Radiometric dating Most absolute dates for rocks are obtained with radiometric methods. These use radioactive minerals in rocks as geological clocks. The atoms of some chemical elements have different forms, called isotopes.

What type of rock works best for absolute dating?

igneous rocks Of the three basic rock types, igneous rocks are most suited for radiometric dating. Metamorphic rocks may also be radiometrically dated. However, radiometric dating generally yields the age of metamorphism, not the age of the original rock.

What method is used to date rocks older than 100000 years?

Radiometric datingDating methodMaterial datedAge range datedLuminescenceTephra, loess, lake sedimentsUp to 100,000 years agoFission trackTephra10,000 to 400 million years agoPotassium-40 to argon-40Volcanic rocks20,000 to 4.5 billion years agoUranium-238 to lead-206Volcanic rocks1 million to 4.5 billion years ago1 more row•May 20, 2011