Oligocene rhodolith beds in the central mediterranean area

Abstract

During the Oligocene, extensive carbonate platforms developed in the central Mediterranean. These areas were colonized by different organisms, being the coralline algae one of the most important contributors to the carbonate production. Red algae produced sediments in shallow seagrass environments, however dominate the mesophotic and oligophotic zones where produced rhodolith beds. The diffusion of red algae during the Oligocene was favoured by reduction in atmospheric CO2, a rise in seawater alkalinity and increasing Mg/Ca ratios. This chapter deals with these deposits analyzing the depositional models and the controlling factors accounting for the origin of rhodolith beds.