Relative versus absolute dating techniques
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.
The main difference between absolute and relative dating is that the absolute dating is a technique to determine the numerical age of a rock or a fossil whereas the relative dating is a technique that determines the relative age.
Furthermore, absolute dating can be done with the use of radiometric dating while relative age is determined with respect to other layers.
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?Carbon-14, the radioactive isotope of carbon used in carbon dating has a half-life of 5730 years, so it decays too fast.It can only be used to date fossils younger than about 75,000 years.Studying the layers of rock or strata can also be useful. If a layer of rock containing the fossil is higher up in the sequence that another layer, you know that layer must be younger in age. This can often be complicated by the fact that geological forces can cause faulting and tilting of rocks.Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods.