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1.
富集地幔^40Ar／^36Ar比率的再评价 总被引：1，自引：0，他引：1
地幔的＾４０Ａｒ／＾３６Ａｒ比率含有重要的有关地球早期脱气程度的信息。许多研究者认为在亏损地幔，比如通过大洋中脊玄武岩（ＭＯＲＢ）采集的样品中＾４０Ａｒ／＾３６Ａｒ比率高达２８０００。然而，富集地幔中的＾４０Ａｒ／＾３６Ａｒ比率存在着激烈的争论。我们使用＾４Ｈｅ／＾４０Ａｒ－＾３６Ａｒ／＾４０Ａｒ和＾４Ｈｅ／＾４０Ａｒ－＾３Ｈｅ／＾４０Ａｒ图重新考察了ＭＯＲＢ和热点火山中Ｈｅ、Ａｒ惰性气体数据。在 相似文献
2.
五大连池火山区气体地球化学特征 总被引：26，自引：1，他引：25
根据泉（池）水中气体的组分和同位素组成,讨论了五大连池火山区气体的来源和运移。１９９７年８月从五大连池火山区泉中采用了９个气、水样品,同年９月测定了游离气和水溶气的气体组分、Ｈｅ同位素幽会和ＣＯ２的δ＾１３Ｃ值。气体以ＣＯ２为主,多数样品的ＣＯ２体积分类大于８０％。Ｈｅ和ＣＨ４的体积分数变化范围大,分别为０．７×１０＾－６－３８０×１０＾－６和４．０×１０＾－６－１８０×１０＾－６。＾３Ｈｅ／Ｈｅ 相似文献
3.
对济阳凹陷南缘与鲁西隆起接合部开展了土壤气Ｈｅ、Ａｒ组分及Ａｒ同位素测定，结果表明Ｈｅ的丰度从５．１—６μＬ／Ｌ（Ｓ．Ｔ．Ｐ），δＨｅ值从－４％－１６％，平均２．５９％；４０Ａｒ／３６Ａｒ比值从２５５—３２５，δ（４０Ａｒ／３６Ａｒ）值从＋１１％－１１％，Ｈｅ异常主要分布在研究区北部，而Ａｒ等值图分布比较复杂。Ｈｅ、Ａｒ、烃三组分之间的组合关系表明有３个远景区，最有意义的是中深层远景区。此外，根据地质分析及Ａｒ同位素特征表明中深层异常远景区不仅是与已知的第三系油田有关，而且还与深部Ｃ—Ｐ煤系地层有关，故属煤成气异常。 相似文献
4.
天然气中氦同位素分布及构造环境 总被引：16，自引：1，他引：16
通过采集天然气样３３４个，测量了它们的氦同位素组成。３Ｈｅ／４Ｈｅ值分布在０５６×１０－８～７２１×１０－６范围。３Ｈｅ／４Ｈｅ值分布与天然气储层时代无明显的相关性，而在空间展布上有较明显的规律。东部含油气区３Ｈｅ／４Ｈｅ值主要分布于１０－７～１０－６范围，西部含油气区在１０－７～１０－８的范围，中部地区分布在０５６×１０－９～０５６×１０－８范围，３Ｈｅ／４Ｈｅ值的分布与我国构造环境大的格局有很好的相关性。３Ｈｅ／４Ｈｅ的高值区构造环境活动性强，低值区具有最稳定的大地构造属性，西部地区３Ｈｅ／４Ｈｅ值介于东部和中部，具有次稳定的构造环境。 相似文献
5.
天然气中的幔源稀有气体 总被引：29，自引：3，他引：29
天然气为地球内流体的重要组成部分，天然气中幔源稀有气体是源于地球深部的地幔挥发分。文章以气体地球化学国家重点实验室有关研究为主，简要综述了此一领域的研究。氦的同位素３Ｈｅ／４Ｈｅ是幔源物质的重要判识指标，天然气中３Ｈｅ／４Ｈｅ值大于１．４×１０－６时，表明有相当数量的幔源挥发分加入到天然气中，它是地球构造活动性强，地幔挥发分可以沿一定断裂体系进入沉积壳层的指示。在一定程度上氩同位素４０Ａｒ／３６Ａｒ及氖同位素２０Ｎｅ／２２Ｎｅ值也可指示构造环境的特征。天然气中稀有气体研究反映了我国东部含油气区具有最活跃的构造环境，中部最稳定，西部次稳定。在东部活跃的构造背景下，造成了幔源挥发分较普遍地加入到沉积壳层天然气中，形成了中国东部发现的世界首例壳－幔复合型氦资源，形成了一批与幔源挥发分成藏有关的二氧化碳资源。东部地区也成为幔源甲烷可能富集成藏的重要区域。 相似文献
6.
