1. Age

2. Relative Dating
Principles:
Uniformitarianism-
Law of Superposition-

3. How do you think scientists tell the age of fossils?

4. Sedimentary Rocks
Sedimentary rocks usually form in horizontal layers. Sedimentary rocks form from erosion and deposition.
This is known as the Principle of Original Horizontality.

5. Let’s Practice
Which event happened first? We will put the five events in order from oldest to most recent.

6. Index Fossils
Index fossils help to identify similar rock layers in different locations.