The Theory of Continental Drift Drifting Continents The Theory of Continental Drift

Alfred Wegener German scientist – 1910 Curious about relationship of continents Wegener’s Hypothesis – All the continents were once joined together as a single landmass and have since drifted apart. Pangaea – Wegener’s name for the supercontinent; means “all lands"; existed 300 million years ago

Continental Drift Wegener’s idea that the continents slowly moved over Earth’s surface to their present locations

Wegener’s Evidence LANDFORMS FOSSILS 3. CLIMATE

Evidence from Landforms The shapes of the continents Folded mountain ranges in South America and Africa that matched up Coal fields in North America and Europe that matched up The Himalaya Mtn. range that formed when India collided with Asia

Evidence from Fossils Fossil – any trace of an ancient organism that has been preserved in rock Glossopteris fossils found on widely separated landmasses (Africa, S.A., Austr., India, Antarct.); seeds too large to be carried by wind or birds; too fragile to be carried by ocean waves Mesasauras fossils – freshwater reptile, found in S.A. and Africa only

Evidence from Climate Tropical plant fossils found in the harsh polar climate of Spitsbergen Glacier scratches in rocks of warm climate areas of South Africa, S.A., India, Austr. Coal beds found in polar climate of Antarctica ? ? ?

Scientists Reject Wegener’s Theory Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents.

Drifting Continents Define: Pangaea, continental drift, fossil Describe Wegener’s theory of continental drift List the 3 main categories of evidence used by Wegener to support his theory Give one example from each of the 3 categories of evidence What was important about the seed of the Glossopteris? Why did scientists reject Wegener's theory?