The Pyramids—Cement or Stone?

Several samples of pyramids from Giza were obtained. The samples were analysed by scanning electron microscopy, electron diffraction by X-rays, powder X-ray diffraction, inductively coupled plasmography, Fourier-transform infrared spectroscopy and other techniques. Some scientists who have recently studied the pyramids have suggested that the pyramids were poured into place, stone by stone. The prevailing theory among Egyptologists is, of course, that the pyramids were built from blocks of natural stone. All of the results obtained during this study directly support the concept that the pyramids are made of limestone and are not cementitious in nature.     

Local amber in a Palaeolithic context in Cantabrian Spain: the case of La Garma A

It is important to determine the geological sources of Palaeolithic ambers in the south of Europe in order to understand the mobility and interchanges of prehistoric societies. Fourier transform infrared (FTIR) spectroscopy analysis carried out on Upper Palaeolithic ambers from La Garma A cave (Cantabria, Northern Spain) allowed us to identify their source area. Their diagnostic features were found to be similar to the amber obtained in the Lower Cretaceous outcrops close to this archaeological site, and to differ clearly from Baltic amber, which has been generally suggested as the amber found in European prehistoric sites. These results show that the origin of the Gravettian amber found in La Garma A is local and, consequently, a hypothetical contact route is not required to be able to account for the presence of this material in the Iberian Palaeolithic context studied here. For the first time it has been demonstrated that the provenance of an archaeological amber in the Iberian Peninsula is local, with both geographical and spectroscopical evidences. Our study also concludes that the archaeological amber of La Garma A possibly belongs to an araucariacean resin that originated from the coniferous forests which grew in the northeast portion of the Iberian Plate c.110-million years ago.     

成都光华村街唐墓出土琥珀的红外分析

我国古代先民很早就意识到琥珀的装饰和药用价值,汉代开始从西域引入琥珀,唐代时琥珀已比较常见。我国古代琥珀多为进口琥珀,琥珀产地分析可以反映中外文化交流情况。国内仅对私人琥珀藏品进行过分析,考古出土琥珀的科技分析尚未见报道。本研究通过红外光谱分析,判定成都光华村街低阶官员唐墓出土红色饰品为琥珀;再与若干产地的琥珀开展红外光谱对比,鉴定其产地为波罗的海地区。琥珀经过丝绸之路到达蜀地并为低阶官员所使用,足见唐代琥珀制品的盛行及当时国际贸易文化交流的盛况。     

Distinguishing between calcites formed by different mechanisms using infrared spectrometry: archaeological applications

Infrared spectrometry is a well-established method for the identification of minerals. Due to its simplicity and the short time required to obtain a result, it can be practiced on-site during excavation using portable infrared spectrometers. However, the identification of a mineral may not be sufficient. For example, a lime plaster floor and a crushed chalk surface have a similar appearance and are composed of the same mineral – calcite. Here we exploit differences in the infrared spectra of geogenic, biogenic and pyrogenic calcites for the identification of each calcite type. The infrared calcite spectrum has three characteristic peaks in the region of 400–4000 cm⁻¹, designated ν₂, ν₃, and ν₄. When a calcite sample is ground, as part of the measurement preparation procedure, some grinding dependent changes will be revealed in the infrared spectrum. With additional grinding, the ν₃ peak narrows and the heights of the ν₂ and ν₄ peaks decrease, when both are normalized to the ν₃ height. By plotting the normalized heights of the ν₂versus the ν₄ of several grindings of the same sample, a characteristic trend line is formed for each calcite type. The trend lines of geogenic calcites have the shallowest slopes and highest ν₄ values when compared to pyrogenic calcites, which can be further divided to ash and plaster/mortar samples. This method can assist in distinguishing between the various calcites, and provide insights into homogeneity and preservation state of the calcitic materials in question.     

Obsidian hydration dating by infrared spectroscopy: method and calibration

Low temperature (90–190 °C) hydrothermal experiments have been conducted on seven obsidians where composition of the glass varies significantly in the concentration of structural water within the unhydrated bulk material. Infrared transmission spectroscopy was used to track the diffusion of molecular water into the glass surface as a function of time and temperature. Long-term (60–360 days) hydration sequences at 90 °C show a t^0.6 time dependence for the mass uptake of molecular water that forms the hydration layer. The structural water concentration of the unhydrated bulk obsidian is highly correlated with the pre-exponential and activation energy and may be used to estimate the Arrhenius constants. In addition, secondary ion mass spectrometry (SIMS) hydrogen profiling of Napa Glass Mountain obsidian hydrated at 90 °C reveals that the early stages of diffusion exhibit a dynamic behavior that includes a fluctuating hydrogen concentration and a changing diffusion coefficient that slows with time.     

