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Forces of Change
 Earth
is composed of three layers- the core,
the mantle, and the crust.
 Very center is the core.
- super hot but solid inner core.
- 4000 miles under the surface.
-Surrounding the inner core is a
Liquid OUTER CORE. 85,000F
-Next to outer core is a thick
Layer of hot dense rock called the MANTLE.
-Crust = rocky shell from 2miles through 75
miles thick.
 Continental
Drift- Theory that the continents
were once joined and then slowly drifted
apart.
 Magma-
Molten rock
Subduction- Process by which mountains can form as sea plates dive
beneath continental plates.
Accretion- Slow process in which a sea plate slides under a continental
plate, creating debris that can cause continents to grow outward.
Spreading- Process by which new land is created when sea plates pull
apart and magma wells up between the plates.
Fault- A crack or break in the earth’s crust.
 Weathering-
process that breaks down rocks
on the earth’s surface into smaller pieces.
 Erosion-
wearing away of the earth’s surface
by wind, glaciers, and moving water.
 Loess- Fertile, yellow-grey soil deposited by
wind.
 Glaciers-
large bodies of ice that slowly move
across the earth’s surface.
 Moraines-
Piles of rocky debris left by
melting glaciers.