Depth profiles of the D/¹⁶O ratio determined using NanoSIMS for D-irradiated samples on the surface (a, c, and e) and in the interior (b, d, and, f). Depth measurement methods and interior data calibration methods are described in Appendices D and E. The upper x-axis gives the raster cycle number, and the lower x-axis the depths according to the NanoSIMS analysis pits. Each data point in panels a, c, and e corresponds to one cycle at one depth. Each data point in panels b, d, and f is the sum analysis result of 160 cycles. The grey region in panels b, d, and f represents the D/¹⁶O ratio of backgrounds for each mineral (less than 9.7 ± 6.8 × 10⁻⁹ for olivine; less than 1.9 ± 0.8 × 10⁻⁸ for pyroxene; and less than 2.3 ± 1.3 × 10⁻⁸ for plagioclase). The error bars represent the standard error of the mean. The dashed red line in panels b, d, and f represents the fitting curve for the decreasing trend of D/¹⁶O. The intersection of the fitting curve with the background value for each silicate indicates the deepest penetration of implanted D: 3619 ± 112 nm in olivine, 4049 ± 50 nm in pyroxene, and 4855 ± 263 nm in plagioclase.