Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238

Details Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238 Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238

Dec 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994e%26psl.128..653r&link_type=abstract

Earth and Planetary Science Letters (ISSN 0012-821X), vol. 128, no. 3-4, p. 653-670

Physics

9

Geochronology, Nuclear Fission, Uranium, Xenon, Lead (Metal), Thorium Isotopes

Scientific paper

U-Xe chronology requires knowledge of the product of the decay constant (lambdasf) and the fractional yield of Xe-136 (Ysf-136) produced by the spontaneous fissin of U-238. However, values derived from U oxides are in conflict with those obtained from U-bearing accessory minerals. We present combined U-Pb and U-Xe data for carefully selected suite of zircon and monazite separates. All samples have precise, concordant or near-concordant U-Pb ages and yield a lambdasf* Ysf-136 value of (6.38 +/- 0.18) x 10-18/a. Recoil loss of fissiongenic Xe was corrected for numerically or circumvented by abrading samples or analyzing very large crystals. Old crystal cores that might have retained their fission Xe but not their radiogenic Pb were not detected in any of the samples. No significant contribution of Xe from Th-232 fission is expected as long as the Th/U ratio is less than or = 10. Taken together, these observations indicate that the derived value for lambdasf* Ysf-136 is correct. This value is similar to that from earlier studies of accessory minerals, but some 20% higher than that determined recently from carefully selected U minerals, including pitchblende, uraninite and coffinite. This suggests that U oxides systematically lose fissiogenic Xe, possibly due to regeneration of the crystal lattice or changes in oxidation state. U-Xe from such minerals should be interpreted with caution.

Affiliated with

Also associated with

No associations

Rating

Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Uranium-xenon chronology: Precise determination of lambdasf* Ysf-136 for spontaneous fission of U-238 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1328588