in natural minerals, the use of laser ablation inductively coupled plasma mass spectrometry for measuring uranium concentration for apatite and zircon fission-track chronometry, and detrital thermochronology based on measuring Nd isotopic compositions on single apatites by laser ablation ICP-MS, to cite a few examples.
All other radiometric dating techniques rely on the relative abundances of a known parent isotope of an element and its corresponding concentration of daughter decay products.
Fission track dating, on the other hand, does not involve the measurement of daughter products, and the concentration of its parent isotope can be misleading because the parent element goes through other types of decay much more often than it goes through spontaneous fission.
Therefore, fission tracks can only date the age of the last cooling of the rock, not necessarily the rock's correct geologic age of formation.
The first condition of a good natural clock is that it has a known initial condition.
Unlike any other dating methods, however, fission tracks leave physical evidence of a radioactive process.
Instead of comparing the ratio of isotopes, the age of a rock is determined by visually counting fission tracks of U.
A note must be made that fission tracks are extremely thermally unstable (Geochronology Group 2005).
The rock crystals will realign upon slight heating, either erasing or greatly shrinking most fission tracks.
As for the procedures used in fission track dating, first rock samples must be collected from a desired study location.
According to the research done by ICR in their book Radioisotopes and the Age of the Earth, they collected various samples from "stratigraphically well-constrained volcanic ash or tuff beds from which Zircons would be extracted" (Snelling 204).
While in Melbourne, minerals were separated from the rock sample because only the hard minerals such as apatite, zircon, sphene, and natural glasses (including obsidian and pitchstone) can be accurately dating using fission tracks.