Across
- 4. gives age in actual years
- 5. newer rock layers are on the top of older ones unless the sequence is disturbed
- 9. remains of animals that represent a period of time
- 10. Rocks found inside of other rocks are the older of the two
Down
- 1. the comparison between two fossils/rocks
- 2. current and most recent of the 3 phanerozoic eras
- 3. Features like faults and dikes are newer than the rock they cut through
- 6. a useful fossil used for the dating and corelating the strata in which it is found
- 7. the amount of time it takes half of a remaining isotope to decay to a daughter product
- 8. first living organism said to be discovered