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Characteristics and origins of primary fluids and noble gases in mantle-derived minerals from the Yishu area,Shandong Province,china

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Science china Earth sciences 2006年第1期49卷 77-87页

作者： MA Jinlong1,2. TAO Mingxin2.3 & YE Xianren2.1. Resources and Environmental School, lanzhou University, lanzhou 730000,{2. 2. key laboratory of gas geochemistry, institute of geology and geophysics, chinese academy of sciences, lanzhou 730000,{2. 3. College of Resources Science & Technology, Beijing Normal University, Beijing 100875,{2. Resources and Environmental School Lanzhou University Lanzhou China key laboratory of {2. geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China College of Resources Science & Technology Beijing Normal University Beijing China

Fluids and noble gases of mantle-derived materials are important tracers forthe mantle information. Compositions of primary fluids and noble gases in mantle-derived mineralsfrom the Yishu area, Shandong Province,{2., were tested by the methods of heat-bursting andheat-melting respectively. The fluids are mainly composed of CO_2. CO and H_2. which account forabout 90% of the total, and are similar to the mantle-derived rocks from other areas of easternchina; ratios of ~3He/~4He in almost all samples range from 0.82.Ra to 2.74 Ra, whereas^(40)Ar/^(36)Ar from 2.9.5 to 758.8. Both ranges are much lower than those of the typical oceanmantle-derived samples (such as MORB) and primarily reflect the influences of the atmosphericcomponents and the radiogenic isotopes. Ratios of C/~3He range from 2..6 x 10~9 to 1050 x 10~9,N_2.Ar from 92. to 56612. and N_2.~3He from 2.5 x 10~9 to 2. x 10~9, similar to those in westernUnited States and New Zealand which belong to the tectonic plate collision regions. The ratios fallin the intersect of mantle-crust-atmosphere in the comprehensive tracer-charts, reflecting theinfluences of the atmosphere and the crusts with organic components. Our results suggest that thecomposition of the primary fluids and the isotopic ratios of the noble gases may either reflect theevolution process of mantle-derived rocks connected with the rise and eruption of magma, or theinfluence of the ancient subduction-plate on the continental mantle of this region.

关键词： noble gases, primary fluids, mantle-derived minerals, Yishu area.

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The consideration and choice on exploiting energy source

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chinese Science Bulletin 1999年第18期44卷 1717-1728页

作者： WANG XianbinState key laboratory of {2. geochemistry, lanzhou institute of geology, chinese academy of sciences , lanzhou 730000, china State key laboratory of {2. geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences Lanxhou China

A problem of petroleum energy crisis will probably be faced in the late 2.st century. It is impossible to discover the giant oil fields again based on the traditional knowledge and theory of petroleum geology. From the global development point of view as well as the situation in china, the five choices of energy source in the future are to ( i ) extend the field of exploration in conventional petroleum and natural {2. source, and exploit oil-{2. source in ocean and

关键词： energy sources in the future unconventional gas coal hydrogen controllable nuclear fusion 3He source on the moon.

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Research progress in studies on the coalbed gas geochemistry

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Progress in Natural Science:Materials International 2006年第3期16卷 215-220页

作者： TAO Mingxin (College of Resources sciences & Technology, Beijing Normal University, Beijing 100875, china {2. laboratory of gas geochemistry, institute of geology and geophysics, chinese academy of sciences, lanzhou 730000, china) College of Resources sciences and Technology Beijing Normal University Beijing 100875 China key laboratory of {2. geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China

The current situation of geochemical studies on coalbed gas is reviewed in this paper. Generally, coalbed gas is composi-tionally dominated by methane with δ13C1 values ranging approximately from - 80‰ to - 10‰. However, few isotopic studies have been carried out on other components of coalbed gas except for hydrogen and carbon dioxide, whose δDCH4 values available for utilization vary from - 333‰ to - 117‰, and δ13CCO2.values from - 2.. 4‰ to + 18. 6‰. Two major types of coalbed gas, thermogenic gas and secondary biogenic gas, have been identified, and there are also some other classification criteria. Compared with conventional natural gases, coalbed gas has a wide distribution range of δ13C1 and δ13CCO2.values, especially possessing some extremely heavy values. Current problems that remain unsolved in the coalbed gas geochemistry include the variation mechanism, controlling factors and application of carbon and hydrogen isotopes of methane, the relation between the values of δ13C1 and Ro, the systematic classification scheme and criterion of genetic types, and the application of the coalbed gas geochemistry in evaluating target districts of the coalbed gas exploration.

关键词： coalbed gas geochemistry isotopic composition genetic type novel resource.

