Across
- 3. the age of a rock is determined by radioactive dating
- 4. the rock cutting through the layers is younger than the layers.
- 5. the oldest rocks are on the bottom and the youngest on top.
- 8. the age of a fossil determined by another one
- 9. the exact age of a rock
Down
- 1. when an igneous rock forms in a layer
- 2. the rock inside of another rock has to be older for the second one to form around it
- 6. the age of a rock comparing it to another
- 7. the study of earth