K–Ca dating

K–Ca dating, or potassium-calcium dating, is a chronological dating technique used to determine the age of geological materials. It is based on the decay of potassium-40 (K) into calcium-40 (Ca) and argon-40 (Ar), a technique often referred to more specifically as K-Ar dating. However, K–Ca can sometimes refer more broadly to methods involving the relative abundances of potassium and calcium isotopes.