Caspian Sea and a Pleistocene stage, that includes glaciation cycles and the creation of the present Volga River. During the first stage, the Tethys Sea had evolved into the Sarmatian Lake, that was created from the modern Black Sea and south Caspian, when the collision of the Arabian peninsula with Western Asia pushed up the Kopet Dag and Caucasus Mountains, setting definitive south and west boundaries to the Caspian basin. This orogeneic movement was continuous throughout the years, while Caspian was regularly disconnecting from the Black Sea. In the late Pontian, a mountain arch rose across the south basin and divided it
Black Mountain (range) appearance of its profile from Cwm Tawe to the south. Black Mountain (range) The Black Mountain () is a mountain range in South and West Wales, straddling the county boundary between Carmarthenshire and Brecknockshire (the latter currently administered as part of the unitary authority of Powys) and forming the westernmost range of the Brecon Beacons National Park. Its highest point is Fan Brycheiniog at 802 metres or 2,631 ft. The Black Mountain also forms a part of the Fforest Fawr Geopark. The Black Mountain should not be confused with the Black Mountains in the east of the National Park, nor