Argon argon dating limitations

A second problem is that for technical reasons, the measurement of argon and the measurement of potassium have to be made on two different samples, because each measurement requires the destruction of the sample.If the mineral composition of the two sample is different, so that the sample for measuring the potassium is richer or poorer in potassium than the sample used for measuring the argon, then this will be a source of error.

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The amount of argon sublimation that occurs is a function of the purity of the sample, the composition of the mother material, and a number of other factors.These factors introduce error limits on the upper and lower bounds of dating, so that final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure and/or open-air.The reasoning is as follows: the atmosphere does not only contain Ar as being atmospheric argon.However, this only works if all the excess argon did indeed come from the atmosphere.Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites.

In these materials, the decay product is able to escape the liquid (molten) rock, but starts to accumulate when the rock solidifies (recrystallizes).Potassium–argon dating, abbreviated K–Ar dating, is a radiometric dating method used in geochronology and archaeology.It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar).Due to the long half-life, the technique is most applicable for dating minerals and rocks more than 100,000 years old.For shorter timescales, it is unlikely that enough Although it finds the most utility in geological applications, it plays an important role in archaeology.(argon), the atom typically remains trapped within the lattice because it is larger than the spaces between the other atoms in a mineral crystal.