Across
- 3. Dating gives age in actual years.
- 5. First living things on Earth.
- 8. The top most layer is the youngest, and the bottom layer is the oldest.
- 9. Useful for dating and correlation the strata in which it is found.
- 10. The amount of time it takes for half of a remaining isotope to decay to a daughter product.
Down
- 1. The 2 ways that are used to determine the age of rocks and fossils.
- 2. Oldest fossils found here.
- 4. Any rock/fragment that's included inside of another rock is older than the rock in which it is included.
- 6. Represent a period of time.
- 7. Any feature that cuts across a sequence of rocks, is younger than everything it cuts.