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Evidence from carbon isotope measurements for biological origins of individual long-chain n-alkanes in sediments from the Nansha Sea,china

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chinese Science Bulletin 2002年第7期47卷 578-581页

作者： DUAN Yi & WANG ZhipingState key laboratory of {2. geochemistry, lanzhou institute of geology, chinese academy of sciences, lanzhou 730000, china institute of Environmental Science, Beijing Normal University, Beijing 100875, china State key laboratory of {2. geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences Lanzhou China institute of Environmental Science Beijing Normal University Beijing China

Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show that the long-chain n-alkanes have a light carbon isotopic composition and a genetic feature of mixing sources, and low-latitude higher plants and microbes are considered to be their main end member sources. Based on the abundances and carbon isotopic compositions of individual n-alkanes, the fractional contributions of the two end member sources to individual n-alkanes are quantitatively calculated by using a mixing model. The obtained data indicate that the fractional contributions of the two biological sources are different in the three samples. A trend is that the contribution of microbes increases with the depth. These results provide the theory basis and quantitatively studied method for carbon isotopic applied research of individual n-alkanes.

关键词： modern marine sediment individual n-alkane carbon isotopic composition biological source.

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Hydrogen isotopic characteristics and their genetic relationships for individual n-alkanes in plants and sediments from Zoigê marsh sedimentary environment

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Science china Earth sciences 2010年第9期53卷 1329-1334页

作者： DUAN Yi1, ZHENG ChaoYang2.& WU BaoXiang1 1 key laboratory of Petroleum Resources Research,{2., chinese academy of sciences, lanzhou 730000, china 2.Department of geology, Northwest University, Xi’an 710069, china key laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China Department of geology Northwest University Xi’an China

To understand internal relations of their hydrogen isotopic compositions in typical marsh environment, we, using GC-IRMS analytical technique, measured the hydrogen isotopes of individual n-alkanes in the herbaceous plant, woody plant leaf, and sediments from Zoigê marsh in china. The results show significant differences in the hydrogen isotopic compositions of n-alkanes among the different kinds of plants and the different species in the same kind. δD values of n-alkanes in the herbaceous plants (from -2.4‰ to -184‰) are lighter than those in woody plant leaf ( from -195‰ to -142. ), and the hydrogen isotopic compositions of n-alkanes in K. tibetica P. are lighter than P. pratensis L. The mean δD values of n-alkanes in the sediments from Zoigê marsh reflect that they were derived from herbaceous plants, which is consistent with the peat samples being composed mainly of herbaceous plant remnants. The significant differences in hydrogen isotopic compositions of n-alkanes among the sedimentary samples are caused possibly by environment factors and the difference in input quantity of different herbaceous plants. A certain negative correlation exists between the δ13C and δD values of n-alkanes in the samples, and plant types can be distinguished using the cross plot of δD vs. δ13C values of n-alkanes in the plants. These data and recognitions provide scientific basis for hydrogen isotopic applied research of individual n-alkanes.

关键词： marsh environment plants sediments individual lipids hydrogen isotopes genetic relationship

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Pollen records of Holocene vegetation and climate changes in the Longzhong Basin of the chinese Loess Plateau

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Progress in Natural Science:Materials International 2007年第12期17卷 1445-1456页

作者： Tang Lingyu1 and An Chengbang2.1. Nanjing institute of geology and Paleontology,{2., Nanjing 2.0008, china 2. key laboratory of Western china’s Environment Systems, MOE, lanzhou University, lanzhou 730000, china) Nanjing institute of geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China key laboratory of Western{2.'s Environment Systems Lanzhou University Lanzhou 730000 China

Pollen records with an average time resolution of 2.-2.0 years from Holocene loess sections at Dingxi, Qin'an, and other localities of Gansu Province reveal a detailed history of vegetation and climate changes in the western Loess Plateau. For most time of the Holocene, the landscape was dominated by grasslands or forest steppes. However, during the middle Holocene (7.5-5.8 ka BP), relatively dense forests developed, and the endemic vegetation flourished, suggesting a much warmer and more humid climate condition than the present. Superimposed upon this general pattern are several dry intervals marked by the episodic expansion of grasslands or forest steppe. Xeric vegetation expanded after 3.8 ka BP, indicating a trend towards dry conditions.

关键词： pollen records glasslands coniferous forests Holocene Loess Plateau.

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SHRIMP zircon U-Pb geochronology of early Mesozoic felsic igneous rocks from the southern Lancangjiang and its tectonic implications

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Science china Earth sciences 2006年第10期49卷 1032-1042页

作者： PENG Touping1,2. WANG Yuejun1, FAN Weiming1, LIU Dunyi3, SHI Yuruo3 & MIAO Laicheng4 1. key laboratory of Isotope Geochronology and {2., Guangzhou institute of {2., chinese academy of sciences, Guangzhou 510640, china 2. Graduate University of chinese academy of sciences, Beijing 100039, china 3. SHRIMP isotope laboratory, chinese academy of Geological {12., Beijing 100037, china 4. institute of geology and geophysics, chinese academy of sciences, Beijing 10002., china key laboratory of Isotope Geochronology and {2. Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Graduate University of chinese academy of sciences Beijing China SHRIMP isotope laboratory Chinese Academy of Geological Sciences Beijing China institute of geology and {2. Chinese Academy of Sciences Beijing China

