New vocab

3. uniformitarianism is a principle that geologic process that occurred in the past can be explained by current geologic process
5. Superposition is a principle that states that younger rocks lie above older rocks if the layers have not been disturbed
6. Relative dating is any method of determining whether an event object is older or younger than other events or objects
8. Geology is the scientific study of the origin, history, and structure of earth and the processes
9. A fossil is the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock
10. Climate is the weather conditions in an area over a long period of time
11. Geologic time scale is the standard method used to divide earth's long natural history into manageable parts
12. Unconformity is a break in the geologic record created when rock layers are eroded or when sediment is not deposed for a long period of time
13. Absolute dating is any method of measuring the age of an event or object in years

1. Half-life is the time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope
2. Radioactive decay is the process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element
4. A trace fossil is a fossilized structure, such as a footprint or a coprolite, that formed in sedimentary rock by animal activity on or within soft sediment
7. The ice core is a long cylinder of ice obtained from drilling through ice caps or ice sheets; used to study past climates
8. Geologic column is 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