Lead isotope dating

31-Oct-2016 18:25

They then measure the present radiogenic lead ratio in a rock sample and interpolate the age of the sample from a table of age versus the radiogenic lead ratio constructed from Equation 2.

This estimate is generally discordant with the first three isochron estimates.

This method reaches the pinnacle of radioisotope dating methods in terms of complication and convolution.

Since we do not want to be tossed to and fro by every teaching that cunning men put in front of us, let’s carefully investigate this method’s viability as a reliable clock for terrestrial and extraterrestrial rock formations.

They further reason that the loss of radiogenic Pb out of the rock formation causes discordant lines that intersect the ideal curve at the time of original crystallization and the time elapsed since complete closure to migration of any form, assuming all assumptions are rigorously satisfied.

In this way, the Pb-Pb method attempts to deal with any loss of radiogenic Pb during the life of the rock formation.

Thus, they can only be applied to certain minerals such as zircon and monazite crystals.First, we assume, as a corollary to the closed system assumption, that U is constant in time even though they have different decay constants.Third, we assume that a clever application of l’Hôpital’s rule from elementary calculus will provide us with a reasonable primordial value for the radiogenic Pb ratio, i.e., (Pb concentrations in the rock we are dating?The sixth assumption assumes that at the time a mineral was formed in a rock, the Pb it contains was separated from the U and Th parents, and thus its isotope ratio has remained constant.How does one use radioisotope decay as a clock when it has been removed from the rock sample being dated?

Thus, they can only be applied to certain minerals such as zircon and monazite crystals.First, we assume, as a corollary to the closed system assumption, that U is constant in time even though they have different decay constants.Third, we assume that a clever application of l’Hôpital’s rule from elementary calculus will provide us with a reasonable primordial value for the radiogenic Pb ratio, i.e., (Pb concentrations in the rock we are dating?The sixth assumption assumes that at the time a mineral was formed in a rock, the Pb it contains was separated from the U and Th parents, and thus its isotope ratio has remained constant.How does one use radioisotope decay as a clock when it has been removed from the rock sample being dated?Examples abound of discordant and just plain wrong dates obtained with these gold-standard dating methods. Ngauruhoe yielded a Pb-Pb isochron age of 3.908 ± 0.390 x 10 Why would anyone accept them as scientific fact when they aren’t based on reasonable assumptions and don’t faithfully reproduce empirical data? I presented these issues in detail because scientists and lay people alike deserve a thorough and comprehensive answer.