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1.
研究了新疆阿尔泰特地区阿克提什坎金矿床的稀土元素及矿区二长花岗岩平衡的热液中稀土元素的组成特征及配分模型,并应用Grang等位线方法讨论了热液蚀变作用过程中稀土元素的行为。研究表明,在热液蚀变作用过程中,稀土元素保持惰性,成矿热液与岩浆热液关系不大,成矿物质主要来源于围岩。  相似文献   
2.
根据郯庐断裂带鲁皖段早第三纪、中新世以及更新世玄武岩的稀土元素特征的研究,应用稀土判据探讨了区内玄武岩的形成机制。稀土元素和常量元素的相关关系显示,郯庐断裂带新生代3个阶段玄武岩成岩过程中分离结晶作用不明显,其形成机制应该为上地幔部分熔融作用。通过多种稀土元素联合协变关系也同样反映了这些玄武岩的形成机制为上地幔部分熔融作用,同时也显示区内新生代玄武岩的稀土元素特征继承了其源区物质的稀土元素特征。这一结论与区内Sr,Nd同位素研究的结果相吻合。  相似文献   
3.
苏皖四处凹凸棒石粘土矿床稀土元素地球化学研究   总被引:4,自引:2,他引:4  
研究了苏皖四处凹凸棒石粘土矿床不同类型矿石的烯土元素组成及其变化特征。研究表明玄武岩首先风化形成蒙皂石族粘土矿物,在此过程中稀土元素没有明显的分馏作用,强风化的玄武岩重稀土元素强烈亏损;如果玄武岩在地表进一步风化形成红土型蒙脱石粘土,则发生明显的铈正异常,中稀土亏损而轻稀土和重稀土又重新富集,这反映了当时大陆地表特殊的氧化条件和盆地湖水溶液的胶体吸附作用。玄武岩在原地进行水-岩作用,发生递进化学风化,其稀土元素地球化学特征与玄武岩及其风化产物的稀土元素化学特征基本一致,总量略低,显示REE没有大量迁移流失,沉积型凹凸棒石粘土的稀土元素地球化学特征也与玄武岩及其风化产物的稀土元素地球化学特征相似,但同时表现出轻重稀土比值磁大,铕正异常,表明沉积型凹凸棒石粘土的物源基本上是来源于玄武岩的风化产物,但REE配分模型受玄武岩风化残积物的制约。  相似文献   
4.
5.
Timothy D. Lash  Shaohua Chen 《Tetrahedron》2005,61(49):11577-11600
Nitrogen-15 labeled pyrroles have been prepared from commercially available 15N glycine or sodium nitrite using the Barton-Zard, Knorr, and Kleinspehn approaches. These pyrroles were used as intermediates in the synthesis of per-15N labeled porphyrins needed for the analysis and assignment of vibrational spectra for sedimentary porphyrins. Etioporphyrin-I was prepared via pyrromethene intermediates, while etioporphyrins II-V and a related tetrahydrobenzoporphyrin were synthesized via stepwise routes involving the copper(II) mediated cyclization of a,c-biladienes as the key step. Detailed analyses of both the proton and carbon-13 NMR spectra provide nitrogen-15 coupling constants for these important structures.  相似文献   
6.
广西合山石村矿超高有机硫煤饱和烃特征分析   总被引:1,自引:0,他引:1  
以合山石村矿超高有机硫煤为研究对象,利用带能谱的扫描电镜(SEM-EDX)及气相色谱(GC)和色谱-质谱联用(GC-MS)分析技术,综合分析探讨了研究区样品中有机质来源、沉积环境及物源输入。结果表明,研究区样品镜质体反射率均值1.76%,全硫含量均值6.01%,其中有机硫含量占比达94.3%,为高成熟度的超高有机硫煤。饱和烃色谱图中未分辨的复杂混合物(UCM)鼓包明显,前峰及双峰型均有分布,前峰型主峰碳为C_(16)、C_(18)、C_(21),双峰型主峰碳为C_(18)、C_(27),化合物降姥鲛烷、脱氢松香烷、咔达烯均有发现,规则甾烷C_(27)、C_(28)、C_(29)均呈"V"型分布,说明沉积母质受藻类等低等水生生物与高等植物双重输入的影响。姥植比参数、C_(31-35)藿烷呈阶梯式递减的分布特征表明在海相碳酸盐台地成煤带中存在一定的氧化条件。扫描电镜中拍摄到的铁含氧硫酸盐、细胞充填环状黄铁矿说明在沉积质晚期成岩阶段受到一定程度热液作用影响。  相似文献   
7.
A preliminary study of simulated thermal maturity has been conducted to evaluate the oil, gas and hydrocarbon generation potential of sphagnum coal in the Jinsuo brown coal basin, Yunnan Province and to understand the characteristics of the element composition and biomarkers in the course of thermal alteration. The experimental result was compared with that of xylitic coal, a kind of lithotype of soft brown coal. It is considered that sphagnum coal possesses the potential of forming economic accumulation of oil and gas. Its highest proportion of oil and hydrocarbon generation is 510 mg/g Corg. and 232.1 mg/g Corg. respectively. At an R_(ran)~° value of 2.51%, the ratio of gas generation from sphagnum coal attains to 620.5 ml/g Corg. In view of sphagnum coal being different from the conventional soft brown coal in various respects such as coal forming raw materials and enviroments as well as physico-chemical properties, it is Suggested as a special kind of source rock for coal-generated oil and gas.  相似文献   
8.
应用仪器中子活化(INAA)、电感耦合等离子体原子发射光谱(ICP AES)和原子吸收光谱(AAS)对神华集团马家塔露天矿2-2#煤层中Hg、As、Se、Pb、Be、Cr、Cd、Ni、Th、U、Mn、Mo、Co、Sb和Br共15种有害痕量元素的质量分数进行测定。结果表明,绝大部分痕量元素的质量分数都明显低于中国煤中元素质量分数的平均值,只有Hg和Mn的质量分数偏高,其中Hg的质量分数异常高;通过分析痕量元素在煤层垂向剖面上的质量分数变化特性,揭示出痕量元素在煤层中分布的非均一性,分析了影响痕量元素分布与富集的因素;通过痕量元素之间以及与黄铁矿硫、Fe、Al、Ca、P的聚类分析,研究了痕量元素之间以及与煤中不同矿物组分之间的亲和特性。  相似文献   
9.
We present the results of a re-analysis of a previously published carbon isotope data-set related to coralline sponges in the Caribbean Sea. The original interpretation led to the discrimination between a pre-industrial period, with a signal controlled by solar-induced climatic variations, followed by the industrial era, characterized by a progressive δ13C negative shift due to the massive anthropogenic carbon emissions. Our re-analysis allowed to extract from the raw isotopic data evidence of a solar forcing still visible during the industrial era, with a particular reference to the 88-year Gleissberg periods. These signals are related to slope changes in both the δ13C versus time and the δ13C versus carbon emission curves.  相似文献   
10.
Abstract

