1993 Fiscal Year Final Research Report Summary
The distribution of elements of the igneous carbonate rock affected by alteration
| Project/Area Number |
03452073
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
鉱物学(含岩石・鉱床学)
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| Research Institution | Himeji Institute of Technology |
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Principal Investigator |
HAGA Nobuhiko Himeji Institute of Technology, Faculty of Science, Ass.Porfessor, 理学部, 助教授 (60011748)
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| Co-Investigator(Kenkyū-buntansha) |
HAGIYA Kenji Himeji Institute of Technology, Faculty of Science, Res.Ass., 理学部, 助手 (70237907)
OMASA Masaaki Himeji Institute of Technology, Faculty of Science, Professor, 理学部, 教授 (30092159)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Igneous Carbonate Rock / Cathodoluminescence / X-ray fluorescence |
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| Research Abstract |
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
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Research Products
(6 results)
