Figure 4. Scanning electron microscope images showing the pyrite framboids (PF1) interpreted as microbial colonies within the light-grey minor lamellae of Zoophycos spreiten. (a–d) PF1 consist of non-sheathed, hollow (black arrow in b) and infilled (white arrow in b) sub-micron balls with smooth opening, (b) is the close-up of (a), and (d) is the close-up of (c). PF1 shallowly penetrate into surfaces of the detrital feldspars in (a) and (c).