The Theory of Continental Drift Alfred Wegener was a German meteorologist. In 1910 he formed the hypothesis that the continents had once been joined together in a single landmass and have since split apart and moved to their present location. Wegener called this supercontinent Pangaea, meaning “all lands.” Pangaea existed about 225 million years ago. Wegener’s theory that the continents have slowly moved over Earth’s surface became known as continental drift.

Evidence for Continental Drift Wegener gathered evidence to support his theory. In particular he studied: Landforms Fossils Evidence that showed how Earth’s climate had changed over millions of years

Evidence from Landforms Africa and South America seem to “fit” together. A mountain range that runs east to west in South Africa lines up with a mountain range in Argentina. Brazilian coal fields line up with identical coal fields in South Africa. European coal fields line up with coal fields in North America.

Evidence from Fossils Glossopteris was a fernlike plant from about 250 million years ago. Fossils of it have been found in small areas in Africa, South America, Australia, India, and Antarctica. Glossopteris has a seedlike structure to it that was too large to be carried such great distances by wind and too fragile to survive a trip by water. The only thing that makes sense is if the land had once been closer together.

Climate Evidence Fossils of tropical plants have been found on Spitsbergen on land that is above the Arctic Circle. Geologists have found deep scratches in rock caused by glaciers in South Africa.

Why did scientists reject Wegener’s theory? Even though he provided evidence that the continents had drifted, Wegener could not explain how it happened. For this reason, geologists of his day rejected his theory.