Geological Time Scale

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Across
  1. 3. layers
  2. 4. a rock found inside another rock is older of the two
  3. 8. More advanced than prokaryote contains an nucleus
  4. 9. how long an isotope takes to decay
  5. 10. when modern plants and animals developed
Down
  1. 1. Oldest layer on the bottom
  2. 2. example faults cutting through rock
  3. 5. determining a rocks age using radioactive material
  4. 6. first organism
  5. 7. starts with an assumption of what happened