Frasnian 'lower reef' (dolomitized) and early Famennian 'upper reef' (limestone).
Rare macrofauna (Amphipora).
Microgranular silts with spherical algae, forams,
cyanophyceans, red algae.
Ref. 1394: Various algae, Girvanella, stromatoporoids, corals.
380 m thick. 6-11 % porosity.