Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed.

What are the two types of dating rocks?

​There are two main ways to determine the age of a rock, these are Relative dating and Absolute dating. Relative dating is used to determine the relative order of past events by comparing the age of one object to another.

What rocks are used for dating?

Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years. So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil.