1. Relative and Absolute Age Law of Superposition

2. Relative and Absolute Dating There are two major ways to date geologic events: Relative dating-how old a rock is compared to surrounding rocks Absolute dating-actual number of years since the rock was formed

3. Relative Dating The various relative dating methods tell you whether a specific rock or layer of rocks is younger or older as compared to surrounding rocks This type of dating does not give an exact age for the rock

4. The Law of Superposition states that in an undisturbed sequence of sedimentary rock: Each layer is older than the one above Each layer is younger than the one below

5. Law of Superposition
a vertical set of strata (layers) is a chronological record of the geologic history of that strata
Youngest layers are on top and oldest on bottom

6. Law of Superposition

7. Absolute Dating
Absolute dating can give you the exact age of a rock
This is accomplished using radioactive dating, which is also referred to as radiometric dating
Based on the regular radioactive decay of certain elements