Alfred Wegener first proposed the theory of continental drift.
Continental drift was Wegener’s theory that all continents had once been joined together in a single landmass and have drifted apart since.
Wegener named this supercontinent Pangaea .
Wegener’s theory was rejected by scientists because he could not explain what force pushes or pulls continents.
Continental drift video clip Continental drift
Wegener searched and found three main pieces of evidence. Geologic - evidence in the layers of rocks across continents Fossil - evidence in the places certain fossils are found Climate - evidence in the changing climates during the past
Fit of Continents Across the Atlantic Mountain ranges in South America line up exactly with those in Africa! Geologic evidence
Fossil evidence Notice how fossils lined up across continents! http://evolution.berkeley.edu/evolibrary/images/history/fossils3.gif
Amazing Facts: Did you know... ...that India was once in the Southern Hemisphere connected to Antarctica? ...that North America was once surrounded by warm, tropical seas? ...that Africa was once covered by glaciers, which were kilometers in thickness? ...that the Sahara desert was once a tropical rain forest? Climate change
As North America has drifted to different latitudes, changing climates were experienced. This shows the changes in the state of New Mexico. An example of the proof for changing climate: At one time, the area that is New Mexico was below the equator!
Wegener's problem He could not find the force that was causing the continents to drift. Because of this, he could not convince anyone that continents could move. He died in Greenland on an expedition. At the time of his death, no one believed his hypothesis! Technology developed during the 1940’s changed all that!