So any Ar40 we find deep inside a rock sample must be there as a result of K40 decay. Plants acquire it through photosynthesisand animals acquire it from consumption of plants and other animals. The second number is the standard deviation or error for the date. To question it seems to be beyond the bounds of reason. Login or Sign up.
All living plants and animals contain carbonand while most of the total carbon is carbon, a very small amount of the total carbon is radioactive carbon
There are several ways of measuring this movement that themselves have nothing to do with radiometric dating. Montgomery and David Dathe c. I found several good sources, but none that seemed both complete enough to stand alone and simple enough for a non-geologist to understand them. Three independent methods of dating these islands, and they all agree within acceptable ranges of error. Try refreshing the page, or contact customer support. By contrast, potassium and calcium are two of the most active elements in nature.