lower Sarmatian (middle Serravallian)
Buildups mainly of calcite precipitates
of microbial and inorganic origins. Skeletal framework represented by serpulid tubes and bryozoan skeletons (in places) is of minor importance. Other biota is taxonomically
impoverished but often rich in individuals and comprises few species of bivalves, gastropods, foraminifers and ostracods typical of brackish, semi-marine environment.