Transcript Continental Drift

Continental Drift
Chapter 10, Section 1
Continental Drift
• Theory that states that all continents
slowly move through time.
– Suggests that all continents were joined in
one continent, Pangaea, which began to
break apart about 200 million years ago.
Continental Drift
• Developed by Alfred Wegener in early
1900’s.
• Controversial idea as Wegner had no
reason why the continents should move.
– Stated that the spin of the Earth caused less
dense continental crust to plow through more
dense oceanic crust.
Support for Continental Drift
• Matching coastlines.
Support for Continental Drift
• Fossils
– Matching fossils across continents.
Support for Continental Drift
• Changes in climates
– Evidence of glaciers found in tropical areas
and fossil ferns found in polar areas.
Support for Continental Drift
• Matching rocks across continents
– Ex. – Same age/composition rock layers in
Appalachians as in Greenland and western
Europe.