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1.
La-Ce法岩石标准物质和Ce同位素标准溶液研制   总被引:3,自引:0,他引:3  
报道了La-Ce法岩石标准物质的研制结果。标准物质选自峨眉山玄武岩中的新鲜微晶玄武岩(编号EQB),具有间隐结构,矿物组成相对均一。岩石经粉碎和均一化加工,成为粉末后分装成1000小瓶。经均匀性和稳定性检验合格后,对该岩石标准物质的Ce同位素比值和La、Ce元素含量进行了测定和定值统计,其结果分别表示为:138Ce/142Ce=0.0225755±0.0000003,Ce=(117.4±1.3)μg/g,La=(55.8±0.9)μg/g。对二氧化铈化学试剂进行了溶液制备,以用于Ce同位素分析仪器标准物质。标准溶液编号为CBRICeO2,其138Ce/142Ce比值的测定统计值为0.0225748±0.0000006。为检验所制标准物质分析数据的准确度,对国际标样进行了比对测量,其中JMC304标准溶液的138Ce/142Ce比值测定结果为0.0225762±0.0000015,USGS玄武岩标样BCR-2的La和Ce元素含量测定结果分别为(25.2±0.6)μg/g(2σ)和(54.2±0.8)μg/g(2σ),所获数值与文献报道值或证书值在误差范围内相符。  相似文献   

2.
陈娟  唐红峰  灌瑾  王宁 《矿物学报》2014,(2):290-295
在综合对比已有Hf同位素分析方法的基础上,我们选用Ln-Spec(100-150目,H+)特效树脂和多接收器电感耦合等离子体质谱(MC-ICPMS)对4件标准物质和19件岩石样品(新疆东准噶尔的花岗岩及其包体18件、玄武岩1件)进行了全岩Hf同位素研究。所获得的国际标准物质BCR-1、BHVO-2、W-2的176Hf/177Hf比值与文献报道的结果在误差范围内一致,表明所采用的全岩Hf的化学分离和溶液的Hf同位素质谱测定方法是可靠的。本文首次报道了中国花岗岩标样GRS-1的176Hf/177Hf比值,结果为0.282547?07(2?)。依据新疆东准噶尔花岗岩及其包体样品的全岩176Hf/177Hf比值、全岩样品在等离子体质谱(ICP-MS)上测定的Lu、Hf含量和岩石的形成年龄(300 Ma),得到这些样品的全岩εHf(t)。它们与对应样品的锆石εHf(t)在误差范围内总体上的一致性表明,ICP-MS测定的Lu、Hf含量可以用来计算年龄值约300 Ma的全岩初始Hf同位素组成。玄武岩样品QS08-1的全岩εHf(t)与该蛇绿岩套斜长花岗岩的锆石εHf(t)的高度吻合,为利用全岩176Hf/177Hf比值和ICP-MS测定的全岩Lu、Hf含量,研究没有或难以选出锆石的较年轻岩石的Hf同位素组成提供了很好的实例。  相似文献   

3.
使用AGMP-1M阴离子交换树脂提纯样品中的Fe同位素,利用Nu1700大型多接收等离子体质谱在高分辨率模式下测定铁同位素比值,采用标样-样品交叉法校正仪器的质量歧视效应,对回收率、化学流程本底、酸度效应、浓度效应进行了检验,建立了可靠的高精度铁同位素分析技术。本文测定了常用地质标准样品(BCR-2,BHVO-2,AGV-2,GSR-2,GSR-3)的Fe同位素组成,测定结果与文献报道值在误差范围内一致,其测试精度优于(BCR-2,BHVO-2,AGV-2,GSR-3)0.03‰(2SD)。GSR-2可能受Fe含量较低(TFe_2O_3=4.95%)和均一性的影响,获得的δ~(56)Fe和δ~(57)Fe的测试精度分别为0.05‰和0.07‰(2SD)。  相似文献   

4.
镉元素在火成岩中的含量多为100×10-9级别,由于基体效应、同质异位素和离子团等的干扰,精确测定火成岩中镉含量一直存在挑战。本研究选取2个国际常用的火成岩标准(BCR-2,玄武岩;OU-3,花岗岩),通过3种不同的测试方法测定其中的镉含量,包括常规法、树脂分离法和双稀释剂法。结果显示,常规微量方法获得的2个标样的镉含量高于推荐值或报道值2~3倍,但经树脂分离后的测试值与推荐值基本一致。由于树脂分离过程可能存在镉的丢失,双稀释剂法能校正树脂分离过程中造成的镉同位素分馏,校正后的镉含量比树脂分离法获得的镉含量更高,进一步验证了树脂分离过程对镉含量的影响。相较于ICP-MS,由于MC-ICP-MS具有更高的测试精度和准确度,因此,我们推荐BCR-2和OU-3的镉含量分别为195 ng/g和260 ng/g,其中本研究获得OU-3的镉含量比推荐值低(推荐值为380ng/g),而BCR-2与多数文献报道值接近。本研究对调查火成岩样品中镉及其同位素组成提供了基础。  相似文献   

