Argon-Argon Dating

International audienceArgon–argon dating is a radioisotopic method based on the natural, spontaneous radioactive decay of an isotope of potassium, 40K, at a known rate to produce an isotope of argon, 40Ar. This method is one of the most versatile, precise and accurate of all radioisotopic dating tools applied to volcanic materials. Over the last 25 years it has been regarded as the benchmark to constrain the temporal framework in volcanic areas for the evolution of fauna, flora, and hominids during the Pliocene and Pleistocene periods. This entry is not an exhaustive treatment of the Ar–Ar dating method, but provides a general view of the method and gives examples of its application to archaeology