Across
- 3. study of earthquakes
- 7. determine age by amount of isotope
- 11. another name for tectonic plate
- 13. study of magnetic fields in prehistoric Earth
- 15. two plates sliding past each other
- 16. hot material rises and cold, dense material falls
- 17. tectonic forces that destroy land
- 18. isotopes becoming stable
- 19. tectonic forces that create new land
- 20. exactly how old
Down
- 1. where one plate slides beneath another
- 2. travels from an earthquake's focus
- 4. two plates moving towards each other
- 5. determine how old compared to others
- 6. movement of Earth's crust
- 8. two plates moving away from each other
- 9. atom, give or take neutrons
- 10. space rock that hit Earth
- 12. checkpoint for radioactive decay
- 14. stable part of Earth's continental crust