Continental Drift Inside Earth 1.3 Pages 28-32
Alfred Wegener • Proposed a super continent he called Pangaea(“All Earth”) • Called his hypothesis 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 • Fit of the Continents • Fossil • Evidence • Landforms
Fit of the Continents • The coast of S. America and Africa fit together like a puzzle • N. America and Africa • The Red Sea.
Landforms • Mountain features • South African Mt. ranges line up with a mountain range in Argentina • European coal fields line up with coal fields of North America.
Fossils • Fossil: trace of an organism preserved in 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.
Fossils • 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 • 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
What to Work On • Read textbook pages 28-32 • Answer Section Review questions 1-4 Due: Friday, September 28th