Tree ring dating wikipedia
Of course, species of tree tend to produce two or more growth rings per year.But other species produce scarcely any extra rings.
The correlation is possible because, in the Southwest region of the United States, the widths of tree rings vary from year to year with the rainfall, and trees all over the Southwest have the same pattern of variations.Carbon from these sources is very low in C-14 because these sources are so old and have not been mixed with fresh carbon from the air.Thus, a freshly killed mussel has far less C-14 than a freshly killed something else, which is why the C-14 dating method makes freshwater mussels seem older than they really are.ICR creationists claim that this discredits C-14 dating. Answer: It does discredit the C-14 dating of freshwater mussels, but that's about all.Kieth and Anderson show considerable evidence that the mussels acquired much of their carbon from the limestone of the waters they lived in and from some very old humus as well.
If we extrapolate as far back as ten thousand years ago, we find the atmosphere would not have had any C-14 in it at all.