geological time scale
Across
- 4. the actual age of a rock
- 5. piece of the earth broke off and became the moon
- 8. in an undisturbed sequence of rocks the oldest rocks are at the bottom and the newest are at the top
Down
- 1. any feature that cuts across a sequence of rocks is younger than everything it cuts
- 2. Any rock or fragment that's included inside of another rock is older than the rock in which it is included
- 3. The amount of time it takes half a remaining isotope to decay to a daughter product
- 6. bones of creatures
- 7. a guess of the age of a rock