湖南万古金矿床地幔流体成矿的氦同位素证据 总被引：21，自引：2，他引：21
从湖南万古金矿区采集４件石英样品进行了氦同位素测定，获得了＾３Ｈｅ／＾４Ｈｅ值２３１×１０＾－６－１４６０×１０＾－６的数据，该数据反映了在万古金矿床形成时富＾３Ｈｅ流体与成矿作用。而这种富＾３Ｈｅ流体可能是受构造活动影响，由地幔岩石减压部分脱气造成动力学分馏而形成。 相似文献
7.
白云鄂博矿床独居石氧同位素组成特征及其意义 总被引：1，自引：0，他引：1
独居石和氟碳铈矿是超大型稀土矿床－白云鄂博矿床中最主要的稀土矿物。对独居石的氧同位素研究工作国内外开展得很少，本研究对独居石氧同位素制样方法进行了讨论。在计算的独居石－水氧同位素分馏方程：１０＾３ｌｎα＝－０．０９１－４．２２４×（１０＾３／Ｔ）＋３．８９６（１０＾６／Ｔ＾２）基础上，分析了矿床白云石型矿石和萤石型矿石中独居石的氧同位素组成。独居石δ＾１８Ｏ值的变化范围为３．５‰－１１．４‰，其中 相似文献
8.
天然气中N2来源及其地球化学特征分析 总被引：17，自引：1，他引：16
天然气中Ｎ２来源很多,其地球化学特征也各不相同：①大气源Ｎ２：Ｎ２／Ａｒ≤８４,且δ＾１５ＮＮ２≈０‰（ＡＴＭ）;②地壳超深部和上地幔来源的原生Ｎ２：δ＾１５ＮＮ２≈－２‰－＋１‰,且伴生Ａｒ的＾４０Ａｒ／＾３６Ａｒ〉２０００和Ｈｅ／＾４Ｈｅ〉１０＾－６;③微生物反硝化作用生成的Ｎ２：δ＾１５ＮＮ２〈－１０‰和地下水中的ＮＯ＾３－及ＮＯ＾２－浓度异常高;④未成熟沉积有机质经微生物氨化作用形成的Ｎ２ 相似文献
9.
广东东镇岩体微区^40Ar／^39Ar年龄及其意义 总被引：3，自引：0，他引：3
采用激光显微探针＾４０Ａｒ／＾３９Ａｒ测年技术（简称微区＾４０Ａｒ／＾３９Ａｒ法）对广东云开地区东镇岩体含眼球体的片麻状花岗质岩石中单矿物作了同位素年龄测定，获得眼球体内核中的巨晶状钾长石年龄（４１９．４０±４．３７）×１０＾６ａ。眼球体角缘中重结晶微粒状钾长石年龄（２７２．６３±３．１３）×１０＾６ａ，眼球体外壳中的强应变长条纹黑云母年龄（１７７．８４±２．２９）×１０＾ａ。暗色条带中的弱应变板 相似文献
10.
11.
Spinel lherzolite found in Damaping, northern Zhangjiakou, Hebei Province occurs as xenoliths in the Hannuoba basalts that
consist of alkali basalt and tholeiite. Spinel lherzolites contain 50%–70% olivine (Fo: 90%), 10%–20% clinopyroxene (predominantly
Di), 10%–30% orthopyroxene (predominantly En), and less than 5% spinel.3He/4He and40Ar/38Ar ratios in the olivine are 7.56×10−7 and 299.1, respectively.3He/4He and40Ar/38Ar ratios in the orthopyroxene (enstatite) are 9.1×10−7 and 307, respectively. Olivine grains are fractured irregularly, and pyroxene grains characterized by well developed cleavages,
which would have resulted from explosion during the rapid eruption of lava from the deep interior to the surface. The lower
isotope ratios of helium and argon may indicate that the spinel lherzolite xenoliths were derived from the strongly degassed
and depleted upper mantle, and that the mantle is inhomogeneous.3He losses to some extent might affect the helium isotope ratios.
The project was financially supported by the National Natural Science Foundation of China (No. 49273185). 相似文献
12.
同位素示踪技术在地质研究中的某些应用 总被引：7，自引：0，他引：7
文中介绍了同位素示踪技术的基本原理,回顾了利用氢氧同位素示踪成矿溶液来源,研究水岩反应所取得的重要成果和最新进展;提出水岩相互作用是一个连续的演化过程,可分三个阶段,不同阶段的交换温度、水／岩比及体系的平衡、封闭情况是不一样的。以太古宙条带状硅铁建造为例,介绍了硅同位素示踪技术的新进展,证明了太古宙条带状硅铁建造为海底喷气成因,条带状构造与海底热液的周期性喷发有关。文中还介绍了氦同位素在示踪幔源组份方面的最新进展,指出我国东部油气区天然气中的氦、氩、二氧化碳等有相当一部分来自地幔;根据太平洋中部多金属结核的氦同位素组成和分布特征,提出成矿物质主要来源于海底热液活动,结核的一个圈层可能代表了一次大的海底热液活动。 相似文献
13.
