the act of decomposing a substance into its constituent elements

assign a date to; determine the (probable) date of

geological dating that relies on the proportions of radioactive potassium in a rock sample and its decay product, argon

a chemical analysis used to determine the age of organic materials based on their content of the radioisotope carbon 14; believed to be reliable up to 40,000 years

geological dating based on the proportions of radioactive rubidium into its decay product strontium; radioactive rubidium has a half-life of 47,000,000,000 years