Plate Tectonic

3. Line. A break in Earth's crust where rocks on either side move past one another
5. The rigid outer layer, of Earth that includes the crust and upper mantle
7. These currents within the Earth's mantle drive plates moving
9. The partially molten layer of Earth's mantle below the lithosphere.
11. The process by which denser oceanic crust sinks into the mantle that's beneath a less dense plate
12. A supercontinent that began to break apart around 175 million years ago
15. Arc. A chain of volcanic islands that are formed at tectonic plate boundary
17. Type of plate boundary where two plates run into one another and create mountains
19. Spreading. Process where new oceanic crust is created at mid-ocean riges

1. A break in the Earth's crust where blocks of the crust slide relate to each other
2. Tectonics. The theory that explains the movement of the Earth's plates
4. The boundary were two plates begin to move away from one another.
6. Type of boundary that occurs when two plates pass one another.
7. Drift. The theory proposed by Alfred Wegener that suggests continents were at one point connnected
8. Boundary. Type of boundary where two plates slide past one another horizontally
10. Zone. The process where one tectonic plate sinks below another
13. Valley. A long, narrow valley that's formed by the stretching of Earth's crust.
14. Circular pattern of heated material rising and cooler material sinks
16. Boundary. Type of boundary where two plates spread apart from one another and create new crust.
18. Boundary. The type of boundary where two plates run into one another and create mountain ranges.