Geologic Time Scale

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Across
  1. 4. First glaciers formed
  2. 5. Age of a rock layer compared to another
  3. 6. dead animal made into stone
  4. 9. Earth crust cooled
  5. 10. In the middle of era with dinosaurs
Down
  1. 1. rocks are older when they're deeper
  2. 2. age in yrs from fossils or radiation
  3. 3. 50% life of a radioactive material
  4. 7. Chaotic earth condition
  5. 8. 66 million yrs ago to today