woar

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Across
  1. 3. fossil that froms when organic material is pressed between layers of rock
  2. 7. occurs when a species dies out and no longer lives on the planet
  3. 8. the branch of science involving the physical composition and history of earth
  4. 10. method of determining the age based on measuring radioactive elements
  5. 16. fossil that forms when organic material is trapped in ice, rock, amber or tar
  6. 17. the system of time measurement involving the formation and changes to earth
  7. 18. a fossilized piece of evidence of an organisms activity
Down
  1. 1. states that younger rock is found above older rock when comparing sedimentary rock layers
  2. 2. remains or impression of an organism preserved in petrified rock
  3. 4. subdivision of a period shortest division of geologic time
  4. 5. very large division of geologic time usually referred to as the longest division of time
  5. 6. age determination of the age of a rock based on the surrounding evidence
  6. 9. subdivision of a eon
  7. 11. fossil that forms when a mold is filled with sediment and hardens into the shape of that organism
  8. 12. refers to the information provided by all the discovered fossils throughout earths history
  9. 13. subdivision of an era
  10. 14. a common fossil found in ment areas from a specific time. used to help identify the age of other formations
  11. 15. fossil that forms when minerals solidify into rock around the shape of the original organisms. leaving a cavity behind