Potassium-argon dating

Potassium-argon dating is a method used to determine the age of rocks and minerals. It relies on measuring the amount of argon gas trapped inside mineral crystals, which accumulates over time from the radioactive decay of potassium-40. When a volcanic rock cools and solidifies, argon gas escapes, effectively resetting the clock. Over millions of years, potassium-40 decays into argon-40 at a known rate. By comparing the ratio of potassium to argon in a sample, scientists can calculate how long ago the rock solidified, providing an estimate of its age.