Radiocarbon dating volcanic ash
If a fossil has been dated radiometrically in one place, correlation allows use to work out the age in other places.
In the above example, we know that the fossil in Nevada is slightly older than the ash layer dated to 507 million years old.
The geological time scale is used by geologists and paleontologists to measure the history of the Earth and life.
The various confounding factors that can adversely affect the accuracy of carbon-14 dating methods are evident in many of the other radioisotope dating methods.Geologists call this simple observation the Principle of Superposition, and it is most important way of working out the order of rocks in time.Ordering of rocks (and the fossils that they contain) in time from oldest to youngest is called .We can say that same species in Oklahoma must also be about 507 million years old, even though there is no volcanic ash layer present at this site.Carbon dating is used to determine the age of biological artifacts up to 50,000 years old.