Our transcription: Plate tectonics is built on the premise that the outer skin of the Earth is composed of individual slabs or plates. These rigid plates, which can be continental in size and in some places hundred of kilometers thick slide around on a partially molten mantle layer below. Where the plates collide or move apart or slide past one another, a great variety of geologic activity results. Ocean basins open and close, mountain belts emerge, and volcanoes erupt. All accompanied by countless earthquakes and the formation of new rocks and landforms. Although we still have a great deal to learn about the mechanisms in the Earth's interior, which cause the plates to move, most scientists agree that the concept of plate tectonics is valid.
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