What is absolute and relative age dating
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.
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.
By measuring the ratio of the amount of the original (parent) isotope to the amount of the (daughter) isotopes that it breaks down into an age can be determined.
Absolute dating is the process of determining an age on a specified chronology in archaeology and geology.Absolute age-dating tells how long ago an event occurred. Using these methods, geologists have created a geologic time scale for organizing past times in earth’s history. If a radioactive isotope is said to have a half-life of 5,000 years that means after 5,000 years exactly half of it will have decayed from the parent isotope into the daughter isotopes.Then after another 5,000 years half of the remaining parent isotope will have decayed.