Earth-Space Ch 15
Across
- 1. Age that is the actual age.
- 5. Age dating by tree rings.
- 6. Age that is in comparison with other ages.
- 9. 4.6 billion years old
- 10. Preserved remains of past organisms.
- 13. Layers of rocks that are similar in composition.
- 14. Fossils that include shells, bones, and teeth.
- 16. Stresses that push toward each other.
- 17. Fossils that indicate the relative age of the rock in which it is found.
Down
- 2. Rings of wood equaling 1 year of tree growth.
- 3. Paired deposits of sediments in glacial lakes.
- 4. Amount of time required for half of radioactive atoms to decay.
- 7. The inside of sheets of ice.
- 8. Fossils that are evidence of activity of an organism. Includes tracks and bite marks.
- 9. Fossilized tree sap.
- 11. Atoms of an element that has a different number of neutrons.
- 12. A gap between rock of very different ages.
- 15. An impression made in sediment.