RUI: Evaluating the Limits and Capabilities of Plasma Chemical Oxidation for Accelerator Mass Spectrometry

RUI：评估加速器质谱等离子体化学氧化的局限性和能力

• 批准号: 1917310
• 负责人: Ruth Ann Armitage
• 金额: $ 12.26万
• 依托单位: Eastern Michigan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1917310&HistoricalAwards=false
• 关键词: RUI; Evaluating; Limits; Capabilities; Plasma

Knowing the age of ancient artifacts helps archaeologists better place human activities into absolute time frames. Radiocarbon dating is one of the most important developments in archaeology from the 20th century, making it possible to directly date materials from the past. However, many artifacts are too small or fragile to survive the standard methods for preparing samples for radiocarbon dating. Dr. Ruth Ann Armitage, of Eastern Michigan University, and her team of collaborating archaeologists and students will evaluate the use of plasma chemical oxidation (PCO) for preparing samples of small, fragmentary or fragile artifacts for radiocarbon dating by accelerator mass spectrometry (AMS). The focus of the project is dating endangered rock art, burned bone, and fragments shed from fragile textiles that would otherwise be difficult or impossible to radiocarbon date directly. PCO has been used for decades as a way to extract organic carbon from inorganic carbon matrices to date rock paintings. It is also a way to date fragile organic materials without destroying them, allowing for repeated dating of the same sample. However, much remains to be learned about the capabilities and limitations of the PCO technique. Validation of the PCO method is critical to applying it in a meaningful way to answer questions about the age of artifacts that might otherwise be overlooked. The Armitage group has a long track record of collaborative work between chemists and archaeologists to better understand past human society and behavior through radiocarbon dating and chemical analysis of artifacts. This project will develop a method for handling, processing and radiocarbon dating archaeological samples that could not be dated otherwise, adding to what is known about people and their activities in the past. The award supports a diverse group of scientists and students at a predominantly undergraduate institution (PUI) doing novel, anthropologically-relevant archaeology research in collaboration with archaeologists.Dr. Armitage and her team seek to demonstrate the accuracy, precision and minimum sample size that can be AMS dated with PCO sample preparation through comparative studies of rock painting samples, calcined bones, and textile fragments. Their work will aid in understanding the effects of chemical pretreatments on samples dated in this way, as well as improving the method so that it can become more widely applicable. The proposed project will investigate the fundamental limitations of the PCO method in order to optimize its use for otherwise difficult to date archaeological materials. The project examines minimally-destructive and rapid methods for reliably dating these types of samples with AMS radiocarbon analysis. Successful completion of the proposal's objectives will improve the ability to date archeological materials. The team seeks to validate PCO as a sample preparation method for AMS radiocarbon analysis through comparative measurements and chemical analysis. The project results will be disseminated through a conference symposium, workshop, and book to disseminate the results of the project to a diverse audience of anthropological archaeologists and physical scientists.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

了解古代文物的年龄有助于考古学家更好地将人类活动置于绝对的时间框架中。放射性碳测年是20世纪世纪以来考古学最重要的发展之一，使直接测定过去材料的年代成为可能。然而，许多人工制品太小或太脆弱，无法通过标准的放射性碳测年样品制备方法保存下来。东密歇根大学的Ruth Ann Armitage博士和她的考古学家和学生合作团队将评估等离子体化学氧化（PCO）用于制备小型，碎片或易碎文物的样品，以通过加速器质谱法（AMS）进行放射性碳测年。该项目的重点是测定濒危岩石艺术，烧焦的骨头和从脆弱的纺织品上脱落的碎片的年代，否则很难或不可能直接进行放射性碳年代测定。PCO作为一种从无机碳基质中提取有机碳的方法已经使用了几十年，直到岩画的日期。这也是一种在不破坏脆弱有机材料的情况下测定其年代的方法，允许对同一样品进行重复测定。然而，关于PCO技术的能力和局限性还有很多东西有待了解。PCO方法的验证对于以有意义的方式应用它来回答可能被忽视的文物年龄问题至关重要。阿米蒂奇小组在化学家和考古学家之间有着长期的合作记录，通过放射性碳测年和文物的化学分析更好地了解过去的人类社会和行为。该项目将开发一种处理、加工和放射性碳测年考古样品的方法，这些样品无法以其他方式测年，从而增加了对过去人类及其活动的了解。Armitage博士和她的团队通过对岩画样品、煅烧骨和纺织品碎片的比较研究，试图证明使用PCO样品制备AMS测年的准确性、精确度和最小样品量。他们的工作将有助于了解化学预处理对以这种方式测定年代的样品的影响，并改进该方法，使其能够更广泛地应用。拟议的项目将调查PCO方法的基本局限性，以优化其在其他难以确定考古材料日期的情况下的使用。该项目审查了利用AMS放射性碳分析对这些类型的样品进行可靠测年的最小破坏性和快速方法。成功完成该提案的目标将提高考古材料的日期能力。该团队试图通过比较测量和化学分析来验证PCO作为AMS放射性碳分析的样品制备方法。该项目的成果将通过一个会议专题讨论会，研讨会和书籍传播的项目成果，以传播给不同的观众的人类学考古学家和物理学家。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。