Page "Fossil" Paragraph 62

Since the early years of the twentieth century, absolute dating methods, such as radiometric dating ( including potassium / argon, argon / argon, uranium series, and, for very recent fossils, radiocarbon dating ) have been used to verify the relative ages obtained by fossils and to provide absolute ages for many fossils.

Radiometric dating has shown that the earliest known stromatolites are over 3. 4 billion years old.

Various dating methods have been used and are used today depending on local geology and context, and while there is some variance in the results from these dating methods, nearly all of them provide evidence for a very old Earth, approximately 4. 6 billion years.