广东三水盆地天然气非烃组分同位素地球化学 总被引：1，自引：0，他引：1
根据广东省三水盆地天然气中氦、氩、二氧化碳和氮等非烃组分的稳定同位素地球化学特征,探讨了该区天然气的来源以及大地热流。测得天然气中3He/4He（R）值为（1.60-6.36）×10-6,比大气的3Ne/4He（Ra）值(1.4×10-6)大:氩的稳定同位素组成(40Ar/36Ar=450-841)较大气氩富40Ar;二氧化碳的δ13C（PDB）值在-20-2‰的范围内,δ13N（Air）值在-57-+95‰之间:根据（?）He,4He值求得研究区的大地热流值（Q）为72-82mWm-2。大地热流和非烃组分同位素组成的高值以及研究区特别发育的火山岩等地质资料表明三水盆地有较强的地球深部流体（物质的和热的）向上溢出。一些油气藏中相当一部分氦、氩和氮来自地幔,各种天然气中均混有地壳来源的非烃气体。贫13C的二氧化碳气主要为地层中有机质分解的产物;富13C的二氧化碳则主要来自岩石化学反应的产物,并混有深部来源的二氧化碳。相当一部分大地热流源于上地幔。 相似文献
14.
1IntroductionOnthenorthernmarginoftheNorthChinaplatformislocatedoneofthemostimportantAu Ag polymetallicore concentratedzones,wherethereareavarietyoforetypes .Soithasbeenat tractingeverincreasingattentionofmanygeologists (PeiRongfuetal.,1 998;ShenBaofengetal.,1 994 ;LuSongnianetal.,1 997;HuShouxietal.,1 994 ;ChenYuchuan ,1 999;ZhaiYushengetal.,1 999) .Manyscholarspresentedtheirresearchresultsinvariousaspects.How ever ,thesourceofore formingmaterialshaslongbeenafocusofdiscussion .Studieso… 相似文献
15.
Helium, Argon, and Xenon Isotopic Compositions of Ore-formingFluids in Jinding-Baiyangping Polymetallic Deposits,Yunnan, Southwest China 总被引：13，自引：0，他引：13
The Jinding superlarge lead and zinc deposit has attracted the attention of geologists of the world and its metallogenesis has long been in dispute. This paper takes the Jinding deposit and the Baiyangping Cu-Ag-Co deposit which was recently found at about 30 km north of Jinding as one ore belt, and, based on researches on the helium, argon, and xenon isotopic compositions of primary inclusions in ore-forming solutions of the main stage, the authors have found that the 3He/4He ratio of the ore-forming fluid is 2.7′ 10- 6 (varying from 0.19 to 1.97 Ra), the 4He/40Ar ratio (0.24- 3.12) is close to the mantle characteristic ratio, and the xenon isotopic composition and evolution show characters of the mantle xenon. The above results reveal the characteristics of mantle source and crust-mantle fluid mixing (mantle helium reaching 32%) and the metallogenic contributions of the deep processes in the Jinding-Baiyangping ore belt. 相似文献
16.
Baode Wang Shuyin Niu Aiqun Sun Huabin Hu Yaming Liu Lijun Guo Shuo Wang 《中国地球化学学报》2008,27(3):235-241
In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range, though some debates still exist on the metallogenesis and sources of ore-forming materials. Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids, and the first He and Ar isotope data have been obtained from the study region. ^3He/^4He ratios in 14 samples collected from 7 mining districts are 2.17×10^-6-12.52×10^-6, averaging 6.86×10^-6 and their R/Ra ratios are 1.56-9.01 Ra, averaging 4.37 Ra. By projecting the data points onto the ^3He-^4He concentrations diagram, all the points fall near the mantle helium area. The calculated mantle-source helium ratios are within the range of 19.58%-76.96%, with an average of 49.52%. Argon isotopic characteristics are close to those of mantle source, indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures. 相似文献
17.
