Across
- 2. any rock or fragment that is included inside of another rock is older than the rock in which it is included
- 6. using radioactivity to find an exact age
- 8. any feature that cuts across a sequence of rocks, is younger than everything it cuts
- 9. a fossil used to find ages of other fossils
- 11. the current era
Down
- 1. closest to top is youngest closest to bottom is oldest
- 3. using the law of superposition to find a age
- 4. before mesozoic,after precambrian.
- 5. the amount of time it takes for half a remaining isotope to decay to a daughter product
- 7. age of the dinos
- 10. rock layers