新疆小河墓葬出土毛纤维老化状况的研究

利用光学显微镜、扫描电镜对新疆小河墓葬出土的毛纺织品进行形貌观察,并采用红外显微镜对样品进行测试,对出土自不同地层墓葬的样品归类分析讨论。本研究的目的是补充文物数据库;初步讨论了小河墓葬出土毛制品的保存状况;以小河墓地为例,讨论了墓葬位置对毛纤维老化状况的影响。结果显示:新疆小河墓葬出土毛织品的埋葬位置对毛织品的劣化状况有较大影响。劣化形式表现为:纤维横向、纵向的裂痕;红外光谱中酰胺Ⅱ带与酰胺Ⅰ带吸收峰峰高比值的变化;纤维上附着的结晶物推测为雨水或地下水带入的结晶盐。     

基于可见光谱特征提取的敦煌壁画颜料识别方法研究

为了对壁画颜料种类进行无损识别,根据不同的物质对光的吸收特性不同,决定着光谱反射率不同这一特性,提出一种基于可见光谱的颜料识别方法,并对敦煌壁画所用颜料进行了分析。提取可见光谱曲线二阶导数负数部分表征曲线峰值区域的几何轮廓,利用中值金字塔对提取结果进行三层分辨率表征以突出曲线峰值位置信息,归一化三种表征尺度并组合构建特征空间F,以欧氏距离为准则对壁画采样点与颜料库样本进行相似度判别,从而识别出壁画用颜料信息。结果表明,本研究构建的识别方法能够对壁画颜料种类进行无损识别,在壁画数字存档及修复领域具有一定的应用前景。     

Spectrochemical Characterization of Red Pigments Used in Classic Period Maya Funerary Practices

We studied the composition, colour chromaticity and form of application of red pigments in human bone samples from seven Classic period Lowland Maya sites. The samples were analysed by X‐ray diffraction, scanning electron microscopy (SEM) and X‐ray energy‐dispersive spectroscopy (EDS). Colour was measured using conventional colour identification standards (Munsell) and reflectance spectroscopy. Cinnabar and hematite were identified as the pigments used. We conclude that the reflectance method has advantages over conventional visual results, as it provides precise, objective and quantifiable optical data to distinguish the chromaticity, colour saturation and brightness of the pigments.     

Recent analyses of the excavated textile find from Grave 35 HTR73, Kerameikos cemetery,Athens, Greece

The following study presents the results of instrumental analyses performed on the excavated textile find HTR73 from the Kerameikos cemetery in Athens. In Greece, preservation of excavated textiles is rare, mainly due to the unfavourable environmental conditions prevailing. The Kerameikos textile find is from the 5th century BC, and has been preserved in association with copper, which is the most common type of preservation in Greece. Past analyses had indicated the presence of silk fibres, of the Bombyx mori silkworm, the use of which was not common in Classical Greece. In the present study, non-destructive instrumental analytical techniques were applied, namely ESEM and FTIR microspectroscopy, for the purpose of material identification. None of the techniques applied confirmed the presence of silk. However, cellulosic bast and possibly cotton fibres were identified. The presence of cotton is an equally rare phenomenon for the Classical period in Greece.     

A FRESH LOOK AT A LITTLE-KNOWN SOUTHEASTERN COPPER PLATE

Abstract

Chauga (38OC47) is a mound site now under Lake Hartwell at the head of the Savannah River in Oconee County, South Carolina. Excavations in 1958–1959 by the University of Georgia recovered a Mississippian copper plate. Upon comparison to others of its kind, it is clear that this lesser-known plate encompasses some interesting design features, most notably the presence of the only known depiction of a chunkey stone on copper. We have recently created a more accurate representation of its design. The plate appears to portray many similarities to depictions of Birdman dancers: kilted dancers and dancing elders within the “Stack” style. Birdman themes are common in Mississippian iconography. Given the importance that copper plates have for interpreting Mississippian art and belief systems, this updated examination provides useful new information for researchers studying Mississippian iconography.