Science Crossword Puzzel

3. if the circulation of material is caused by difference in temperature or density it is called what?
6. reversal when the magnetic field reverses direction what is it called?
9. pull when a slab sinks and pulls on the rest of the plate it is called what?
10. cold rigid outermost rock layer of the mantle is called what?
13. plate boundaries when 2 plates separate it is called what?
15. drift what causes the continents to separate?
18. ridges mountain ranges in the middle of the ocean are called what?
19. plate boundary when 2 plates collide it is called what?
20. tectonics theory this states that the earth's surface is made of plates that move with respect of each other.

1. plates there are 7 of these in total, 6 continental and 1 oceanic, what are they?
2. what was the first supercontinent called?
4. spreading new crust forms along a mid-ocean ridge is called what?
5. polarity when magnetic objects point north is called what?
7. what word do geologists use to describe forces shape the earth's surface?
8. when the denser plate sinks below the more buoyant plate it is called what?
11. plate boundary when 2 plates slide past each other it is called what?
12. push when plates move away from the ridge it is called what?
14. Wegener who named Pangea?
16. Drag when convection currents in the mantle cause a force that causes motion it is called what?
17. polarity magnetic objects reverse direction and point south called what?