Tethys crumpled as the early African and Eurasian continents drifted together. The other is Tethys - a forerunner of the modern Indian Ocean. One is the ancestor of the Pacific Ocean. Geoscientists have proposed two sites for where the subduction might have taken place when Pangaea began breaking apart. These sites are where surface rock plunges into Earth’s interior and melts again. That occurred at sites known as subduction zones. The Atlantic Ocean started to form between what would become North America and Africa.īecause Earth’s size didn’t change, the creation of a new ocean had to be balanced by the destruction of crust somewhere else. Some 100 million years later, Pangaea began breaking apart. Earth scientists refer to this mega-continent as Pangaea (pan-GEE-uh). All of Earth’s major landmasses were squashed into one huge supercontinent. Roughly 300 million years ago, there was no Africa or North America. It also is one reason the planet’s continents sit in different locations today than they did in the distant past. Their movement is one reason earthquakes can occur. These pieces of the planet’s crust slowly grow, shrink and move. The outer shell of the Earth is covered with more than a dozen tectonic plates. And the shrinking of the ancestor of the Indian Ocean may have been all it took to do that, he argues in a newly published analysis. The scientist concludes that Pangaea - the supercontinent that once held most of Earth’s land - appears to have been ripped apart. Those plates carry the landmasses and seafloors as they move across Earth’s syrupy, bendable mantle. That’s the conclusion of a scientist who reexamined what tectonic plates were doing around 200 million years ago. The breakup of an ancient supercontinent may have been an outside job.
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