Why are index fossils useful for dating rocks list of white label dating sites
Any type of organism can be distinctive, but not so many are widespread.Many important index fossils are of organisms that start out life as floating eggs and infant stages, which allowed them to populate the world using ocean currents.Because most fossil-bearing rocks formed in the ocean, the major index fossils are marine organisms.
Thus, their time on Earth may have been confined to short period of time.
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.
Since the organisms that became index fossils lived only during specific intervals of geologic time, geologists can estimate the ages of rock layers based on the particular index fossils they contain.
Carbon dating is used to determine the age of biological artifacts up to 50,000 years old.
This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils (like those of the dinosaurs alleged to be millions of years old).