About 250 million years ago, in the late Permian, a rift appeared in the northern margin of the South Pan-continent (later Gondwana, that is, the joint ancient land), forming an ocean, and the Paleo-Tethys ocean structure was opened and formed. Today, the world geological structure pattern is formed on the basis of Tethys structure. About 250 million years ago, in the late Permian, a rift appeared in the northern margin of the South Pan-continent (later Gondwana), the West Melia continent began to split, and a new ocean began to appear in the southern part of the Paleo-Tethys Ocean. In the next 60 million years, the Ximelia plate separated from the Pangaea and moved northward, narrowing the southeastern margin of the Paleo-Tethys Ocean to the northern part of the Pangaea. A new ocean, Tethys Ocean, has emerged between the southern Pangea and Zimbabwe (now Turkey, Iran, Afghanistan, Tibet, zhina and Malaya), replacing the original position of the Tethys Ocean.

During the Jurassic period, 65.438+0.5 billion years ago, the West Melia collided with the North Pangea (later Laoya) and formed a subduction zone called Tethys Trench. As the sea level rises, the Tethys Sea extends westward to Europe. At the same time, Pangea split into Lauea and Gondwana, and the Atlantic Ocean began to appear. In Jurassic and Cretaceous (about 1 100 million years ago), Gondwana began to split, Africa and India left northward and crossed the Tethys Ocean, and the Indian Ocean began to appear. There are continental plates pushing the Tethys Sea. In the late Miocene/kloc-0.5 million years ago, the Tethys Ocean was reduced to the Tethys Channel, or the Second Tethys Sea.

Today, India, Indonesia, the Indian Ocean and other areas were all covered by the Tethys Ocean in the past. Today, the Mediterranean Sea is the remnant of the West Tethys Ocean, while the Black Sea, Caspian Sea and Aral Sea are the remnants of the Deputy Tethys Sea. Most of the floor of the Tethys Ocean was submerged under the continents of Cimelia and Lauea. Geographers such as Hughes found fossils of marine life in the rocks of the Himalayas.

This area used to be the bottom of the Tethys Ocean, until the Indian mainland collided with the Chimera mainland, causing the bottom to rise. There is similar evidence in the European alpine orogeny, which shows that the African plate caused the Alps.

For paleontologists, the Tethys Ocean is very important, because there are many continental shelves around the Tethys Ocean, and many biological fossils inhabiting oceans, swamps and estuaries can be found in these former continental shelves, which can be used to study biological changes for a long time. Pre-Tethys (Proterozoic-Early Paleozoic) was formed about 2.5-350 million years ago.

The ancient Tethys (Late Paleozoic-Early Mesozoic) developed and prospered in about 350-200 million years.

The NeoTethys (Late Mesozoic-Cenozoic) was closed for about 200 million to 2 million years.