Continental Drift

1
Continental Drift

• A Time Line

2
Alfred Wegener (1910-1920)

• Proposed Theory of Continental Drift based on
  puzzle-like fit of continents
• Discovered three key pieces of evidence
• Fossil clues (glossopteris and mesosaurus)
• Glacial clues (striations in no-glacial areas)
• Rock clues (Appalachian Mtn and Greenland/Europe)
• Died without substantial proof of HOW continents
  could move

3
Arthur Homes (1930s)

• Explained Continental Drift
• Power of magma convection in the mantle
• Sea-floor spreading
• mountain building
• Still had no hard data for proof, but answered
  the question of HOW the continents COULD move

4
Harry Hess (1960s)

• Proved seafloor spreading
• Sonar mapped the ocean floor
• Molten material
• Drilling samples
• Geomagnetism
• Technology finally caught up with the great minds
  of the scientists