Earth's Surface Ch4 - Geological History

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Across
  1. 1. - when some older layers are eroded away, and then new rock forms where the older layers were.
  2. 5. - when lava hardens on the surface
  3. 6. - the gradual change in living things over long periods of time
  4. 8. – the time it takes for half of the radioactive atoms to decay
  5. 10. - animals without backbones
  6. 11. - a record of the life forms and geological events in Earth’s history
Down
  1. 2. - when elements break down over time, at a constant rate, by releasing particles and energy
  2. 3. - animals with backbones.
  3. 4. - the preserved remains or traces of living things.
  4. 7. - a break in Earth’s crust
  5. 9. - when magma pushes into rock layers and hardens without reaching the surface
  6. 12. - a fossil that occurs in many different areas and represents a type of organism that existed only briefly
  7. 13. - a hollow area in sediment in the shape of an organism
  8. 14. - a solid copy of the shape of an organism