One common radiometric method for dating volcanic deposits is: potassium-argon dating (radiopotassium dating).

What is a commonly used radioisotope for radiometric dating?

Early Primate Evolution: Isotopes Commonly used for Radiometric Dating. uranium-238 and potassium-40.

What is knowing the age of something in comparison to other things?

The abundances of parent and daughter isotopes in a sample can be measured and used to determine their age. This method is known as radiometric dating. The amount of time that it takes for half of the parent isotope to decay into daughter isotopes is called the half-life of an isotope (Figure 5b).