The method 2005 online dating
26-Nov-2017 21:01
For example: Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.Young-Earthers have several methods which they claim to give "upper limits" to the age of the Earth, much lower than the age calculated above (usually in the thousands of years).
The resulting plot has data points for each of five meteorites that contain varying levels of uranium, a single data point for all meteorites that do not, and one (solid circle) data point for modern terrestrial sediments.Over time, the amounts of Pb-206 and Pb-207 will change in some samples, as these isotopes are decay end-products of uranium decay (U-238 decays to Pb-206, and U-235 decays to Pb-207).This causes the data points to separate from each other.The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites.
This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204).A young-Earther would object to all of the "assumptions" listed above.