Abstract
Uranium-thorium and uranium-protactinium dating
Abstracts with programs - Geological Society of America, Vol.32(7), p.325
Geological Society of America, 2000 annual meeting
2000
Abstract
The principles of uranium-series dating, which include U/Th and U/Pa dating, have been known since the turn of the last century (Bateman, 1910) soon after the discovery of radioactivity and actually before the discovery of isotopes. However, uranium-series dating was not done prior to the 1950's because of the inability to measure natural concentrations of rare uranium-series isotopes. U/Th dating was first performed by Barnes et al. (1956) with alpha-counting methods that would become the standard technique for the next 3 decades. Mass spectrometric techniques (Edwards et al., 1987) resulted in large reductions in sample size requirements and large improvements in age precision. Development of U/Pa dating was analogous, with the first U/Pa dating performed in 1968 by Ku using decay counting techniques. Mass spectrometric techniques for Pa were first accomplished by Pickett et al. (1994) and applied to U/Pa dating by Edwards et al. (1997). As with U/Th dating, mass spectrometric U/Pa techniques resulted in large sample size reductions and improvements in precision. Moreover, by combining the two, one can test the accuracy of an age (Cheng et al., 1998) in much the same way as one can test the accuracy of U/Pb ages of zircons. By applying these techniques to appropriate materials (e.g. inorganic carbonates and coralline aragonite), one can obtain precise ages, tested for accuracy, over the last 600,000 years. These methods promise to place the chronology of a wide range of late Quaternary events on a precise, absolute time scale. Active areas of inquiry include: climate change from high resolution long-term records from caves, climate change from corals, sea level history, C-14 calibration and atmospheric and oceanic C-14 history, and the timing of the latter stages of human evolution. (Barnes et al., Science 124, p. 175; Bateman, Proc. Cambridge Phil. Soc. 15, p. 423; Cheng et al., GCA 62, p. 3437; Edwards et al. (1987), EPSL 81, p. 175; Edwards et al. (1997), Science 276, p. 782; Ku, JGR 73, p. 2271; Pickett et al., Anal. Chem. 66, p. 1044. )
Details
- Title: Subtitle
- Uranium-thorium and uranium-protactinium dating
- Creators
- R. Lawrence Edwards - University of MinnesotaJeffrey A DoraleHai ChengChuan-Chou Shen
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.32(7), p.325
- Conference
- Geological Society of America, 2000 annual meeting
- Publisher
- Geological Society of America (GSA)
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, 2000 annual meeting
- Language
- English
- Date published
- 2000
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240910702771
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