Ratburi Group
Algal boundstone facies
Lime mudstone, sparry calcite, trapped fragments of brachiopods, foraminifera and crinoids.
Skeletal bioclaste calcisponges, phylloid algae, branching dasycladacean algae.
Boundstone bodies 10-30 m thick and 10-50 wide. 
Micritic crusts, stromatactis-like cavities, radial-fibrous and blocky calcite.
