FIG. 14 in The Sarmatian (middle Miocene) "petrified forest" of Gramada (NW Bulgaria): role of the calcareous crusts

FIG. 14. — GR4 outer layer microfacies; A-C, general views showing the appearance in micritic columns making spaces partially filled by peloidal and oolitic accumulations; D, filamentous crusts surrounded by elongated branched cellular structures (type 5); E, composite corallinaceous crusts (types 2 and 3);. F, cellular crusts (type 3); G, crust with Girvanella-like filament; H, accumulations of peloids resembling faecal pellets; I, details of grains with an oolitic cortex. Scale bars: A-C, 5 mm; D, E, 500 µm; F-H, 200 µm; I, 100 µm.