Mounds consist of a core of bafflestone texture, with abundant sphinctozoans, hermatypic corals, inozoans, hydrozoans, solenoporaceans and dasycladaceans, covered on top by a boundstone formed by clusters of tubular organisms (serpulids) encrusted by Spongiostromata and with abundant interspace voids filled in by synsedimentary cements. At the top of the bioconstructions there exists a micrite facies with abundant fenestrae. The thickness of a single mound ranges from 1 to 10 m.

The mounds developed at the edge of a platform seaward of a calcarenite barrier.