science and Technology of china,Hefei 230026,china 2.CAS key laboratory of isotope Geochronology and Geochemistry,Guangzhou Institute of Geochemistry,Guangzhou,510640,china

Tan-Lu fault belt is an important deep fault belt in east china and Asian continent,and its southern part is the key part for geology,where the series of mylonites were developed in the ductile shear zones since its shifting *** plastic deformation is commonly occurring in the *** deformed biotite and feldspar may record the chronological information since the period of deformation,the age from the deformed minerals may represent the important period of the history of deformation and even the shifting movement of the fault *** and plagioclase samples separated from the mylonite samples were determined by 40Ar/39Ar fast neutron activation *** the basis of the deformed minerals with microscope and TEM observation,the stop-heating technique is hired here for determination of Ar/Ar *** ages from single minerals were obtained with the plateau ages of and isoclines ages of 98.49± 0.32Ma-113.89±0.31Ma and 98.80±0.19Ma-113.99±0.27Ma,*** two types of Ar/Ar thermochronology ages are well consistent,so that the convinced deformed ages are supposed to be 98Ma-114 *** 40Ar/39Ar thermochronology ages may represent the cooling ages of the shifting movement of Tan-Lu fault belt.

关键词： ductile shear zones plastic deformation mlonites 40Ar/39Ardating Tan-Lu fault belt

Silurian granulite-facies metamorphism,and coeval magmatism and crustal growth in the Tongbai orogen,central china

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Silurian granulite-facies metamorphism,and coeval magmatism ...

中国矿物岩石地球化学学会第13届学术年会

作者： WANG Hao~1,WU Yuan-bao~(1,2),GAO Shan~1,ZHANG Hong-fei~1, LIU Xiao-chi~1,GONG Hu-jun~2,PENG Min~3,WANG Jing~4,YUAN Hong-lin~2 1.State key laboratory of Geological Processes and Mineral Resources,Faculty of Earth Sciences,china University of Geosciences, Wuhan 430074,china 2.State key laboratory of Continental Dynamics,Department of geology,Northwest University,Xi’an 710069,china 3.Institute of Geophysical and Geochemical Exploration cags,Langfang 065000,china 4.Anhui Institute of geology,Hefei 230001,china

It is intriguing whether the formation of granulite in an orogenic belt is related to magmatism and crustal *** Tongbai orogen is one of the particular areas in the Qinling-Tongbai-Dabie-Sulu orogen that contains both granulites and associated arc magmatic rocks,and thus is an optimal place to address this ***,the formation age and genesis of the granulites and their relations to the magmatic rocks have not yet been well *** situ LA(MC)-ICPMS U-Pb dating,and trace element and Lu-Hf isotope analyses were undertaken on zircon grains from gneiss,granulite,gabbro and granodiorite *** zircons in three granulite samples and a gneiss sample have core-rim *** cores have oval or rounded shapes,oscillatory zones,high Th/U ratios and variable U-Pb ages,suggesting a detrital *** youngest group of the detrital zircons yields a weighted mean pb/U age of(450-±5) Ma,which is interpreted as the maximum depositional age of their protoliths.A major age cluster is ca.450～490 Ma,corresponding to prolonged arc magmatism in the northern Tongbai and Qinling *** group of ages range from 660 to 950 Ma,implying that the Qinling Group

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Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

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Chinese Science Bulletin 2003年第B06期48卷 106-110页

作者： LIU Jihua~(1,2,3), CHEN Lirong~1, WANG Yingxi~4 & HAN Jianxiu~5 1. Institute of Oceanology, Chinese Acadcmy of ences, Qingdao 266071. china 2. key Lab of Marine Sedimentology and Environmental geology, First Institute of Oceanograpgy, State Oceanic Administration, Qingdao 266061. china 3. Graduate School, Chinese Academy of Sciences, beijing 100039. china 4. Modern Analysis Center, Nanjing University. Nanjing 210093. china 5. Guangzhou Marine Investigation Bureau, Guangzhou 510760. china 1. Institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 2. key Lab of Marine Sedimentology and Environmental geology First Institute of Oceanograpgy State Oceanic Administration 266061 Qingdao China 3. Graduate School Chinese Academy of Sciences 100039 Beijing China 4. Modern Analysis Center Nanjing University 210093 Nanjing China 5. Guangzhou Marine Investigation Bureau 510760 Guangzhou China

Fifty-six samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG354) and ICP, the Nd isotopic compositions (εNd(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2 to -2.97 and 4 fluctuation cycles existed during 24.06-22.02 Ma. 4 low εNd(t) values (about -6.4) correspond to high CaCO3 contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma,22.88 Ma and 22.26 Ma, respectively. High εNd(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74-22.37 Ma and 22.06-22.02 Ma, respectively.

关键词：同位素钕示踪原子海水演化中新世太平洋微化石分光计持续期海水样品

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