Geologic Time Scale

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Across
  1. 3. determines the relative order of past events
  2. 5. most accurate form of dating, uses the decay of radioactive material
  3. 6. middle life, time of the dinosaurs
  4. 7. preserved remains or traces of animals, plants or other things from the past
  5. 8. special fossils that indicate the boundaries of geological time
  6. 12. a branch of geology dealing with how sedimentary rock layers are arranged
  7. 13. history of life as documented by all fossils
Down
  1. 1. marks the beginning of Earth, about 4.6 billion years ago
  2. 2. all of Earth's history represented on a chronological chart
  3. 4. the newest rock layers are on top and the oldest are on the bottom
  4. 9. late life, humans developed
  5. 10. layers of sedimentary rock
  6. 11. early life, Pangaea formed, life developed rapidly