Types of radiometric dating methods
Below is a table of radiometric ages derived from groups of meteorites: As shown in the table, there is excellent agreement on about 4.5 billion years, between several meteorites and by several different dating methods.Note that young-Earthers cannot accuse us of selective use of data -- the above table includes a significant fraction of all meteorites on which isotope dating has been attempted. 286) , less than 100 meteorites have been subjected to isotope dating, and of those about 70 yield ages with low analytical error.See the Isochron Dating FAQ or Faure (1986, chapter 18) for technical detail.A young-Earther would object to all of the "assumptions" listed above.The formation of diagenetic xenotime is principally related to redox cycling of Fe-oxyhydroxides and microbial decomposition of organic matter, leading to elevated concentrations of dissolved phosphate and rare earth elements (REE) in sediment pore-waters.Xenotime has the properties of an ideal U–Pb chronometer, containing elevated levels of U (generally 1000 ppm) and very low concentrations of initial common Pb.The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed.
Diagenetic xenotime occurs in a wide variety of rock types, including conglomerate, sandstone, siltstone, shale, phosphorite and volcaniclastic rocks, varying from early Archaean to Mesozoic in age.
If the source of the solar system was also uniformly distributed with respect to uranium isotope ratios, then the data points will always fall on a single line.