Geochemical and mineralogical investigations of plutonic rocks from the Meiβen massif indicate different magmatic evolution trends of the Freital sequence as well as for the central part of the complex Constant ε-NdT-345 values of ?1.5 of the Freital sequence and major/trace element data point to a fractional crystallization process. Based on ε-Nd values, 147Sm/144Nd ratios as well as on geochemical data affinities to alkali basalts cannot be excluded.

Analogous conclusions have been drawn regarding mineral chemical data [10] and cathodoluminescence spectra of apatite [13]. Assimilation of old continental crust, reflected by relics of apatite and zircon, may be the reason that the ε-Nd values plot at the lower end of the “mantle array”. The pyroxene-monzodiorite from Gröba belongs to the same source environment as the Freital sequence (Nd-characteristics).

The geological evolution of the central part of the studied plutonic complex is completely different to the Freital sequence: most of the intrusions show signatures of open system fractionation processes. The ε-NdT-345 value of ?1.46 of the Leuben monzonite indicates a narrow relation to the Freital sequence, whereas the ε-NdT-345 value of +2.27 of the Spitzgrund monzonite either reflects the derivation of another basic material then the Freital-type or the participation of other mixing component(s) from geologically young crust.

Fabric and mineral chemical investigations of the porphyry-like granite GII point to a mixing process of basic xenocrysts, resembling the corresponding minerals of the Freital sequence, and granite melts [10]. Large amounts of old zircon cores [11] indicate the inheritance of continental crust components by the Hauptgranit. Isotopic investigations on various granitic samples (GII, Hauptgranit and Riesensteingranit) reflect an increasing trend towards the crustal source(s) of their parental melts. The ε-NdT-345 values are ?3.75, ?4.16 and ?6.13, respectively.

Chemical parameters and the ε-NdT value of the Riesensteingranit agree with data of granites from the Saxonian Granulite Massif (see e.g. Wand et al. [8]; von Quadt, 1992). Thus, it may be possible that both granite types derived from similar sources.  相似文献   
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