Geological Time Scale

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Across
  1. 3. Dating gives age in actual years.
  2. 5. First living things on Earth.
  3. 8. The top most layer is the youngest, and the bottom layer is the oldest.
  4. 9. Useful for dating and correlation the strata in which it is found.
  5. 10. The amount of time it takes for half of a remaining isotope to decay to a daughter product.
Down
  1. 1. The 2 ways that are used to determine the age of rocks and fossils.
  2. 2. Oldest fossils found here.
  3. 4. Any rock/fragment that's included inside of another rock is older than the rock in which it is included.
  4. 6. Represent a period of time.
  5. 7. Any feature that cuts across a sequence of rocks, is younger than everything it cuts.