Dating of Early Hominid Sites by the Racemization and Accelerator Mass Spectrometry of Protein Amino Acids in Ostrich Eggshells

通过鸵鸟蛋壳中蛋白质氨基酸的外消旋化和加速器质谱法测定早期原始人类遗址

• 批准号: 8805555
• 负责人: Gifford Miller
• 金额: $ 12.07万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1990-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8805555&HistoricalAwards=false
• 关键词: Dating; Early; Hominid; Sites; Racemization

The eggshells of the African Ostrich (Struthio camelus) are frequently found in association with cultural remains in sites throughout Africa, the Near East and Asia. Proteinaceous material involved in secretion of the calcite matrix of the eggshells is retained with almost no loss over time spans in excess of 100,000 years, despite nearly complete hydrolysis into the constituent amino acids. Laboratory simulation of extreme- leaching environments confirms that effectively no leaching of amino acids from the eggshells occurs. Ostrich eggshells thus offer the closest approximation to a perfect closed system of any material yet studied. The method has potential to provide chronological control for the critical period in hominid development beyond the range of radiocarbon dating back to approximately 200,000 years or more. The PI will evaluate the isoleucine epimerization reaction in ostrich eggshells by measuring D/L ratios in eggshell from stratified sites and in independently-dated material, as well as in a series of elevated- temperature experiments, and will use these data to refine a computer-simulation of non-linear epimerization kinetics. The construction of a reliable model to convert D/L ratios into absolute age, and the development of a rapid procedure for the isolation of milligram quantities of amino acids from carbonate fossils will provide significant improvements in the dating of Old World hominid sites.

非洲鸵鸟（Struthio camelus）的蛋壳 常与遗址中的文化遗迹联系在一起 在整个非洲、近东和亚洲。 蛋白质 参与分泌方解石基质的物质， 蛋壳被保留下来，几乎没有随着时间的推移而损失， 超过10万年，尽管几乎完全水解成 氨基酸的组成。 实验室模拟极端- 沥滤环境证实， 蛋壳中的氨基酸。 鸵鸟蛋壳因此 提供了最接近完美的封闭系统的任何 材料还在研究中。 该方法具有提供 原始人类关键期的年代控制 放射性碳的范围之外的发展可以追溯到 大约20万年或更久。 PI将评估 鸵鸟蛋壳中异亮氨酸差向异构化反应 测量蛋壳中的D/L比， 在一系列的高层次的材料中， 温度实验，并将使用这些数据来完善一个 非线性差向异构动力学的计算机模拟。 的 建立一个可靠的模型，将D/L比率转换为 绝对年龄，以及快速程序的开发， 从碳酸盐中分离毫克量的氨基酸 化石将提供重大改进， 旧大陆原始人遗址。