Across
- 2. - States that sedimentary layers are laid down originally in horizontal layers and so if they are titled something has disturbed them
- 6. - States that an inclusion must be older than the rock it is enclosed in.
- 7. - States that an igneous rock, fault, or other geologic feature must be younger than any rock across which it cuts; used to determine relative age.
- 8. - Enables scientists to determine the numerical age of rocks and other objects
- 9. - The study of rock layers (strata) and the sequence of events they reflect
- 11. - A technique used to determine the absolute age of a fossil on the basis of the amount of a radioactive element it contains.
- 12. - A break in the earth's crust; younger than the rocks it cuts across.
- 13. - States that processes that occur on Earth today also occurred in the past in the same manner.
Down
- 1. - Distinctive fossils used to establish and correlate the relative ages of rock layers and the fossils they contain.
- 3. - Layers of rock, representing various periods of deposition.
- 4. - Dating of earth's history using rocks and fossils
- 5. - A way to describe the age of one object or event compared to another object or event; does not use numbers.
- 7. - States that younger layers of rock are deposited on top of older layers; used to determine relative age.
- 10. - The length of time required for half of the radioactive atoms in a sample to decay.
- 14. - An igneous rock layer formed when magma hardens beneath Earth's surface; younger than the rocks it cuts across.