1. Continental Drift & Plate Tectonics

2. Continental Drift Theory
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

3. Evidence Summary Geographic fit of South America and Africa
Fossils match across oceans
Rock types and structures match across oceans

4. Geographic Fit
Continents look like they could be part of a giant jigsaw puzzle
Here’s how they moved apart

5. Fossils Match
Plant and animal fossils found on the coastlines of different continents

6. 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

7. Rock Structures Match Across Oceans
Same rock patterns found in South America, India, Africa, Antarctica and Australia

8. Rock Structures Match Across Oceans

9. Alfred Wegener
German meteorologist and geophysicist
Developed Theory of Continental Drift
Used 3 pieces of evidence
Early 1900s

10. The theory that states that parts
of Earth’s crust drift/float on top
of the liquid mantle (convection currents).

11. PANGAEA
-Gigantic super-
Continent that existed over 200 million years ago.
-Means “ALL EARTH”

12. Evidence
-Continents fit together
Like puzzle pieces
-Same fossils were
Found where pieces fit
Together
-Similar landforms found
On each continent

13. Europe
North
America
Asia
Africa
South
America
Australia
Antarctica

14. 8. Juan De Fuca
Eurasian
North American
Arabian
10. Cocos
11. Caribbean
Philipine
African
Pacific
South American
15. Caroline
Indo-australian
Nazca
Scotia
Antarctic

15. Divergent “Dividing” Transform “Sliding” Convergent “Colliding”
Forms mountains
Indo-Australian plate collides with Eurasian plate to form Himalayan Mountains.
Divergent
“Dividing”
On land, forms rift valleys
In ocean, forms sea floor spreading
“Mid-Atlantic Ridge”
Causes earthquakes
San Andres Fault
Transform
“Sliding”