Calcareous microbialites and associated biota in the mediterranean coastal lagoons and ponds of southern France: a key for ancient bioconstructions?

Abstract

Microbialites were found in various lagoons of the Mediterranean coast of southern France. They preferentially develop on pebbles on the edge of semi-enclosed water bodies, which can be temporarily dewatered and desiccated. The microbialitic building is achieved episodically with variations in the characteristics of the different layers. Its cerebroid and pustular appearance is the most remarkable macroscopic feature. Occasionally, other organisms may be involved in the construction, such as bryozoans and serpulid worms that form also in other places small unconsolidated bioconstructions. The analogy of these phenomena with bryozoans-serpulid-microbialite reefs occurring during Miocene in Paratethys, like those noticed in Romania, proposed by some authors, is considered unlikely, despite some common features.