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The Cracked Crust

Geologists used to think that the Earth’s crust was like a solid shell, and that the continents had always been where they are today. But in the early 1900s a German scientist named Alfred Wegener came up with a revolutionary new theory. The continents were drifting, carried along by movements in the Earth’s crust. This theory became known as continental drift. The theory supposed that long ago all the continents were joined together into a great supercontinent (Pangaea) then gradually drifted apart. This explained something that people had realized for years—that the continents of South America and  Gradual movements  of the crust slowly  but surely alter  the face of the Earth.

∆ The supercontinent Pangaea began to break up about 200 million years ago. The continents gradually drifted to where they are today.

∆ The Earth 200 million years ago

Africa look as if they would fit together like pieces of a jigsaw. The continental drift theory said that they were once joined. As they split apart, the sea flooded in, creating the Atlantic Ocean. ∆ Australian kangaroos are marsupials. Marsupials are also found in South America, suggesting that these continents were once joined.

∆ The Earth 65 million years ago

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