The Isla de Mona facies model proposed is composed of three major facies: lagoonal, patch reef-core and patch reef-slope. Lagoonal facies within patch reefs are composed of horizontal beds with skeletal packstones-wackestones. Primary components of lagoonal beds are red algae, echinoids, mollusks and benthic foraminifera. Patch reef-core facies are defined by packages of coral bounded by skeletal grainstone-wackestone. The reef “framework” is basically monospecific mainly composed of two coral genera: Stylophora and Caulastrea portoricensis. Patch reef-slope facies are characterized by steeply dipping beds (~20°) composed of skeletal rudstone and grainstone-packstone with coral fragments, rhodoliths, benthic and planktonic foraminifera.
Stratigraphic vertical zonation on Miocene carbonates shows a transition from deeper-water corals (>20m depth) to fore reef branching corals colonies (20 to 10m depth). Pliocene carbonates shows a vertical transition from reef crest branching corals to back reef head corals colonies (<10m depth). Strontium isotope values from dolomites and vertical variations in coral-morphologies suggest that the carbonate deposition have been affected by relative sea level fluctuations. Diagenesis during reef development resulted in micritization of skeletal components and reduction of primary porosity through cementation and after reef development resulted in the creation of secondary porosity though dissolution and dolomitization.