HELIUM-URANIUM DATING OF CORALS
HELIUM-URANIUM DATING OF CORALS
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DOI：
10.1016/0016-7037(73)90058-6
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发表时间：
1973-01-01
影响因子：
5
通讯作者：
BENDER, ML
中科院分区：
文献类型：
--
作者：
BENDER, ML
摘要 Fanale 和 Schaeffer (1965) 测定了珊瑚和其他文石化石的 He U 年龄，发现结果与独立的年龄估计基本一致。作为对化石珊瑚 He U 年龄可靠性的更广泛和严格的测试，我确定了 45 个独立测年的新生代珊瑚的 He U 年龄。还确定了铀和钍同位素组成以及 Rn 222 保留率作为一致性检查。结果表明，满足下列一致性检验并进行下列修正后，即可得到可靠的年龄： 1.(1)珊瑚为未重结晶文石。 2.(2) 不存在Th 232，表明样品不含污染碎屑。 3.(3)U 234 U 238 和Th 230 U 234 比值与He/U年龄一致。 4.(4) Rn 223泄漏率小于5%。 5.(5)对继承的氦气进行了修正。 6.(6) 对 U 和 U 子体衰变期间从珊瑚壁“射出”的 α 粒子进行了修正。
Abstract Fanale and Schaeffer (1965) determined He U ages of corals and other aragonitic fossils and found that the results generally agreed with independent age estimates. As a more extensive and rigorous test of the reliability of He U ages of fossil corals, I have determined He U ages on forty-five independently dated Cenozoic corals. Uranium and thorium isotope compositions and Rn 222 retentivities were also determined as consistency checks. The results indicate that reliable ages are obtained when the following consistency tests are met and the following corrections are made: 1.(1) corals are unrecrystallized aragonite. 2.(2) Th 232 is absent, indicating that the samples are free of contaminating detritus. 3.(3) U 234 U 238 and Th 230 U 234 ratios are concordant with the He/U age. 4.(4) Rn 223 leakage is less than 5 per cent. 5.(5) a correction is made for inherited helium. 6.(6) a correction is made for alpha particles ‘shot out’from the coral walls during U and U daughter decay.