Crossword Puzzle
Across
- 2. a sheet, quantity, or thickness of material, typically one of several, covering a surface or body
- 5. a period of time in history marked by notable events
- 10. are fossils used to define and identify geologic periods
- 11. when a mold is filled by sediment and hardens
- 13. When rocks bend
- 15. The preserved traces or remains of an animal
- 16. geologic age of a fossil organism or rock
- 17. is the process of determining an approximate computed age in archaeology and geology.
- 20. actual part of an organism preserved in Ice,Amber,or Tar
- 24. types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water
- 27. gaps in the geologic record that may indicate episodes of crustal deformation, erosion, and sea level variations
- 28. a core sample from a glacier that can tell us the climate of the past
- 29. when magma or lava is cooled and forms this rock
Down
- 1. the time taken for the radioactivity of a specified isotope to fall to half its original value.
- 3. when a tree grows and creates rings it tells us weather patterns over time
- 4. The assumption that things that occur now have happened in the past
- 6. a fossil with a film coating that consists of the element carbon
- 7. a tree that has transitioned into stone by minerals
- 8. when original rock is subject to heat and pressure causing both physical and chemical change
- 9. which states that sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top
- 12. impressions made on the ground by an organism like Burrows,Droppings,and Tracks
- 14. where has been significant displacement along the fractures as a result of earth movement
- 18. a hollow impression made by an organism
- 19. a chart of major biological and geological eras
- 21. a long and distinct period of history with a particular feature
- 22. when rocks change shape and bend from the inside of earth's layers
- 23. a unit of geological time during which a system of rocks is formed
- 25. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find
- 26. an indefinite and very long period of time