Luis Pomar

Changes in coral-reef structure through the Miocene in the Mediterranean province: Adaptive versus environmental influence

Well-documented Mediterranean examples of Miocene carbonate platforms, with complete exposures from shallow-water to basinal facies, provide evidence for temporal changes in reef-building capacity of zooxanthellate corals. In pre–late Tortonian platforms, small coralgal patches and mounds occur from platform top to the toe of slope, but they did not build to sea level. In contrast, barrier reefs with unequivocal reef-crest structures that reached sea level are documented in late Tortonian–early Messinian platforms. We suggest that a change in both calcification rates and bathymetric zonation was the result of coevolution of corals and Symbiodinium zooxanthellae, coeval to global cooling and, at least at a regional scale, a geochemical change that supported widespread aragonite precipitation through the late Miocene.

Sea-Level Changes, Carbonate Production and Platform Architecture: The Llucmajor Platform, Mallorca, Spain

The stratal architecture of the Upper Miocene coral-reef platform of southwestern Mallorca, Spain, is controlled by high-frequency changes in accommodation and sediment supply (carbonate production), in the absence of significant compaction and subsidence during progradation. In this example, carbonate production and accommodation changes are not independent factors and both are, in turn, controlled by the changes of sea-level and morphology of the depositional profile of the basin floor.

Response: Commentary: Evaluating the Role of Seagrass in Cenozoic CO2 Variations

Dipartimento Scienze della Terra, Università Roma La Sapienza, Rome, Italy, 2 Istituto di Geologia Ambientale e Geoingegneria (CNR), Sez. Sapienza, Dipartimento Scienze della Terra, Università Roma La Sapienza, Rome, Italy, Càtedra Guillem Colom Casasnovas, Universitat de les Illes Balears, Palma de Mallorca, Spain, 4 Laboratorio de Zoología, Departament de Biologia, Universitat de les Illes Balears, Palma de Mallorca, Spain