Fe同位素的MC-ICP-MS测试方法

过渡族元素同位素研究是新兴的研究领域和国际研究前沿, 是同位素地球化学研究的热点。本研究利用Neptune型多接收等离子质谱(MC-ICP-MS), 采用标准-样品-标准交叉校正和以Cu为内标的方法对仪器的质量歧视进行校正, 对浓度效应、基质效应、干扰元素扣除和测试的长期重现性进行了检验, 建立了高精度的Fe同位素测试技术。这两种校正方法对实验室标准HSP I Fe在一段时间内δ56Fe和δ57Fe的测试结果分别为0.08‰(2SD)和0.14‰(2SD)分析精度达到国际同类实验室水平, 测试结果在误差范围内与文献值完全一致。     

洋壳蚀变过程中Cu和Zn同位素分馏:对海洋Cu和Zn循环的制约

<正>铜(Cu)和锌(Zn)属于第一过渡族金属元素,分别有2种(63Cu、65Cu)和5种(64Zn、66Zn、67Zn、68Zn、70Zn)稳定同位素。Cu-Zn都属于生命元素,它们在海洋中的地球化学循环对海洋生产率发挥着重要作用。现有研究表明,海水的δ65Cu和δ66Zn分别为ca.0.9‰和ca.0.5‰,显著重于河水的Cu-Zn同位素组成(δ65Cu=ca.0.6‰和δ66Zn=ca.0.3‰);说明海洋中至少存在一个具有轻Cu-Zn同位素组成的储库。海底Fe-Mn结壳和碳酸盐岩石海洋Cu-Zn输出的重要渠道。已有研究表明,三大洋中的Fe-Mn结壳的δ65Cu和δ66Zn分别为0.44±0.23‰和1.04     

常用锂同位素地质标准物质的多接收器电感耦合等离子体质谱分析研究

锂同位素研究是非传统稳定同位素地球化学研究的前沿,已广泛应用于从地表到地幔的岩石圈及流体等固体地球科学的研究领域。准确测定锂同位素比值是应用该同位素体系的前提。本文报道了国际上7种常用地质标准物质(BHVO-2、JB-2、BCR-2、AGV-2、NKT-1、L-SVEC、IRMM-016)的锂同位素组成数据。分析中采用硝酸-氢氟酸混合酸消解岩石标准样品,通过3根阳离子交换树脂(AG50W-X8,200~400目)填充的聚丙烯交换柱和石英交换柱对锂进行分离富集,利用Neptune型多接收器电感耦合等离子体质谱(MC-ICPMS)测定锂同位素比值,使用标准-样品交叉法(SSB)校正仪器的质量分馏。实验得到这7种常用地质标准物质的锂同位素组成与测试精度(2SD)分别为:δ7LiBHVO-2—L-SVEC=4.7‰±1.0‰(n=53),δ7LiJB-2—L-SVEC=4.9‰±1.0‰(n=20),δ7LiBCR-2—L-SVEC=4.4‰±0.8‰(n=8),δ7LiAGV-2—L-SVEC=6.1‰±0.4‰(n=14),δ7LiNKT-1—L-SVEC=9.8‰±0.2‰(n=3),δ7LiL-SVEC—L-SVEC=-0.3‰±0.3‰(n=10),δ7LiIRMM-016—L-SVEC=0.0‰±0.5‰(n=10),这些数据在误差范围内与国际上已发表的数据一致。Li同位素分析精度可以达到大约0.5‰,长期的分析精度即外部重现性≤±1.0‰,达到了国际同类实验室水平。7种常用地质标准物质的锂同位素组成数据的发表为锂同位素研究提供了统一的标准,使地质样品的锂同位素数据的质量监控成为可能。在基质效应的研究中,使用不同量的IRMM-016配制的标准溶液过柱,深入探讨了样品量对锂同位素测定值的影响,结果表明,在现有测试精度下,只要分析样品的锂含量达到100μg/L,且不超过树脂的承载量,样品的锂同位素组成在误差范围内与真值吻合,样品量的大小不影响锂同位素测定结果的准确性。     

