Fig. 2.

Biogenetic fabrics in the mat-related structures. The MRS textures are shown through SEM images. a Tufted microbial fabrics developed above the poorly-sorted quartz sandstone. Yellow and blue arrows point to tufts and quartz grains, respectively. b A void-filling titanium oxides that may have filled an oxygen bubble produced within the microbial mat. c Nearly-circular void filled with titanium oxides at the tip of a cone-like feature (green arrows) Detrital dioctahedral micas (e.g., muscovite) are shown by purple arrows