Across
- 2. the time taken for the radioactivity of a specified isotope to fall to half its original value.
- 4. Dinosaurs appeared in the Triassic ___.
- 6. ___ is the largest time division
- 7. rocks inside of other layers are older
- 8. We are in the Caenozoic ___.
- 10. Determining a rock's age based on major events in geologic time.
Down
- 1. the older rock layers are underneath the newer rock layers
- 3. The smallest geologic time division is a(n) ___
- 5. faults, dikes, intrusions, etc. are newer than the rock they cut through
- 9. Finding a rock's age by determining the half-life (using radioactive material)