FIG. 10. — A-G in The Sarmatian (middle Miocene) "petrified forest" of Gramada (NW Bulgaria): role of the calcareous crusts

FIG. 10. — A-G, GR1 Mactra limestone microfacies; A, overview showing horizontal deposit of disarticulated Mactra shells; B-D, Mactra valves within peloidal sediment; the structure of pellets recalls faecal pellets; E, porcelaneous nubecularid test; F, sediment with peloids and oolites showing variable nuclei; G, undetermined honeycomb bioclasts; H-L, GR2 microfacies; H, general view showing the succession of micritic crusts (cr) and peloid accumulations (pel); I, thin crusts (type 1) attributable to Corallinaceae; J, thin crusts (type 1) attributable to Corallinaceae; K, very micritized corallinaceous crust (type 2), revealing thin lines of cells; L, ostracod shells with finely oolitized outlines within the peloidal sediment. Scale bars: A, E-G, J, K, 200 µm; B, C, I, 500 µm; D, L, 100 µm; H, 5 mm.