Most accurate form of radiometric dating
Some evidence is also presented to show that radiometric results that are in agreement with the accepted geological time scale are selectively published in preference to those results that are not in agreement.The geological time scale and an age for the Earth of 4.5 b.y.
It can be used to date rocks that formed from about 1 million years to over 4.5 billion years ago with routine precisions in the 0.1–1 percent range.
So, we have a “clock” which starts ticking the moment something dies.
Obviously, this works only for things which were once living.
The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below).
However, use of a single decay scheme (usually Pb) leads to the U–Pb isochron dating method, analogous to the rubidium-strontium dating method.