Absolute dating is the process of determining an age on a specified chronology in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty of accuracy. The potassium-argon dating method has been used to measure a wide variety of ages. The potassium-argon age of some meteorites is as old as 4,,, years, and volcanic rocks as young as 20, years old have been measured by this method. Learn how potassium-argon isotopic dating works and how it is especially useful for determining the age of lavas. Potassium-Argon Dating Methods. Search the site GO. Science. Geology Basics Types of Rocks Archaeological Dating Techniques Used to Determine an Artifact's Age.