Figure 9

SEM images of iron-rich microspherules (a–i) from PU25 (102.5—105 cmbs). See “Microspherule EDS Data” in Supplementary Figs. 16–22. EDS elemental map data and point EDS measurements suggest that significant oxygen depletion had occurred on exposed interior surfaces of the broken spherule (Fig. 9a) (Supplementary Fig. 16).