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
Caspian Sea around 4 million bbl/day. Additionally, Iran has an estimated 988.4 trillion cubic feet of natural gas, around 16 percent of total world reserves, which makes it to play a key role in the global energy security equation. Russia's economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015. Russia's extensive mineral and energy resources are the largest such reserves in the world, making it second leading producers of oil and natural gas globally. The Caspian Sea region presently is a significant, but not major, supplier of crude oil to world markets, based