PDF(Pubmed)
Abstract：
Electron spin resonance coupled with uranium-series dating (ESR/U-series) of carbonate hydroxyapatite in tooth enamel is the main technique used to obtain age determinations from Pleistocene fossils beyond the range of radiocarbon dating. This chronological information allows to better understand diachronic change in the palaeontological record, especially with regard to the evolution of the genus Homo. Given the relative paucity of human teeth at palaeontological and archaeological localities, ESR/U-series is widely applied to the teeth of ungulate species. However, the accuracy of ESR/U-series ages is greatly affected by the incorporation of uranium in the enamel during burial in sediments. It has been shown that uranium content is positively correlated with an increased degree of atomic order in carbonate hydroxyapatite crystals, the latter determined using infrared spectroscopy. Here we present a reference infrared spectral library of tooth enamel from African ungulates, based on the grinding curve method, which serves as baseline to track the diagenetic history of carbonate hydroxyapatite in different species and thus select the best-preserved specimens for dating.
摘要：
牙釉质中碳酸盐羟基磷灰石的电子自旋共振与铀系列测年（ESR/U系列）相结合，是用于从放射性碳测年范围之外的更新世化石中获得年龄测定的主要技术。这些时间信息可以更好地了解古生物学记录的历时变化，特别是关于人属的进化。鉴于古生物学和考古学地区人类牙齿的相对匮乏，ESR/U系列广泛应用于有蹄类动物的牙齿。然而,ESR/U系列年龄的准确性受到埋藏在沉积物中的搪瓷中铀含量的影响。已经表明，铀含量与碳酸盐羟基磷灰石晶体中原子序的增加呈正相关，后者使用红外光谱测定。在这里，我们提供了来自非洲有蹄类动物的牙釉质的参考红外光谱库，基于磨削曲线法，作为基线，以跟踪不同物种中碳酸盐羟基磷灰石的成岩历史，从而选择保存最好的标本进行测年。
