Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Continental Drift & Plate Tectonics Continental Drift Theory • Click on Title to watch Wegener Video • May need to put the closed caption on • First 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 • Wegner didn’t make up this theory out of the blue – like all scientists, he based it on evidence Evidence Summary • Geographic fit of South America and Africa • Fossils match across oceans • Rock types and structures match across oceans Geographic Fit • Continents look like they could be part of a giant jigsaw puzzle • Here’s how they moved apart Fossils Match • Plant and animal fossils found on the coastlines of different continents Fossil Fuel in Antarctica • Tropical plant remains (coal deposits) found in Antarctica – this is evidence that Antarctica was once much warmer and much closer to the equator, since tropical plants don’t grow in Antarctica today Rock Structures Match Across Oceans • Same rock patterns found in South America, India, Africa, Antarctica and Australia Rock Structures Match Across Oceans Evidence - North America Europe Asia Africa South America Australia Antarctica 8. Juan De Fuca Eurasian North American Arabian 10. Cocos Pacific 11. Caribbean African South American Nazca Scotia Philipine 15. Caroline Indo-australian Antarctic Alfred Wegener - German meteorologist and geophysicist - Developed Theory of Continental Drift - Used 3 pieces of evidence - Early 1900s The theory that states that parts of Earth’s crust drift/float on top of the liquid mantle (convection currents). Evidence -Continents fit together Like puzzle pieces -Same fossils were Found where pieces fit Together -Similar landforms found On each continent Evidence -Continents fit together Like puzzle pieces -Same fossils were Found where pieces fit Together -Similar landforms found On each continent