Geologic Time Scale and Fossils

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Across
  1. 3. determining the relative order of past events without determining their absolute age; determine older and younger based on relationships
  2. 5. the first 4 billion years of Earth's history including the Hadean, Archean and Proterozoic eons
  3. 7. the start of the phanerozoic eon and the paleozoic era marked by an unparalleled emergence of organisms between 542-530MA
  4. 9. the second largest unit of time for the geologic time scale that is divided into periods
  5. 11. a unit of geological time during which a system of rocks formed; further divided into epochs
  6. 13. this occurs when pore spaces in an organism's remains are filled with minerals that precipitate out of solution and sometimes leaves behind some of the original bone
  7. 15. chemical compound that is solid and stable at room temperature and has a specific formula and crystalline structure
  8. 16. a large landmass or supercontinent that formed during the late Neoproterozoic when Pangaea first split into two parts
  9. 17. this increases an organism's chance of becoming a fossil because it helps preserve the delicate parts
  10. 18. the current period on Earth which includes the most recent ice age and the "Age of Humans"
  11. 19. smallest unit of geological time during which a rock series is deposited
  12. 20. Earht's current eon from present day to about 542MA when a period of rapid evolution of complex animals began
Down
  1. 1. any preserved remains or traces of ancient life
  2. 2. when the original organic carbon in an organism's body degrades and a coating of black carbon forms on the top of the dead organism
  3. 4. the current geological epoch on Earth that began approximately 11,650 years ago after the last glacial period
  4. 6. the extinction of a large number of species within a relatively short period of geological time
  5. 8. fossils only form with sediment quickly covers the organism's remains so they do not decompose
  6. 10. material deposited by water, wind and glaciers
  7. 11. to turn a once living tissue into stone
  8. 12. fossilized feces
  9. 14. the original landmass that existed when all continents were joined about 300-200 MA in the late Paleozoic and early Mesozoic eras
  10. 21. the largest unit of time for the geologic time scale