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1.
陕西商县—丹凤地区丹凤群变质玄武岩的微量元素和同位素地球化学 总被引：26，自引：10，他引：26
丹凤祥变质玄武岩可以分为两类：一类是ＬＲＥＥ富集型的钙碱性玄武岩，另一类是ＬＲＥＥ平坦型的拉斑玄武岩。ＬＲＥＥ富集型的变质玄武岩［（Ｃｅ／Ｙｂ）Ｎ为５～２０］贫Ｔｉ、Ｎｂ、Ｔａ，Ｔｈ＞Ｔａ，Ｎｂ／Ｌａ＜０．８，Ｈｆ／Ｔｈ＞８，Ｚｒ／Ｙ＜３，表明其形成于消减带之上的洋内岛弧环境。该玄武岩的εＮｄ（ｔ）＝＋４．９～＋７．３，εＳｒ（ｔ）＝３．０～＋３２，可能是亏损地幔端元（ＤＭＭ）与第二类富集地幔端元（ＥＭⅡ）混合形成的。大多数玄武岩的（２０６Ｐｂ／２０４Ｐｂ）ｉ比值（１６．５～１７．６）较低，（２０８Ｐｂ／２０４Ｐｂ）ｉ和（２０７Ｐｂ／２０４Ｐｂ）ｉ比值（分别为３６．２～３６．９和１５．３～１５．５）较高，ε１８Ｏ变化较大（５．５‰～９．２‰）。因此，根据微量元素和同位素地球化学资料，丹凤群变质玄武岩的源区可能包括下述组分：１）亏损的软流圈地幔（ＤＭ）；２）富集地幔（ＥＭ）；３）洋内岛弧下地壳（镁铁和超镁铁质岩）；４）消减带岩片带入的组分。而ＬＲＥＥ亏损的拉斑玄武岩具ＭＯＲＢ的特征，Ｔｈ／Ｔａ和Ｌａ／Ｔａ比值近似等于１，ＴｉＯ２＝１．６５％，Ｔｉ／Ｖ＝２２，指示来自亏损的软流圈地幔，形成在与消减作用无关的拉张 相似文献
2.
武当地块基性岩墙群及耀岭河群基性火山岩的Sr、Nd、Pb、O同位素研究 总被引：15，自引：4，他引：11
武当地块基性岩墙群与耀岭河群基性火山岩的 Ｓｒ、 Ｎｄ、 Ｐｂ 同位素特征反映它们具相同的混合地幔源区。前者的（８７ Ｓｒ／８６ Ｓｒ）ｉ＝ ０６９０５～０７０６１, ε Ｎ ｄ （ｔ） ＝ － １９～５０, Δ２０８ Ｐｂ／２０４ Ｐｂ＝ ３５４９～１９０２６, Δ２０７ Ｐｂ／２０４ Ｐｂ＝ ４～８５, Ｔｈ／ Ｔａ 低, Ｌａ／ Ｙｂ 变化大;后者的（８７ Ｓｒ／８６ Ｓｒ）ｉ＝ ０６４８７～０７０７５,ε Ｎ ｄ（ｔ）＝ ０１１～３９４, Δ２０８ Ｐｂ／２０４ Ｐｂ＝ － ８１５８～２１９９５, Δ２０７ Ｐｂ／２０４ Ｐｂ＝ ４４４～１６６８, Ｔｈ／ Ｔａ 和 Ｌａ／ Ｙｂ 较高。这指示它们的源区以岩石圈亏损地幔和第２ 类富集地幔为主要混合组分, 耀岭河群基性火山岩曾遭受地壳物质的混染。结合它们具大陆拉斑玄武岩地球化学特征, 代表同源异相裂谷环境的产物推断, 南秦岭基底陆块在新元古代时曾发生过一次重要裂解作用, 并向早古生代秦岭洋盆转变。 相似文献
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南极乔治王岛中——新生代岩浆岩Sr—Nd—Pb同位素组成及源区特征 总被引：7，自引：1，他引：7
对乔治王岛１１个火山岩和２个侵入岩样品做了Ｓｒ－Ｎｄ－Ｐｂ同位素分析，其中（８７Ｓｒ／８６Ｓｒ）ｉ＝０．７０３２６～０．７０３９２，εＮｄ＝３．０２～６．７２，２０６Ｐｂ／２０４Ｐｂ＝１７．７７６～１８．５１５，２０７Ｐｂ／２０４Ｐｂ＝１５．．５０６～１５．５７１，２０８Ｐｂ／２０４Ｐｂ＝３７．８６８～３８．３０８。根据以上同位素组成及其相互关系并结合岩石学和微量元素特征及火山岩中熔融包裹体成分，得出以下结论：（１）研究的乔治王岛岩浆岩起源于亏损地幔（ＤＭＭ）和地幔流体交代成因的富集地幔ＥＭＩ混合形成的源区；（２）该源区具有广义Ｄｕｐａｌ异常，它正是由于ＥＭＩ组份加入即通过流体交代作用而产生的；（３）流体主要是俯冲深海沉积物脱碳酸盐作用而释放出的富ＣＯ２流体。 相似文献
4.
