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Platetechtonics. Continental Drift The theory discovered by Alfred Wegener that states the continents were once connected but later drifted apart to their.

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Presentation on theme: "Platetechtonics. Continental Drift The theory discovered by Alfred Wegener that states the continents were once connected but later drifted apart to their."— Presentation transcript:

1 Platetechtonics

2 Continental Drift The theory discovered by Alfred Wegener that states the continents were once connected but later drifted apart to their current locations.

3 Evidence supporting continental drift 1)Shapes of the continents - The continents fit together like a jigsaw puzzle. The first piece put in place was the Eastern side of South America and the Western side of Africa

4 Evidence supporting continental drift 2)Matching geological structures Mountain Ranges: -Mountain Ranges on one continent end at the coast and appear to continue on a different continent Types of rock: - Similarities between the fold and age of rocks were found on different continents

5 Evidence supporting continental drift 3) Matching Fossils: - The fossils of one species were found on two separate continents. - Of these the most important was a freshwater reptile found in Africa and South America(it would not be able to cross the ocean)

6 Evidence supporting continental drift 3) Paleoglaciation: When glaciers move forward or retreat they leave u-shaped valleys in the earth. -Many of these were found in tropical parts of Africa and South America : These places are now found in the tropics where glaciers would not form -The pattern of the glaciers on these continent only make sense if the continents were together at some point

7 Layers of the Earth

8

9 Layer of the Earth

10 Layers of the Earth

11 Crust: Outer most layer. Made of solid brittle rock Lithosphere: Contains the crust and the uppermost mantle. Made up of the tectonic plates

12 Layers of the Earth Crust: Outer most layer. Made of solid brittle rock Lithosphere: Contains the crust and the uppermost mantle. Made up of the tectonic plates Athenosphere: found above the upper mantle. Made up of partly molten rock Mantle: the thickest layer on the earth. Broken into two parts upper and lower

13 Layers of the Earth Crust: Outer most layer. Made of solid brittle rock Lithosphere: Contains the crust and the uppermost mantle. Made up of the tectonic plates Athenosphere: found above the upper mantle. Made up of partly molten rock Mantle: the thickest layer on the earth. Broken into two parts upper and lower Upper Mantle: Made of partly molten rock containing Fe and Mg (lava the consistency of toothpaste) Lower Mantle: Solid dense material also containing Mg and Fe

14 Layers of the Earth Outer Core: A liquid made mainly from iron and nickel Inner Core: A solid mixture of mainly iron and nickel at 5000 – 6000 C. The high pressure makes it solid


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