Figure 16. Biotic characteristics and textures of Microfacies 3 sinter. (1) Colonisation of sinter surface by bacilli. (2) Patchy silicification of cells by nanospheres (<100 nm) of silica. (3) Overview of sinter section showing a predominantly massive, vitreous texture, although cavities are also present. Silicified, sandy sediment underlies sinter. (4) Diatoms and spherical cells cemented into sinter. (5) Clusters of cemented pennate diatoms aligned perpendicular to the approximate air-water interface (dashed blue line). (6) Close-up of (5) showing aligned pennate diatoms.