11:00 AM - 11:15 AM
[MIS13-08] Non-destructive, wide-area, and microscopic compositional and mineralogical analysis by combined use of μXRF and μXRD and its application to wide area of earth and planetary sciences
Keywords:μXRF, μXRD
X-ray fluorescence analysis (XRF) and X-ray diffraction analysis (XRD) are fundamental analytical methods for obtaining information on the chemical composition and mineralogy of materials, and are widely used in various fields of earth and planetary sciences. Conventionally, both XRF and XRD are mostly performed on powder samples (and glass beads made from powders), requiring 0.1-1 g of each sample for analysis. The need for powdering result in sampling bias and homogenization of the compositional variations of the fine scales in the samples. These can be essential problems in earth and planetary sciences, which deals with phenomena over a wide range of spatial scales.
Recent advances in X-ray analysis technology have made it possible to analyze and map small areas of several tens of micrometers in diameter for both XRF and XRD, and μXRF and μXRD analysis, which were previously possible only using synchrotron radiation, are now possible at the laboratory level, but there are still not many examples of application in Japan. At the Atmosphere and Ocean Research Institute of the University of Tokyo, μXRF (Bruker M4 TORNADO PLUS) and μXRD (Bruker D8 DISCOVER) have been successively introduced and started operation over the past few years. As examples of current applications in structural geology, μXRF has been able to depict compositional variations within a polished slab samples of fault rocks, and pinpoint analysis of a thin section of fault rock using μXRD has revealed that the crystallinity of illite increases and calcite disappearance occurred at slip planes (Kimura, G. et al., 2021, G-cubed, e2021GC009855).μXRF is suitable for compositional mapping of polished rock slabs, while μXRD is suitable for pinpoint analysis of mineral composition in thin sections, calcite/aragonite classification of biogenic minerals, and orientation evaluation of clay minerals, and is expected to be applied to a wide range of Earth and planetary science fields, including extraterrestrial materials and experimental products in the future.
Recent advances in X-ray analysis technology have made it possible to analyze and map small areas of several tens of micrometers in diameter for both XRF and XRD, and μXRF and μXRD analysis, which were previously possible only using synchrotron radiation, are now possible at the laboratory level, but there are still not many examples of application in Japan. At the Atmosphere and Ocean Research Institute of the University of Tokyo, μXRF (Bruker M4 TORNADO PLUS) and μXRD (Bruker D8 DISCOVER) have been successively introduced and started operation over the past few years. As examples of current applications in structural geology, μXRF has been able to depict compositional variations within a polished slab samples of fault rocks, and pinpoint analysis of a thin section of fault rock using μXRD has revealed that the crystallinity of illite increases and calcite disappearance occurred at slip planes (Kimura, G. et al., 2021, G-cubed, e2021GC009855).μXRF is suitable for compositional mapping of polished rock slabs, while μXRD is suitable for pinpoint analysis of mineral composition in thin sections, calcite/aragonite classification of biogenic minerals, and orientation evaluation of clay minerals, and is expected to be applied to a wide range of Earth and planetary science fields, including extraterrestrial materials and experimental products in the future.