The distribution of elements of the igneous carbonate rock affected by alteration

受蚀变影响的火成碳酸盐岩元素分布

• 批准号: 03452073
• 负责人: HAGA Nobuhiko
• 金额: $ 3.97万
• 依托单位: Himeji Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452073/
• 关键词: Igneous Carbonate Rock; Cathodoluminescence; X-ray fluorescence; 火成性炭酸塩岩; カソードルミネッサンス; 変質鉱物; カソ-ドルミネッセンス

Carbonatite is the igneous intrusive rock whose main components are carbonate minerals. The distribution of the trace elements in fine mineral texture of the carbonatites from southern Brazil was investigated by means of cathodoluminescence (CL) attachment for polarized microscopy, which was purchased by this grant. The CL of Mn^<2+> and REE (rare earth elements) was observed in carbonate minerals, apatite and others in carbonatites. The spectrometer for visible light was applied for CL light through optical microscope, and results in the successful determination of the wavelength of CL emission. Calcite that includes 100 - 5000 ppm of Mn^<2+> shows yellow CL and dolomite, which also contains trace amount of Mn^<2+>, shows orange yellow CL.Although it is almost impossible to distinguish between the grains of calcite and dolomite under optical polarized microscope, CL makes to differentiate them very easy. The exsolution texture of dolomite in calcite was observed very clearly and quickly. Apatites in carbonatite also emit white to blue CL light. Their activators are found to be Mn^<2+> and REE ions such as Eu^<2+> and Sm^<3+>. The quantitative analyzes with the acuracy of percentage order were made using Electron Probe Micro Analyzer (EPMA) for constituent minerals in the carbonatite thin section. Also polarized microscope was used for the determination of the mineral species. The microbeam X-ray fluorescence analysis using the synchrotron radiation X-ray was used for mapping of the two-dimensional distribution of trace elements in thin section. This revealed Mn and Fe distributes in dolomite more than in calcite. Semi-quantitative analysis shows about 5,000 ppm content of Mn in dolonite grains. the chemical shift of XANES of Mn K-edge in calcite and dolomite suggests that Mn^<2+> substitutes in Ca^<2+> or Mg^<2+> sites in these rhombohedral carbonate crystals. The studies of behavior of distribution of trace rare earth

碳酸盐岩是以碳酸盐矿物为主要成分的火成岩侵入岩。本研究通过阴极发光（CL）偏光显微镜附件研究了巴西南部碳酸岩细矿物结构中微量元素的分布。碳酸盐矿物、磷灰石和碳酸岩中的其它矿物中均观察到Mn^<2+>和稀土元素的化学发光。用可见光分光光度计对化学发光进行了光学显微镜测量，成功地确定了化学发光的发射波长。含Mn^<2+> 100 - 5000 ppm的方解石显示黄色CL，含微量Mn^<2+>的白云石显示橙子黄色CL。虽然在光学偏光显微镜下几乎不可能区分方解石和白云石的颗粒，但CL使区分它们变得非常容易。白云石在方解石中的出溶结构观察得非常清楚和迅速。碳酸岩中的磷灰石也发射白色至蓝色CL光。它们的激活剂为Mn^<2+>和Eu^<2+>、Sm^<3+>等稀土离子。利用电子探针对碳酸盐岩薄片中的组分矿物进行了百分级精度的定量分析。还用偏光显微镜测定了矿物的种类。采用同步辐射X射线微束X射线荧光分析技术，对薄片中微量元素的二维分布进行了测绘。这表明Mn和Fe在白云石中的分布多于方解石。半定量分析显示白云石颗粒中Mn的含量约为5，000 ppm。方解石和白云石中Mn K边的XANES化学位移表明，Mn ^2+取代了菱面体碳酸盐晶体中的Ca ^2+或Mg^2+位置。微量稀土元素分布行为的研究

项目成果

H.Nagata: "Type B epitaxial growth of ceria thin film on Si(111) subtrate" Journal of Crystal Growth. 123. 1-4 (1992)

H.Nagata：“Si(111) 基板上二氧化铈薄膜的 B 型外延生长”《晶体生长杂志》。

K.Hagiya: "Modulation in Co-a^^°kermanite" Proc.Japan Acad.68B. 25-29 (1992)

K. Hagiya：“Co-a^^°kermanite 的调制”Proc.Japan Acad.68B (1992)。

Kenji, Hagiya: "Changes of structure of Co-akermanite at elevated temperatures" Acta Crystallographica. AS49. 340-340 (1993)

Kenji，Hagiya：“高温下钴镁石结构的变化”晶体学报。

芳賀 信彦: "鉱物における非調和熱振動" 姫路工業大学研究報告. 4. 25-34 (1993)

Nobuhiko Haga：“矿物中的非谐波热振动”姬路工业大学研究报告4. 25-34 (1993)。

萩谷 健治: "The Modurated Structure of Synthetic Co-Akermanite,Ca_2CoSi_2O_7" Acta Crystallographica. B49. 172-178 (1993)

Kenji Hagiya：“合成 Co-Akermanite，Ca_2CoSi_2O_7 的调制结构”《晶体学报》B49（1993）。