ROMAN GLASS‐MAKING AT COPPERGATE,YORK? ANALYTICAL EVIDENCE FOR THE NATURE OF PRODUCTION*

Ceramic vessels and associated vitreous debris, excavated at Coppergate, York, UK, have been interpreted as the remains of Roman glass‐making from the raw materials. This paper reports the results of analysis of this assemblage by XRF, ICPS, XRD, SEM– EDAX and thin‐section petrography. These findings suggest that some ceramic vessels, used as crucibles, have been subjected to temperatures up to 1200°C, well above the firing temperatures of the local domestic assemblage from which they were selected. Analysis of quartz‐rich debris, intimately mixed with glass in some samples and in others interleaved with glassy phases, indicates partially reacted glass‐making raw materials, with α‐quartz, tridymite and cristoballite phases represented. This could represent evidence either of a failed attempt to frit the raw materials, or a batch that had not fully fused. Variability in the composition of glass at the site is viewed in the light of glass‐making technology, and possible interpretations concerning this episode are discussed in the light of the archaeological evidence.     

The economic development of West Africa

Almost all documented landslides in Scotland belong to one of four categories: non‐rotational rock slope failures (major rockfalls, translational slides, topples or sags, often in some combination); rotational rock slope failures; debris flows; and translational slides in drift or regolith. Non‐rotational rock slope failures are particularly common on Highland metamorphic rocks, especially schists, and on igneous scarps in the Hebrides and Midland Valley; rotational rock slope failures almost invariably occur in weak sedimentary rocks overlain by resistant igneous rocks; and debris flows are most common on sandy drift or regolith. Former glacial activity has also been of importance in determining landslide distribution. The great majority of rock slope failures are ancient features, but debris flows and small translational slides in drift (both triggered mainly by intensive rainstorms) are much more frequent at present and cause much greater damage, particularly to communications.     

Egyptian sculptures from Imperial Rome. Non-destructive characterization of granitoid statues through macroscopic methodologies and in situ XRF analysis

Aegyptiaca-like Domitian’s obelisk is now decorating Bernini’s fountain on Piazza Navona or the Egyptian lions flanking Michelangelo’s stairs towards the Capitol figure prominently amidst Rome’s cultural heritage. Motivations for the import, contextualization, and copying of these objects during the Imperial Roman period are as heavily debated as they are ill understood. Provenance determination plays an important role in these discussions in terms of a (supposed) dichotomy between Egyptian (real) versus egyptianising (copy) but has only been applied stylistically and never been tested analytically. A scientific characterization of the materials themselves is even lacking altogether, as is an investigation into the cultural and symbolic meaning of the materials used. This paper is a first attempt to address these important lacunae on the basis of an explorative study of a selected sample of Egyptian statues from Rome. The identification and provenance attribution of the materials used for these statues are often problematic due to their relatively fine-grained nature and dark color. Therefore, a full non-destructive analysis of Egyptian statues in dark-colored rocks is presented in this study, with the stones evaluated by macroscopic examination and handheld X-ray fluorescence (XRF) analysis. The implemented methodology has allowed a distinction between greywacke and several varieties of granitoid rocks. In order to evaluate the potential for source attribution, a comparison was made between the results of our analyses and geochemical data for several granitoid rocks from Egypt. This has suggested Aswan as most likely source. The results presented here indicate that handheld XRF analysis can be used for the assessment of compositional variability in and potentially for the provenance of granitoid rocks, provided that a fine-grained area of the material can be measured on multiple locations, and if these values can be assessed on (in)consistencies with other published reference materials.     

