Across
- 2. Newer fossils on top, older on bottom
- 5. fossil that is useful for dating
- 7. events that happened with fossils and rocks
- 9. Exact age of rock or fossil
- 10. Rate of decay
Down
- 1. Time where dinosaurs were around
- 3. Rock fragemnts in other rocks
- 4. Radioactive decay of isotopes
- 6. rock is relative to another layer
- 8. Cutting a fossil to see what it is