C14 dates by the accelerator mass spectrometer (AMS) method show the ages of coal, oil, and diamonds to usually be in the 40k year range, and they can't get any results in the 40k to 90k range, which is what the method was designed to achieve, so what's up with that?
If those deposits are actually millions of years old, there should be only C14 from contamination, but the researchers have ruled that out, "intrinsic C14" are what they are dealing with, after many procedures performed on the sample to make sure it's intrinsic C14 which they are measuring.
Nuclear Instruments and Methods in Physics Research B have published many articles about this "problem," see also: Giem, P., Carbon-14 content of fossil carbon, Origins, 51, 6-30, 2001.
If those deposits are actually millions of years old, there should be only C14 from contamination, but the researchers have ruled that out, "intrinsic C14" are what they are dealing with, after many procedures performed on the sample to make sure it's intrinsic C14 which they are measuring.
Nuclear Instruments and Methods in Physics Research B have published many articles about this "problem," see also: Giem, P., Carbon-14 content of fossil carbon, Origins, 51, 6-30, 2001.