Production technology and knowledge transfer of calcite-tempered grey ware bowls from 2nd- to 5th-century ce Noricum (Austria)

Aspects of 2nd- to 5th-century ce Roman production technology and knowledge transfer in southern Austria (known as Noricum) were examined. With no evidence for workshops identified in the study area, 44 grey ware bowls from two sites at Aguntum and Lavant were studied macroscopically, and combined with optical microscopy, X-ray powder diffraction, prompt gamma activation, neutron activation and scanning electron microscopy, in order to understand whether one (large) workshop supplied these bowls, or whether the bowls were produced by several (small) workshops nearby. Combined with information from the geological background, the results were used to tentatively indicate the production location. The results indicate that the grey ware bowls from Aguntum and Lavant were produced by local workshops nearby. The bowls were manufactured with similar clay sources, tempered with crushed calcite-marble rocks from the Tauern Window, their surface smoothed and burnished, and fired between 800 and 850°C in a reducing atmosphere of an open fire. This is taken to suggest that Roman potters, who were located at Aguntum and Lavant, shared strategies of raw materials selection, paste preparation, finishing and firing, and transferred technological knowledge through time.     

PROVENANCING OF LIGHTWEIGHT VOLCANIC STONES USED IN ANCIENT ROMAN CONCRETE VAULTING: EVIDENCE FROM TURKEY AND TUNISIA

The mastery of the use of lightweight rocks in concrete as a means of controlling the thrusts of large‐scale vaults was among the most important contributions of the Roman builders to the development of vaulted architecture. The string of volcanoes along the Tyrrhenian coast of Italy produced a variety of lightweight rocks, which allowed the builders in Rome to develop highly sophisticated ways of manipulating form and mass to create stable structures. The use of lighter rocks in vaults and heavier in foundations occurs from the mid‐first century bc in Rome, but the systematic use of imported lightweight rocks only began in the early second century ad under Trajan ( Lancaster 2005 , 59–64). Soon thereafter, the technique of using lightweight stones to build large vaults spread throughout the empire, usually to areas that had a local source of lightweight volcanic material. However, there was also a seaborne trade in lightweight rocks to areas that did not have local sources of such material. The intention of our analysis is to determine as precisely as possible the provenance of the lightweight stones used in vaulting of two areas of the Mediterranean, modern Turkey (ancient Cilicia) and Tunisia (ancient Africa Proconsularis), and thus to provide a better understanding of the nature of this trade.     

苏家村遗址烧土样品的过火温度研究

烧土制品作为最早的人工建筑材料,使人类的居住环境得到了根本性的改善。然而,学界关于烧土建筑的成因存在人为烘烤处理、缘自火焚、废弃习俗等多种观点。通过科技手段研究烧土制品的过火温度,有助于科学分析烧土建筑的成因,探讨与之相关的建筑工艺,丰富史前建筑史研究。磁学研究表明,考古遗址中的土壤及其他沉积物在受热后新生成了磁铁矿、磁赤铁矿等强磁性矿物导致磁性显著增强,且矿物成分和磁性几乎不会再发生变化;但当重烧的温度接近或大于原始烧成温度时,样品中原始矿物的破坏或新矿物的生成,会引起矿物磁性的改变。基于这一原理,实验室内分析受热黏土的磁化率随再加热温度的变化特征,可反映烧土制品的过火温度。苏家村遗址是大汶口文化晚期至龙山文化中期早段一处重要的聚落遗址,遗址中第5层为厚约20～40 cm的红烧土层且覆盖整个遗址,推测为房屋倒塌造成的建筑垃圾堆积层或人为堆积层,出土大量烧土块。本研究利用X射线衍射分析法、X射线荧光光谱分析法和磁化率法等对苏家村遗址出土的烧土样品开展了组成及构造特征和样品的过火温度的综合分析。结果表明,苏家村遗址烧土样品中的白灰层中人为地添加了白色陶土原料,土层中有意地添加了植物残骸作...     