多接收器等离子体质谱法Zn同位素比值的高精度测定

详细报道了Zn同位素比值的多接收器等离子体质谱(MC-ICP-MS)高精度测定方法,包括:MC-ICP-MS Zn同位素测量过程中的质量歧视校正、同质异位素干扰评估、基质效应调查和同位素测量的长期重现性检验.研究表明,在测定条件下,运用标样一样品交叉法能有效地进行仪器质量歧视校正.同质异位素干扰的评估通过3种方式进行,即:在高分辨状态下同质异位数干扰信号的直接测定,低分辨状态下Zn同位素原始数据间相关关系的检验和低分辨下浓度梯度效应研究.结果表明,在低分辨模式下,尽管66Zn、67Zn、68Zn的同质异位素干扰信号很小,但的确存在,要获得准确同位素比值,必须使标样和样品的浓度在合适的范围内匹配.在基质效应方面,主要考察Fe对Zn同位素比值测定的影响.结果表明,当溶液中Fe/Zn(质量比)不大于0.2时,Fe对Zn同位素比值测定无影响.重复性测定中,δ66ZnGSB-Romil=6.96‰±0.11‰(2sd),δ67ZnGSB-Romil=10.4‰±0.20‰(2sd),δ68ZnGSB-Romil=13.8‰±0.22‰(2sd),达到国际同类实验室先进水准.运用所建立的方法,对地质岩石成分分析国家标准物质GBW 07270(闪锌矿)进行了Zn同位素平均成分测定为:δ66Zn=6.71‰±0.03‰(20),δ67Zn=10.08‰±0.05‰(20),δ68Zn=13.37‰±0.07‰(2σ).     

玄武岩标准样品铁铜锌同位素组成

报道了三种玄武岩标准样品(BCR-2、BIR-1a和GBW 07105)的铁铜锌同位素数据。实验使用HNO3-HF混合酸消解玄武岩标准样品;AGMP-1阴离子交换树脂分离提纯样品中的铜铁锌,利用多接收等离子体质谱仪(MC-ICPMS)测定铁铜锌同位素比值,分析过程中使用样品-标准-样品交叉法校正仪器的质量分馏。实验得到BCR-2、BIR-1a和GBW 07105标准样品的高精度铁铜锌同位素组成(95%置信水平的不确定度)分别为:δ56FeBCR-2-IRMM014=0.070‰±0.018‰(2SD),δ65 CuBCR-2-SRM976=0.16‰±0.04‰(2SD),δ66 ZnBCR-2-IRMM3702=-0.072‰±0.020‰(2SD);δ56 FeBIR-1a-IRMM014=0.044‰±0.026‰(2SD),δ65CuBIR-1a-SRM976=0.027‰±0.019‰(2SD),δ66 ZnBIR-1a-IRMM3702=0.085‰±0.032‰(2SD);δ56FeGBW 07105-IRMM014=0.126‰±0.039‰(2SD),δ65 CuGBW 07105-SRM976=0.12‰±0.01‰(2SD),δ66ZnGBW 07105-IRMM3702=0.22‰±0.03‰(2SD)。这些数据在误差(不确定度)范围内与国际上已发表的数据是一致的。三个玄武岩标准样品的铁铜锌同位素组成数据的发表为铁铜锌同位素研究提供了统一的标准,使地质样品的铁铜锌同位素数据的质量监控成为可能。     

俯冲进变质过程中铁同位素分馏行为——以大别—苏鲁造山带为例

<正>大量研究表明,上地幔铁同位素组成是不均一的,上地幔平均值为δ56Fe=0.025±0.025‰[1]。玄武岩具有比上地幔整体偏重的铁同位素组成,因产出构造环境不同其δ56Fe略有不同:洋中脊玄武岩(MORB)δ56Fe=0.105±0.039‰(2SD,n=46);洋岛玄武岩(OIB)δ56Fe=0.121±0.075‰(2SD,n=61);岛弧玄武岩(IAB)δ56Fe=0.060±0.089‰(2SD,n=25)。地幔部分熔融过程中,铁同位素存在显著分馏,显著不同于其他类     

多接收器电感耦合等离子体质谱法测定土壤标准物质铜同位素组成

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。     

铝土矿中锂同位素分离提纯方法的建立

铝土矿是极端风化作用的产物,也是锂的重要载体,由于其资源量巨大,对铝土矿中锂的富集机制和分布规律的研究将有利于找矿预测。锂同位素的高效准确分析是深入认识矿物中锂的富集机制和分布规律的基础。铝土矿样品由于化学稳定性较强,溶样过程较为复杂,且Al、Na、Ca、K等基体元素含量远高于锂,给锂的纯化增加不少难度。本文采用内径5mm、柱长190mm的聚四氟乙烯离子交换柱和AG50W-X12阳离子交换树脂,以0.5mol/L硝酸为淋洗液淋洗34mL,收集最后的12mL,即可完成对铝土矿中锂的完全纯化回收。该纯化方法减少了淋洗液的使用量,提高了实验效率。采用该方法对国际标样L-SVEC、RGM-2、GSP-2进行锂的纯化,通过多接收电感耦合等离子体质谱仪(MC-ICP-MS)测试锂同位素组成,得到的δ~7Li测试值分别为-0.26‰±0.09‰(2SD,n=3)、3.19‰±0.37‰(2SD,n=3)、-0.78‰±0.22‰(2SD,n=3),与前人报道一致,验证了该方法的可靠性。此外,采用本方案对铝土矿国家标样(GBW07182)进行锂的纯化,δ~7Li测定值为10.16‰±0.21‰(2SD,n=3)。     

