Alfred Wegener A scientist who believed the continents used to
be close together. He studied the world map and noticed that the
continents could fit together like puzzle pieces.
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Theory of Continental Drift Wegeners belief that the continents
move.
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Pangaea 1 supercontinent All the landmasses combined About 250
million years ago
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What was the evidence for Pangaea? Geologic Fossils
Glacial
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Geological Similar rocks and mountains found on the coast of
Southwest Africa and Eastern South America.
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Fossils are the remains from once living things. The same
fossils were found on the coasts of continents that fit together.
Fossils
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Glacial Glacial deposits (sediments) are found on continents
that could have fit together.
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Critics Many scientists did not believe Wegener because he
couldnt explain what force moved continents.
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Between the 1950s-1960s, the Theory of Plate Tectonics was
developed. This theory stated that continents are part of moving
tectonic plates. Evidence of seafloor spreading helped prove this.
Theory of Plate Tectonics
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Tectonic Plates Pieces of earths crust Found on the
lithosphere. 2 types: a.)oceanic b.)continental
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Seafloor Spreading The widening of the ocean. New oceanic crust
is formed through volcanic activity.