15 March 2026

On my way to somewhere else I found …

We think of Europe and Asia as separate land masses yet they are on one continent called Eurasia. In fact they used to be separated by the Turgai Strait which closed up 60 million years ago. But before the strait formed, they were stuck together. Here’s how plate tectonics affected Eurasia.

• 250 million years ago (million years is abbreviated Ma) Europe and Asia were in one large land mass called Pangaea which existed from 330 to 200 Ma. It included all the present day continents.
• At 170 Ma Pangaea began breaking apart.
• The Turgai Strait formed east of the Ural Mountains at 160 Ma. Europe and Asia separated.
• The Turgai Strait was always somewhat shallow. By 60 Ma it became shallower and narrower and was closed by 29 Ma. Europe + Asia became Eurasia.

These static maps show the breakup of Pangaea with a thin yellow line for the location of the Turgai Strait. (NOTE: I think the 120 Ma map is inaccurate because it puts the Turgai Strait west of the Ural Mountains but it was always east. I drew the yellow line on the water anyway.)

Mollweide Paleographic Maps of Earth from Wikimedia

Musing on Pangaea: How do we know all the continents were one big land mass?

• The continents’ shapes fit together like a jigsaw puzzle.
• Geologists found “matching geological trends between the eastern coast of South America, the east coast of North America (namely the Appalachian Mountains), and the western coast of Africa.” i.e. same rocks of same age in the Appalachians and NW Europe.
• Fossils of the same animals and plants, all of the same age, are spread across the southern continents.