Young earth creationism looks to the Bible as its authority for the origins and development of life, plus historical accounts of what has happened (both to human cultures and the earth) since time began.Naturalistic evolution looks to the fossil record as its authority.This problem is now reduced by the careful collection of samples, rigorous crosschecking and the use of newer techniques that can date minute samples.Volcanic rocks – such as tuff and basalt – can be used in dating because they are formed at a particular moment in time, during an eruption.The atoms of some chemical elements have different forms, called isotopes.These break down over time in a process scientists call radioactive decay.Scientists have determined, using radiocarbon dating, the age of fossils in the fossil record.
A common problem with any dating method is that a sample may be contaminated with older or younger material and give a false age.
Using relative dating the fossil is compared to something for which an age is already known.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
There are two main methods determining a fossils age, relative dating and absolute dating.
Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages.