Plate Tectonics

8. all the continents were once part of a supercontinent.
9. is when the denser plate sinks below the more buoyant plate in a process.
11. tectonics states that earths surface is made of rigid slabs of rock, or plates, that move with respect to each other.
12. plate boundaries form where two plates collide.
13. polarity is a state in which magnetized objects would reverse direction and orient themselves to point south.
16. polarity is a state in which magnetized objects will orient themselves to point north.

1. is the cold and rigid outermost rock layer.
2. plate boundary forms when two plates separate.
3. drift when continents are in constant motion on the surface of earth.
4. spreading the process by which new oceanic crust forms along a mid-ocean ridge and older oceanic crust moves away from the ridge.
5. is the circulation of material caused by differences in temperature and destiny.
6. reversal occurs and the magnetic field reverses direction.
7. ridges the mountain ranges in the middle of the oceans.
10. push is when rising mantle material at mid-ocean ridges creates the potential for plates to move away from the ridge with a force.
14. plate boundary forms where two plates slide past each other.
15. pull is when a slab sinks, it pulls on the rest of the plate with a force