Presentation on theme: "To explain what is meant by continental Drift To state why people did not believe Alfred Wegner when he put forward this theory To state the evidence."— Presentation transcript:
To explain what is meant by continental Drift To state why people did not believe Alfred Wegner when he put forward this theory To state the evidence to support the theory of continental drift
1. Matching fossils on found in both South America and South Africa Coastlines of Africa and South America seemed to join could they have once been the same? Matching layers of rocks in different continents
300 million years ago there was only one supercontinent PANGEA which broke into smaller continents which moved apart
Wegeners explanation did not give convincing evidence Land bridges were thought to connect continents so fossils of animals would be found on both continents Scientists thought the forces to move the continents were too big
1950s the ocean floor was investigated and it was evident that continental Drift could happen Now continental drift is known to happen because of convections currents in the mantle
What is the theory of continental drift ? What evidence is there for it? Why was this theory not accepted for many years? What causes tectonic plates to move? Where do earthquakes and volcanoes occur? Why are earthquakes and volcanoes difficult to predict?