Across
- 2. calendar of the Earth's history
- 7. age in actual years
- 8. newer rock layers are on top of older ones
- 9. rocks found inside other rocks are older
- 10. time of the dinosaurs
Down
- 1. fossil used for dating the rock layer it's found in
- 3. if it cuts across rock layers it's younger
- 4. time it takes for 1/2 an isotope to decay
- 5. age of rock compared to rock in other layers
- 6. hardened remains of a once living organism