Vocab

4. A long cylinder of ice obtained from drilling through ice caps or ice sheets
5. The scientific study of the origin, history, and structure of Earth and the processes that shape the Earth
7. A method of determining the absolute age of an object by comparing the relative percentages of a radioactive isotope and a stable isotope
11. A fossilized structure, such as a footprint print or a coprolite
12. Any method of determining whether an event or object is older or younger than other events or objects
14. 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

1. The process in which a radioactive isotope breaks down into a stable isotope of the same element or another element
2. A principal that states that younger rock lies above older rock if the layers have not been disturbed
3. The standard method used to divide Earth’s long natural history into manageable parts
6. A principal that geologic processes that occurred in the past can be explained by current geologic processes
8. Any method of measuring the age of an event or object in years
9. The time required for half of a sample of radioactive isotope to break down by radioactive decay to form a daughter isotope
10. The weather conditions in an area over a long period of time
13. The trace or remains of an organism that lived long ago