what are the best dating websites - Index fossil relative dating
Then after another 5,000 years half of the remaining parent isotope will have decayed.
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.
Throughout the history of life, different organisms have appeared, flourished and become extinct.
Many of these organisms have left their remains as fossils in sedimentary rocks.
Some fossils, called index fossils, are particularly useful in correlating rocks.