In 1935, Klemperer and, independently, Newman and Walke (1935), ascribed, from reasons of isotope systematics, the activity of potassium to a-then unknown — rare isotope K40. This was the first good guess. In 1935, A. O. Nier actually discovered this isotope and found its abundance to be 1.19 · 10-4 of the total K.

When was potassium-argon dating invented?

The potassium-argon (K-Ar) isotopic dating method is especially useful for determining the age of lavas. Developed in the 1950s, it was important in developing the theory of plate tectonics and in calibrating the geologic time scale.

Who created the potassium argon dating?

The radioactive decay scheme involving the breakdown of potassium of mass 40 (40K) to argon … … dating were developed, among them potassium–argon dating and dating by thermoluminescence.