Carbon-14 cannot be used to date biological artifacts of organisms that did not get their carbon dioxide from the air.
This rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock.
Many geologists claim that radiometric “clocks” show rocks to be millions of years old.
However, to read any clock accurately we must know where the clock was set at the beginning.
They can provide fairly precise information about the age of a rock layer.
The age of the carbon in the rock is different from that of the carbon in the air and makes carbon dating data for those organisms inaccurate under the assumptions normally used for carbon dating.
This restriction extends to animals that consume seafood in their diet.
Radioactive dating refers to the process of measuring the age of an object using the amount of a given radioactive material it contains.
Relative dating, meanwhile, measures the order of past events, without determining their absolute age.