unit 2 vocab

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Across
  1. 2. A trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock
  2. 3. A principle that states an younger rock is above an older rock if layers have not been distributed
  3. 6. The scientific study of the origin, history, and structure of earth and the processes that shape earth
  4. 8. The weather conditions in an area for a long period of time
  5. 10. A long cylinder of ice obtained by drilling through ice caps or ice sheets used to study past climate
  6. 12. Any method of determining an object older or younger than other events or objects
  7. 14. A method of determining the the absolute age of an object by comparing the relative percentages of a radioactive isotope and a stable isotope
  8. 15. A fossilized structure such as a footprint that formed in sedimentary rock
Down
  1. 1. The standard method used to divide earth’s long natural history into manageable parts
  2. 4. A principle that geologic processes that occurred in the past can be explained by current geologic processes
  3. 5. A break in geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time
  4. 7. The process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element
  5. 9. Any method of measuring the age of an event or object in year (260)
  6. 11. The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope
  7. 13. An ordered arrangement of of rock layers that is based on relative ages of the rocks and in which the oldest rocks are at the bottom