5.
元素La和Ce同属低活动性的稀土元素,能够对碎屑岩物源进行示踪。但目前尚缺乏对碎屑岩LaCe同位素体系的研究。本文以峡东泗溪南华纪—震旦纪碎屑岩为研究对象,进行了Ce同位素组成分析。结果显示:这些碎屑岩的138 Ce/142 Ce比值为0.022 583 2~0.022 587 8,εCe(t)值变化于1.06~6.13,整体上呈逐渐升高的演化特征,并与εNd(t)值呈耦合关系。结合碎屑岩Nd同位素分析结果认为,峡东南华纪—震旦纪碎屑岩的主要来源,以古元古代—中元古代甚至更老的地壳岩石为主,并存在幔源初生地壳物质加入。  相似文献   

6.
利用MC-ICPMS精确测定143Nd/144Nd和Sm/Nd比值   总被引:43,自引:14,他引:43  
多收集器等离子体质谱(MCICPMS)用于分析SmNd同位素时,质量分馏系数(β)与同位素的质量数呈线性关系.可以采用两种方法进行质量分馏校正:双分馏系数内部校正法(DFIC)和单分馏系数外部校正法(SFEC).采用DFIC法,对国际标样ShinEtsuJNdi1和实验室标样NdGIG进行了为期五个月的143Nd/144Nd比值测量统计,结果分别为0.512120±0.000012(2σSD)、0.511532±0.000013(2σSD).采用SFEC法,对NdGIG标样的测量统计结果为0.511525±0.000015(2σSD).两种方法的测量结果在分析误差范围内与其推荐值或TIMS测量值完全一致.对加Ce和Sm的NdGIG混合溶液分别进行了Ce和Sm对143Nd/144Nd比值分析的干扰校正研究和Sm/Nd比值测量,结果显示,143Nd/144Nd比值分别与Ce/Nd、Sm/Nd测量值呈线性关系,Sm/Nd测量值与其质量比值亦呈很好的线性关系.这表明利用MCICPMS可以快速精确地测定存在Ce、Sm干扰的样品的143Nd/144Nd比值,同时可获得精确的Sm/Nd比值,而无需加入稀释剂.这就使直接测定地质样品的SmNd等时线年龄成为可能.  相似文献   

7.
近年来,铜同位素在表生环境和生物地球化学中的应用越来越广泛,尤其是土壤的铜同位素组成可以示踪环境污染物来源及生物地球化学过程。目前,对土壤铜同位素进行研究时,主要以硅酸岩标准物质为标样来衡量土壤样品铜同位素测定的准确性和精确性。但土壤与硅酸岩中铜、基质离子及有机质的含量等存在很大差异(如:硅酸岩中的铜含量80μg/g,一些土壤中的铜含量很低,20μg/g),将硅酸岩标准物质作为标样来监测土壤样品的数据质量缺乏代表性。为了弥补这一缺陷,本文精确测定4个国家土壤标准物质(GBW07443、GBW07425、GBW07427、GBW07389)的铜同位素组成,并将其作为检验土壤样品铜同位素测定过程中的标准。实验中采用高温高压反应釜消解样品,利用AG MP-1M树脂进行纯化,全流程空白2ng,回收率≥98%,通过多接收器电感耦合等离子体质谱仪(MC-ICP-MS)采用标样-样品-标样间插法进行仪器分馏校正,δ~(65)Cu的长期测试外精度优于0.05‰(n=306, 2SD)。GBW07443、GBW07425、GBW07427和GBW07389的铜同位素组成分别为-0.04‰±0.04‰(n=9, 2SD)、-0.07‰±0.05‰(n=12, 2SD)、-0.06‰±0.04‰(n=12, 2SD)、-0.02‰±0.06‰(n=12, 2SD)。这些土壤标准物质的铜同位素组成均位于0附近,大致为自然界土壤铜同位素比值变化范围(-0.5‰~+0.5‰)的中间值,且样品容易获得,其化学和铜同位素组成均一,适合作为监控土壤铜同位素化学及质谱分析数据可靠性的标准物质。  相似文献   

