For example, C14 leaches at an accelerated rate from organic material saturated in water, especially saline water.Fourthly, for C14 to test accurately the artefact must have been protected from contamination.
Thirdly, the environment in which the artefact lies heavily impacts on the rate of decay.
Organic matter, being porous, can easily be contaminated by organic carbon in groundwater.
This increases the C12 content and interferes with the carbon ratio.
My favourite quote of all time from max planck theoretical physicist, “Science progresses funeral by funeral.” How true that is.
Hi there, just a brief comment, you say: "(iron cannot be tested using C14)" and strictly speaking of course pure iron contains no carbon and thus cannot be dated by the C14 method.