Consider some molten rock in which isotopes and elements are distributed in a reasonably homogeneous manner.Its composition would be represented as a single point on the isochron plot: Note that the above is somewhat simplified.Age "uncertainty" When a "simple" dating method is performed, the result is a single number.There is no good way to tell how close the computed result is likely to be to the actual age.
In addition, it requires that these measurements be taken from several different objects which all formed at the same time from a common pool of materials.
The simplest form of isotopic age computation involves substituting three measurements into an equation of four variables, and solving for the fourth.
The equation is the one which describes radioactive decay: If one of these assumptions has been violated, the simple computation above yields an incorrect age.
Each such age would match the result given by the isochron.
Gain or loss of In order to make the figures easy to read (and quick to draw), the examples in this paper include few data points.
Isochron methods avoid the problems which can potentially result from both of the above assumptions.