冀西北水泉沟正长岩杂岩体的成因 总被引：11，自引：5，他引：11
水泉沟碱性正长岩杂岩体侵入于太古宇桑干群变质岩中，岩体主要由碱性长石正长岩、角闪碱长正长岩、正长岩、石英碱长正长岩等组成，属碱性岩系列，在岩石的石英颗粒中见有熔融包体的存在。岩石的稀土元素分布模式呈平滑的右倾模式，无明显的铕异常。岩石的Ｐｂ同位素组成为２０６Ｐｂ／２０４Ｐｂ＝１６．４５７～１８．２８６、２０７Ｐｂ／２０４Ｐｂ＝１５．２７０～１５．４７２、２０８Ｐｂ／２０４Ｐｂ＝３６．５３９～３７．３９３，石英的δ１８Ｏ值为８．０‰～８．５‰，（８７Ｓｒ／８６Ｓｒ）ｉ≈０．７０５，岩石的ｔＤＭ为１．６～１．９Ｇａ，εＮｄ（ｔ）为－７．４５～－１３．１，明显大于区域基底的εＮｄ（ｔ）值（－２０±）。以上结果表明，岩体为上地幔和下地壳物质部分熔融的产物。岩体角闪石３９Ａｒ－４０Ａｒ年龄３２７Ｍａ，为海西期岩浆作用的产物 相似文献
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汉诺坝玄武岩中辉石岩类包体Nd、Sr、Pb同位素及其成因信息 总被引：13，自引：1，他引：13
对汉诺坝地区的１２个辉石岩和１个麻粒岩包体进行了Ｎｄ、Ｓｒ、Ｐｂ同位素测定，发现辉石岩组成有很大变化，１４３Ｎｄ／１４４Ｎｄ比值为０．５１１６０—０．５１３１４，８７Ｓｒ／８６Ｓｒ比值为０．７０２９—０．７０８６，２０６Ｐｂ／２０４Ｐｂ比值为１５．９４２—１８．６８３，２０７Ｐｂ／２０４Ｐｂ比值为１５．２６４—１５．５６９，２０８Ｐｂ／２０４Ｐｂ比值为３６．２１３—３８．７４４，显示了其复杂成因ｑ推测具有高Ｓｒ、低Ｎｄ和低Ｐｂ同位素组成的辉石岩是地幔早期富集的产物，与麻粒岩、辉长岩包体有类似成因；具有弱至中等亏损的Ｎｄ、Ｓｒ同位素和高放射成因Ｐｂ的辉石岩是亏损地幔近期富集或交代的产物 相似文献
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武当地块基性岩墙群及耀岭河群基性火山岩的Sr,Nd,Pb,O同位素研究 总被引：9，自引：2，他引：7
武当地块基性岩墙群与耀岭河群基性火山岩的Ｓｒ、Ｎｄ、Ｐｂ同位素特征反映它们具相同的混合地幔源区。前者的（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．６９０５￣０．７０６１,εＮｄ（ｔ）＝－１．９￣５．０,Δ＾２０８Ｐｂ／＾２０４Ｐｂ＝３５．４９￣１９０．２６,Δ＾２０７Ｐｂ／＾２０４Ｐｂ＝４￣８５,Ｔｈ／Ｔａ低,Ｌａ／Ｙｂ变化大;后者的（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．６４８７￣０．７０７５,εＮｄ（ｔ）＝０ 相似文献
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夏杖子金矿严格受构造破碎带控制，围岩蚀变主要为钾长石化、黄铁矿化、硅化和碳酸盐化。矿石中自然金有显微金和次显微金两种状态，金的成色为８３５～９２９；矿石包裹体成分主要以Ｈ２Ｏ为主，另含有ＣＯ２、Ｋ＋、Ｎａ＋、Ｆ－、Ｃｌ－和ＳＯ２－４等离子；矿石的稳定同位素组成：δ３４Ｓ为－２３．３８‰～－１４．４７‰，δＤ为－９１．７‰～７３．１‰，δ１８ＯＨ２Ｏ为５．６８～６．２５‰，２０６Ｐｂ／２０４Ｐｂ为１６．４１１～１６．６１５，２０７Ｐｂ／２０４Ｐｂ为１５．２２８～１５．２５６，２０８Ｐｂ／２０４Ｐｂ为３６．２６８～３６．３５６；矿石、脉岩和岩体具有相似的ＲＥＥ、Ｋ、Ｒｂ、Ｓｒ及微量元素地球化学特征。矿床中金的富集与成矿构造、围岩蚀变、矿化期次和矿石类型等多种因素有关，成矿作用发生于燕山晚期（１０５．４±７．２Ｍａ），成矿热液主要为岩浆热液，成矿物质来源于硅铝壳中下部太古代结晶基底，矿床成因为中－低温热液金矿床。最后对矿床的找矿标志进行了总结，指出了找矿方向，认为夏杖子金矿具有较好的找矿远景，尤其是矿床深部 相似文献
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南天山托云盆地晚白垩世——早第三纪玄武岩的地球化学特征 … 总被引：18，自引：0，他引：18
