Plate tectonics

4. Boundary The boundary formed by the collision of two tectonic plates.
6. Boundary The boundary between tectonic plates that are sliding past each other horizontally.
7. Break in a body of rock when one block moves relative to another
8. Ridge Underwater mountain ranges where new seafloor is created at a divergent boundary.
11. type of crust in land, made of granite, less dense
12. Zone Location where two plates collide and the denser ocean plate descends below the other.
16. sudden, violent movements of the tectonic plates along a boundary
17. spreading The process by which new oceanic crust forms as magma rises towards the surface and solidifies. The mechanism for Continental Drift.

1. type of plate boundary - two plates move slide past each other
2. type of crust, ocean floor, made of basalt, more dense
3. Name for the super continent which contained all the plates together.
5. Openings in Earth's crust from which molten rock, dust, ash, and hot gases flow or erupt
9. Boundary The boundary between two tectonic plates that are moving away from each other.
10. Drift The idea that the continents once formed a single landmass, broke up, and drifted to their present locations.
11. The thin and solid outermost compositional layer of the Earth above the mantle.
13. Extremely deep areas in the ocean that are created by a subducting plate.
14. Arc Formed by two oceanic plates colliding volcanoes to form new land
15. Tectonics The theory that the Earth is broken into plates and are in motion due to convection currents in the asthenosphere (upper mantle).