Doctoral Dissertation Research: Archaeomagnetism in the U.S. Southeast

在Michael Schiffer博士的指导下，Stacey Lengyel女士将收集和分析完成博士论文所需的数据。这个项目旨在为在美国东南部工作的考古学家提供一种新的方法来确定他们的考古发现的年代。通过这个项目将建立的技术被称为“考古磁年代测定法”，它使用保存下来的地球磁北极位置变化的记录来确定被烧毁的、富含粘土的考古特征的年代，比如烹饪炉、陶器窑或被烧毁建筑物的墙壁和地板。在过去的30年里，这项技术已经成功地应用于美国西南部、欧洲和日本的遗址测年，该项目旨在使这项技术在美国东南部也成为可能。考古地磁测年取决于以下事实：1)地球的磁北极绕着地理自转轴以几十年为单位漂移；2)燃烧过的、富含粘土的考古特征，如烹饪炉，准确地记录了磁北极在最后一次燃烧时的位置（例如，最后一次使用烹饪炉）。当从一个给定地区的年代确定的考古特征（例如，一个灶台也产生了放射性碳年代）收集到足够的考古磁方向数据时，就可以以区域参考曲线的形式构建一个考古磁变化的主记录。然而，由于磁场的局部变化，每个参考曲线仅在2000公里宽的区域内有效。因此，本项目的目标是建立东南地区的参考曲线，从而使该地区的考古磁定年成为可能。这个项目很重要，因为它将为在美国东南部工作的考古学家提供一种建立、验证和完善时间框架的方法，这些框架是解决有关过去文化的基本人类学问题所必需的。通过为研究人员提供对考古数据更严格的时间控制，通过该项目开发的区域考古磁曲线将使考古学家能够跨越时间和空间，在各种尺度上检查社会文化过程的作用，范围从子遗址水平（例如，结构之间）到泛大陆水平（例如，田纳西河谷和凤凰盆地之间）。简而言之，东南考古磁曲线的完成将为研究人员提供一种独立的测年方法，它不仅补充了现有的计时工具，而且，当与这些工具结合使用时，将允许对史前文化过程进行更短暂的精细处理。该奖项还将有助于培养一名有前途的青年科学家。

Under the direction of Dr. Michael Schiffer, Ms. Stacey Lengyel will collect and analyze data necessary for the completion of her doctoral dissertation. This project seeks to provide archaeologists working in the U.S. Southeast with a new way to date their archaeological findings. The technique that will be established through this project is called archaeomagnetic dating, and it uses preserved records of changes in the position of the earth's magnetic north pole to date burned, clay-rich archaeological features such as cooking hearths, pottery kilns, or the walls and floors of burned structures. This technique has been used successfully over the past 30 years to date sites throughout the U.S. Southwest, Europe and Japan, and this project aims to make the dating technique possible in the U.S. Southeast as well.Archaeomagnetic dating depends on 1) the fact that the earth's magnetic north pole drifts around the geographic rotation axis on the order of decades, and 2) the fact that burned, clay-rich archaeological features, such as cooking hearths, accurately record the position of the magnetic north pole at the time they were last fired (e.g., the last time a cooking hearth was used). When enough archaeomagnetic directional data are collected from well-dated archaeological features (e.g., a cooking hearth that also yielded a radiocarbon date) in a given region, a master record of archaeomagnetic change can be constructed in the form of a regional reference curve. However, due to local variations in the magnetic field, each reference curve is only valid over a 2000-km wide region. Therefore, the goal of this project is to construct the reference curve for the Southeast, thus making archaeomagnetic dating possible in this region.This project is important because it will provide archaeologists working in the U.S. Southeast with a means of establishing, verifying, and refining the temporal frameworks needed to address basic anthropological questions about past cultures. By furnishing researchers with tighter temporal control over the archaeological data, the regional archaeomagnetic curve developed through this project will allow archaeologists to examine the play of sociocultural processes across time and space and at a variety of scales, ranging from the sub-site level (e.g., between structures) to the pan-continent level (e.g., between the Tennessee River Valley and the Phoenix Basin). In short, the completion of the Southeast archaeomagnetic curve will provide researchers with an independent dating method that not only complements existing chronometric tools, but, when used in conjunction with those tools will allow for more temporally refined treatments of prehistoric cultural processes. This award will also assist in training a promising young scientist.