Across
- 2. Forms when the mud or sand hardens into stone where an organism's footprint, trail, or burrow is left behind.
- 8. type of rock formed under or above ground when magma or lava cools
- 10. Forms when organisms or parts, like leaves, stems, flowers, fish, are pressed between layers of soft mud or clay that hardens, squeezing almost all the decaying organism away and leaving the carbon imprint in the rock.
- 12. the complete elimination (dying out) of a species due to its inability to survive and adapt to its environment.
- 13. forms when a mold is filled with sand or mud that hardens into the shape of the organism.
- 14. forms when sediments bury an organism and the sediments change into rock; the organism decays, leaving a cavity in the shape of the organism.
- 16. the study of the rocks, processes, and history of Earth.
- 17. fossil) forms when minerals soak into the buried remains, replacing them and changing them into rock.
- 18. rock formed by deposition of sand, clay and other pieces of rock that are compacted together under pressure.
- 19. the system of chronological measurement that relates to the history of events in Earth's past, consisting of fossils and major events. This timeline includes the divisors of the 4.6 billion years of Earth's geologic and biologic existence and divides time into eons, eras, periods, and epochs. The divisions of the time scale are based on major events that have caused major geologic or biologic changes throughout history, such as mass extinctions.
- 20. the fossil known to have lived in a particular geologic age that can be used to determine the date of the rock layer in which it was found.
Down
- 1. determining the age or order of things from the past or past events without knowing or calculating the actual age.
- 3. a radioactive heavy metal that is an abundant source of nuclear energy that has 14 known isotopes used in radioactive dating.
- 4. the measurement of the known rates of decay of radioactive materials found in an object, that are used to determine the age of that object.
- 5. Form when entire organisms or parts of organisms are prevented from decaying by being trapped in rock, ice, tar, or amber.
- 6. rock created from the transformation of other types of rock through heat and pressure.
- 7. a core sample of ice removed from a sheet of ice. Properties of the ice and the crystallized components in the ice are used to reconstruct climatic record.
- 9. states rock layers that cut across other rock layers are younger than those they cut.
- 11. the preserved remains or traces of an organism that lived in the past.
- 15. In undisturbed rock layers, newer layers will be deposited over older layers.