Technology of Medieval Mortars: An Investigation into the Use of Organic Additives

This work proposes a multi‐analytical approach to determine the additives in historical mortars, the use of which is widely described in bibliographical sources, but has rarely been reported in the literature. A protocol to thoroughly analyse mortars was created (optical microscopy, X‐ray diffraction, infrared spectroscopy, thermal analyses and gas chromatography – mass spectrometry). These techniques, which had already been carried out on samples from various sites from the Roman to the modern era, determined that additives had only been used in the mortars from the internal masonry at our sampling site: the medieval military shipyard of Amalfi (Italy). The investigations yielded information on the production technology, and FT–IR and GC–MS revealed a saccharide material‐based additive in the mortars, of plant origin. The FT–IR spectra suggested the presence of a natural gum, which has been used since ancient times to strengthen the cohesion properties of mortars and their resistance to tensile stress.     

Evidence for Complexities in the RHX Dating Method

The rehydroxylation (RHX) dating method applicable to virtually all baked clay fragments still requires testing and new developments. Here, we have obtained new weighing measurements from Syrian medieval ceramic fragments. In particular, they allow us to illustrate the scatter in RHX behaviour that may exist between different potsherds of the same age and found at the same archaeological site, thus having experienced the same effective lifetime temperature, and even between samples collected from the same artefact. Thanks to a so‐called time‐span analysis, we also report on some complexities in data sets previously obtained by Wilson et al. (2009, 2012, 2014).     

文物中蜡类材料的热裂解-气相色谱/质谱识别

为识别文物中蜡质原材料,以及文物保护修复工作中常用蜡类材料的类别,研究通过在线甲基化热裂解-气相色谱/质谱联用技术对蜂蜡、棕榈蜡、小烛树蜡、地蜡、石蜡等蜡类材料进行分析检测。研究发现:蜂蜡的主要裂解产物为直链烷烃、直链脂肪酸、直链醇、含羟基脂肪酸;棕榈蜡为直链醇、直链脂肪酸、脂肪酸衍生物;小烛树蜡为直链烷烃、直链脂肪酸、直链醇、羽扇豆醇及其衍生物、计曼尼醇及其衍生物、脂肪酸衍生物;地蜡、石蜡等矿物蜡的主要裂解产物为直链烷烃。不同蜡中裂解产物的种类及其相对含量分布规律均有所区别,因此通过在线甲基化热裂解-气相色谱/质谱联用技术可以实现不同种类蜡的区分。通过所建立的方法及总结的数据,研究推断故宫旧藏清代紫檀木边座嵌玉人鸂鶒木山水图插屏中镶嵌珐琅构件所用棕色蜡为蜂蜡,所用白色蜡为矿物蜡及少量蜂蜡。本研究所建立方法易于推广,适用于文物中蜡类材料的准确、快速识别。     

热脱附-气质联用法无损测定函套中挥发性物质的探索研究

热脱附-气质联用法作为一种无损分析技术,可以用于测定函套中的挥发性物质。为此,用Tenax-TA吸附管对10种目标化合物进行吸附,在优化的色谱条件下,苯、甲苯、乙酸正丁酯、乙苯、间/对二甲苯、苯乙烯、邻二甲苯、正十一烷和糠醛等组分相关性良好。对实际样品进行测定,可以实现函套等装具中挥发性有害物质的分离分析。研究结果对纸质文献的保护有参考作用。     

Identifying biomolecular origins of solid organic residues preserved in Iron Age Pottery using DTMS and MVA

The chemical characterisation of solid organic residues found in ceramic vessels, can provide archaeologists with valuable information about ancient diets. Although several selective analytical techniques have been applied to the analysis of specific classes of compounds, such as extractable lipids, waxes, terpenoids and protein fragments, a non-selective analytical technique is required to characterise and categorise complete solid organic residues. In this study, Direct Temperature-resolved Mass Spectrometry (DTMS) is used for the characterisation of 34 solid residues situated on vessels recovered from an indigenous settlement from the Roman period at Uitgeest – Groot Dorregeest (The Netherlands). Sample preparation is limited to grinding very small samples (5–10 μg) and suspending them in water. DTMS analysis of aliquots (1–2 μL) of this suspension gave information about a broad range of organic compounds, such as lipids, polynuclear aromatic hydrocarbons, markers for residual proteins and polysaccharides, and for newly formed complex condensed polymers. Multivariate analysis of the DTMS spectra identified five different chemotypes: groups of residues with comparable chemical characteristics. The biomolecular origin of each of these chemotypes is identified by comparison with experimentally charred reference materials. The chemotypes A₁ and A₂ consist of charred residues identified as starch-rich foods (mixed with animal or plant products), chemotype C consists of protein-rich charred animal products without starch, chemotype B contains smoke condensates from wood fires, and chemotype D consists of special protein-rich and lipid-free foods or non-food products.     

