Fig. 7

XFM map (A) showing an embedded section of the saturated burial phase experiment. Panels 1, 2, & 3 on the map highlight the presence of calcium bearing secondary carbonate minerals growing on weathered grains boundaries of the primary minerals cementing the grains together. Multiple nucleation sites are visible within the larger (ca. 50 μm) carbonate minerals (see panels 1, 2 and 3). Tile 1a shows the presence of nano scale (10 nm) amorphous carbonate nodules covering the surface of more well-developed carbonate minerals. Lightly etched sections of carbonate (panels 2a and 3a) reveal underlying rod-shaped bacteria embedded within the cement. Poor level of microbial preservation due to the multiple drying and embedding treatments involved in the creation of the thin sections