Earth History

2. fossil that forms when a mold is filled with sediment and hardend into the shape of that organism
5. the branch of science involving the physical composition and history of earth
8. occurs when species (organism) dies out and no longer lives on the planet
9. fossil that forms when organic material is trapped in ice, rock, amber, or tar
10. subdivision of an eon (paleozoic,mesozoic,cenozoic)
13. fossil that forms when organic material is pressed between layers of rock
14. subdivision of a period;shortest division of geologic time
16. a fossilized piece of evidence of an organism's activity (footprint)

1. states that younger rock is found above older rock when comparing sedimentary rock layers
3. the system of time measurement involving the formation of and changes to earth
4. determination of the age of a rock based on the surrounding evidence
6. a common fossil found in many areas from a specific time;used to help identify the age of other formations
7. remains or impression of an organism preserved in petrified rock
9. subdivision of an era
11. method of determining the age based on measuring radioactive elements(radiometric)
12. refers to the information provided by all of the discovered fossils throughout earth's history
14. very large division of geologic time; usually referred to as the longest division of time
15. fossil that forms when minerals solidify into rock around the shape of the original organism, leaving a cavity behind