Building a Timeline

3. a rock or sediment layer used as a marker, such a meteorite strike or volcanic eruption
5. remains or traces of living things
7. the law that says if one geologic feature cuts across another feature, the feature it cuts across is older.
8. gaps in the rock record
10. 3 rock formations in Arizona and Utah that are far apart but match up.
11. the matching of rock layers
12. the volcano that erupted in Washington state in the 1980s.
13. when a layer of sedimentary rock overlies a layer of igneous or metamorphic rock.
14. the law that states if one rock contains pieces of other rocks, the rock containing the pieces is younger.
15. when horizontal layers of sedimentary rock are laid down on top of tiled, eroded layers.

1. the law that states that the youngest rocks are at top and the oldest rocks are on bottom.
2. fossils that were on Earth for a short amount of time, abundant, and inhabited many locations.
4. the law that states that most rock forming materials are deposited in horizontal layers.
6. when a horizontal layer of sedimentary rock overlies another horizontal layer of sedimentary rock that has been eroded.
9. the law that states that sediments are deposited in continuous sheets in lateral directions.