Carbonate Forum 2020

This work contains sedimentological and compositional information on the development of Miocene coral colonies in the Mediterranean Sea, global important period for the increase in coral reefs. Stratigraphic sections located in Syracuse in south-eastern Sicily, allowed us to characterize compositional and textural through three sections at Faro Santa Croce, Ognina, Plemmirio, from the upper Tortonian-lower Messinian Monte Carrubba formation, and one at Punta Bonico, from the Burdigalian-Serravallian Calcari di Siracusa member. Our interpretations of these strata were compared with other published models for the Sicilian and Mediterranean area. The three sections of Monte Carrubba formation are characterized by varying lithofacies, that shows the occurrence of corals in a deep environment. Specifically, the lithofacies CB (corals boundstone), often encrusted by red algae and serpulids, is indicative of a variable depositional depth (mid-inner ramp) for the presence, in some areas, of Nummulitidae, planktonic foraminifera and non-articulated red algae hint a meso-oligophotic zone. The components of the other lithofacies suggests, instead, shallow environments from lagoon, seagrass zone to the possible presence of little oolitic shoals in the carbonate margin. Finally, the small succession of Punta Bonico is composed of three lithofacies: FR (rhodolits floatstone), FC (coral floatstone) and GB (bivalves grainstone). In the first, Miogypsina suggests meso-oligophotic environments. The second lithofacies has associations of articulated red algae and Miliolids that indicate euphotic zone deposition, although Miogypsina and rare planktonic foraminifera indicate a deeper environment. Finally, composition and texture of the last lithofacies indicates high hydrodynamic energy typical of an inner ramp euphotic zone. The Punta Bonico section doesn’t show us satisfying results to locate corals in deeper environment but, comparing the lithofacies with some carbonate ramps from the same age, we had associated them in an inner-mid ramp contest. Different speech is for the upper Tortonian-lower Messinian sections, because our findings reveal a spread of coral colonies in deeper habitat while previous authors (Pedley, 2007) put them in euphotic zone. In addition, this could be another confirm of mesophotic coral buildups in a middle ramp zone as was discover by Morsilli et al, 2012 in the southern Pyrenees, Spain. The novelty of this study consists in the discovery of deeper coral colonies during the Miocene age, while all previous studies associated them in shallow environment. Even if this study is far from create an exhaustive model, it contains elements that shed new light on the Mediterranean coral successions. In addition, it establishes the basis of future studies with the aim of a detailed investigation of deeper coral colonies, based on a careful observation of the outcrops up to laboratories analysis.