Geologic Time Scale
Across
- 3. the technique scientists use to determine the absolute age of a material
- 4. in undisturbed sedimentary rock layers, older layers of rock lie beneath younger layers
- 9. any rock fragment thats included inside of another rock is older than the rocks its included in
Down
- 1. an igneous rock that forms when magma cools and hardens after cutting through existing rock
- 2. any feature that cuts across a sequence of rocks is younger than everything it cuts
- 5. the actual or exact age of a rock or fossil, or how long ago it formed
- 6. the science of the study of earth
- 7. describes the age of a rock or fossil in comparison to another rock or fossil
- 8. a gap in the rock record
- 10. forms of life which existed during limited periods