Across
- 4. The preserved remains of a once living organism
- 6. A non-living part in the ecosystem that changes the environment
- 9. Something that is always changing
- 11. The age of something based off of another object
- 14. Fossil of footprints
- 15. a distinct period of time
- 16. A fossil used to tell when an organism lived
- 17. Method used to see how old an object is
- 19. A source of water
- 21. Science that deals with fossils and plants
- 23. The tool used to tell rock formations
- 24. the idea that earth has always changed in uniform ways
- 25. food being made via a energy source
Down
- 1. when a layer of sediments becomes eroded before a new layer
- 2. The sediments on the base are older than the sediments on top
- 3. A length of time
- 5. The cut in a object is younger than the feature it is in
- 7. Earliest time in Earth's history
- 8. Time for a radioactive object to reduce
- 10. A event that has a large amount of the population die
- 12. A living organism that shapes it's environment
- 13. The exact age of an object
- 18. the way plants get food
- 20. A event that starts a new period
- 22. The progressing development of something