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Published byHubert Arnold Modified over 9 years ago
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Platetechtonics
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Continental Drift The theory discovered by Alfred Wegener that states the continents were once connected but later drifted apart to their current locations.
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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
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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
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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)
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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
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Layers of the Earth
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Layer of the Earth
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Layers of the Earth
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Crust: Outer most layer. Made of solid brittle rock Lithosphere: Contains the crust and the uppermost mantle. Made up of the tectonic plates
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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
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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
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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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