Mapping Mesolithic and Neolithic cultures behaviours and interactions with nature and properties of rocks in Western France

Multivariate statistical methods are used to study recent Prehistory lithics from the Armorican Massif, allowing us to classify them in more or less distinct groups according to the structural and mineralogical qualities of rock types involved. Analyses are carried out on metamorphic, sedimentary and magmatic rocks making up lithics collected from 31 localities. The petrographic properties are determined by polarizing microscope (POM), while the mechanical properties are obtained by Vickers's indentation method (VI), compression/traction (CT) and ultrasound echography (UE). The results provide us with important information about the management of lithic raw materials used by various human and cultural groups during the Mesolithic and Neolithic of the Armorican Massif. The more commonly used materials show a homogeneous and stable distribution of regional technology styles. The rock types exhibiting mature and homogeneous structures possess the better qualities for knapping (fracture energy G_Ic) and use (edge toughness M₁), and are more involved in exchange. The application of Upward Hierarchical Classification (UHC) and Principal Component Analysis (PCA) allows us to identify the classes of materials as well as the causes of variations of rock type abundance within the lithic assemblages of the Mesolithic and the Neolithic. In this way, we can then also predict the discovery of archaeological artefacts in areas lacking any known indications of the exploitation of outcropping materials.     

Technological aspects of Mesopotamian Uruk pottery: estimating firing temperatures using mineralogical methods,thermal analysis and luminescence techniques

The Middle Uruk phase in Mesopotamia (3600–3500 bc) has been characterised by the massive production of “bevelled rim bowls” (BRBs). They are characterised by their similar shape and volume in Mesopotamia and surroundings. However, their production method has not been studied in detail, including the firing temperature. The determination of the firing temperature of ancient pottery has been attempted by studying mineral phase transformation sequences; although, very little knowledge exists about such transformations in mixtures or thermal analyses. These methods usually provide imprecise firing temperatures between 500 and 800 °C, as other factors such as the raw materials or firing time and conditions must be considered. As an alternative, luminescence techniques have been tested with promising results, as they have provided reliable maximum firing temperatures for ancient pottery at mild conditions (below 600 °C) with high precision. In this work, the firing temperatures of BRB samples from two archaeological sites located in the Middle Euphrates Valley (Syria) have been studied using mineralogical, chemical and thermal analysis. Both mineral characterization techniques and thermal analyses show agreement and firing probably below 600–700 °C. Luminescence yields ambiguous results but circumstantial evidence on the firing temperature between 400 and 550 °C.     

Firing Techniques of the Impasti from the Protohistoric Site of Concordia Sagittaria (Venice)

⁵⁷Fe Mössbauer spectroscopy provided relevant information on the firing techniques employed in manufacturing concotto and coarse pottery, two types of fired clay mixtures (impasti) of the protohistoric settlement site of Concordia Sagittaria. The firing techniques of Concordia were reconstructed by comparing the Mössbauer patterns of the artefacts with those of the local raw clays fired in the laboratory. The concotto was produced in kilns by firing clay mixtures under oxidizing conditions at 700–1000°C, or at lower temperatures in the open air. The firing of these clay mixtures containing mainly ground pieces of waste pottery, resulted in hard and variously coloured construction materials, particularly suitable for humid environments. In turn, the coarse pottery was produced by firing clay mixtures more homogeneous than those used for the artefacts of concotto. The firing of coarse pottery was performed under reducing conditions at about 900°C with a final exposure to air by opening the hot kiln. Light and agreeable coarse pottery, with a red surface on the grey-black core, was obtained when the effective temperature of air was higher than 500°C.     

Human-planted alder trees as a protection against debris flows (a dendrochronological study from the Moxi Basin, Southwestern China)

Large debris flows have destroyed the infrastructure and caused the death of people living in the Moxi Basin (Sichuan Province, Southwestern China). Inhabitants of the Moxi Basin live on the flat surfaces of debris-flow fans, which are also attractive for farming. During the monsoon season debris flows are being formed above the fans. Debris flows can destroy the houses of any people living within the fan surfaces. In order to prevent the adverse effects of flows, people plant alder trees (Alnus nepalensis) at the mouths of debris flow gullies running above debris flow fans. Alders are able to capture the debris transported during flow events. Trees are well adapted to surviving in conditions of environmental stress connected with abrupt transport and deposition of sediment from debris flows. Numerous wounds, tilting and bending of alder trees caused by debris flows only very rarely cause the death of trees. By dating scars and dating the time of alder tilting (through the analysis of annual rings), we have determined the frequency of debris flows occurring at the mouth of the Daozhao valley. In 1980–2012 within the studied debris-flow fan and the Daozhao gully, 2 large debris flow events occurred (1996, 2005) and some smaller events were probably recorded every 2–3 years.     

