Potassium argon method radiometric dating
by Tas Walker One of the most widely used dating methods is the potassium-argon method, which has been applied to ‘dating’ rocks for decades, especially igneous rocks that have solidified from molten magma.
The attraction of the method lies in the fact that one of the daughter elements is argon which is an inert gas.
On the other hand, if the rock was later disturbed by a geological upheaval and lost argon the age would be too young. In other words, he checks to see if his calculated result falls into the range where he expects it to fall, given the geological situation of where he found his rock.Shortly after Becquerel's find, Marie Curie, a French chemist, isolated another highly radioactive element, .The realisation that radioactive materials emit rays indicated a constant change of those materials from one element to another.It is impossible to distinguish between them experimentally.So, how do we work out how much excess argon we have? In this case the method is again salvaged by changing his assumptions about the past.