Continental Drift Theory B.Sc. Semester-I Dr. Mohd. Tufail Department of Geography, Govt. Post Graduate College Rajouri

PLATE TECTONICS Continental Drift: 4 minutes How the Earth was Made----1.5 Billion Years Ago Talks about evidence of continental drift like the fresh water trilobite Alfred Wegener

CONTINENTAL DRIFT Alfred Wegner was one of several people who thought the continents looked like they fit together, so he proposed the continental drift theory in 1912. Wegner was a meteorologist and astronomer so needless to say other scientists thought he was out of his field of study.

His studies concluded that at one time all the continents were joined together in one land mass called Pangaea. 1. Laurasia was the name given to the northern part of Pangaea 2. Gondwanaland was the name given to the southern part of Pangaea

PANGAEA means “all land” Scientists thought this theory was outrageous because even though Wegner had evidence of one large land mass, he didn’t have the answers to what force (engine) “floated the plates”. He was laughed at and did not live to see his theory accepted. PANGAEA means “all land” This animation begins with the continents in their present location, and then moving back in time to form PANGAEA. The circles represent fossil evidence that Wegner used to prove his Continental Drift Theory.

Wegner had 5 pieces of evidence to prove his continental drift theory: WHERE’S THE EVIDENCE Wegner had 5 pieces of evidence to prove his continental drift theory: PUZZLE PIECES: The continents, especially South America and Africa, seemed to fit together like a puzzle.

Do you think they swam all the way across the oceans? NO! FOSSIL EVIDENCE: Wegner noticed that plant and animal fossils were found on different continents. Do you think they swam all the way across the oceans? NO! This would lead people to believe that the continents were once joined. Glossopteris…seed much to large to be windblown Mesosaurus…lived in fresh water and could not have lived in salt water

3. ROCK EVIDENCE: Huge belts of rocks found in Africa and South America were identical. Not only were they the same, but they would match up (age, thickness, types) if the continents were put together. Matching Mountains The Appalachian Mountains that disappear off the coast of Newfoundland match mountains in the British Isles and Scandinavia which are comparable in age and structure.

4. GLACIER EVIDENCE: There is proof that glaciers moved from Africa, through the Atlantic Ocean, and then on towards South America. This would be much easier if the Atlantic Ocean were not there

Glacial Striations…Scratches glaciers leave on rocks as they travel

DVD on Continental Drift 5. CLIMATE EVIDENCE: Warm weather plants have been found in the Arctic… but it’s not warm there! Glacier deposits have been discovered in tropical and desert locations…it’s not cold there, either! The continents had to have been at different locations in the geological past.

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