Archaeomagnetic dating of archaeological sites from Switzerland and Bulgaria

Baked materials from three archaeological sites in Switzerland and one in Bulgaria have been examined and dated archaeomagnetically. The detailed rock-magnetic properties of the burnt clay collected have already been studied therefore and have been published elsewhere (Geophysical Journal International 153 (2003) 146). The main aim of this paper is to determine the terminus ante quem for the last firing of the clay collected from pottery kilns or burnt layers. The directional and intensity results of the ancient geomagnetic field corresponding to the time of the structure's last firing are given for each site. These geomagnetic parameters are then compared with reference curves to provide archaeomagnetic dates for the last use of the kilns. Application of archaeomagnetism as a dating tool is only possible for those regions that already have reference curves. Bulgaria is fortunate in having established reference curves covering almost the last 8000 years. Two Swiss sites were dated using only directional results on the basis of existing palaeodirectional results for Switzerland as well as the French directional reference curves. The archaeomagnetic dates of three of the sites were then compared to archaeological evidence and available radiocarbon dates. The palaeointensity data obtained from this study will enrich the existing archaeomagnetic database for western Europe.     

Chemical characterization of some potsherd pavements from parts of Yorubaland in southwestern Nigeria

Several samples of potsherd pavement were recovered during excavation and archaeological reconnaissance of six sites, along the trade and migration route of the Yoruba of southwestern Nigeria. A significant feature of these pavements is the similarity to Ife in design which consists of a herringbone design, with a ritual pot embedded in their middle. Microscopic analysis of samples shows the presence of high proportions of non-plastic grains, mainly quartz, micas, minor plagioclases, and traces of ferruginous grains, tourmaline and amphibole, interpreted as being produced by low temperature firing. Major, trace and rare earth elements' composition of 21 samples of sherds was determined using Inductively Coupled Plasma (ICP-MS) technique. The chemistry of the potsherd samples is generally similar to regolith derived from granitic rocks, which are abundant in the area. Principal component analysis (PCA) was used to reduce the number of variables and model-based cluster analysis was used to find clusters in the PCA scores. Model-based clustering found one major cluster in the data set, which corresponds to the local weathered granitic/pegmatitic raw materials near the sites. Our work shows that the technology for the manufacture of these pavements might have originated from Ile-Ife, but the production was geologically controlled.     

Tracing firing technology through clay properties in Cuzco,Peru

The purpose of this study was to identify changes in firing practices that occurred during a timeframe that saw the introduction of European kiln technology to the Andes (AD 900–1800). Pottery from an excavated context at the archaeological site of Aqnapampa in the southern highlands of Peru was examined for changes in paste recipes that adapted local materials to increased firing temperatures indicative of evolving firing technologies. Sherds (60) and fragments refired to 890 °C from 12 stratigraphic levels were compared by style, surface treatment, paste color, and vitrification structures (ESEM). Four technological phases of the Cuzco pottery sequence emerged and were used to evaluate the trajectory of a single decorative style (Killke). Previously thought to have been produced in pre-Inca times and curated into later periods, the Killke sherds presented evidence that the style was produced using technologies introduced in the Inca and Spanish Colonial Period.     

