Radiometric dating of rocksfossils Adult iphone sexcams
Lead-206 and lead-207 are also believed to be present in primordial lead since there is insufficient uranium to account for all the lead.Just how much lead-206 and 207 were present at the beginning, nobody knows. As a uranium ore ages, the ratio of lead-206 to lead-204 increases as does the ratio of lead-206 to lead-207.There is a large body of discordant data but concordant data are scarce.In 1955 a symposium on radiometric dating was held from which the following was given in the summary: “Radioactive ‘dating’ has been perhaps the most widely publicised of geochemical techniques, but of several known dating methods based on radioactivity, only C-14 dating has developed to the point where it yields consistently reliable ages.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.
The basic theory of radiometric dating is briefly reviewed.
They estimated the age of the Earth by substituting the lead isotope ratios of certain meteorites in the Holmes-Houtermans equation.
In this equation the primordial lead ratios are required.
Since the lead in meteorites can no longer be ascribed to uranium/thorium decay, it may also be taken to represent primordial lead.
Therefore, since the lead isotope ratios for the majority of meteorites are the same as present day common lead ratios and may also be assumed to represent primordial lead, the billion year age chronology disappears.