Dissertation Research: Obsidian Hydration Dating: Testing the Underlying Assumptions of Temperature Measurements in Archaeological Sites

在David Meltzer博士的指导下，Rosanna Ridings女士将为她的博士论文收集数据。她的工作目标是提高黑曜石水化年代测定的准确性，为了实现这一目标，她将分析从新墨西哥州北部里约热内卢Grande附近的Pot Creek Pueblo遗址精心挖掘和控制的黑曜石工具样本。黑曜石（火山玻璃）因为容易剥落和拥有锋利的边缘，被广泛用于制造石器的珍贵材料。由于刚剥落的表面会形成可测量的水化皮，而且皮的深度与时间有关，许多科学家试图用皮的厚度来确定工具制造的年代。然而，众所周知，外壳的发育与温度有关，这第二个自变量也必须考虑在内。由于气候和温度随时间而波动，考古学家还没有确定应该如何进行温度测量以及随后的分析应该如何进行。里丁斯女士的工作将有助于解决这个问题。首先，她将对目前用于测量和估计考古遗址有效水化温度的三种方法进行系统的比较。然后她将比较结果。其次，将利用树木年轮宽度和同位素组成来确定过去850年波特克里克普韦布洛的气候。西南地区是独一无二的，因为树木年轮数据是可用的。最后，她将模拟人工制品的沉积历史，以整合有效水化温度随时间的变化。然后，她将使用这些数据分析黑曜石文物本身。考虑到过去在现场的工作，这些材料的年代可以独立确定。这项研究之所以重要，有几个原因。它将有助于发展和完善一种重要的考古年代测定技术，这种技术在世界许多地方都得到了应用。它还将协助培训一位极有前途的年轻科学家。

Under the direction of Dr. David Meltzer, Ms Rosanna Ridings will collect data for her doctoral dissertation. The goal of her work is to increase the accuracy of obsidian hydration dating and to accomplish this she will analyze carefully excavated and well controlled samples of obsidian tools from the site of Pot Creek Pueblo which is located near the northern Rio Grande, New Mexico. Obsidian (volcanic glass) because it is easy to flake and holds a sharp edge was a widely prized material used to manufacture stone tools. Because freshly flaked surfaces develop a measurable hydration rind and because the depth of the rind is time dependent, many scientists have attempted to use rind thickness to determine age of tool manufacture. However, it is also known that rind development is temperature dependent and that this second independent variable must also be taken into account. Since climate and therefore temperature fluctuate over time, archaeometrists have not determined how temperature measurements should be taken and how subsequent analysis should proceed. Ms Ridings' work will help to resolve this issue. First, she will conduct a systematic comparison of the three methods currently used for measuring and estimating effective hydration temperatures in archaeological sites. She will then compare the results. Secondly, climate of Pot Creek Pueblo will be determined over the last 850 years using both tree ring width and isotopic composition. The Southwest in unique because of the tree ring data which is available. Finally, she will model the depositional history of the artifacts to integrate the change in effective hydration temperature over time. She will then use these data to analyze the obsidian artifacts themselves. Given past work at the site, the age of these materials can be independently determined. This research is important for several reasons. It will help to develop and refine an important archaeological dating technique which is employed in many parts of the world. It will also assist in the training of an extremely promising young scientist.