Radiometric dating is self-checking, because the data (after certain preliminary calculations are made) are fitted to a straight line (an "isochron") by means of standard linear regression methods of statistics.The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
It was in large part due to the desire to understand the age of the Olduvai hominid remains that pioneering attempts were made to date geologically young materials using the K-Ar method.
decay or the rate of other cumulative changes in atoms resulting from radioactivity. The various isotopes of the same element differ in terms of atomic mass but have the same atomic number..
One half-life is the amount of time required for of the original atoms in a sample to decay.
This problem is now reduced by the careful collection of samples, rigorous crosschecking and the use of newer techniques that can date minute samples.
Volcanic rocks – such as tuff and basalt – can be used in dating because they are formed at a particular moment in time, during an eruption.