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Internal
Structure of the Earth |
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Internal Structure of the Earth
The earth is made up
of a series of layers that formed early in the planet's history, as
heavier material gravitated toward the center and lighter material
floated to the surface. The dense, solid, inner core of iron is
surrounded by a liquid, iron, outer core. The lower mantle consists of
molten rock, which is surrounded by partially molten rock in the
asthenosphere and solid rock in the upper mantle and crust. Between some
of the layers, there are chemical or structural changes that form
discontinuities. Lighter elements, such as silicon, aluminum, calcium,
potassium, sodium, and oxygen, compose the outer crust.
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