Carbon 13 dating
This process of ingesting C-14 continues as long as the plant or animal remains alive.
The C-14 within an organism is continually decaying into stable carbon isotopes, but since the organism is absorbing more C-14 during its life, the ratio of C-14 to C-12 remains about the same as the ratio in the atmosphere.
Libby in 1949, and has become an indispensable part of the archaeologist's tool kit since.U of I researchers should specify U of I funds (i.e., CFOP) to be used for payment during sample submission.External submitters should receive a UIUC Banner account prior to sample submission. Payment can be made online by going to and logging in with the UIUC Banner account number assigned to your department, group, or business.The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample.By looking at the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a formerly living thing fairly precisely. So, if you had a fossil that had 10 percent carbon-14 compared to a living sample, then that fossil would be: t = [ ln (0.10) / (-0.693) ] x 5,700 years t = [ (-2.303) / (-0.693) ] x 5,700 years t = [ 3.323 ] x 5,700 years Because the half-life of carbon-14 is 5,700 years, it is only reliable for dating objects up to about 60,000 years old.