托云盆地晚白垩世－－早第三纪碱性橄榄玄武岩Ｓｒ、Ｎｄ、Ｐｂ同位素组成表明,本区玄武岩以低Ｓｒ、Ｐｂ和相对高的Ｎｄ同位素值（＾８７Ｓｒ／＾８６Ｓｒ为０．７０３５５４￣０．７０３８８４;＾１４３Ｎｄ／＾１４４Ｎｄ为０．５１２８３８￣０．５１２９０４;＾２０６Ｐｂ／＾２０４Ｐｂ为１８．００６３￣１８．４７２０;＾２０７Ｐｂ／＾２０４Ｐｂ为１５．４４１１￣１５．５０６０;＾２０８Ｐｂ／＾２０４Ｐｂ为３７． 相似文献
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青藏高原岩石圈演化的记录：藏北超钾质及钠质火山岩的岩石学与地球化学特征 总被引：56，自引：12，他引：44
藏北鱼鳞山超钾质火山岩为一中等规模的熔岩被, 可分为三期。前两期主要为霞石黝方白榴石响岩、霞石白榴斑岩等, 后期主要为方钠石霓石粗面岩、霓霞粗面岩等。时代为１８～３０ Ｍａ。本区超钾质岩浆 Ｓｉ Ｏ２ 强烈不饱和、强碱性、高度富集 Ｌ Ｒ Ｅ Ｅ及 Ｌ Ｉ Ｌ Ｅ、放射成因 Ｓｒ、 Ｐｂ 及非放射成因 Ｎｄ 同位素 （８６ Ｓｒ／８７ Ｓｒ＝ ０７０８７６６～０７０９１６２, ２０６ Ｐｂ／２０４ Ｐｂ＝ １８８８２８８８～ １９１０４７５１, ２０７ Ｐｂ／２０４ Ｐｂ＝ １５６４２０３７ ～ １５８２８４５８, ２０８ Ｐｂ／２０４ Ｐｂ＝ ３９１３８９２１ ～ ３９６８６８３５ 及１４３ Ｎｄ／１４４ Ｎｄ＝ ０５１２１１６ ～０５１２３４２）,其上述特征指示岩浆源区为受到地壳物质强烈交代的富集 Ｅ Ｍ Ｉ Ｉ型地幔。藏北拉嘎拉钠质碱性橄榄玄武岩为高原面上的剥蚀残丘, 时代为６０ Ｍａ。其岩石学、 Ｒ Ｅ Ｅ、微量元素及 Ｓｒ Ｎｄ Ｐｂ 同位素指示了岩浆源区为受到洋壳俯冲物质交代的轻度富集地幔。本研究结果指示, 羌塘高原南部富集地幔的形成可能是受到印度板块俯冲的影响。 相似文献
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本文首次对桐柏山花岗岩类的Ｐｂ、Ｏ、Ｓｒ同位素进行研究。其长石铅同位素组成是２０４Ｐｂ＝１．４００（１．３８９－１．４１１），２０６Ｐｂ／２０４Ｐｂ＝１７．１４８（１６．８４７－１７．４３８），２０７Ｐｂ／２０４Ｐｂ＝１５．４２８（１５．３７８－１５．４８４），２０８Ｐｂ／２０４Ｐｂ＝３７．８８６（３７．５８３－３８．２９６）。与邻区花岗岩类相比，基本相当于胶东地区。全岩矿δ１８Ｏ＝８．４８（７．４９－９．３７）。８７Ｓｒ／８６Ｓｒ（ｉ）＝０．７０９０（０．７０６４－０．７１３８）。这些数据结合岩石矿物特征表明，本区花岗岩类的成因类型属Ⅰ型或同熔型。铅同位素组成揭示本区大地构造可能归属华北地台。 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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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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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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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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Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献
18.
岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
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Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA 总被引：1，自引：0，他引：1
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. 相似文献