Plotta Formation

The Plotta Formation is mainly composed of white, grayish or blackish porous chert. Locally, at its base, a thin breccia layer is developed. It is composed by small subrounded limestone clasts, angular relict chert fragments and dark siliceous crust

Stars in the Silurian sky: Echinoderm holdfasts from the Carnic Alps, Austria

A small collection of echinoderm holdfasts from the Ludlow Cardiola Formation of the Carnic Alps (Austria) contains a wide range of morphologies as a response of environmental adaptation. In general, the holdfasts have a globous and massive dome-like profile with several processes arranged in a sub-radial disposition, so to create a sort of ‘star-like’ outline. A small central depression is common but not present on all specimens. The distinctive holdfasts are preserved in an iron-rich phase, documenting a substitution that has also affected other non-echinoderm calcareous material

Vinz Formation

The Vinz Formation consists of four well-bedded facies listed in order of decreasing abundance. Facies A: well bedded medium dark gray, medium to thick bedded, poorly sorted coral- and stromatoporoid-bearing rudstone (more rarely floatstone) with clasts up to about 10 cm of diameter and poorly sorted very coarse to fine grainstone matrix; sometimes rudstone shows a fining upward trend up to grainstone; Facies B: medium dark gray, thin to medium bedded, wackestone to packstone with moderate yellow thin laminae of silt; Facies C: medium dark gray, thin to thick bedded, often fining upward, moderately to well sorted locally laminated grainstone (from very coarse up to granules to fine-grained) to packstone; Facies D: rare medium light gray, medium to thick bedded, moderately to well sorted crinoidal-bearing grainstone with sparite cement