time marches on

12345678910111213141516171819
Across
  1. 2. remains of an organism that lived long ago
  2. 3. a unit of geologic time that includes multiple periods
  3. 5. _______ states that younger rocks lie on older rocks
  4. 6. cavity made in object by shell or other body
  5. 7. _______ states that geological processes happen suddenly
  6. 9. a subdivision of a geologic period
  7. 11. ______ states that geological processes happen over time
  8. 14. death of every member of a species
  9. 15. the first uniformitarianism
  10. 18. an arrangement of rock layers in which the older rocks are at the bottom
Down
  1. 1. fossilized mark formed in soft sediment
  2. 4. measuring the age of an event or object in years
  3. 7. ____ _____ created the theory of evolution
  4. 8. unit of geologic time into which eras are divided
  5. 10. fossil that forms when mold is filled
  6. 11. a break in the geologic record created when rock layers are eroded or sediment is not deposited over a long time
  7. 12. fossil that is found in only one geologic age
  8. 13. determining weather a object is older or younger than others
  9. 16. the scientific study of fossils
  10. 17. ______ are four hundred million years old and are also called phacops
  11. 19. largest division of geologic time