Across
- 5. the crust and upper mantle
- 8. present geologic processes are the key to the past
- 9. the study of the earth and its processes
- 11. natural resources like trees, fish, and algae
- 12. probably 85% iron and 4-5% nickel
Down
- 1. takes up about 84% of the earth by volume
- 2. supports a very old earth
- 3. recources that once used are gone forever
- 4. natural resources that can readily by replaced
- 6. the earth's outer layer
- 7. short for Mohorovicic discontinuity
- 10. a way to manage resources by reuse