Brecciaform limestones with fragments of 'algae' and stromatoporoids.
Many reef builders in common with Nyurolka basin:
Tabulate corals:
Riphaeolitidae (Riphaelites and Echyroporfa)
Favosites clarus

Rugose corals:
Dendrostella bilaterale
D. vulgaris

and many stromatoporoids