Figure shows the smoothed spectra after the preliminary noise reduction step for a sampled point. For comparison, all the spectra in the 10 blocks are rescaled to the intensity scale of the observed counts. The reference spectrum (top left) is the average of all the spectra over the observed area (the same area as the bright field image shown in the left of Figure ). Three main peaks were observed for C, O, and Si, which compose the sample. The peak at 1.1 keV is attributed to gallium (Ga). We observed that it scatters over the area, and thus its averaged intensity over the whole image is relatively enhanced compared to the pointwise intensity of Ga-peak and the averaged intensity of C-peak. Except for the reference spectrum, three colored plots of spectra correspond to three principal phases of the sample-Si, SiO 2 , and SiC-as colored in the annotated image (right of Figure ). Note that the observed spectra (top second left) are quite noisy, with at most, counts of four for this sampled point. The counts from C are remarkably smaller than O and Si.