Earth Science

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Across
  1. 1. The long record of Earth’s history divided into eras, periods, and epochs.
  2. 5. Remains or traces of ancient living things.
  3. 6. The time it takes for half of a radioactive substance to decay.
  4. 11. Type of dating that gives the actual age of rocks in years.
  5. 12. Matching rocks from different places by age or fossils.
  6. 13. Type of element used in absolute dating methods.
  7. 14. Type of rock where fossils are most commonly found.
  8. 15. A gap in the rock record showing erosion or lack of deposition.
Down
  1. 2. A law that says faults or intrusions are younger than the rocks they cut through.
  2. 3. A fossil used to define and identify specific time periods.
  3. 4. Type of dating that tells which rock is older or younger, not exact age.
  4. 7. The study of rock layers and layering.
  5. 8. Law stating the oldest rocks are at the bottom.
  6. 9. Pieces of one rock type found inside another; older than the rock containing them.
  7. 10. Law that says rock layers are originally deposited flat.