It is from this field of study that fossils and artifacts are dated based on the perceived age of the geological layers in which they are located.Geologists determine the age of rocks, fossils, and sediments using a variety of methods including relative and absolute dating.
In some cases such as Carbon-14 dating, radioactive dating actually gives strong evidence for a young Earth, while other methods such as K-Ar dating and Isochron dating are based on faulty assumptions and are so unreliable as to be useless.
Age dating the Earth (Geochronology) is the scientific study of the age of the Earth and the temporal sequence of events related to the formation of the planet and the history of life on Earth.
The word is derived from Geo meaning Earth, and chronology, which is the study of time, or a record of events in the order of their occurrence (timeline).
The methods are all ultimately calibrated to relative dates of the geologic column, such that data that conflicts with a fossil's or rock's placement in the geologic column is explained away by the evolutionary theoretical system.
For example, Carbon-14 would decay to nothing in well under 1 million years, so if Carbon-14 is found in a dinosaur fossil it is interpreted as resulting from contamination.
U has a known rate, and as such the number of tracks is theoretically related to the age of the sample.