Across
- 1. very large division of geologic time; usually referred to as the longest division of time
- 3. refers to the information provided by all of the discovered fossils throughout earth's history
- 4. subdivision of an era
- 6. subdivision of a period; shortest division of geologic time
- 9. fossil that forms when a mold is filled with sediment and hardens into the shape of that organism
- 10. states that younger rock is found above older rock when comparing sedimentary rock layers
- 11. remains or impression of an organism preserved in petrified rock
- 13. the system of time measurement involving the formation of and changed to earth
- 15. fossil that forms when organic material is pressed between layers of rock
- 16. the branch of science involving the physical composition and history of earth
Down
- 1. occurs when a species (organism) dies out and no longer lives on the planet
- 2. fossil that forms when organic material is trapped in ice, rock, amber or tar
- 5. a fossilized piece of evidence of an organism's activity (footprint)
- 7. method of determining the age based on the surrounding evidence
- 8. a common fossil found in many areas from a specific time; used to help identify the age of other formations
- 12. fossil that forms when minerals solidify into rock around the shape of the original organism leaving a cavity behind
- 14. subdivision of an eon (paleozoic, mesozoic, cenozoic)