ESR Dating of Pleistocene Hominid Sites

克拉克·豪厄尔博士将与麦克马斯特大学的施瓦茨博士和格伦博士合作，改进ESR测年技术，将其应用于牙釉质，并确定一系列重要考古遗址的年代。ESR测年技术是基于对储存在晶格中的能量的测量，这些能量是环境放射性轰击的结果。储能量可以通过电子自旋共振(ESR)谱来确定。然后根据累积的能量剂量与剂量率的比率确定晶体的年龄，这是环境中放射性元素浓度的函数。这种方法可以应用于大型哺乳动物的牙釉质，因此适用于大多数更新世史前遗址，年龄长达数百万年。该项目包括两个阶段。第一个实验将由一系列实验组成，以提高该技术的准确性和可靠性。在第二项研究中，研究人员将继续对具有人类学意义的遗址的样本进行年代测定。这项研究之所以重要，有两个原因。对于超过40,000年的大多数考古遗址，缺乏可靠和广泛适用的测年技术(这是放射性碳测年的有效时限)。如果ESR能够被确立为一种可行的技术，那么许多考古遗址就可以确定年代，从中获得的信息将大大增加。这项技术也将对地质学家、古生物学家和其他关注过去的科学家有用。其次，豪厄尔、施瓦茨和格伦博士计划考察的具体地点本身就很重要。

In collaboration with Drs. Schwartz and Grun at McMaster University, Dr. Clark Howell will work to improve the ESR dating technique, apply it to tooth enamel, and determine the ages of a series of significant archaeological sites. The ESR dating technique is based on the measurement of energy stored in crystal lattices which result from the bombardment by environmental radioactivity. The amount of stored energy can be determined by electron spin resonance (ESR) spectroscopy. The age of the crystal is then determined from the ratio of the accumulated energy dose to the dose rate, which is a function of the concentration of radioactive elements in the environment. This method can be applied to the tooth enamel of large mammals and is thus applicable to most Pleistocene prehistoric sites for ages up to a few million years. The project includes two stages. The first will consist of a series of experiments to increase the accuracy and reliability of the technique. In the second, the investigators will continue to date samples from anthropologically significant sites. This research is important for two reasons. Reliable and widely applicable dating techniques are lacking for most archaeological sites over 40,000 years in age (this is the effective time limit for radiocarbon dating). If ESR can be established as a workable technique, many archaeological sites could then be dated and the information derived from them would be greatly increased. The technique would also be useful to geologists, paleontologists, and other scientists concerned with the past. Secondly, the specific sites which Drs. Howell, Schwartz, and Grun plan to examine are important in their own right.