The reef facies may correspond to platform rim biolithite reefs, or to ramp-like oolitic shoals and patch reefs. Reef builders include coralline sponges, microbial crusts and sessile foraminifera, various microproblematica (Microtubus, Bacinella) and corals. Back-reef environments are characterized by algal-foraminiferal facies with coated grains, oncoids and foraminifera, and a grapestone facies. 

Reef facies intercalated with volcanics. Cummulative thickness of reef facies about 340 m.