Sediments exposed to high temperatures: reconstructing pyrotechnological processes in Late Bronze and Iron Age Strata at Tel Dor (Israel)

Many of the sediments analysed from Tel Dor (Israel) show structural alterations indicating that they were exposed to high temperatures. This observation is consistent with the abundant evidence for use of pyrotechnology from the earliest exposed Middle Bronze Age strata through the Roman period. Such structurally altered sediments may well represent one of the more widespread and durable records of pyrotechnology, and as such could be invaluable for reconstructing past human activities. The specific aims of this research are therefore to develop the means for identifying local sediments that were altered by different pyrotechnological activities and to elucidate the varying circumstances whereby sediments were exposed to high temperatures in a Late Bronze and Iron Age 1 section.     

Changes in the body,glaze and enamel compositions of early Meissen porcelain, 1723–c.1740

The evolution of early Meissen body, glaze and colorant compositions is examined using X-ray fluorescence spectroscopy (XRF) measurements on three artefacts that can be accurately dated to the period 1723–c.1740. The results are interpreted based on recipes recorded in the earliest documents of the Meissen archives. The pure Aue kaolinite contains low levels of Ti and can be distinguished from secondary clays, for example, clay from Colditz. The excess Ti in the glaze versus the body reported earlier and confirmed by the present authors is explained by the exclusive use of Colditz clay for the glaze, as described in the recipes before 1730, providing a terminus ante quem for Meissen porcelain exhibiting this particular asymmetry. After 1730, the presence of elevated Ti in the body could serve as a marker for the experimental admixture of clays to Aue kaolinite to alter its properties. Based on the detection of As, Ba and Bi, it is suggested that smalt from Erzgebirge was the colorant for blue enamels until at least 1725.     

The transport amphorae of Gela: a multidisciplinary study on provenance and technological aspects

Mineralogical, petrographic and chemical analyses were performed on thirty-eight samples of transport amphorae found at Gela, an important Greek colony on the southern coast of Sicily. Based on macroscopic observation, the amphorae, which are datable between the second half of the 6th and the end of the 5th century B.C., were supposed to be local because of similarities to the common wares from the same site. Therefore, in order to verify the provenance of the samples, they were compared to a reference group of locally made ceramics (kiln spacers, kiln wasters, common wares, ancient mud bricks, modern bricks) and twelve samples of local clayey sediments. The results of the analyses have allowed the assignment of all the amphorae to Gela, with the exclusion of five samples, maybe produced in neighbouring sites, and to determine for the first time the archaeometric characteristics of the Geloan medium-coarse ceramics. The aim of our research has also been to investigate some technological aspects of this production, as the location of the clay sources, the methods of clay preparation, and, in particular, the causes of the typical whitening effect on the surface of the vessels.     

Long-term clay raw material selection and use in the region of Classical/Hellenistic to Early Byzantine Sagalassos (SW Turkey)

A provenance study was carried out on coarse ceramics from the Classical/Hellenistic to Mid-Byzantine city of Sagalassos, SW Turkey. The ceramics were sampled from the excavations of the city, and clay raw materials were sampled throughout its ancient territory. Used techniques were optical microscopy and electron microprobe analysis on thin sections, geochemical analysis (fusion ICP/MS and mineralogical analysis (X-ray diffraction). The geochemical/mineralogical diversity in the ceramics is not as wide as for the clay raw materials. It seems that even at the restricted scale of this study, the resources were limited to the area around the ancient site. The differences between the ceramics are likely due to the use of different ophiolitic clay bodies being exploited for their production.     

Ceremonial objects or household items? Non‐destructive μ‐XRD2 and μ‐XRF studies on three Neolithic hematite axes from Qatar

Three small stone axes were collected by the joint Qatari‐German South Qatar Survey Project (SQSP) at two places close to the eastern and western coast of Qatar in autumn 2012. Associated with settlement remains, flint artefacts and pieces of ?Ubaid pottery, the implements have been dated to the fifth millennium BCE. Non‐destructive μ‐XRD² and μ‐XRF analyses could, for the first time, prove the use of hematite as the raw material for the manufacture of these tools in Arabia. The absence of major hematite sources in the region and the special characteristics of hematite — a unique metallic shine of polished pieces and the blood‐red colour that appears during the manufacturing process — suggest the highly symbolic character of these objects.     

