Fig. 4

Carbonate lithofacies of the Cassina beds. a–c Laminite lithofacies. a Polished section exhibiting the typical lamination of the background sedimentation. In addition, a thin turbidite layer is visible in the uppermost part. b Wavy alternation of irregular dark (organic-matter rich) and bright (calcisiltite) laminae. Photomicrograph. c Bedding plane surface with non-size-sorted, thin-shelled nodosariid foraminifers. Photomicrograph. d–h Turbidite lithofacies. d Normally graded lime packstone to lime mudstone; close-up view of the turbidite layer in the uppermost part of a. Photomicrograph. e Reworked bioclasts (foraminifers). Photomicrograph. f Calcarenite sublithofacies. Lower bedding plane bearing a reworked, broken rostrum of a large Saurichthys (MCSN 8096, probably S. macrocephalus). g Micritic limestone sublithofacies. Polished section of a virtually structureless layer. Compare to plate 1, b in Bernasconi (1994). h Marly limestone sublithofacies. Polished section. Scale bars 10 mm (a, f–h); 0.5 mm (b–e)