Vocabulary for Unit Three: Earth’s Layers and
Plate Tectonics
1.
Crust
The outer layer of the Earth
2.
Continental Crust
Made of light granitic rock
3. Oceanic Crust
Made of dense basaltic rock
4. Mantle
Largest layer of the Earth located
directly under the crust
5. Convection Currents
are circular currents caused by the
difference in temperatures from the
bottom to the top of the mantle
6. Mohorovicic Discontinuity
Boundary between the crust and the
mantle
7. Lithosphere
The crust and the upper rigid layer of
the mantle
8.
Asthenoshpere
Lower layer of the upper mantle that
flows and moves the plates of the
Earth
9. Outer Core
The layer located directly under the
mantle
10. Inner Core
The inner core is composed of nickel
and iron under such great
temperatures and pressures that the
metals are in a solid state of motion
11. Plates
The thin, fragile, and rigid lithosphere
is broken up into 12 main plates
12. Continental Drift Theory/
Plate Tectonic Theory
theory that states that the Earth's
surface is broken into pieces that
move and have moved for millions of
years
13.Pangaea
Super continent 250 million years
ago. The seven continents were all
connected together into one huge land
mass.
14.Seafloor spreading
Process that forms new seafloor as hot
material is forced upward
15.Convergent plate boundaries
where crust is destroyed as one plate
dives under another collide to form
mountains or a subduction zone
16.Divergent plate boundaries
where new crust is generated as the
plates pull away from each other
17.Transform plate boundaries
where crust is neither produced nor
destroyed as the plates slide
horizontally past each other