Wegener's Theory

Wegener's Theory

1. The idea of Continental Drift was put forward by Alfred Wegener in 1915

   • His fellow scientists found his theories hard to accept
     • He couldn't explain how the continents had moved
   • His theory was shown to be right almost 50 years later
     • Scientists found that the seas floor is spreading apart in some places, where molten rock is spewing out between two continents
       • This led to a new theory called plate tectonics
     • Proof for his theory
       • The same types of fossilised animals and plants are found in South America and Africa
       • The shape of the east coast of South America fits the west coast of Africa, like pieces in a jigsaw puzzle
       • Matching rock formations and mountain chains are found in South America and Africa

2. In the past scientists thought that mountain ranges were caused by the Earth's crust shrinking as the early molten earth cooled

   • Wegener suggested the mountains were formed when the edge of a drifting continent collided with another, causing it to crumple and fold.
     • For example, the Himalayas were formed when India came into contact with Asia.