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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, {3. University, lanzhou 73.000,{2. 2. key laboratory of gas geochemistry, institute of geology and geophysics, chinese Academy of sciences, lanzhou 73.000,{2. 3. College of Resources Science & Technology, Beijing Normal University, Beijing 100875,{2. 1. Resources and Environmental School Lanzhou University Lanzhou 730000 China 2. key laboratory of gas geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China 3. College of Resources Science & Technology Beijing Normal University Beijing 100875 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 ~3.e/~4He in almost all samples range from 0.82.Ra to 2.74 Ra, whereas^(40)Ar/^(3.)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/~3.e range from 2..6 x 10~9 to 1050 x 10~9,N_2.Ar from 92. to 56612. and N_2.~3.e 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.

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. {3. of gas geochemistry, institute of geology and geophysics, chinese Academy of sciences, lanzhou 73.000, china) [a]College of Resources sciences & Technology Beijing Normal University Beijing China [b]key laboratory of {2. {3. Institute of Geology and Geophysics Lanzhou 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 δ13.1 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 - 3.3. to - 117‰, and δ13.CO{3.values from - {3.. 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 δ13.1 and δ13.CO{3.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 δ13.1 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.

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 10003., china 3. SHRIMP isotope laboratory, chinese Academy of Geological sciences, Beijing 10003., 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-13.) 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.

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. {3., lanzhou institute of geology, chinese Academy of sciences, lanzhou 73.000, china institute of Environmental Science, Beijing Normal University, Beijing 100875, china 1. State key laboratory of {2. {3. Lanzhou Institute of Geology Chinese Academy of Sciences 730000 Lanzhou China 2. institute of Environmental Science Beijing Normal University 100875 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.

Forcing mechanism of the Pleistocene east Asian monsoon variations in a phase perspective

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Science china Earth sciences 2005年第10期48卷 1708-1717页

作者： TIAN Jun1,2. WANG Pinxian1, CHENG Xinrong1, WANG Rujian1 & SUN Xiangjun1,3.1. State key laboratory of Marine {2., Tongji University, Shanghai 2.0092. china 2. institute of geology and geophysics, chinese Academy of sciences, Beijing 10002., china 3. {13. of Botany, chinese Academy of sciences, Beijing 100093. china State key laboratory of Marine {2. Tongji University Shanghai{3. institute of geology and {2. {3. Academy of sciences Beijing china institute of Botany chinese Academy of {2. Beijing{3.

The deep sea records from the ODP Sites 1143.and 1144 in the northern and southern South china Sea (SCS), including foraminiferal δ 18O and δ 13., Opal% and pollen percentage, reveal that the variations of the east Asian monsoon have been closely correlated with the variations of the Earth’s orbital parameters (eccentricity, obliquity and precession) and the global ice volume on orbital scale. All the monsoonal proxies show strong 100 ka, 41 ka and 2. ka cycles. Although G. ruber δ 13. of Site 1143.is coherent with the ETP (ETP= normalized (eccentricity + obliquity-precession) at eccentricity, obliquity and precession bands, most of the coherent relationship focuses on the precession band, and the other monsoonal proxies are coherent with the ETP only at the precession band, which indicate that precession dominates the Pleistocene tropical climate changes. The phase relationship of the monsoonal proxies with the foraminiferal δ 18O implies that the global ice volume changes have played a significant role in modulating the east Asian monsoon climate, at least dominating the winter monsoon. This forcing mechanism of the east Asian monsoon is apparently different from that of the Indian ocean mon-soon. The variations of the east Asian monsoon at the precession band, at least that of the winter monsoon, have been controlled not only by the sensible heating but also by the latent heating of the surface water in the South china Sea.

关键词： South china Sea, ODP, east Asian monsoon, orbital forcing, global ice volume.

Digital image analysis of palaeoenvironmental records and applications

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chinese Science Bulletin 2002年第23期47卷 1957-1963,2025-2026页

作者： SUN Donghuai1,2. LIU Yu2.& TAN Ming3.. South china Sea {3. of Oceanology, {2. Academy of sciences. Guangzhou 5103.1, china 2. State key laboratory of Loess and Quaternary geology, Earth Environmental {3., {2. Academy of sciences, Xi’an 710075, china 3.{12., {2. Academy of sciences, Beijing 10002., china South china Sea institute of Oceanology Chinese Academy of Sciences Guangzhou China State key laboratory of Loess and Quaternary {2. Earth Environmental Institute Chinese Academy of Sciences Xi’an China institute of geology and {2. Chinese Academy of Sciences Beijing China

Environmental change signals in geological or biological records are commonly reflected on their reflecting or transmitting images. These environmental signals can be extracted through digital image analysis. The analysis principle involves section line selection, color value reading and calculating environmental proxy index along the section lines, layer identification, auto-chronology and investigation of structure evolution of growth bands. On detailed illustrations of the image technique, this note provides image analyzing procedures of coral, tree-ring and stalagmite records. The environmental implications of the proxy index from image analysis are accordingly given through application demonstration of the image technique.

