Geologic Time Vocabulary

4. Scaly skin and lays eggs.
7. Fossils- A type of fossil that can provide clues about the activities of a ancient organism.
8. Time Scale- Is a record of the life forms and geologic events in Earth's history.
9. Soft loose earth.
11. Surface where new rock layers meet a much older rock surface beneath them.
14. Lives part of its life on land,and part of its life int he water.
17. A long and distinct period of history with a particular feature or characteristic.
19. Mesozoic Era is divided into the Triassic,the Jurassic,and the Cretaceous.These divisions of the Geologic Time Scale are called...
20. Fossil- A fossil formed when minerals replace all or part of an organism.
24. Scientist who studied rock.
27. Rate of decay of each radioactive element in constant it never changes.
29. When all the atoms in a particular type of matter are the same.

1. Fossil- A fossil must be widely distributed that existed only briefly.
2. An object made by shaping molten metal or similar material in a mold.
3. Magma cools and hardens into a mass of igneous rock.
5. Rock- A form in horizontal layer.
6. Is a warm-blooded vertebrate that feeds its young milk.
10. Made of tiny particles.
12. Without backbone.
13. Lava that hardens on the surface.
15. Extinction- Many types of living things became extinct at the same time.
16. With backbone.
18. type of organism that no longer exists on earth.
21. Decay- An atom releases energy and particles as it changes to a new kind of atom.
22. Age- Of a rock is its age compared to the ages of other rocks.
23. Age- Of a rock is the number of years since the rock formed.
25. A process by which all different kinds of living things have changed over long periods of time.
26. Film- A type of fossil,or preservation.They are thin Film coatings which consist predominantly of the chemical element.
28. A break in earth's crust.
30. Of Superposition- To determine the relative ages of relative ages of sedimentary rock layers.