FIG. 9 in The Sarmatian (middle Miocene) "petrified forest" of Gramada (NW Bulgaria): role of the calcareous crusts

FIG. 9. — Main components of crusts: A, B, type 1, thin crust attributable to corallines; C, D, type 2, micritic masses attributable to corallines showing a preserved cellular structure; E, F, type 3, cell alignments within a micritic crust with an indistinctly fine structure, possibly attributable to Corallinaceae; G, H, type 4, networks of filaments with micritic outlines within micritic masses, recalling a cyanobacterial structure of the Girvanella type; I, J, type 5, elongated cell structures, sometimes branched; K, type 6, rounded micritic masses with fine fan-shaped filaments recalling small cyanobacterial constructions; L, M, type 7, lumpy micritic clumps of probable microbial origin; N, O, type 8, cellular structures of variable size exhibiting a Bacinella-like character. Scale bars: A, F, J-L, 200 µm; B-D, G, H, M, N, 100 µm; E, I, O, 500 µm.