过渡族金属元素同位素分析方法及其地质应用

由于同位素分析方法的改进和多接收电感耦合等离子体质谱仪 (MC ICP MS)的应用 ,近年来过渡族金属元素 (Cu ,Zn和Fe)同位素地球化学有了长足进步 ,成为国际地学领域的一个前沿研究方向。Cu同位素在自然界中的变化最大 ,δ65Cu值为 - 3.70‰～ +2 .0 5‰ ;Zn和Fe同位素变化比Cu同位素变化小 ,δ66Zn值为 - 0 .6 4‰～ +1.16‰ ,而δ56Fe值为 - 1.6 2‰～ +0 .91‰。自然界中各种无机过程 (从高温到低温 )和生物有机过程均能使Cu ,Zn和Fe同位素发生分馏。Cu、Zn和Fe在自然界中广泛分布于各类矿物、岩石、流体和生物体中 ,并广泛参与成岩成矿作用、热液活动和生命活动过程。因此 ,这些过渡族金属元素同位素已在陨石和宇宙化学、矿床学 ,海洋学和生物学等领域的研究中取得了显著成效 ,并将成为地球科学中具有巨大应用前景的一种新的地球化学手段。     

胶东望儿山金矿床氢-氧同位素地球化学

胶东金成矿省位于华北克拉通东南缘,是我国最重要的黄金集区,约占全国黄金储量的25%。其中约90%的金资源量集中于胶东半岛的西北部,主要受3个一级断裂带(三山岛断裂带、焦家断裂带和招平断裂带)控制。望儿山金矿床赋存于晚侏罗世玲珑型黑云母花岗岩中,受焦家断裂带的次级断裂带(望儿山断裂带)控制,是胶东地区受二级断裂带控制的已探明规模最大的金矿床,同时发育蚀变岩型矿化和石英脉型矿化。金矿化与硅化和绢云母化蚀变密切相关,矿体多呈脉状,主要为矿区内主干断裂F1和F5控制的1号和5号矿体以及F1和F5的次级断裂控制的3号和23号矿体。矿石分为蚀变岩型和石英脉型,主要由石英、绢云母及黄铁矿、黄铜矿、方铅矿、闪锌矿等金属硫化物等组成。本研究通过详细的野外和岩相学、矿相学观察,依据蚀变特征、脉体穿插关系及矿石结构构造和矿物共生组合,将成矿过程分为四个阶段:黄铁矿-石英-绢云母阶段(Ⅰ)、石英-黄铁矿阶段(Ⅱ)、石英-多金属硫化物阶段(Ⅲ)和石英-碳酸盐阶段(Ⅳ)。针对不同高程、不同成矿阶段、不同矿石类型、不同矿体,系统采集了26件样品,分别挑选石英单矿物进行氢、氧同位素测试,总体δD值分布于-77.3‰~-54.2‰,δ18O值分布于-5.56‰~7.20‰,Ⅰ阶段δD=(-62.2±6.6)‰(n=8),δ18O=(4.60±1.52)‰(n=8);Ⅱ阶段δD=(-62.5±4.5)‰(n=7),δ18O=(0.47±2.86)‰(n=7);Ⅲ阶段δD=(-66.5±3.9)‰(n=8),δ18O=(-0.44±2.21)‰(n=8);Ⅳ阶段δD=(-65.6±4.5)‰(n=3),δ18O=(-4.43±1.09)‰(n=3)。根据氢-氧同位素组成及流体混合作用图解和水-岩交换氢氧同位素演化曲线,得出变质水与大气降水的混合流体与成矿相关。成矿流体来源主要为胶东群变质水,随着成矿作用的进行,更多大气降水混入成矿流体,成矿Ⅲ、Ⅳ阶段流体很可能以大气降水为主。成矿流体依据其流动方式主要分为渗透式流动和隧道式流动两种,蚀变岩型矿石的氧同位素组成较为集中,表明渗透式流动很可能是形成蚀变岩型矿石的成矿流体的主要流动方式;石英脉型矿石的δ18O值分布范围较大并小于或等于蚀变岩型矿石的δ18O值,表现出成矿流体的隧道式流动特征。在垂向上δD值表现出由深部到浅部总体降低的趋势,可能是在流体沸腾过程中发生了动力学分馏。横向上δ18O值的变化与已探明的矿体规模之间具有明显的负相关关系,很可能表明F1和F5断裂是具有低δ18O值大气降水下渗的主要通道,混合后的成矿流体沿F1和F5断裂运移的同时向其两侧的次级断裂流动。成矿流体与玲珑黑云母花岗岩不断发生水-岩交换作用,并发生减压沸腾作用,可能是导致望儿山金矿床同位素梯度变化及巨量金沉淀成矿的最主要原因。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

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.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

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.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

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.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

NONMETALS DEPOSITS

正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)     

MATHEMATICAL GEOLOGY

正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,     

PROSPECTING EXPLORATION

正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)     

STRUCTURAL GEOLOGY

正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-     

STRUCTURAL GEOLOGY

正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with