Earth's History Choice Board

6. A long cylinder of ice obtained from drilling through ice caps or ice sheets; used to study past climates
8. The process in which a radioactive isotope tends to break down into a stable isotope of the same element of another element.
10. The scientific study of the origin, history, and structure of Earth and the processes that shape Earth.
11. The standard method used to divide Earth's long natural history into manageable parts.
12. Principle that geologic processes that occurred in the past can be explained by current geologic processes.
14. A principle that states that younger rocks lie above older rocks if the layers have not been disturbed

1. Any method of determining whenether an event or object is older or younger than other events or objects
2. A method of determining the absolute age of an object by comparing the relative percentages of a radioactive (parent) isotope and a stable (daughter) isotope.
3. The weather conditions in an area over a long period of time
4. The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock
5. Any method of measuring the age of an event or object in years
7. The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope.
9. An automated system for capturing, storying, retrieving, analyzing, manipulating and displaying geographic data.
12. A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time
13. fossilized structure, such as a footprint or a coprolite, that formed in sedimentary rock by animal activity on or within soft sediment