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Story of the Earth

Continental drift

South America and Africa drift apartSouth America and Africa drift apart The vast landmasses we call the continents have not always been where they are today. Earth’s outer shell is divided up into large slabs, called tectonic plates. These plates, which include both the continents and the floors of the oceans, shift very slowly about. This is called continental drift, part of the process known as plate tectonics. Over hundreds of millions of years, the continents have drifted around the globe, while the oceans have widened or narrowed accordingly. Just looking at a map of the world today gives us clues of where the continents were once positioned. It is easy to imagine South America, for example, tilted slightly and fitted snugly into the western coast of Africa—which is exactly where it was 135 million years ago.

Thingvellir, Iceland, where two tectonic plates meetThingvellir, Iceland, where two tectonic plates meet
The break-up of PangaeaThe break-up of Pangaea

The break-up
of Pangaea

Over hundreds of millions of years, entire continents have wandered around the globe, colliding into one another or drifting apart. About 280 million years ago, they came together to form a single “supercontinent” called Pangaea. There was no Atlantic Ocean, and the Americas were jammed up against Africa and Europe.

Since then, the continents have slowly split apart again, although some pieces, such as India and Asia, have collided with each other. During the Jurassic Period (201–145 million years ago), the continents began to move apart. Pangaea separated into two: Laurasia and Gondwana. This drift continued through the Cretaceous Period (145–66 million years ago). The continents are still in motion today.

India's drift northwardsIndia's drift northwards

India moves north

The break-up of Pangaea continues today, with the gradual widening of the Great Rift Valley of East Africa. It will eventually form an arm of the Indian Ocean.

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