Continental Drift Theory

Alfred Wegner and Continental Drift Theory Alfred Wegner was a German meteorologist & geophysicist who developed the first theory of continental drift. Continental Drift is the gradual movement of the continents across the earth’s surface. meteorology: study of weather geophysics: study of the physics of earth.

Wegner’s Evidence He used 3 pieces of evidence to develop his theory: The continents fit together like puzzle pieces The same fossils were found where the pieces fit together Similar landforms were found on the different continents

Alfred Wegener Observed He observed that South America and Africa fit together like puzzle pieces.

Alfred Wegener Researched As he began to conduct research he found that Brazil and Africa had fossils of extinct animals that were the same!

Rock Formations The rock layers that form the Appalachian mountains of the eastern U.S. matched quite well with those in Scotland. Strata rock formations that make up the Santa Catarina system in Brazil matched those that form the Karro system in South Africa.

Plant Fossils, too He found extinct plants had left their fossils in both Africa and Brazil. He also found that rocks in Alaska contain fossil palm tree leaves, though there have not been palm trees at that latitude for a very long time!

Tropical Plants in the Arctic Wegener found that tropical plants such a ferns that grow in areas around the equator had left fossils on an island in the arctic which is near the North Pole.

Wegener Posed Questions How could rocks be exactly the same in Brazil and Africa? How could fossils be exactly the same in Brazil and Africa? How could tropical fossils be found at the North Pole?

Wegener Inferred Alfred Wegener proposed that the continents must move. He thought that at one time the continents must have all been connected in one big super continent. He called that super continent Pangaea