The SHRIMP zircon U-Pb geochronology of three typical samples, including two monzo nitic granites from the Lincang batholith and a rhyolite from the Manghuai Formation are presented in the southern Lancangjiang, western Yunnan Province. The analyses of zircons for the biotite monzonitic granites from the northern (02.X-137) and southern (2.JH-10) Lincang batholith show the single and tight clusters on the concordia, and yield the weighted mean 2.6Pb/2.8U ages of 2.9.4 ± 3.0 Ma and 2.0.4 ± 3.6 Ma, respectively, representing the crystallized ages of these granites. The zircons for the rhyolitic sample (02.X-95) from the Manghuai Formation give a weighted mean 2.6Pb/2.8U age of 2.1.0 ± 5.0 Ma. These data suggest that the igneous rocks from the Lincang granitic batholith and Manghuai Formation have a similar crystallized age. In combination with other data, it is inferred that both were generated at a narrow age span (~2.0 Ma) and were originated from the postcollisional tectonic regime. An early Proterozoic 2.6Pb/2.8U apparent age of 1977±44 Ma is additionally obtained from one zircon from the biotite monzonitic granite (southern Lincang batholith), indicative of devel- opment of the early Proterozoic Yangtze basement in the region. These precisely geochronological data provide important constraints on better understanding the Paleozoic tectonic evolution of the Tethys, western Yunnan Province.

关键词： SHRIMP zircon U-Pb dating, Middle Triassic, Lincang granitic batholith, Manghuai Formation rhyolite, southern Lancangjiang.

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PGE patterns of ores of Dajing Cu-polymetallic deposit in Linxi County, Inner Mongolia:Indicator to source of metallogenic elements

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chinese Science Bulletin 2002年第13期47卷 1119-1124页

作者： CHU Xuelei, SUN Min & ZHOU Meifuinstitute of geology and {2., chinese academy of sciences, Beijing 10002., china key laboratory of Mineral Resources, institute of geology and geophysics, chinese academy of sciences, Beijing 100101, china Department institute of geology and {2. Chinese Academy of Sciences Beijing China key laboratory of Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Department of Earth sciences The University of Hong Kong Hong Kong China

By comparing PGE patterns of sulfide ores with that of basic-ultrabasic dikes occurring in the Dajing Cu-polymetallic deposit, we discover that there are similar positive slopes between the basic-ultrabasic dikes and the black ores composed mainly of sphalerite and galena, reflecting affinity of their source. The PGE patterns of the yellow ores composed basically of chalcopyrite, arsenopyrite and pyrite are actually different. One is close to the pattern of the mantle 1herzolite, and others resemble the pattern of the basic rocks. However, the concentrations of Ru are higher in the yellow ores, reflecting that sulfur attains or approaches saturation in their parent magma. The PGE characteristics of ores and dikes show that the magmas derived from the deep of crust and the metallogenic elements were supplied mainly by growth material of the crust. In addition, the mantle-derived magma also offered some elements.

关键词： Da Hinggan area polymetallic deposit PGE pattern hypomagma.

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Quantitative assessment of the complexity of geological structures in terms of seismic propagators

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Science china Earth sciences 2010年第1期53卷 54-63页

作者： FU LiYun key laboratory of the Earth’s Deep Interior,{2. of geology and geophysics,chinese academy of sciences,Beijing 10002.,china key laboratory of the Earth’s Deep Interior Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

How a wave interacts with heterogeneous media has been pursued by many *** complexity of subsurface heterogeneities is seismologically a relative concept to wavelengths of seismic waves.A growing perception is that velocity variations,propagation angles,and computational accuracies are closely related at a variety of scales.A tentative strategy to quantitatively evaluate the complexity of subsurface heterogeneous media is presented in this article to see what scales of geological heterogeneities to be captured by *** express complex subsurface structures as the slowness-and angularheterogeneity spectra to quantify velocity contrasts and dipping-angle distributions of complex geological *** the other hand,the scaling characteristics of a propagator are measured through dispersion analysis by its angular spectra plotted against refractive indexes and propagation angles,respectively.A parameter termed as imaging efficiency is introduced by associating the geological heterogeneity spectra with the propagator's angular spectra to understand the coherent interference between the medium's heterogeneity and the propagator's scaling ***,a complexity coefficient can be defined to evaluate geological complexities in terms of *** application of this strategy is demonstrated to the SEG/EAEG salt model.

关键词： geological heterogeneity spectra seismic imaging propagator’s angular spectra imaging efficiency complexity coefficient

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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 {2. of Oceanology key laboratory of Marginal Sea geology, South china Sea {2. of Oceanology and Guangzhou {2. of geochemistry, chinese academy of sciences, Guangzhou 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 {2. South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Graduate University of the chinese academy of sciences Beijing China

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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