Across
- 2. how much matter or mass is in something.
- 4. the measure of matter.
- 6. a theory that sea floor spreading is the cause of what we have today.
- 7. canyons that are in the ocean and absorb land.
- 11. a line or point where a region ends and a new one begins.
- 12. when two plates shear against each other.
- 15. ridges in the land that form big mountains.
- 17. the amount of how much space is being taken up.
- 19. alfred wegner called a supercontinent this.
- 20. the outermost layer of the earth.
Down
- 1. an area where molten rock rises and forms magma.
- 3. when mid-ocean ridges form new land.
- 5. a big landmass
- 8. when denser material goes below the less dense material.
- 9. a mountain that forms when magma rises from the earth.
- 10. a major belt of some volcanos.
- 13. a mixture of molten rock.
- 14. a flow of liquids that rise and fall.
- 16. a long string of islands.
- 18. forms when molten rock go to the surface.