Radiometric dating encyclopedia

Also, by extrapolating backward in time to a situation when there was no lead that had been produced by radiogenic processes, a figure of about 4.6 billion years is obtained for the minimum age of the Earth.This figure is of the same order as ages obtained for certain meteorites and lunar rocks.It may be used to date a wide range of natural and man-made materials.

For example, a study of the Amitsoq gneisses from western Greenland used five different radiometric dating methods to examine twelve samples and got agreement to within 30 million years on an age of 3,640my.The oldest known rocks on Earth, estimated at 4.28 billion years old, are the faux amphibolite volcanic deposits of the Nuvvuagittuq greenstone belt in Quebec, Canada.A radiometric dating technique that measures the ratio of the rare earth elements neodymium and samarium present in a rock sample was used to produce the estimate.Radiometric dating is also used to date archaeological materials, including ancient artifacts.Radiometric dating methods are used to establish the geological time scale.