Effect of Beam Current and Diameter on Electron Probe Microanalysis of Carbonate Minerals
- 9 Downloads
The effect of operating conditions on the time-dependent X-ray intensity variation is of great importance for the optimal EPMA conditions for accurate determinations of various elements in carbonate minerals. Beam diameters of 0, 1, 2, 5, 10, 15, and 20 μm, and beam currents of 3, 5, 10, 20, and 50 nA were tested. Ca, Mg, Zn, and Sr were found to be more sensitive to electron beam irradiation as compared to other elements, and small currents and large beam diameters minimized the time-dependent X-ray intensity variations. We determined the optimal EPMA operating conditions for elements in carbonate: 10 μm and 5 nA for calcite; 10 μm and 10 nA for dolomite; 5 μm and 10 nA or 10 μm and 20 nA for strontianite; and 20 nA and 5 μm for other carbonate. Elements sensitive to electron beam irradiation should be determined first. In addition, silicate minerals are preferred as standards rather than carbonate minerals.
Key wordscarbonate minerals electron probe microanalysis characteristic X-ray time-dependent intensity beam current beam diameter
Unable to display preview. Download preview PDF.
This work was supported by the Natural Science Foundation of China (No. 41403022) and the Fundamental Research Funds for the Central Universities, China University of Geosciences (Wuhan) (No. CUGL150401). We are grateful to two anonymous reviewers for providing valuable comments and suggestions, which helped to improve this manuscript significantly. The final publication is available at Springer via https://doi.org/10.1007/s12583-017-0939-x.
- Essene, E. J., 1983. Solid Solutions and Solvi among Metamorphic Carbonates with Applications to Geologic Thermobarometry. Reviews in Mineralogy, 11(1): 77–96Google Scholar
- Kerrick, D. M., Eminhizer, L. B., Villaume, J. F., 1973. The Role of Carbon Film Thickness in Electron Microprobe Analysis. American Mineralogist, 58(9/10): 920–925Google Scholar
- Lane, S. J., Dalton, J. A., 1994. Electron Microprobe Analysis of Geological Carbonates. American Mineralogist, 79(7/8): 745–749Google Scholar
- McGee, J. J., Keil, K., 2001. Application of Electron Probe Microanalysis to the Study of Geological and Planetary Materials. Microscopy and Microanalysis, 7(2): 200–210Google Scholar
- Meier, D. C., Davis, J. M., Vicenzi, E. P., 2011. An Examination of Kernite (Na2B4O6(OH)2·3H2O) Using X-Ray and Electron Spectroscopies: Quantitative Microanalysis of a Hydrated Low-Z Mineral. Microscopy and Microanalysis, 17(5): 718–727. https://doi.org/10.1017/s1431927611000602 CrossRefGoogle Scholar
- Smith, M. P., 1986. Silver Coating Inhibits Electron Microprobe Beam Damage of Carbonates. Journal of Sedimentary Research, 56(4): 560–561. https://doi.org/10.1306/212f89c7-2b24-11d7-8648000102c1865d CrossRefGoogle Scholar
- Spray, J. G., Rae, D. A., 1995. Quantitative Electron-Microprobe Analysis of Alkali Silicate Glasses: A Review and User Guide. The Canadian Mineralogist, 33(2): 323–332Google Scholar
- Stormer, J. C., Pierson, M. L., Tacker, R. C., 1993. Variation of F and Cl XRay Intensity due to Anisotropic Diffusion in Apatite during Electron Microprobe Analysis. American Mineralogist, 78(5–6): 641–648Google Scholar
- Yang, S. Y., Jiang, S. Y., 2012. Chemical and Boron Isotopic Composition of Tourmaline in the Xiangshan Volcanic-Intrusive Complex, Southeast China: Evidence for Boron Mobilization and Infiltration during Magmatic-Hydrothermal Processes. Chemical Geology, 312/313: 177–189. https://doi.org/10.1016/j.chemgeo.2012.04.026 CrossRefGoogle Scholar
- Yang, S. Y., Jiang, S. Y., 2013. Occurrence and Significance of a Quartz-Amphibole Schist Xenolith within a Mafic Microgranular Enclave in the Xiangshan Volcanic-Intrusive Complex, SE China. International Geology Review, 55(7): 894–903. https://doi.org/10.1080/00206814.2012.752662 CrossRefGoogle Scholar
- Yang, S. Y., Jiang, S. Y., Palmer, M. R., 2015a. Chemical and Boron Isotopic Compositions of Tourmaline from the Nyalam Leucogranites, South Tibetan Himalaya: Implication for Their Formation from B-Rich Melt to Hydrothermal Fluids. Chemical Geology, 419: 102–113. https://doi.org/10.1016/j.chemgeo.2015.10.026 CrossRefGoogle Scholar
- Yang, S. Y., Jiang, S. Y., Zhao, K. D., et al., 2015b. Tourmaline as a Recorder of Magmatic-Hydrothermal Evolution: An in-situ Major and Trace Element Analysis of Tourmaline from the Qitianling Batholith, South China. Contributions to Mineralogy and Petrology, 170(5/6): 1–21. https://doi.org/10.1007/s00410-015-1195-7 Google Scholar
- Ye, M., Zhao, H., Zhao, M., et al., 2017. Mineral Chemistry of Biotite and Its Petrogenesis Implication in Lingshan Granite Pluton, Gan-Hang Belt, SE China. Acta Petrologica Sinica, 33(3): 896–906 (in Chinese with English Abstract)Google Scholar
- Zhang, H. C., Zhu, Y. F., Feng, W. Y., et al., 2017. Paleozoic Intrusive Rocks in the Nalati Mountain Range (NMR), Southwest Tianshan: Geodynamic Evolution Based on Petrology and Geochemical Studies. Journal of Earth Science, 28(2): 196–217. https://doi.org/10.1007/s12583-016-0922-1 CrossRefGoogle Scholar
- Zhao, D. G., Zhang, Y. X., Essene, E. J., 2015. Electron Probe Microanalysis and Microscopy: Principles and Applications in Characterization of Mineral Inclusions in Chromite from Diamond Deposit. Ore Geology Reviews, 65: 733–748. https://doi.org/10.1016/j.oregeorev.2014.09.020 CrossRefGoogle Scholar