Geologic Time Scale Crossword Puzzle

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Across
  1. 5. rule that states that any feature that cuts through rock, is younger than the rock
  2. 6. rule that states that if a rock is lower, its older
  3. 7. finding the age of a rock in comparison with another rock
Down
  1. 1. Remains of a plant or animal that are preserved in rock
  2. 2. a way to find the age of a rock by finding its rate of decay
  3. 3. Rule that states that if a rock is inside another rock, it is older
  4. 4. rate of decay for an isotope with half remainging