Transcript Document
CONTINENTAL DRIFT http://www.tectonics.caltech.edu/movi es/outreach/sumatra/pangaea.mov Alfred L. Wegener Geologist Alfred Wegener noticed similar rocks & fossil remains were found on continents which seemed to fit together. This lead to the Theory of Continental Drift, which states that all the contintnents were once together in a giant landmass. He called this “super” continent Pangaea. In 1912 Wegener published the first version & died defending his theory. PANGAEA the large landmass that included all of Earth’s present day continents Support for Continental Drift 1. SHAPE OF THE CONTINENTS Continents fit together like puzzle pieces Support for Continental Drift 1. SHAPE OF THE CONTINENTS Wegener was not the only one to notice the fit of the continents. 1858: Antonio Pelligrini depicted Africa and South America connected. He was one of the first scientists to publish maps depicting the apparent fit of the continents. Support for Continental Drift 2. FOSSIL EVIDENCE SAME FOSSILS: DIFFERENT CONTINENTS Mesosaurus was incapable of swimming across a large ocean. Support for Continental Drift 3. ROCK EVIDENCE – Mountain ranges SAME ROCK: DIFFERENT RANGE Existing mountain ranges separated by vast oceans contain rocks of identical mineral content. A prime example are the Appalachian Mountains in the eastern U.S and the Caledonian Mountains in the British Isles. Support for Continental Drift 4. GLACIAL SCARS orSAME Grooves Grooves, different continents. Support for Continental Drift 5. LOCATION OF COAL DEPOSITS AND ROCK TYPES Coal deposits have been found in temperate and polar regions; however, coal is formed in tropical regions. Similar rock types were found Support for Continental Drift 6. Evidence of similar climates Evidence of the same climate regions such as deserts were discovered on different continents. CONTINENTAL DRIFT IN DOUBT Why didn’t people believe in continental drift? People couldn’t image how the earth could be millions of years old People couldn’t image a force great enough to move the continents BUT by the 1960’s evidence would prove continental drift is TRUE and lead to the theory of Plate Tectonics…. The story continues (as does all good science!)