vocabulary review

3. extinctions the extinction of many species on Earth within a short period of time
5. cutting relationships the principle that if one geologic feature cuts across another feature, the feature that it cuts across is older
6. the preserved remains or evidence of past living organisms
8. horizontality principle that most rock-forming materials are deposited in horizontal layers
11. a principle stating that geologic processes that occur today are similar to those
12. a rock or sediment layer with distinctive characteristics that make it easily identifiable in correlation
13. a chart that divides Earth's history into different time units based on changes in the rocks and fossils
14. the age of rocks and geologic features compared with other nearby rocks and features
15. a method used by geologists to fill in the missing gaps in an area's rock record by matching rocks and fossils from separate locations

1. the numerical age, in years, of a rock or object
2. a surface where rock has eroded away, producing a break, or gap, in the rock record
4. a piece of an older rock that becomes a part of a new rock
7. fossils a fossil representative of a species that existed on Earth for a short length of time, was abundant, and inhabited many locations
9. the principle that in undisturbed rock layers, the oldest rocks are on the bottom
10. continuity principle that sediments are deposited in large, continuous sheets in all lateral directions