Ancient carbonate reefs as geological heritage: state of knowledge and case example.

Ancient carbonate reefs, which represent specific palaeoecosystems, are promising as geological heritage sites (geosites). The bibliographical survey allows to identify 30 palaeoreef localities already interpreted in the terms of geoheritage. These were described in 18 countries from the different parts of the world; many palaeoreefs were reported from Europe and North Africa. The ages of the considered palaeoreefs differ, and they tend to concentrate in the Early–Middle Paleozoic, the Late Triassic–Jurassic, and the Late Cretaceous–Neogene intervals. The correspondence between the global dynamics of the reef growth in the Phanerozoic and the stratigraphical distribution of the palaeoreef-related geosites is uncertain. As a case example, three palaeoreefs from the Western Caucasus are taken into account. These are the Raskol (latest Permian), Tkhach–Sakhray (Late Triassic), and Oshten (Late Jurassic) palaeoreefs, which can be brought in correspondence to the global reef booms. They are important for geological research, education, and tourism. Generally, the present knowledge of the ancient carbonate reefs as geoheritage remains incomplete. The related research is perspective, and it requires cross-disciplinary cooperation of specialists. [ABSTRACT FROM AUTHOR]