- B.A., World Sciences, University of the latest Hampshire
Developed into the 1950s, it absolutely was crucial in developing the idea of dish tectonics plus in calibrating the geologic time scale.
Potassium does occur in 2 stable isotopes ( 41 K and 39 K) plus one radioactive isotope ( 40 K). Potassium-40 decays having a half-life of 1250 million years, and thus 50 % of the 40 K atoms have died from then on period of the time. Its decay yields argon-40 and calcium-40 in a ratio of 11 to 89. The K-Ar method works by counting these radiogenic 40 Ar atoms caught inside minerals.