nuclideis one that is produced by a process of radioactive decay.
Radiogenic nuclides (more commonly referred to as 'radiogenic isotopes') form some of the most important tools in Geology. They are used in two principal ways:
1) In comparison with the quantity of the radioactive 'parent isotope' in a system, the quantity of the radiogenic 'daughter product' is used as a
radiometric datingtool (e.g. uranium-lead geochronology).
2) In comparison with the quantity of a non-radiogenic isotope of the same element, the quantity of the radiogenic isotope is used as an
isotopic tracer(e.g. 206Pb/204Pb). This technique is discussed in more detail under the heading isotope geochemistry.
Leadis perhaps the best example of a radiogenic substance, as it is produced from the radioactive decay of uraniumand thorium. Specifically, Pb-206 is formed from U-238, Pb-207 from U-235, and Pb-208 from Th-232. Other substances considered radiogenic are argon-40, formed from radioactive potassium, and nitrogen-14, which is formed by the decay of carbon-14. U-238, U-235, and Th-232 themselves are likely to be radiogenic as well, being formed from the decay of those nuclei of the elements heavier than uranium which do not undergo spontaneous fission, just after they were formed in stellar supernovae.Other important examples of radiogenic elements are radonand helium, both of which form during the decay of heavier elements in bedrock. The global supply of helium is radiogenic.
Radiogenic isotopes used in Geology
The following table lists some of the most important radiogenic isotope systems used in Geology, in order of decreasing
half-lifeof the radioactive parent isotope. The values given for half-life and decay constant are the current consensus values in the Isotope Geology community. [cite book | author=Dickin, A.P. | year=2005 | title=Radiogenic Isotope Geology | url=http://www.onafarawayday.com/Radiogenic/ | publisher=Cambridge University Press] Extinct nuclides are not presently included. **indicates ultimate decay product of a series.
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Look at other dictionaries:
radiogenic — [rā΄dē ōjen′ik] adj. [ RADIO + GENIC] produced by ionizing radiation … English World dictionary
radiogenic — adjective Date: 1935 produced by or determined from radioactivity < radiogenic isotopes > < radiogenic tumors > … New Collegiate Dictionary
radiogenic — /ray dee oh jen ik/, adj. 1. Physics. produced by radioactive decay: radiogenic lead; radiogenic heat. 2. having qualities or characteristics that broadcast well; suitable for presentation on the radio. [1925 30; RADIO + GENIC] * * * … Universalium
radiogenic — 1. Producing rays of any sort, especially electromagnetic rays. 2. Caused by x or gamma rays. * * * ra·dio·gen·ic .rād ē ō jen ik adj produced or caused by radioactivity <radiogenic isotopes> <radiogenic cancer> * * * ra·di·o·gen·ic… … Medical dictionary
radiogenic — ra•di•o•gen•ic [[t]ˌreɪ di oʊˈdʒɛn ɪk[/t]] adj. phs produced by radioactive decay: radiogenic lead; radiogenic heat[/ex] • Etymology: 1925–30 … From formal English to slang
radiogenic — adjective a) Of, pertaining to, or caused by radioactivity b) Particularly suited to radio broadcasting … Wiktionary
radiogenic — produced by radioactive disintegration Causation and Formation … Phrontistery dictionary
radiogenic — adj. suitable for radio broadcast; produced by radioactive decay … English contemporary dictionary
radiogenic — [ˌreɪdɪə(ʊ) dʒɛnɪk, dʒi:n ] adjective 1》 produced by radioactivity. 2》 suitable for broadcasting by radio. Derivatives radiogenically adverb … English new terms dictionary
radiogenic — ra·dio·gen·ic … English syllables