PGE (PLATINUM GROUP ELEMENTS) COSMOCHEMISTRY ON IRON

PGE（铂族元素）铁的宇宙化学

• 批准号: 07640652
• 负责人: HIRATA Takafumi
• 金额: $ 1.41万
• 依托单位: TOKYO INSTITUTE OF TECHNOROGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640652/
• 关键词: PLATINUM GROUP ELEMENT; IRON METEORITES; ENEMENTAL DISTRIBUTION; ICP MASS SPCTROMETRY; LASER MICROPROBE TECHNIQUE; 白金属元素; レニウム; レーザー試料導入システム; 太陽系形成

This paper describes in isotopic measurements that have been made with an inductively coupled plasma mass spectrometry (ICP-MS) and presentsresults of new experiments aimed at further progress of the isotope geochemistry. In situ measurement of the platinum group elements (PGE) and Re by laser ablation-ICPMS allows fractionation patterns to be established between host (kamacite) and Ni-rich exsolved phases (taenite and plessite). Measurements on two IAB iron meteorites (Canyon Diablo and Odessa) show that for the Ni-rich phases ; a) there is no significant fractionation for Ru and Rh, b) Pd is enriched and c) Ir, Os and Pt are strongly depleted. We suggest that in the case of kamacite, taenite and plessite, the controlling mechanism is ionic size with the order of ions (small to large) being Ir-Os-Pt- (Re) -Rh-Ru-Pd. This progression plots as a smooth curve on a diagram of relative abundance distribution versus ionic size. A comparison of PGE and Re data on iron meteorites with publish … More ed data from CI chondrites indicate that there is little or no relative fractionation between the elements. The exception is Re that is clearly enriched in kamacite relative to chondrites. This confirms earlier observations on the fractionation of Re/Os between bulk IAB irons and CI values. Metallic veins cutting graphite inclusions within the Canyon Diablo IAB meteorite are interpreted as a melt fraction from the iron meteorite. Abundance ratios for PGE and Re between kamacite and the metallic vein are similar to abundance ratios between kamacite and Ni-rich phases. The fact that those elements with large ionic radii (Rh, Ru and Pd) are concentrated in the metallic veins adds weight to the view that they represent a melt fraction.Our in-situ measurements of the PGE and Re demonstrate that elemental fractionation takes place both during melt segregation and solid state diffusion (exsolution). The data have important implications for the Re/Os geochronometer and indicate that measurements of 187Os/186Os ratios on individual phases within iron meteorites may provide a potential mineral isochron. Less

本文介绍了用电感耦合等离子体质谱（ICP-MS）进行的同位素测量，并介绍了旨在进一步发展同位素地球化学的新实验结果。原位测量的铂族元素（PGE）和Re的激光烧蚀-ICPMS允许分馏模式之间建立主机（kamacite）和富镍exsolved相（taenite和plessite）。对两块IAB铁陨石（峡谷Diablo和敖德萨）的测量表明，对于富镍相：a）Ru和Rh没有明显的分馏，B）Pd富集，c）Ir、Os和Pt强烈贫化。我们认为，在kamacite，taenite和plessite的情况下，控制机制是离子的大小顺序（小到大）的Ir-Os-Pt-（Re）-Rh-Ru-Pd。这种进展在相对丰度分布与离子大小的关系图上绘制为平滑曲线。铁陨石PGE和Re数据与文献的比较 ...更多信息 来自Cl同位素的艾德数据表明，元素之间几乎没有或没有相对分馏。例外的是Re明显富集在kamacite中。这证实了早期的观察散装IAB铁和CI值之间的Re/Os分馏。金属脉切割石墨夹杂物内的峡谷暗黑IAB陨石被解释为熔融部分的铁陨石。铁纹石与金属脉之间的PGE和Re丰度比与铁纹石与富Ni相之间的丰度比相似。事实上，这些元素与大离子半径（Rh，Ru和Pd）集中在金属静脉增加重量的观点，他们代表了熔体fraction.Our的PGE和Re的原位测量表明，元素分馏发生在熔体偏析和固态扩散（出溶）。这些数据具有重要的意义，Re/Os地质年代计，并表明，测量187 Os/186 Os的比例对个别阶段内的铁陨石可能提供一个潜在的矿物等时线。少

项目成果

Kozo, Uto, Richard.M., Conray, Takafumi Hirata, Shigeru Uchiumi: "Devel opment of K-Ar Dating System at Geological Survey of Japan." Bull.Geol.Surv.Japan. 46 (5). 239-249 (1995)

Kozo, Uto, Richard.M., Conray, Takafumi Hirata, Shigeru Uchiumi：“日本地质调查局 K-Ar 测年系统的开发”。

Takafumi Hirata: "Lead Isotopic Analysis using Multiple Collector-Inductively Coupled Plasma Mass Spectrometry coupled with Modified External Correction Method for Mass Discrimination Effect" Analyst. 121. 1407-1411 (1996)

Takafumi Hirata：“使用多收集器感应耦合等离子体质谱法结合改进的质量辨别效应外部校正方法进行铅同位素分析”分析师。

平田岳史: "マルチュレクター誘導結合プラズマ質量分析法による高精度同位体分析のための同位体差別効果の補正法" 分析化学. 45. 465-472 (1996)

Takeshi Hirata：“使用多反应器电感耦合等离子体质谱法进行高精度同位素分析的同位素辨别效应的校正方法”分析化学 45. 465-472 (1996)。

Takafumi Hirata: "Precise Isotopic Analysis by Multiple Collector -Inductively Coupled Plasma Mass Spectrometry." BUNSEKI KAGAKU. 45. 465-472 (1996)

Takafumi Hirata：“通过多收集器进行精确同位素分析 - 电感耦合等离子体质谱法。”

Barrat, J.A., Keller, F., Amosse J., Taylor, R.N., Nesbitt, R.W.and Hirata, T.: "Determination of rare earth elements in sixteen silicate reference samples by ICP-MS after Tm addition and ion-exchange separation." Geostandards Newsletter. 20. 133-139 (199

Barrat, J.A.、Keller, F.、Amosse J.、Taylor, R.N.、Nesbitt, R.W. 和 Hirata, T.：“在添加 Tm 并进行离子交换分离后，通过 ICP-MS 测定 16 个硅酸盐参考样品中的稀土元素。