Since the half-life of <SUP>14</SUP>C is only 5715 years, after 50,000 years only about 1/500th of the <SUP>14</SUP>C remains - and since even initially it is only present as a minute proportion of the whole (0.0000000001% of all Carbon atoms), measuring the exact quantity present with precision enough to be of use for dating purposes is extremely difficult. For this reason, scientists do not generally attempt to carbon date material that is believed to be older than about 50,000-60,000 years old. However, isotopes with longer half-lives may be used.
Additional anomalous results from carbon dating, which reinforce its limitations, include the inability to date carbonate rocks, which by confound the science behind the dating technique. Citation?{{fact}}
== References ==