The Utility of Shell Temper for Ceramic Analysis

密西西比州立大学的埃文·皮科克博士和布伦达·柯克兰博士以及密苏里大学的维吉尼·伦森博士将进行研究，以测试一种追踪过去人口流动和贸易网络的新方法。了解古代人口趋势和经济联系是解开任何特定地区历史的关键。在过去，定居点之间的联系有多大？商品是在哪里生产的，它们是如何从市场流向消费者的？特定的定居点之所以声名鹊起，是因为有能力控制货物流动吗？古代人口流动与历史上已知的美洲原住民或其他后裔群体的分布有什么关系？随着用于化学分析文物的新仪器的开发，人们对这些话题的兴趣也在增长。例如，考古学家使用各种方法对古代陶器碎片进行化学分析，并试图将它们与现场采集的粘土样本进行匹配，以确定陶器粘土最初是在哪里获得的。虽然这种方法产生了一些令人兴奋的结果，但它因许多因素而变得复杂。在一小块区域内可能会出现许多不同的粘土层，一个粘土层可能在很大的面积上是化学均一的，或者陶工在制作陶器时可能会将不同的粘土混合在一起。如果要更充分地实现陶瓷来源解决人类学和历史重要性问题的承诺，解决这个问题是必要的。这项研究将有助于了解美国原住民的史前历史，并有助于让美国人了解这个国家过去的一个重要部分。化学采购陶土的另一种选择是分析陶工与粘土混合的其他材料；这种额外的材料被称为“回火”。大约从公元1000年开始，碾碎的淡水贻贝壳在北美东部的一大片土地上被用作陶器回火。随着淡水贻贝的成长，它们会将栖息的溪水的化学特征构建到贝壳中。因此，来自不同排水系统的贝壳在化学上是不同的。通过将作为食物垃圾丢弃的贝壳与不同地点陶器的脾气进行化学比较，考古学家理论上可以准确地确定陶器制造的确切溪流，甚至溪段。皮科克博士和他的同事们将通过分析从密西西比州亚祖盆地的几处遗址中发现的贝壳和贝壳回火的陶器来测试这种新方法。亚祖盆地是一片广阔的地貌，被许多不同的溪流排干，这些溪流将中大陆与墨西哥湾连接起来，并提供了现成的旅行路线，几个世纪前可能就沿着这些路线进行了陶罐或其他文物的交易。分析将使用电感耦合等离子体质谱仪进行，只需少量的贝壳或贝壳回火即可。还将探索使用个别元素，如锶的同位素来改进方法。作为一项特殊的考古测试案例，我们将分析之前被鉴定为“异国情调”的陶器，以及乔治湖遗址遗弃的贝壳。乔治湖遗址是密西西比州亚祖县一个有大约1000年历史的大型聚落。如果成功，这种方法应该适用于世界上任何生产贝壳回火陶器的地方。

Dr. Evan Peacock and Dr. Brenda Kirkland, Mississippi State University, along with Dr. Virginie Renson, University of Missouri, will undertake research to test a new method for tracing past human population movements and trade networks. Understanding ancient demographic trends and economic links is key for unraveling the history of any particular area. How interconnected were settlements in the past? Where were goods produced, and how did they flow from market to consumer? Did particular settlements gain prominence due to an ability to control the flow of goods? How do ancient population movements relate to the historically known distribution of Native American or other descendant groups? Interest in such topics has grown as new instruments for chemically analyzing artifacts have been developed. For example, archaeologists chemically analyze ancient pottery sherds using a variety of methods and try to match them to clay samples taken in the field, to determine where the pottery clay was originally obtained. While this approach has produced some exciting results, it is complicated by a number of factors. Many different clay beds can occur over a small area, a clay bed can be chemically homogenous over a very large area, or potters may have mixed different clays together when making pottery. Addressing this problem is necessary if the promise of ceramic sourcing for addressing questions of anthropological and historical import is to be more fully realized. The research will contribute to understanding the prehistory of United States Native Americans and serve to inform Americans on an important part of the country's past.An alternative to chemically sourcing pottery clay is to analyze other materials mixed with the clay by potters; such extra materials are called "temper." Beginning about AD 1000, crushed freshwater mussel shell was used as pottery temper over a huge expanse of eastern North America. As freshwater mussels grow, they build the chemical signature of the stream waters they inhabit into their shells. Shells from different drainages therefore are chemically distinct. By chemically comparing shells discarded as food waste with temper from pottery at different sites, archaeologists theoretically can pinpoint the precise stream, or even stream segment, where the pottery was made. Dr. Peacock and his colleagues will test this new method by analyzing shells and shell-tempered pottery recovered from several sites in the Yazoo Basin of Mississippi, a vast landscape drained by many different streams that connected the mid-continent with the Gulf of Mexico and provided ready travel routes along which pots or other artifacts may have been traded centuries ago. Analysis will be done using an Inductively Coupled Plasma-Mass Spectrometer, for which only small amounts of shell or shell temper are needed. The use of individual elements, such as isotopes of Strontium, to refine the method, also will be explored. As a particular archaeological test case, pottery previously identified as stylistically "exotic" and discarded shells from the Lake George site, a massive, ca. 1,000 year-old settlement in Yazoo County, Mississippi, will be analyzed. If successful, this method should be applicable to any place in the world where shell-tempered pottery was produced.