关键词： digital image environmental records.

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 73.000, china 2.Department of geology, Northwest University, Xi’an 710069, china 1. key laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China2. Department of Geology Northwest University Xi’an 710069 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 δ13. and δD values of n-alkanes in the samples, and plant types can be distinguished using the cross plot of δD vs. δ13. 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

Neogene eolian deposits within the West Qinling Mountains:Climatic and tectonic implications

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chinese Science Bulletin 2010年第15期55卷 1483-1487页

作者： GE JunYi 1,2.& GUO ZhengTang 3.1 State key laboratory of Loess and Quaternary {2. (SKLLQG),institute of Earth Environment,chinese Academy of sciences,Xi’an 710075,china 2.Graduate University of chinese Academy of sciences,Beijing 100049,china 3.key laboratory of Cenozoic {2. and Environment,institute of {2. and geophysics,chinese Academy of sciences,Beijing 10002.,china State key laboratory of Loess and Quaternary {2. (SKLLQG) Institute of Earth Environment Chinese Academy of Sciences Xi''an 710075 China Graduate University of chinese Academy of sciences Beijing 100049 China key laboratory of Cenozoic {2. and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The Qinling Mountains constitute a key climate barrier between southern and northern *** recent investigations revealed widely spread eolian deposits of Neogene age mantling the piedmont highlands of the intermountain basins within West ***-mammalian fossils dated a 150.2.m section (NL-VI) near Xihe for the late Miocene to Pliocene (～10-4 Ma).Soil micromorphology,grain-size and geochemical analysis consistently define typical loess-soil alternations for the upper (0-66 m) and lower (98-150.2.m) parts of the section,with the middle section (66-98 m) having been affected by episodic slope *** results add important insights to the earlier studies about the widespread eolian deposition in northern{3. during the Miocene,prior to 8 *** also suggest that the basic configuration of the ridges and inter-ridge basins of West Qinling has already formed by ～10 *** well-preserved eolian deposits are unlikely to support intense substratum deformation and rapid uplift of West Qinling since the late Miocene.

关键词：秦岭山脉风尘堆积构造意义气候新近纪晚中新世地球化学分析风尘沉积

Discovery of seep carbonate nodules as new evidence for gas venting on the northern continental slope of South china Sea

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chinese Science Bulletin 2006年第10期51卷 1228-1237页

作者： CHEN Zhong1,2.3. YAN Wen1,2.3. CHEN Muhong1,3. WANG Shuhong1,2.3. LU Jun1,3. ZHANG Fan1,3. XIANG Rong1,3. XIAO Shangbin1,3. YAN Pin1,2.3.& GU Senchang1,2.3.1. South china Sea institute of Oceanology, {2. Academy of Sci-ences, Guangzhou 5103.1, china 2. Guangzhou Center for gas Hydrate Research, {2. Academy of sciences, Guangzhou 5103.1, china 3. key laboratory of Marginal Sea geology, South china Sea institute of Oceanology and Guangzhou institute of geochemistry, {2. Academy of sciences, Guangzhou 5103.1, china South china Sea institute of Oceanology Chinese Academy of Science Guangzhou China Guangzhou Center for gas Hydrate Research Chinese Academy of Sciences Guanzhou China key laboratory of Marginal Sea {2. South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China

Seep carbonate nodules were firstlycollected from the southwestern Dongsha area onnorthern continental slope of South china Sea formineralogical and geochemical studies. The resultsof X-ray diffraction show that carbonate nodules arecomposed of Fe-rich domolite,siderite and a few cal-cite and aragonite, as well as a small quantity ofnon-carbonate minerals such as goethite, quartz andclay minerals. Fe-rich dolomite and siderite charac-terized by euhedral microcrystalline structure weredirectly precipitated at cold seeps. The δ 13. valuesfor Fe-rich dolomite and siderite in the bulk nodulesvary from ?18.2.‰ to ?3..07‰, and the δ 18O valuesrange from 0.42.to 2.76‰. Their moderate depleted13. reflects that carbon origin is possibly thermoge- netic gas or mixed gas, which is evidence of gasventings in the seafloor. Moreover, massive wormtube fossils related to cold seeps were found on thesurfaces of carbonate nodules, and the conduitsand/or channels in semi-solidified nodules whichwere not filled by carbonate or sediment were alsoobserved. A preliminary conclusion is that activemicro gas venting with a conduit/channel diameterrange from 2.0 μm to 600 μm possibly exists inmodern seafloor of the carbonate nodule area.

关键词：渗出碳酸盐节碳氧同位素甲烷渗漏天然气水化物