Pontian Stage (from Pont-Euxin) consists of continental fluviatile or lacustrine deposits forming the final stage of the Miocene cycle. The Pontian includes the famous deposits of Pikermi near Athens and is distinguished palaeontologically by the appearance of Hipparion, Mastodon longirostris, the presence of M. turricensis, the last Dinotherium; Rhinoceros schleierma cheri, Gazella deperdita. Marine equivalents of the Pontian occur in certain parts of Algeria and have been called the Sahelian (after Sahel d'Oran). In eastern Europe where the huge stretch of the eastern Mediterranean was separated from the western the true Pontian is underlain by a brackish water series (the Sarmatian, from the country of the Sarmates in the south of Russia), which may be the equivalent of the upper Vindobonian.
Turning now to the North •sea Miocene, the regression of the sea at the end of the Oligocene was such that the lowest Miocene is found only in Denmark, Schleswig-Holstein and the neighbour hood of Hamburg and is absent from England, Belgium and Hol land. The middle Miocene is marked by a southward transgres sion, the sea reaching as far south as Bremen and Osnabruck in Germany and covering much of Belgium where ferruginous sands constitute the Bolderian (Bolderberg, near Hasselt, Belgium). The presence of Aquitanian fossils in the Bolderian suggests a con nection with the Atlantic at this time. The upper Miocene is
represented by glauconitic sands near Antwerp, the Anversian of the Belgians. It is still doubtful whether the Miocene is repre sented in England except by lavas and some interstratified beds on the west coast of Scotland and northern Ireland. A Miocene fauna is found in the "Boxstones" at the base of the East Anglian Pliocene and it is claimed on palaeontological grounds that part of the Lenham beds, occurring in pockets in the chalk downs of Kent and Surrey, is Miocene.
Outside Europe the Miocene is well displayed in parts of northern India (where the Gaj series is Burdigalian) and has yielded a rich harvest of mammalian remains (especially from the Bugti beds) ; in the old gulfs of south-eastern Asia it is partly marine, partly continental—including, for example, the upper part of the Peguan of Burma, whilst the lower part of the fresh water Irrawaddian is Pontian. Along the Atlantic slope of the United States and around the Gulf of Mexico the complete Mio cene series is present, the Sarmatian and Pontian occur also in California. Miocene rocks are important in the West Indies and the Antilles. (See under EOCENE.) See the writings of G. E. Pilgrim in the Records of the Geological Survey of India on the correlation of Eastern deposits. (L. D. S.)