A radiographic study of the extent of variation in cortical bone thickness in soay sheep

In order to assess the effect of nutrition on bone mass, radiographs of metopodia from skeletal collections of Soay sheep (Ovis aries) were taken of animals subject to seasonal stress (from the island of Hirta, Hebrides) and those living in good nutritional conditions (from the Institute of Animal Physiology, Babraham, Cambridge). A third set of radiographs was taken at 3 month intervals over a single year on living Soay sheep kept under good conditions at the Rowett Research Institute, Aberdeen.Measurements were taken on the radiographs of length, minimum shaft width (SW) and medullary cavity width (MCW), while combined cortical thickness (CCT) was calculated. The ewes from Hirta had significantly lower values for CCT than those from Babraham, whereas the rams showed no significant reduction in CCT. Since no seasonal variation in CCT was detected in the well nourished Rowett ewes, this indicates a differential effect of poor environmental conditions on bone metabolism in ewes. It is proposed here that this may be related to the additional stress imposed by gestation and lactation on female animals living under conditions of seasonally restricted food supply.     

The multivariate statistical analysis and XRD analysis of pottery at Xigongqiao site

A series of pottery samples excavated from the Xigongqiao site in Tengzhou city of Shandong province was determined using inductively coupled plasma atomic emission spectrometry. Together with excavation data and archaeological analysis, the potential for provenance and technology of unearthed ancient pottery was studied by using multivariate statistical analysis and X-ray powder diffraction pattern (XRD) analysis. In order to characterize and classify these earthenware samples, the major and minor/trace element concentrations were studied with both cluster analysis and principal component analysis. The results showed that there were three different groups in cluster analysis dendrogram in good correlation with their colors. This indicated that the potteries were made from clays of different composition. These results were in agreement with the results of principal component analysis. XRD analysis further assessed the validity of multivariate statistical analysis.     

The Political,Social and Scientific Contexts of Archaeological Investigations of Mass Graves in Spain

The recovery of historic memory of the Spanish Civil War is a multilayered initiative to escape both the romanticism of the Franco era, in which only the glory of the victors was celebrated while their past atrocities were ignored, and the cautiousness of the post-Franco democracy, for which forced amnesia of the Civil War was considered a sacrifice for the greater good. In the past five years the efforts to recover historic memory have gained empirical footing by employing archaeological methods to locate, enumerate and identify the victims of extrajudicial executions. The ultimate goals of such work include the production of a more accurate historical statement of past events, the repatriation of missing persons to their families, and the documentation of physical evidence that may allow families to seek civil restitutions. While the scientific methodology is fairly straightforward, the process is nonetheless inherently political in that various government bodies can and do impede recovery efforts. This paper contextualizes the current political and social climate of human rights investigations in Spain by illustrating some of the recent recovery efforts in Catalonia and Andalucia.     

Comparing the survival of osteocalcin and mtDNA in archaeological bone from four European sites

The small mineral-binding bone protein, osteocalcin, has been applied in a number of studies on ancient bone due to predictions of its long-term stability. However, the intact protein has not been shown to survive in ancient bone devoid of DNA, which is a much more phylogenetically informative biomolecule. In this investigation, the survival of osteocalcin is directly compared to the amplification of mtDNA in a set of 34 archaeological samples from four sites throughout Europe. We also present unpublished osteocalcin sequences of seven mammalian species in addition to the 19 published sequences to highlight phylogenetic limitations of this protein. The results indicate that the intact osteocalcin molecule survives less in archaeological samples than mtDNA and is more subject to the temperature of the archaeological site. Amino acid analyses show the persistence of the dominant protein collagen in samples that failed both osteocalcin and mtDNA analyses. The implications these findings present for biomolecular species identification in archaeological and palaeontological material are that, although proteins do survive beyond ancient DNA, osteocalcin does not appear to be the most ideal target.     

Characterization of dyestuffs in ancient textiles from Xinjiang

Extraordinarily well-preserved organic remains from mortuary and settlement sites, including mummified bodies, are scattered along the outer, oasis-laden rim of the Tarim Basin in Xinjiang Province, China, ranging in date from about 1400 BC to the late first millennium BC. Specimens of textile finds from Chärchän, dated at about 1000 BC were selected for dye analysis using newly developed protocols employing high performance liquid chromatography with spectrophotometric and mass spectrometric detection. A single blue (from an indigo plant), a red (from madder, a Rubia species) and two yellow dyes were detected, although the exact plant source for none of them could be identified with certainty. This research offers new insights in the interpretation of textile finds from prehistoric Xinjiang, and more generally, of early Bronze Age Eurasia.