New insights about the construction and use of shell mounds from the geochemical analysis of mollusks: an example from the greater San Francisco Bay

A new method developed by Schweikhardt et al. (2011) for the geochemical analysis of bay mussels is applicable (when combined with radiocarbon assessments) for examining the seasonal construction patterns and growth cycles of coastal mound sites over time. Ideally suited for the analysis of mollusk fragments in museum collections, this method allows archaeologists to evaluate divergent models about the functions of mound sites, as well as the mobility practices and social organizations of the mound builders. In this case study, the method is employed to examine two adjacent mounds (Ellis Landing, Brooks Island) in the San Francisco Bay Area, California to assess whether their occupants may have participated in a broader multi-site community dating to the Late Period (1100–250 BP).     

Characterization of prehispanic cosmetics found in a burial of the ancient city of Teotihuacan (Mexico)

The present paper reports the chemical data obtained on samples of pigmenting materials contained in 31 miniature vessels found in a burial found in Teopancazco, a multiethnic neighborhood center located in the southeastern sector of the archaeological site of Teotihuacan (Central Mexico) and the analytical protocol established for the complete characterization of these archaeological materials. For this purpose a multi-technique approach based on the combination of several non destructive and micro-destructive instrumental techniques, namely, light microscopy (LM), scanning electron microscopy-X-ray microanalysis (SEM-EDX), transmission electron microscopy (TEM), voltammetry of microparticles (VMP), X-ray microdiffraction (μXRD), X-ray diffraction (XRD), UV-Vis spectrophotometry, FTIR spectroscopy and gas chromatography-mass spectrometry (GC-MS) has been developed in an attempt to completely characterize these materials. These instrumental techniques provide reliable and complementary data including elemental and mineralogical composition, identification of functional groups as well as speciation studies of electroactive species. Among the most relevant findings, volcanic pyroclastic rocks and clayey soils, most probably, from the Teotihuacan valley as well as galena, jarosite and mica from other provenances in Mesoamerica, have been identified. Charcoal and Ocote resin have also been identified. The chemical composition of the samples is discussed with a view to the possible function as cosmetic materials and their use in funerary rites. The results have been critically compared with those others obtained in other ancient civilizations. The study carried out on the materials found in the burial 105 is especially relevant insofar it represents the first evidence, scientifically characterized, of the use of cosmetics in Mesoamerica at this early period (AD 200-550).     

THE MATERIALS OF HOYSALA TEMPLES AND SCULPTURES: A PETROGRAPHIC CHARACTERIZATION

Talcxhlorite schist is the material commonly used by the sculptors and builders of the Hoysala dynasty, which ruled i n the western part of India south of the Deccan from the eleventh to the mid-fourteenth century. Forty-one samples from seven Hoysala sites were examined by petrographic microscopy and electron beam microprobe analysis. Although it is difficult to distinguish between some of the rocks from the different sites. many contain minerals that can be valuable in distinguishing between different possible quarry sources.     

The Mineralogical Characteristics of the Lamboglia 2 Roman‐Age Amphorae from the Central Adriatic (Croatia)*

The mineralogical characteristics of four Lamboglia 2 Roman‐age amphorae excavated from ancient underwater shipwreck localities in the central Adriatic were investigated. X‐ray diffraction and optical microscopy analyses showed that the amphorae have similar primary mineral compositions, mainly consisting of quartz, plagioclase, potassium feldspar, diopside, illite and calcite, most probably originating from clayey Eocene flysch deposits used as raw materials in manufacture. The difference in mineral composition between these samples is recognized from the presence or absence of melilite, high‐magnesium calcite, aragonite, gypsum and analcime. It was shown that melilite is a secondary mineral formed during the firing process, while the others, which build up through incrustation of marine benthonic communities on the amphora walls and fill the cracks in the amphora bodies, were formed by crystallization in seawater. The firing of the original pieces of amphorae showed that melilite could be formed at temperatures higher than 800°C, most probably through interaction between calcite and silicate minerals present in the raw materials. The presence of melilite, and the absence of illite and calcite, were used to estimate the firing temperature of the amphorae during their production.     

