| A | B |
|---|
| Relative Dating | the determination of the age of a rock or event in relation to the age of other rocks or events |
| Absolute Age | the actual age of a rock or event |
| Principle of Superposition | Younger rock layers are found above older rock layers (if undisturbed) |
| Intrusion | Molten magma that sqeezes into preexisting rocks and solidifies |
| Extrusion | Lava that solidifies on the Earth's surface |
| Inclusion | a body of older rock within an igneous rock |
| Correlation of rocks or events | Makes it possible to show that rocks or events from different places are the same age |
| Bedrock | an area's local rock |
| Fossils | the remains or evidence of former living things |
| Index Fossils | Fossils of organisms that lived for a short period of time over a wide geographic area |
| Volcanic Ash | particles of extusive igneous rock shot out of a volcano |
