Continental Drift CH 4 Prentice Hall p.118-122
Continent of North America • It is now the year 2450. • Look at your pieces of the map of North America. • Write a problem. • Write a hypothesis for your problem.
Continent of North America • Create a table to organize pieces of evidence that support your hypothesis. (4 pieces minimum. • Hint: • Look at surface features. • Think about the things that you can’t see on a map, what would be on the actual surface that could serve as evidence?
Alfred Wegener • A German scientist- proposed a super continent he called Pangaea “All Land” • Proposed his hypothesis of continental drift. • Wrote the Origins of the Continents & Oceans 1915. Layers of Earth Menu
Continental Drift • All continents were once together and have slowly drifted over time to their current locations. • Pieces of Evidence: • Climatic Evidence • Fossil • Evidence • Landforms • Fit of the Continents
Fit of the Continents • The coast of S. America and Africa fit together like a puzzle. • Up to the 1900’s thought the continents remained fixed. CD Rift Evidence
Landforms • Mountain features & other features • South African Mt. ranges line up with a mountain range in Argentina. • European coal fields line up with coal fields of North America. CD Rift Evidence
Fossils • A trace of an ancient organism preserved in sedimentary rock. • Mesosaurus and Lystrosaurus- reptiles that could not swim across a salty ocean. • Found in places now separated by oceans which suggest that the continents were connected. CD Rift Evidence
Fossils CD Rift Evidence • A trace of an ancient organism preserved in sedimentary rock. • Glossopteris- a tropical fernlike plant. • Found in cooler climates of today, suggest that the continents have since moved. • Seeds were too large to be carried by wind.
Climate Climate • Fossils of tropical plants were found on the island of Spitsbergen, which is in the Arctic Ocean. • A harsh polar climate covered with ice. • 300 million years ago, the island had a warm and mild climate. • Wegener believed it was closer to the equator.
Climate • Glacial Evidence found as deep scratches in rocks on South Africa. • The climate of S. Africa today is too mild. • Suggests that S. Africa was closer to the S. Pole.
Climate CD Rift Evidence • Wegener believed that the climates changed because the position of these places changed. • The continent carries the fossil and rock evidence from where it formed and provide evidence for CD.
Rejected? • Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents. • Geologists rejected his idea until the 1960’s CD Rift Evidence