As others have stated radiocarbon measurements can be compared to calibrations to some degree. Along these lines, see also the isochron method, which uses the s

As others have stated radiocarbon measurements can be compared to calibrations to some degree. Along these lines, see also the isochron method, which uses the slope of a line to back-calculate the original isotopic concentration. The fundamental assumptions is that isotopic concentrations are uniform throughout a sample at the time of birth, but different elements solidify at different concentrations. So by looking at isotopic ratios around a sample you'll find higher concentrations of daughter nuclides where higher concentrations of parents once were. If you plot the data you can look at the slope and see the age. It's easier to see graphically [1]. [1] https://whatisnuclear.com/geology.html https://whatisnuclear.com/geology.html