Uranium to lead dating ashley cole dating cheryl cole look alike
The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below).
However, use of a single decay scheme (usually Pb) leads to the U–Pb isochron dating method, analogous to the rubidium-strontium dating method.
If the sample is old enough – more than about 400 million years – significant loss (leakage) by the sample of its uranium-generated lead will cause discordance between the two uranium-lead ages.
The presence of minerals (or zones within minerals) older than the rock being dated can also cause such age-discordance.
The important characteristic of common lead is that it contains no significant proportion of radiogenic lead accumulated since the time that the mineral or rock phase was formed.
Of the four isotopes of lead, two are formed from the uranium isotopes and one is formed from the thorium isotope; only lead-204 is not known to have any long-lived radioactive progenitor.
Pb) leads to multiple dating techniques within the overall U–Pb system.If modern lead, for example, from marine sediments or modern basalts has the composition of lead in the Earth and if the lead in the troilite phase of iron meteorites has the composition of primordial lead, then a simple model yields about 4.6 billion years for the age of the Earth.This age is in good agreement with the age of the meteorites and the age of the Moon as determined independently.Uranium-lead is one of the oldest and most refined radiometric dating schemes, with a routine age range of about 1 million years to over 4.5 billion years, and with routine precisions in the 0.1- 1 percent range.Uranium-lead dating is usually performed on the mineral zircon (Zr Si O), though it can be used on other minerals such as monazite, titanite, and baddeleyite.
Also, you can't use this to determine age of fossils, correct? I have to give a science presentation on Carbon/Uranium-Lead dating. But you can infer dates for sediments that lie in between igneous layers. Carbon is a bit different; only for organic matter, and only for the past 50,000 years at most.