Concept
The Paratethys sea, Paratethys ocean, Paratethys realm or just Paratethys was a large shallow inland sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in Central Asia. Paratethys was peculiar due to its paleogeography: it consisted of a series of deep basins, formed during the Oxfordian stage of the Late Jurassic as an extension of the rift that formed the Central Atlantic Ocean. These basins were connected with each other and the global ocean by narrow and shallow seaways that often limited water exchange and caused widespread long-term anoxia. Paratethys was at times reconnected with the Tethys or its successors (the Mediterranean Sea or the Indian Ocean) during the Oligocene and the early and middle Miocene times, but at the onset of the late Miocene epoch, the tectonically trapped sea turned into a megalake from the eastern Alps to what is now Kazakhstan. From the Pliocene epoch onward (after 5 million years ago), Paratethys became progressively shallower. Today's Black Sea, Caspian Sea, Aral Sea, Lake Urmia, Namak Lake and others are remnants of the Paratethys Sea. Paratethys formed about 34 Ma (million years ago) at the beginning of the Oligocene epoch, when the northern region of the Tethys Ocean (Peri-Tethys) was separated from the Mediterranean region of the Tethys realm due to the formation of the Alps, Carpathians, Dinarides, Taurus and Elburz mountains. During the Jurassic and Cretaceous periods, this part of Eurasia was covered by shallow seas that formed the northern margins of the Tethys Ocean. However, because Anatolia, the southern boundary of the Paleo-Tethys, is a part of the original Cimmerian continent, the last remnant of Paleo-Tethys Ocean might be oceanic crust under the Black Sea. The Tethys Ocean formed between Laurasia (Eurasia and North America) and Gondwana (Africa, India, Antarctica, Australia, and South America) when the supercontinent Pangea broke up during the Triassic (200 million years ago). The name Paratethys was first used by Vladimir Laskarev in 1924.
