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The existence of two 'parallel' uranium–lead decay routes (238 U to 206 Pb and 235 U to 207 Pb) leads to multiple feasible dating techniques within the overall U–Pb system. The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below).
The three long-lived nuclides are uranium-238 (half-life 4.5 billion years), uranium-235 (half-life 700 million years) and thorium-232 (half-life 14 billion years). The fourth chain has no such long-lasting bottleneck nuclide near the top, so almost all of the nuclides in that chain have long since decayed down to just before the end: bismuth-209.
Zircon is extremely useful for geological dating: when forming, it collects tiny imperfections of uranium, but never lead. It follows that if lead is present in zircon, it must have come from decay of the uranium present. (The process is known as U-Pb dating.) The team measured the concentrations and isotopic compositions of foreign elements ...
Lead–lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite.For most dating requirements it has been superseded by uranium–lead dating (U–Pb dating), but in certain specialized situations (such as dating meteorites and the age of the Earth) it is more important than U–Pb dating.
Uranium–lead dating; Uranium–thorium dating; Uranium–uranium dating This page was last edited on 16 February 2022, at 02:25 (UTC). Text is available under ...
One of the advantages of this method is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 703 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the ...
“This study analyzed a nationally representative sample of U.S. adolescent e-cigarette use to examine whether urine metal levels (i.e., cadmium, lead and uranium) differed by vaping frequency ...
Samarium–neodymium dating; Tephrochronology; Uranium–lead dating; Uranium–thorium dating; Uranium–uranium dating, useful in dating samples between about 10,000 and 2 million years Before Present (BP), or up to about eight times the half-life of 234U. Wiggle matching