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周磊 《矿物岩石地球化学通报》1985,(4)
分别对西藏岗巴与广东南雄的K/T(白垩系/第三系)剖面及四川广元与重庆P/Tr(二叠系/三叠系)界线剖面进行了野外考察和系统取样,还收集了浙江长兴P/Tr界线剖面,国外五个K/T界线剖面及贵州遵义下寒武统剖面的系统样品。利用仪器中子活化分析测定样品中的Ir与其他元素。 1.岗巴K/T界线铱异常:该剖面三个粘土样品中分别测得Ir为7.3、2.5和2.9ppb,较之其上下沉积物(Ir<0.5ppb)显示铱异常;相对深海沉积物而言,这三个剖面富铱层也显示异常。 相似文献
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浙江长兴煤山二叠-三叠系混生层1中微球粒的发现及其意义 总被引:3,自引:0,他引:3
<正> 浙江长兴煤山是中国南部上二叠统长兴阶和二叠、三叠系界线层型剖面(共A,B,C,D,E,Z六条剖面)的所在地。孙亦因等(1984)在D剖面的界线粘土及其上覆的灰黑色泥岩中发现铱异常,提出了二叠、三叠纪交替时可能发生了一次地外来的陨击事件。然而,人们更关心的似乎是作为铱异常物质来源最可靠证据的宇宙尘或微玻陨石是否也存 相似文献
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奥陶系与志留系界线处生物绝灭事件及其与铱和碳同位素异常的关系 总被引:14,自引:1,他引:14
用放射性化学和仪器中子活化分析,研究了宜昌分乡502号奥陶系—志留系界线剖面40多种元素丰度的分布。结果表明,在奥陶系—志留系界线层中铱的丰度突然增至0.64 ppb,显示出明显的铱异常。而且铱和一些亲铁和亲硫元素丰度的变化呈正相关性。在宜昌黄花场剖面的相同界线层中,还存在δ~(13)C偏离。上述地球化学的信号有利于奥陶纪末期生物集群绝灭可能与地外事件有关的设想,并为奥陶系—志留系界线应划在Hirnantia-Kinnella和G.persculptus带之间提供了新的证据。 相似文献
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陕西段家坡黄土剖面中布容/松山古地磁界线附近铱异常的发现及其启示 总被引:3,自引:0,他引:3
利用高灵敏度放射化学中子活化分析方法,对我国陕西段家坡黄土剖面早-中更新统(约0.73Ma)沉积界线附近铱和其它元素的丰度进行了测定。结果表明,在布容/松山(B/M)古地磁界线附近铱的含量明显增大,最大值为46.3pg/g。相对于整个剖面的平均背景值(约15pg/g)大约富集了3倍。用地壳元素钪进行标准化之后,铱异常十分明显,而其它元素在界线附近则没有变化。黄土剖面上铱异常的赋存层位与西南太平洋钻 相似文献
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中国南部贵州省的睦化剖面是国际泥盆纪/石炭纪三个界线层型候选剖面之一。虽然地层和古生物的资料已有发表,但稳定同位素的研究尚未做过。睦化剖面详细的δ~(13)C和δ~(18)O的分析结果揭示,在Siphonodella crenulata牙形石带底部存在一个有意义的短暂δ~(13)C负异常,其值为—8~9‰。这是首次在泥盆纪与石炭纪界线处发现的δ~(13)C负异常,这类似于二叠纪/三叠纪界线、白垩纪/第三纪界线 前寒武纪/寒武纪界线报导的δ~(13)C异常。因 相似文献
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广西桂林南边村剖面作为全球泥盆系-石炭系界线辅助层型剖面,在界线处的δ13 C值、δ18 O值、w(Ni)、w(Al2O3)等都出现一定程度的突变,这为该剖面的高精度地层划分和对比提供了可能性。南边村剖面和黄茆剖面的化学地层学对比显示黄茆剖面长顺页岩的时代应相当于南边村剖面第56层至第60层,而牙形石演化的证据表明南边村剖面的第56层底部为泥盆系-石炭系界线,因此黄茆剖面的泥盆系-石炭系界线应位于长顺页岩底部。Hangenberg事件作为一次泥盆纪-石炭纪之交的全球性事件,在斜坡相的南边村剖面上也有一定的表现,例如w(Al2O3)上升所代表的海退,δ13C值下降代表的生物灭绝事件,以及Ni异常事件。 相似文献
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本文主要介绍了近几年来我国南方和北方海、陆相二叠—三叠纪地层及生物群研究的新进展。前者包括长兴阶的详细划分对比;混生生物群和岩相、地球化学的最新研究成果;界线粘土层中铱异常的发现及界线附近碳、氧同位素的变化等。后者包括甘肃地区晚二叠世甘肃兽和安哥拉植物群的发现;新疆二齿兽与水龙兽混生及北方广大地区二叠—三叠系孢粉系列的建立和对比等。提出浙江长兴煤山和四川华蓥邻水及广元上寺三条剖面可作为海相二叠—三叠系界线层型的候选剖面,新疆吉木萨尔大龙口剖面作为陆相二叠—三叠系界线层型候选剖面,高铱含量表明此时曾发生过重大事件。 相似文献
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S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
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奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
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E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
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Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
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Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km2 and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world. 相似文献
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《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population). 相似文献
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Marta L. PATINO-DOUCE Alberto PATINO-DOUCE Mazhar QAYYUM Roger L. NIELSEN 《Geostandards and Geoanalytical Research》1994,18(2):195-198
We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al2 O3 -SiO2 ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses. 相似文献