Rehydroxylation [RHX]: Towards a universal method for pottery dating

再羟基化 [RHX]：走向陶器测年的通用方法

• 批准号: NE/I014675/1
• 负责人: Christopher Hall
• 金额: $ 34.85万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI014675%2F1
• 关键词: Rehydroxylation; RHX; Towards; universal; method

A research ream from the UoM and UoE has recently proposed a radically new method of dating archaeological ceramics based on rehydroxylation kinetics. This rehydroxylation reaction underlies (and causes) the well known moisture expansion of brick masonry and tile structures and the commonly observed crazing in glazed ceramics. In a paper published by the Royal Society we presented proof of concept of this new method and compelling evidence that the age of ceramic samples up to 2000 y old can be estimated accurately from measurements of the slow progressive mass gain associated with the chemical recombination of water with the fired clay material. We call this method rehydroxylation [RHX] dating. Pottery is an increasingly common find on archaeological sites from the last 10 000 y onwards and many site chronologies depend upon them. However their dating still relies to a large extent on analysing stylistic changes. Radiocarbon dating cannot be applied unless carbon containing inclusions or residues are present and thermoluminescence can be prohibitively complex. Hence, a new method for dating such material is extremely significant. The basis of RHX is that all fired clay ceramics start to gain weight (and expand) as soon as they are removed from the kiln. The weight gain is caused by the chemical combination of atmospheric moisture with the ceramic (rehydroxylation) and continues over the lifetime of the ceramic. Central to RHX is a new time1/4 law, discovered by the applicants, that defines precisely the rate at which fired clay ceramics gain weight over time. This effectively provides the material with an ''internal clock''. A ceramic can be returned to its 'as fired' state by reheating to remove the chemically combined water. The older the material, the greater the mass of water removed by reheating. Following reheating the chemical reaction between ceramic and atmospheric moisture begins again. By monitoring the mass gain over several days we can determine the rate at which that particular material gains mass, and from this we calculate the time that it would take to replace the water removed by reheating. This gives the age of the sample. By the end of the project we aim to have demonstrated that RHX is a well-founded archaeological dating method, suitable for routine use. Its applicability to diverse archaeological scenarios will have been established. The overall objectives of the work are to validate RHX, to quantify the errors and uncertainties, to build end-user confidence and to optimise the methodology to increase sample throughput and hence reduce the cost per sample. The overwhelming response from the international archaeological community strongly indicates that RHX could be of enormous benefit. The method has been described as being 'of profound importance to archaeology' and as having 'the enormous potential to revolutionise the field of dating in archaeology.' Our method therefore has the potential to become as important for dating ceramics as radiocarbon dating is for organic materials. The rehydroxylation process is a remarkable example of a long-term power law kinetic process which apparently extends over millennial timescales. It appears to be a general process in fired- clay ceramics. Better understanding of this will contribute new knowledge to the field of super-slow solid-state reactions and transport processes. The work has wider application to earth sciences in the context of rock weathering and geomorphology. There is some very sparse evidence that soil weathering reactions follow the same rate law that we exploit for dating. The realisation that these processes have a general kinetic framework may have powerful general implications. The potential for the wider application of the work is supported by the paper in which we published our initial dating results being cited in a paper on percolative theories in disordered high temperature superconductors.

最近，来自UoM和UoE的一项研究提出了一种基于再羟基化动力学的考古陶瓷断代的全新方法。这种再羟基化反应是众所周知的砖石结构和瓷砖结构的湿膨胀以及釉面陶瓷中常见的裂纹的基础（并导致）。在皇家学会发表的一篇论文中，我们提出了这种新方法的概念证明和令人信服的证据，即可以通过测量与水与烧制粘土材料的化学重组相关的缓慢渐进的质量增加来准确估计陶瓷样品的年龄，直到2000年。我们称这种方法为再羟基化[RHX]测年。陶器是一个越来越常见的发现考古遗址从过去的10000年起，许多网站年表依赖于他们。然而，他们的约会仍然在很大程度上依赖于分析风格的变化。放射性碳测年法不能应用，除非存在含碳的包裹体或残留物，并且热释光可能非常复杂。因此，一种新的方法来测定这种物质的年龄是非常重要的。RHX的基础是，所有烧制的粘土陶瓷一旦从窑中取出就开始增加重量（并膨胀）。增重是由大气水分与陶瓷的化学结合（再羟基化）引起的，并在陶瓷的使用寿命内持续。RHX的核心是由申请人发现的新的时间1/4定律，其精确地定义了烧制的粘土陶瓷随时间增加重量的速率。这有效地为材料提供了“内部时钟”。陶瓷可以通过重新加热以去除化学结合的水而返回到其“烧制”状态。材料越老，通过再加热除去的水的质量越大。再次加热后，陶瓷和大气水分之间的化学反应再次开始。通过监测几天内的质量增加，我们可以确定特定材料增加质量的速率，并由此计算出重新加热所需的时间。这是样品的年龄。在项目结束时，我们的目标是证明RHX是一种有充分依据的考古定年方法，适合日常使用。它对各种考古情景的适用性将得到确立。这项工作的总体目标是验证RHX，量化误差和不确定性，建立最终用户的信心，并优化方法，以增加样品吞吐量，从而降低每个样品的成本。来自国际考古界的压倒性反应强烈表明，RHX可能会带来巨大的好处。该方法被描述为“对考古学具有深远的重要性”，并具有“革命性的考古学测年领域的巨大潜力”。“因此，我们的方法有可能成为陶瓷测年的重要性，就像放射性碳测年对有机材料一样。再羟基化过程是长期幂律动力学过程的一个显著例子，该过程显然延续了千年的时间尺度。这似乎是粘土陶瓷烧制的一个普遍过程.更好地理解这一点将有助于新的知识领域的超慢固态反应和输运过程。这项工作在岩石风化和地貌学方面对地球科学有更广泛的应用。有一些非常稀少的证据表明，土壤风化反应遵循我们用来测年的速率定律。认识到这些过程有一个一般的动力学框架可能具有强大的一般意义。这项工作的更广泛应用的潜力得到了我们发表的初步测年结果的论文的支持，该论文被引用在一篇关于无序高温超导体中的衰变理论的论文中。

项目成果

The mechanics of moisture-expansion cracking in fired-clay ceramics

粘土陶瓷吸湿膨胀开裂机理

• DOI: 10.1088/0022-3727/46/9/092003
• 发表时间: 2013
• 期刊: Applied Physics
• 作者: Hamilton A

Rehydroxylation (RHX) dating of archaeological pottery

• DOI: 10.1098/rspa.2012.0109
• 发表时间: 2012-11-08
• 期刊: PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
• 影响因子: 3.5
• 作者: Wilson, Moira A.;Hamilton, Andrea;Hall, Christopher
• 通讯作者: Hall, Christopher