Abstract
The isotope 138La makes up 0.089% of natural lanthanum and exhibits a branched decay, by β− to 138Ce and electron capture to 138Ba. The La–Ce isotope scheme is a potentially powerful adjunct to the Sm–Nd method for petrogenetic studies, but the best determination by counting of the β-decay half-life of La (3.02 x 1011 yr)1 is in conflict with geological half-life determinations based on La–Ce and Sm–Nd mineral isochrons2–4. To test these alternatives, I determined a six-point La–Ce isochron on whole-rock samples of Lewisian granulite-facies Archaean gneiss from NW Scotland. Here I report, based on a half-life of 3.02 × 1011yr, a La–Ce age of 2,990 ±400 Myr (2σ), which falls very well within the error of a whole-rock Sm–Nd date on Lewisian granulites of 2,895±100 Myr (2σ). This half-life (equivalent to a La β-decay constant of 2.30 × 10−12 yr-1) is therefore recommended for geological application of the Ce-isotope method.
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References
Sato, J. & Hirose, T. Radiochem. radioanalyt. Lett. 46, 145–152 (1981).
Tanaka, T. & Masuda, A. Nature 300, 515–518 (1982).
Tanaka, T. & Masuda, A. Nature 306, 504 (1983).
Shimizu, H. et al. Terra Cogn. 6, 145 (1986).
Norman, E. B. & Nelson, M. A. Phys. Rev. C27, 1321–1324 (1983).
Norman, E. B. & Nelson, M. A. Nature 306, 503–504 (1983).
Nakai, S. et al. Nature 320, 433–435 (1986).
Weaver, B. L. & Tarney, J. Earth planet. Sci. Lett. 51, 279–296 (1980).
Hamilton, P. J. et al. Nature 277, 25–28 (1979).
Hamilton, P. J. et al. Earth planet. Sci. Lett. 62, 263–272 (1983).
Chauvel, C. B. et al. Earth planet. Sci. Lett. 74, 315–324 (1985).
Taylor, P. N. et al. Geochim. cosmochim. Acta 44, 1437–1453 (1980).
Chapman, H. J. & Moorbath, S. Nature 268, 41–42 (1977).
Dickin, A. P. et al. Contr. Miner. Petr. (in the press).
Dickin, A. P. Nature (in the press).
York, D. Can. J. Phys. 44, 1079–1086 (1966).
Brooks, C. et al. Rev. Geophys. Space Phys. 10, 551–557 (1972).
Nakamura, N. Geochim. cosmochim. Acta 38, 757–775 (1974).
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Dickin, A. La–Ce dating of Lewisian granulites to constrain the 138La β-decay half-life. Nature 325, 337–338 (1987). https://doi.org/10.1038/325337a0
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DOI: https://doi.org/10.1038/325337a0
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