Continental Drift Theory • Proposed by Alfred Wegener in 1912 • 250 million years ago, all of the continents were combined into one super-continent called “Pangaea” • The continents gradually drifted apart to where they are today
Alfred Wegener (German Scientist) • This picture was taken around 1925 (5 years before he died)
Evidence to Support the Theory
“Puzzle Pieces” • Continents look like they could be part of a giant jigsaw puzzle
Distribution of Fossils • Plant and animal fossils found on the coastlines of different continents
Ancient Climates • Tropical plant remains (coal deposits) found in Antarctica • Glaciation in Africa, South America, India, and Australia during the same time
Sequence of Rocks • Same rock patterns found in South America, India, Africa, Antarctica and Australia
Problems With Theory • No mechanism for movement of continents • Wind and currents could possibly move fossils • Theory was not accepted by scientists
Review • What is theory of continental drift? – Continents were once one “super continent” but they slowly drifted apart • What 4 pieces of evidence did Wegner have to support this theory? – Puzzle pieces – Fossils – Ancient climates – Sequence of rocks