- B.A., World Sciences, University of the latest Hampshire
Developed into the 1950s, it absolutely was essential in developing the idea of dish tectonics as well as in calibrating the geologic time scale.
Potassium happens 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 left from then on time period. 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.
just exactly What simplifies things is that potassium is really a reactive steel and argon is an inert gasoline: Potassium is obviously tightly locked up in minerals whereas argon is certainly not section of any minerals. Argon accocunts for 1 percent of this environment. (más…)