Microbes in caves: agents of calcite corrosion and precipitation - Tufas and Speleothems: Unravelling the Microbial and Physical Controls - page 9

Fig. 2. SEM photomicrographs of substrates from the twilight zone of the Old Man Village cave (Grand Cayman).
Figure 2a-f show exposed surfaces (i.e. wall of cave) whereas Figure 2g-l show features beneath exposed surfaces.
(a) General view showing mucus (m) and bacteriformmicrobes on substrate. (b) Filamentous and bacteriformmicrobes
covered calcite substrate. (c) Non-calcified microbes. (d) Bacteriform microbes associated with etched calcite
substrate. (e) Filamentous microbe on surface formed of small, irregular-shaped calcite particles. (f ) Mucus, filaments,
and calcite particles covering surface and openings to borings. (g) General view showing boundary between biofilm