Relative dating is used to determine a fossils approximate age by comparing it to similar rocks and fossils of known ages.
Absolute dating is used to determine a precise age of a fossil by using radiometric dating to measure the decay of isotopes, either within the fossil or more often the rocks associated with it.
It’s often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in.
So, often layers of volcanic rocks above and below the layers containing fossils can be dated to provide a date range for the fossil containing rocks.
Since the rock formation contains both types of fossils the ago of the rock formation must be in the overlapping date range of 415 to 420 million 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.
We define the rate of this radioactive decay in half-lives.Some of the artistic techniques, the placing of the images in the Kapova cave as well as what other human evidence remains, has shown these underground sanctuaries have a connection to those found in the Franco-Canrabrian region—modern day southeastern France.The Kapova cave is located in Bashkiria, a southwestern Russian province near the country’s border with Kazakhstan.For example if you have a fossil trilobite and it was found in the Wheeler Formation.The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.