Mineralogical analysis and dating using the JEOL JXA-8530F FE-EPMA at the JAEA Tono Geoscience Center

Shimizu, Mayuko   ; Sano, Naomi; Suzuki, Kazuhiro

We established a CHIME monazite dating method using R = 100 mm spectrometers and a provenance analysis method using heavy minerals for the dating and analysis of minerals. CHIME dating has traditionally been performed with conventional R = 140 mm spectrometers for measurement of U, Th, and Pb. These spectrometers, however, have low count rates in measurements of Pb. We used a JEOL JXA-8530F FE-EPMA equipped with R = 100 mm spectrometers, a system installed at Tono Geoscience Center in 2014, for the CHIME dating of monazite. We corrected the spectral interferences peculiar to R = 100 mm spectrometers by the method of AA mli and Griffin (1975) for monazite analyses. We calculated the correction factors by a new interference correction method using natural monazites. We also established a quick quantitative analysis and identification method for heavy minerals using the EPMA.