8.
玄武岩作为地幔岩浆的产物,其岩石地球化学特征在反映地幔组分和深部动力学作用方面有着极其重要的意义。本文对东太平洋CC区西部和魏源海山两个潜次(Dive64和Dive66)的9个玄武岩样品进行了年代学、全岩地球化学和Sr-Nd-Pb同位素研究。结果显示,Dive64与Dive66玄武岩样品39Ar/40Ar年龄分别为83.1±0.3 Ma、74.7±0.3 Ma,属于晚白垩世,主体分别为N-MORB和OIB。Dive64为亚碱性玄武岩,REE总体相对平坦,轻重稀土分馏较弱,无明显Eu负异常;Dive66玄武岩为碱性玄武岩,富集轻稀土元素,亏损重稀土元素,无明显Eu、 Ce异常,MgO含量与CaO/Al2O3比值呈反比,与Cr含量、 Sr含量呈略微正相关。Sr-Nd-Pb同位素表明两者的形成可能不止单一源区的贡献,Dive64玄武岩Sr-Nd-Pb同位素比值更靠近DM(亏损地幔)、HIMU(高U/Pb比值地幔)端元,Dive66玄武岩Sr-Nd-Pb同位素比值较接近EMⅠ(Ⅰ型富集地幔)、HIMU端元。...  相似文献   

9.
建立了一个改进的单柱Ln-Spec提取色谱分离Hf方法.用该方法可以有效地分离出岩石样品的基体元素、REE和干扰元素等,并使Hf的回收率>90%、本底<5×10-11g.用该方法对一些国际和国家岩石标样进行了Hf分离,采用单聚焦和双聚焦两种型号的MC-ICPMS测定了Hf同位素组成,国际标样的结果与文献值在误差范围内完全一致,国家标样的Hf同位素结果具有很好的外部重现性.  相似文献   

10.
本文对中国东南沿海不含幔源包体的中生代玄武岩和含幔源包体的新生代玄武岩进行了微量元素和Nd-Sr-Pb同位素对比研究。中生代玄武岩呈Ta、Nb和Hf负异常,低Ce/Pb、Nb/U比值和高La/Nb比值,与岛弧火山岩和陆壳岩石的微量元素特征相类似,说明在岩浆生成和上升过程中,幔源组分受到了陆壳组分的混染。新生代玄武岩呈Ta、Nb正异常和Pb负异常,高Ce/Pb、Nb/U比值和低La/Nb比值,与海岛玄武岩(OIB)相类似,Nd-Sr同位素成分与夏威夷玄武岩类似,因而它们未受明显的陆壳混染。143Nd/144Nd与206Pb/204Pb之间的负相关关系和87Sr/86Sr与206Pb/204Pb之间的正相关关系说明本区新生代玄武岩起源于中等亏损程度的软流圈地幔,并与EMII富集地幔组分发生了混合。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

13.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

14.
《地学前缘(英文版)》2014,(3):I0001-I0003
正1 AIM AND SCOPE GEOSCIENCE FRONTIERS(GSF) is a bi-monthly international journal that publishes in English high quality original research articles and timely reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF aims to bridge innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture  相似文献   

15.
正1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce molar ratio on the composition,crystal structure,and thermal stability of hydrotalcite are examined.Energy-dispersive X-ray spectroscopy(EDS),X-  相似文献   

16.
正20141430 Chen Ji(Key Laboratory of Petroleum Resources,Chinese Academy of Sciences,Lanzhou 730000,China);Shi Ji’an Sedimentary Facies and Models for the Palaeogene-Neogene Deposits on the Northern Margin of the Qaidam Basin,Qinghai Province(Sedimentary Geology and Tethyan Geology,ISSN1009-3850,CN51-1593/P,33(3),2013,p.16-26,14 illus.,16 refs.)  相似文献   

17.
SEISMIC GEOLOGY     
正20141967An Zhanghui(Lanzhou Base of Institute of Earthquake Prediction,CEA,Lanzhou 730000,China);Du Xuebin Study onthe Geo-Electric Field Variation of Sichuan Lushan MS7.0and Wenchuan MS8.0Earthquake(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,56(11),  相似文献   

18.
GEOCHEMISTRY     
正20141357 Guo Tao(School of Mathematics and Science,Shijiazhuang University of Economics,Shijiazhuang 050031,China);Hu Jiawen Assessment on the New Pressure-Volume-Temperature(PVT) Data of Supercritical Water(Geological Journal of China Universities,ISSN1006-7493,CN32-1440/P,19(3),2013,p.447-455,9 illus.,3 tables,32 refs.)Key words:supercritical fluids  相似文献   

19.
正20141074Bao Xijie(Research Institute of Exploration and Development,Daqing Oilfield Company,PetroChina,Daqing 163712,China)Gather Optimal Processing and Application Effect of Prestack AVA Instantaneous Inversion  相似文献   

20.
正China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of Ordovician  相似文献   

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