Dissertation Research: Source Analysis and Hydration Dating of Post-Formative Period Obsidian Artifacts From the Valley of Oaxaca, Mexico

在密苏里大学人类学教授罗伯特·本费尔博士的指导下，迈克尔·伊兰先生将为他的博士论文收集数据。在1991年的实地考察过程中，Elam先生从位于墨西哥中部瓦哈卡谷的蒙特阿尔班考古遗址以及该地区的其他遗址收集了黑铁矿(火山玻璃)样本。它们涵盖了终端形成时期、古典时期和后古典时期，可以追溯到大约公元1-1520年。这些材料在墨西哥政府的批准下已被送回美国，将接受两种分析。一个亚系列将通过黑铁矿水合作用来确定年代。其次，将通过中子活化分析来确定28种元素的浓度，并通过与已知地质沉积物中的样品进行比较，确定考古标本的来源。有了这些数据，埃兰先生将能够确定黑铁矿材料的交换是如何随着时间的推移而变化的，以及蒙特阿尔班在这一过程中所扮演的角色。黑铁矿为美国中部的许多考古研究提供了一个焦点。在史前，它是一种稀有而极有价值的材料，既因为它很容易剥落成工具，也因为它能产生锋利的刀刃。由于黑岩是火山喷发的产物，因此只在高度局部化的离散地区才能发现。由于不同地区的化学成分不同，分析考古标本并将其与特定来源进行匹配是可能的。因此，有可能确定黑岩是如何在史前社会制度中迁徙的，并获得对其经济和政治组织的洞察。蒙特奥尔班展示了许多其他中美洲中心的特征。它崛起了，作为一个小国家的中心获得了地区主导地位，然后又衰落了。然而，这种转变背后的过程并没有被很好地理解，这项研究将有助于阐明这些过程。这项研究之所以重要，有几个原因。它将提供大量考古学家感兴趣的数据。它将阐明贸易在社会复杂性的出现中所起的作用，并将有助于培养一位有前途的年轻科学家。

Under the direction of Dr. Robert Benfer, Professor of Anthropology at the University of Missouri, Mr. Michael Elam will collect data for his doctoral dissertation. During the course of fieldwork in 1991 Mr. Elam collected obsidian (volcanic glass) samples from the archaeological site of Monte Alban, located in the Valley of Oaxaca in central Mexico as well as from other sites in the region. These cover the Terminal Formative, Classic and Postclassic periods and date from ca. AD 1 - 1520. These materials, which have been returned to the U.S. with Mexican government approval, will be subjected to two kinds of analysis. A subseries will be dated by means of obsidian hydration. Secondly, concentrations of 28 elements will be determined through neutron activation analysis and through comparison with samples from known geological deposits the origin of the archaeological specimens can be pinpointed. With these data, Mr. Elam will be able to determine how exchange in obsidian materials changed over time and the role which Monte Alban played in this process. Obsidian has provided a focus for many archaeological studies in Middle America. Prehistorically, it was a rare and extremely valuable material both because it was easy to flake into tools and because it produced razor sharp cutting edges. Since obsidian results from volcanic eruption, it is found only in discrete highly localized areas. Because chemical composition differs from region to region, it is possible to analyze archaeological specimens and match them to a specific source. Thus, it is possible to determine how obsidian moved through prehistoric social systems and gain insight into both their economic and political organization. Monte Alban exhibits the characteristics of many other Middle American centers. It rose, achieved a regional dominance as the center of a small state, and then declined. The processes which underlie this transformation however are not well understood and this research will help to elucidate them. This research is important for several reasons. It will provide data of interest to a large number of archaeologists. It will shed new light on the role which trade played in the emergence of social complexity and will assist in the training of a promising young scientist.