Geologic Time Scale

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Across
  1. 3. The law of ____, states that any rock fragment (or clast) found within another rock body is older than the rock body that contains it
  2. 6. The actual age of a rock, fossil, or artifact, measured in years
  3. 7. The vast timescale of geological and cosmic events, encompassing billions of years
  4. 9. The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock
Down
  1. 1. The law of ____, states that any geological feature (like a fault or intrusion) that cuts across another feature is younger than the feature it cuts
  2. 2. The age of a rock, fossil, or event compared to other rocks, fossils, or events, determining which is older or younger, without specifying a numerical age
  3. 4. The law of ____, states that in undisturbed rock layers, the oldest layer is at the bottom and the youngest is at the top
  4. 5. The time taken for the radioactivity of a specified isotope to fall to half its original value
  5. 8. A very long, indefinite period of time, or in geology, a major division of time, subdivided into eras
  6. 10. An ____ fossil is useful for dating and correlating the strata in which it is found