Variability in single smelting episodes – a pilot study using iron slag from Uganda

Most archaeometallurgical studies of iron smelting are based on the analyses of slag fragments randomly selected from slag deposits, and assume that these samples are representative of the typical smelting conditions of the given context. However, little archaeometallurgical research has been published to explore the variability in slag composition within a single smelt, or between individual smelts at the same production site. The material used in this pilot study originates from two iron smelting sites identified in the Buganda Kingdom, Uganda, dated to the 18th and 19th centuries AD. The remains represent evidence of the industrial scale iron production that supported the growth and power of the kingdom. The slag survives in large clusters of complete blocks, in some cases weighing over 100 kg, each resulting from a single smelting episode in a pit furnace. A multi-sample analytical approach has allowed an insight into the compositional diversity within the slag from single smelting events, reflecting changing parameters in the smelting systems. The internal variation of the slag blocks is subsequently compared within and between sites, to address issues of standardisation and to differentiate two technological traditions that would appear very similar at the macroscopic level. On this basis, some sampling recommendations are made for future slag block studies.     

Provisioning of the Inka army in wartime: obsidian procurement in Pambamarca,Ecuador

Ninety-nine obsidian artifacts from fortified and non-fortified sites in the Pambamarca region of northern Ecuador were analyzed with XRF to examine patterns of procurement of obsidian by soldiers in the Inka army and by the local Cayambes who were resisting Inka conquest. The results show that the Inkas acquired material from several different sources, a pattern consistent with provisioning by subject peoples in partial fulfillment of labor obligations. The Cayambes also acquired material from multiple sources, although they may not have directly procured material from all of the sources because the external boundary of Inka territory bisected the region of obsidian sources. That frontier may have prevented the Inkas from accessing one source, Callejones, from which the Cayambes acquired some of their obsidian. In addition, the Inkas were acquiring some obsidian from the Yanaurco-Quiscatola source, which had been previously abandoned around AD 1000.     

GLASS BY DESIGN? RAW MATERIALS,RECIPES AND COMPOSITIONAL DATA*

Compositional analyses of ancient and historic glasses have often been interpreted in terms of the use of specific raw materials in glass manufacture. However, the known inhomogeneity of many glass‐making raw materials and the insolubilities of some compounds make any explanation of compositional data problematic. This paper looks at three glass‐making alkalis with a view to understanding how the compositions of these raw materials are carried through to the final glass. The chemistry and variability of the raw materials are discussed, as is their contribution to the final glass composition. In addition, the choices and decisions made by glassmakers are acknowledged in the final glass compositions. This combination of factors addresses the complexity of predicting the use of specific raw materials from the finished glass composition.     

用微探针型EDXRF技术研究南宋官窑瓷片的化学组成及其含义

本文报道了用ENGLE-Ⅱ微探针能量色散型X荧光光谱（EDXRF）技术测定一批青瓷残片中的16种元素氧化物的含量．其残片来自浙江杭州地区南宋的郊坛窑和老虎洞窑。由主量元素判别方程。值表明,郊坛和老虎洞青釉瓷均属官窑制品,与龙泉民窑产品有很大差别。从主成分统计分析看出．郊坛下官窑与老虎洞官窑的瓷釉成分有明显不同,但其胎质成分的分布却有部分的重叠。这显示两类同属官窑的制品,其釉料可有不同的矿物组合。但胎料有时会交流使用。从釉层、中间层、和胎层的Al2O3和CaO的含量变化数据表明,郊坛下官窑和老虎洞官窑的青瓷制品有厚度分别为120-140um和230-240μm的中间层,反映出烧造工艺上有一定的差别。化学成分鉴定证实了考古工作者认为老虎洞窑实为史书记载的修内司官窑的观点．