Using relative dating the fossil is compared to something for which an age is already known.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
These techniques can be grouped as numerical, relative dating, and correlation.
As an example of how they are used, radiometric dates from geologically simple, fossiliferous Cretaceous rocks in western North America are compared to the geological time scale.
To get to that point, there is also a historical discussion and description of non-radiometric dating methods.
This activity was selected for the On the Cutting Edge Reviewed Teaching Collection This activity has received positive reviews in a peer review process involving five review categories.
The five categories included in the process are In this lab, students are introduced to the difference between relative and absolute dating, using the students themselves as the material to be ordered.
Geochronologists do not claim that radiometric dating is foolproof (no scientific method is), but it does work reliably for most samples.