How does potassium 40 dating work

Posted by / 16-Jul-2017 04:28

How does potassium 40 dating work

These dating methods have been under constant improvement for more than 50 years.The learning curve has been long and is far from over today.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.Young rocks have low levels of Ar, so as much as several kilograms may be needed.

Argon 40, a gas held prisoner by lava The potassium-argon method is frequently used to date lava flows whose age is between a million and a billion years.Finally, ​the argon atoms are counted in a mass spectrometer, a machine with its own complexities.Three argon isotopes are measured: Ar is determined by comparison to it.The Ar-Ar method is considered superior, but some of its problems are avoided in the older K-Ar method.Also, the cheaper K-Ar method can be used for screening or reconnaissance purposes, saving Ar-Ar for the most demanding or interesting problems.

how does potassium 40 dating work-19how does potassium 40 dating work-75how does potassium 40 dating work-48

The rock samples are crushed, in clean equipment, to a size that preserves whole grains of the mineral to be dated, then sieved to help concentrate these grains of the target mineral.