40Ar39Ar
The 40Ar/39Ar dating method, often referred to as argon-argon (Ar-Ar) dating, is a radiometric dating technique used primarily in geochronology to determine the age of rocks and minerals. This method relies on the natural radioactive decay of potassium-40 (40K) into argon-40 (40Ar), a process that occurs over long geological timescales. Potassium-40 constitutes about 0.012% of natural potassium and decays into 40Ar with a half-life of approximately 1.25 billion years, making it useful for dating materials ranging from a few thousand to several billion years old.
The 40Ar/39Ar technique improves upon the traditional potassium-argon (K-Ar) method by converting a small fraction of
The method is particularly useful for dating volcanic rocks, as the argon is released during crystallization,
Applications of 40Ar/39Ar dating extend beyond geochronology, including studies of tectonic processes, volcanic activity, and even