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Unit 4 lessons 1&2
| Term | Definition |
|---|---|
| Uniformitarianism | a principle that geologic proceses that occured in the past can be explained by current geologic processes |
| Fossil | the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock |
| Trace Fossil | a fossilized structure, such as a footprint or a coprolite, that formed in sedimentary rock by animal activity on or within soft sediment |
| Climate | the weather conditions in an area over a long period of time |
| Ice Core | a long cylinder of ice obtained from drilling through ice caps or ice sheets; used to study past climates |
| Bands | A regular layer to an ice core |
| Relative Dating | any method of determining wether an event or object is older than other events or objects |
| Superposition | a principle that states that younger rocks lie above older rocks if the layers have not been disturbed |
| Unconformity | a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time |
| Geologic Column | 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 |