Autochthony and orientation patterns in Olduvai Bed I: a re-examination of the status of post-depositional biasing of archaeological assemblages from FLK North (FLKN)

Recent excavations at FLK North (Olduvai Gorge, Tanzania) have produced new information on the orientation of archaeological materials at various levels of the site. This information includes the uniform distribution of material azimuths, which contrasts with previous inferences of highly patterned orientations of materials in the Bed I archaeological sites. Those previous inferences of patterned material orientations are based on Mary Leakey's 50-year-old drawings of artifact and fossil bone distribution, but are not verified by our precise measurements of archaeological objects made in situ. Nor do those previous results agree with the general lack of geological, geomorphological, and/or taphonomic data that would indicate significant post-depositional movement of archaeological materials in the sites. We argue here that Leakey's drawings are incomplete (only portions of each assemblage were drawn) and inaccurate in their representation of the original locations, shapes and orientations of most archaeological specimens. This argument is supported by several important mismatches in object representations between a photograph taken of a small portion of the FLK 22 Zinjanthropus site floor before the removal of the archaeological items, and the sketch of the same area drawn by Leakey. Thus, we conclude that primary orientation data of excavations (i.e., direct measurements taken from items) generated prior to object removal are the only valid indicators of the relative isotropy or anisotropy of these important paleoanthropological assemblages.     

INCISED SLIPWARE PRODUCTION AT CASTELFIORENTINO (FLORENCE): THE ‘VIA BERTINI’ SITE (15TH–17TH CENTURIES)*

This study deals with the physical–chemical and mineralogical–petrographic investigations (OM, SEM–EDS, EPMA, ICP, XRpD, Mössbauer and IR) conducted on first‐ and second‐firing wasters belonging to two types of incised slipware (sgraffito), manufactured at Castelfiorentino between the late 15th and the early 17th centuries. Raw materials, colouring agents and firing products were analysed in order to establish the production technology of the ceramic coatings, by means of detailed microtextural and chemical investigations. The pottery underwent two firing processes: the firing of the white slip‐coated ceramic body and a further firing after application of the glaze. The homogeneity of the raw materials, white slip and glaze is remarkable, and demonstrates the use of well‐established recipes with a constant supply of raw materials from the same places. Highly efficient kiln management during both firings is revealed by body–glaze interface reactions.     

Particle size distribution of lithic assemblages and taphonomy of Palaeolithic sites

Lithic debris derived from knapping and used tools can be assimilated to simple sedimentary particles that may undergo size sorting when exposed to geomorphic processes such as streamflow or overland flow. Sorting can be identified by comparing the size distribution of archaeological assemblages to that of experimental core reduction sequences. A new database including different types of raw material (mainly flint and quartzite) and Palaeolithic debitage (blade, Levallois, discoid, on anvil, and shaping) has been built for this purpose. Palaeoeskimo data have also been added to illustrate microlithic industries. For all the debitages and raw materials, the particle size of knapping products >2 mm in width fits with a power-law distribution and shows only minor fluctuations, the range of which is always <15% between experiments (all steps of the chaîne opératoire included up to the final tool). A lithic assemblage derived from block/core knapping or blank/preform production will display a particle size distribution close to the experimental distributions if not subsequently modified. Modifications may originate either from sedimentary processes or from anthropogenic factors. To help distinguishing amongst these, data on the impact of both water flows on sedimentary particles or experimental assemblages, and anthropogenic processes such as importation-exportation (of core, preforms or finished tools) or uneven spatial distribution of the different steps in core reduction and tool production within a site, are reviewed. By contrast to anthropogenic modifications, sedimentary processes are generally typified by strong impoverishment in or selective accumulation of fine-grained (<10 mm) artefacts together with a low intra-site variability (spatial homogenization) or a downslope size trend. Archaeological case studies taken from French Palaeolithic site are then detailed. Evidence for lithic redistribution implies that care should be taken in archaeological site analysis since sorting may impact significantly the initial techno-typological balance of the assemblage.