کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9529030 | 1637780 | 2005 | 17 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Independent fission-track ages (Ï-ages) of proposed and accepted apatite age standards and a comparison of Ï-, Z-, ζ- and ζ0-ages: Implications for method calibration
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The results of 94 determinations of the independent fission-track ages (Ï-ages) of proposed and accepted apatite age standards show that the ages of the accepted standards are consistent with their reference ages but that those of the proposed age standards are not. The FCT and DUR data have been used to calculate Z-, ζ- and ζ0-calibration factors. The ζ0-values agree with independent measurements and with calculated values. The Ï-, Z-, ζ- and ζ0-ages (tÏ, tZ, tζ and tζ0) of 71 samples dated in the course of geological investigations are, on the whole, consistent, although systematic deviations from the mean (tM) exceed the statistical uncertainties. These are, however, â¤Â 2% and traceable to statistical variation, including counting statistics and an extra-Poisson component resulting from somewhat inconsistent track identification criteria. The overall agreement between tZ, tζ and tζ0 implies that measurements of (Ïs/Ïi), Ïd and Ï are reproducible but says nothing about their intrinsic accuracies. The fact that tÏ also agrees with tZ, tζ and tζ0 (tÏ/tM = 1.000 ± 0.001) is inconsistent with the â¼Â 10% length reduction of confined spontaneous tracks in the standards; the same applies to the tÏ/tREF-ratio (mean: 1.009 ± 0.010). It is concluded that the agreement between tÏ and tREF and between tÏ and tZ, tζ and tζ0 is an indication of the fact that the calculated ages are indeed accurate. This implies that the â¼Â 10% reduction of the spontaneous track lengths in FCT and DUR has no measurable effect on their fission-track ages, to within the < 1% resolution of the present datasets.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 222, Issues 3â4, 5 November 2005, Pages 232-248
Journal: Chemical Geology - Volume 222, Issues 3â4, 5 November 2005, Pages 232-248
نویسندگان
Eva Enkelmann, Raymond Jonckheere, Bastian Wauschkuhn,