Coral-oyster patch reefs.
Upt to 3-4 m thick and 18 m wide.
Siliciclastic ramp setting.
Corals are Heliastrea, Porites, Tarbellastrea, Mussismilia.
Oyster Hyotissa squarrosa up to 70 % of the reef.
Rare encrusters. Some rhodolites.
10 % is sparry calcite.