Across
- 2. one plate is more dense than the other
- 3. plates slide past each other and cause earthquakes
- 5. means builder mountains, volcanoes and riff valley
- 8. plates move towards each other and collide
- 10. the solid crust and upper mantel of the Earth's Interior
- 12. plates move away from one another
Down
- 1. are the circulation of material caused by different temperatures
- 4. two plates seem to be moving the fastest away from one another
- 6. in the middle of continents form riff valleys
- 7. behaves like "plastic" material - easily molded
- 9. the spreading of the seafloor causes mid- ocean ridges
- 11. were tectonic plates meet