Absolute and relative fossil dating terrykele on dating sites
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.
Then after another 5,000 years half of the remaining parent isotope will have decayed.
While people are most familiar with carbon dating, carbon dating is rarely applicable to fossils.
Typically commonly occurring fossils that had a widespread geographic distribution such as brachiopods, trilobites, and ammonites work best as index fossils.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
This uses radioactive minerals that occur in rocks and fossils almost like a geological clock.
It’s often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in.
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.
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?