Du Jianguo 《中国地球化学学报》1992,11(3):237-243
Heat flow and the origin of helium in natural gases from fault basins of the continental rift-valley in eastern China are
discussed in terms of helium isotope geochemistry.3He/4He ratios in natural gases from the rift-valley range from 2.23 × 10−7 to 7.21 × 10−6, which are directly proportional to the concentration of helium and ΣNHC/ΣHC ratio in natural gases. Geological and isotope
geochemical data suggest that helium in natural gases consists predominantly of crustal radio-genic and upper mantle-derived
helium. In a simple mixing pattern between crustal He and mantle-derived He, mantle-derived helium in natural gases would
account for 10–60%. Calculated values for heat flow (Q) range from 59.7 to 82.4mWm−2, of which about 60 percent in the rift-valley is derived from the upper mantle. Natural helium reservoirs would be found
in the areas where the upper mantle uplifted greatly and heat flow is large in the continental rift-valley.
The project is financially supported by the National Natural Science Foundation of China. 相似文献
18.
江西相山铀矿田深部多金属矿化成矿流体来源:流体包裹体He-Ar同位素证据 总被引：1，自引：0，他引：1
江西相山铀矿田西部地区实施的铀矿科学深钻3号孔在深部–700 m发现大量铅锌银多金属矿化脉,垂向上呈"上铀下多金属"的分布特征。本文对深部多金属矿化主成矿阶段的黄铁矿、闪锌矿、方铅矿进行了流体包裹体He和Ar同位素组成测定,结果表明,相山深部多金属矿化主成矿阶段的黄铁矿、闪锌矿和方铅矿具有较一致的He、Ar同位素组成,矿物内流体包裹体的~3He含量范围为4.55×10–14～1560×10–14 cm^3·STP/g,~4He含量范围为1.05×10–7～525×10–7 cm^3·STP/g,~3 He/~4He为2.98×10–7～4.96×10–7,即0.21～0.35 Ra,介于地壳(0.01～0.05 Ra)和饱和大气水(1 Ra)之间,明显低于地幔的~3 He/~4He值(6～9 Ra),40Ar浓度为0.969×10–7～157×10–7 cm^3·STP/g,40Ar/36Ar值为303.7～573.9,略高于饱和大气水的Ar同位素组成,结合矿石和蚀变岩石中Li元素富集特征,本文认为相山西部地区深部多金属成矿流体以地壳流体和大气降水为主,成矿流体富Li元素是He同位素明显高于地壳的原因,可能存在少量幔源流体的加入。另外,通过对比前人研究的该地区铀矿化矿石中黄铁矿He-Ar同位素组成,并结合前人对该地区幔源组分明显参与铀成矿的认识,本文认为多金属矿化和铀矿化成矿流体可能并非同一来源。 相似文献
19.
This study is focused on geothermal heat flow and the origin of non-hydrocarbons in natural gases in terms of the isotope
geochemical characteristics of Ar, He, CO2 and N2 in natural gases from the Sanshui Basin, Guangdong Province. China.3He/4He ratios are of (1.60-6.39) × 10-6, and40Ar/36Ar ratios of 450–841. The carbon isotopic composition (δl3C PDB) of carbon dioxide ranges from -20‰ to -2‰. δl5N(air) ratios have a wider range of-57 ‰- +95 ‰. The isotope geochemical characteristics of non-hydrocarbons indicate that He, Ar and N2 in the gas reservoirs enriched in non-hydrocarbons were derived largely from the upper mantle. Non-hydrocarbons in gaseous
hydrocarbon reservoirs consist mainly of crustal radiogenic He and40Ar and some mantle-derived He and Ar, as well as of13C-depleted carbon dioxide and nitrogen generated as a result of thermal decomposition of organic matter in strata. Carbon
dioxide enriched in13C was derived largely from carbonate rocks and partially from the lower crust and upper mantle.
Based on the relationship between geothermal heat flow (Q) and3He/4 He ratio in natural gases, the Q values for the area studied have been calculated. Similar Q values are reported from the
upper mantle uplift area (77 mWm-2) in Huabei and the Tancheng-Lujiang Rift Zone (88 mWm-2). More than 60 percent of geothermal heat flow in the Sanshui Basin may have been derived from the upper mantle.
The project is financially supported by the National Natural Science Foundation of China. 相似文献
20.
We present new helium isotope data from the Macdonald seamount (Austral chain). The helium isotopic ratio varies from 4He/3He=45 000 (R/Ra=16.0) to 200 170 (R/Ra=3.6). The helium content is between 1.5×10?8 and 1.1×10?5 ccSTP/g. These helium results show clearly the presence of primitive mantle material in the source of the Austral chain. Macdonald has the lowest 4He/3He ratio among the Polynesian submarine volcanoes, except Hawaii (Loihi). The simplest explanation for the primitive helium signature is the presence under Macdonald of a mantle plume that derives either from the 670 km or 2900 km boundary layers, or, eventually, from the top of a large mantle dome resulting from a stratified two-layer convection. This plume contains less-degassed material with low 4He/3He ratio. To cite this article: M. Moreira, C. Allègre, C. R. Geoscience 336 (2004). 相似文献