oWegner’s theory is that once a long, long, time ago all the continents were joined together

oThen they broke apart to make the 7 continents here today (see next slide)

Scientist Alfred Wegener wrote a letter to his girlfriend saying , “Doesn’t the east coast of South America fit exactly against the west coast of Africa, as if they had once been joined? This is an idea I’ll have to pursue.”

Later after that he had an hypothesis that a very long time ago the continents were part of one supercontinent which he called PANGAEA!

Some scientists thought that there was once a land bridge but Wegner disagreed. He put all the observations together to come up with the theory. He observed that South American and Africa fit together like a Jigsaw puzzle. He used evidence from the shapes of continents, fossils, landforms, and ancient ice age.

Fossils of identical plants and animals were found on different sides of the ocean

They must have lived on the same continent at some time in the past, because there’s no way they could not have travelled across the huge ocean!

It was noticed that when Wegener put the continents together in his map of Pangaea that landforms from different continents matched

Like the mountains that run east to west across South Africa lined up with the mountains in Argentina

In South Africa unusual rock formations and coal deposits were the same as the ones in Brazil

There were striations caused by ancient glaciers along both coasts of South America and South Africa, patterns formed were the same

Wegener found that continents where the evidence of deposits of glaciers had be found once fit around the south pole where it would have been very cold

He thought of the idea of the continents moving or drifting (continental drift)