Radiometric dating allows us to determine dating malagasy love site

Since 1955 the estimate for the age of the Earth has been based on the assumption that certain meteorite lead isotope ratios are equivalent to the primordial lead isotope ratios on Earth.

In 1972 this assumption was shown to be highly questionable.

Despite this, the momentum gained in the two decades prior to 1972 has made 4.5 b.y.

a popularly accepted “universal constant” even though the foundations on which it was based have been virtually removed.

it is not widely appreciated, outside the ranks of those who work directly in geochronology or meteoritics that, judged by modern standards, the meteoritic lead-lead isochron is very poorly established.Before 1955, ages for the Earth based on uranium/thorium/lead ratios were generally about a billion years younger than the currently popular 4.5 billion years. old Earth is reviewed and deficiencies of the uranium/lead method are discussed.The basic theory of radiometric dating is briefly reviewed.Up until 1972 these could be explained as being contaminated with radiogenic lead from uranium and thorium decay.In 1972, however, Gale showed unequivocally that there is by no means sufficient uranium and thorium to account for what could previously have been called radiogenic lead.