通过^(227)Th测定骨化石的^(231)Pa年代和^(231)Pa/^(230)Th年代

^(231)Pa OR ^(231)Pa/^(230)Th DATING OF FOSSIL BONES VIA ^(227)Th COUNTING

通过测量^(235)U衰变系中的^(227)Th,不用示踪剂可以得到钟乳石、珊瑚和骨化石等的^(231)Pa年代和^(231)Pa/^(230)Th值年代。通常骨化石的含铀量多在几个ppm以上,因而适用于该方法。而骨化石的封闭性差,故需用与本法对比来检验样品的封闭性。

The possibility of dating fossil bones and teeth with the uranium series was tested about more than 30 years ago. Unfortunately, its application is limited due to the unclosed system with respect to U and its daughter elements for most samples. Thus, the comparative measurements of both 230Th and 231Pa(or 231Pa/230Th) ages are required so as to obtain reliable dates.231Pa and/or 231Pa/230Th dating methods via 227Th counting are described in this paper. Their validity has been proved by crosscheck with radiocarbon ages.Several hundred samples of fossil bones and teeth collected from more than 30 paleolithic sites of China were dated in our laboratory. About one-third of these samples show perfect concordancy between the 230Th and 231Pa (or 231Pa/230Th)ages.