With out individual time stamps the process of dating these structures could become extremely difficult.To deal with many of these problems geologists utilize two types of geologic time: relative time and absolute time.If there is too much daughter product(in this case nitrogen-14), age is hard to determine since the half-life does not make up a significant percentage of the material's age.
However, if one knows the scientific formula for interpreting these transitions, the results can be "highly precise" according to paleontologist Guy Narbonne (Kerr, 789).
The half-life of uranium-235 is 704 million years, while the half-life of uranium-238 is 4.5 billion years.
For example, an object with a quarter of its original amount (2x1/2) should be roughly 11,460 years old.
In all radiometric procedures there is a specific age range for when a technique can be used.
He was employed at Caltech's Division of Geological & Planetary Sciences at the time of writing the first edition.