Across
- 1. Any method of measuring the age of an event or object in years
- 4. any method of determining whether an event or object is older or younger than other events or objects
- 5. The Scientific study of the origin, history, and structure of earth and the processes that shape earth
- 6. A principal that geologic processes that occurred in the past can be explained by current geologic processes
- 10. A fossilized structure, such as a footprint or ca coprolite, that formed in sedimentary rock by animal activity on or within soft sediment
- 11. The weather conditions in an area over a long period of time
- 12. A method of determining the absolute age of an object by comparing the relative percentages ofa radioactive isotope
- 14. the process in which a radioactive isotope tends to bread down into a stable isotope of the same element or another element
- 15. A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time
Down
- 2. A long cylinder of ice obtained from drilling through ice caps or ice sheets, used to study past climates
- 3. An ordered arrangement of rock layers that is based on the relative ages of the rocks and in which the oldest rocks are at the bottom
- 7. The standard method used to decide earth's log natural history into manageable parts
- 8. A principal that state that younger rocks lie above older rocks if the layers have no been disturbed
- 9. The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope
- 13. The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock